United States Department of the Interior Bureau of Land Management
Biological Assessment for Boise District Noxious Weed and Invasive Plant Management DOI-BLM-ID-B000-2016-0002-EA
ESA-Listed Aquatic Invertebrates Bruneau hot springsnail (Pyrgulopsis bruneauensis)
ESA-Listed Plants Slickspot peppergrass (Lepidium papilliferum)
Table of Contents
Chapter 1 Introduction ...... 7 Overview ...... 7 Relationship of the Proposed Action to Future Federal Actions ...... 8 Consultation History ...... 9 Relationship of Section 7 Consultation for Future Federal Actions of the Proposed Action ..... 9 Species and Critical Habitats ...... 10 Chapter 2 – Proposed Action ...... 13 Targeted Plant Communities...... 13 Noxious Weeds ...... 13 Invasive Plants ...... 14 Treatment Planning ...... 15 Treatment Methods ...... 17 Design Features and Conservation Measures ...... 19 Monitoring ...... 24 Chapter 3 – Species Life History Summaries ...... 26 Bruneau Hot Springsnail ...... 26 Listing Status and Recovery Plan ...... 26 Species Description ...... 27 Life History and Habitat Characteristics ...... 29 Status and Species Distribution ...... 30 Conservation Needs ...... 31 Threats to the Species ...... 31 Slickspot Peppergrass ...... 33 Listing Status ...... 33 Species Description ...... 34 Life History and Habitat Characteristics ...... 34 Status and Species Distribution ...... 38 Conservation Needs ...... 47 Effects of Climate Change on Slickspot Peppergrass Survival and Recovery Needs ...... 49 Status of the Species in the Action Area ...... 50 Factors Affecting the Species in the Action Area ...... 55 Slickspot Peppergrass Proposed Critical Habitat ...... 59 Current Range Wide Condition of Proposed Critical Habitat ...... 60 Effects of Climate Change on Proposed Critical Habitat for Slickspot Peppergrass ...... 62 Status of Slickspot Peppergrass Proposed Critical Habitat in the Action Area ...... 63 Factors Affecting Slickspot Peppergrass Proposed Critical Habitat in the Action Area ...... 63 Chapter 4 – Description of the Action Area ...... 65 Soils...... 65 Water Resources ...... 66 Vegetation ...... 66 Chapter 5 – Effects Analysis and Determinations ...... 68 Common Effects of Herbicide Treatments to Listed Species ...... 68 Bruneau Hot Springsnail ...... 69 Determination – Effects of Ground-based Herbicide Treatments ...... 73 Slickspot Peppergrass ...... 74 Actions that May Affect Slickspot Peppergrass ...... 75 Determination – Impacts of Herbicide Treatments ...... 76 Slickspot Peppergrass Proposed Critical Habitat ...... 76 Actions that May Affect Slickspot Peppergrass Proposed Critical Habitat ...... 79 Determination - Impacts of Spot Herbicide Treatments ...... 80 Interrelated and Interdependent Effects ...... 80 Cumulative Effects...... 80 Chapter 6 – Literature Referenced ...... 82 Appendices ...... 96 Appendix A - State of Idaho Noxious Weeds and Boise District Invasive Plants List ...... 97 Appendix B – Standard Operating Procedures for Applying Herbicides ...... 102 Appendix C - Three Newly Approved Herbicides for Use on BLM Lands ...... 111 Appendix D - Definitions for terms used in the slickspot peppergrass analysis ...... 120 Appendix E - Summary of Effects Tables ...... 122
List of Acronyms ACEC Area of Critical Environmental Concern ALS Acetolactate Synthase ATV All-Terrain Vehicle BA Biological Assessment BFO Bruneau Field Office BLM Bureau of Land Management BOR Bureau of Reclamation CFR Code of Federal Regulations CWMA Cooperative Weed Management Area DNA Determination of NEPA Adequacy DR Decision Record EA Environmental Assessment EIS Environmental Impact Statement EO Element Occurrence EPA Environmental Protection Agency ERA Ecological Risk Assessment ESA Endangered Species Act HIP Habitat Integrity and Population Monitoring HMA Herd Management Area IDARNG Idaho Army National Guard IDFG Idaho Department of Fish and Game IDL Idaho Department of Lands IFWIS Idaho Fish and Wildlife Information System INFISH Inland Native Fish Strategy ISDA Idaho State Department of Agriculture MFP Management Framework Plan MP Management Plan MRA Minimum Requirement Analysis NEPA National Environmental Policy Act NIDGS Northern Idaho Ground Squirrel OCTC Orchard Combat Training Center OHV Off-Highway Vehicle OPLMA Omnibus Public Land Management Act PBF Physical and Biological Feature PCH Proposed Critical Habitat PEIS Programmatic Environmental Impact Statement PER Programmatic Environmental Report PUP Pesticide Use Proposals RCA Riparian Conservation Area RMP Resource Management Plan ROD Record of Decision ROW Right-of-Way SOP Standard Operating Procedure TEP Threatened, Endangered, or Proposed BDO Boise District Office USC United States Code USDA United States Department of Agriculture USDI United States Department of the Interior USFWS U.S. Fish and Wildlife Service UTV Utility-Terrain Vehicle WSA Wilderness Study Area WSRs Wild and Scenic Rivers Chapter 1 Introduction
Overview The Bureau of Land Management (BLM) Boise District (BDO) has prepared an Environmental Assessment (EA) for an integrated weed management (IWM) plan on public lands to increase the number of herbicides available for use and to expand upon the types of treatment options available for use to include manual, biological, chemical (including ground and aerial application of herbicides) on localized infestations of less than 50 contiguous acres within the BDO boundaries (DOI-BLM-ID-B000-2016-0002-EA). Section 7 consultation has been conducted previously on the BDO on the use of manual, biological control and ground application of herbicides for noxious and invasive weed treatment (USDI BLM 2005 and USFWS 2005 in litt., USDI BLM 2006a and USFWS 2006a in litt.) The current proposal is to conduct section 7 consultation on small-scale aerial application (up to 50 acres) of 13 active ingredients, and ground and aerial application of 3 new active ingredients (USDI BLM 2016). The EA discloses the direct, indirect, and cumulative environmental effects that would result from management and treatment of noxious weeds and invasive plants on BLM lands as required by the National Environmental Policy Act (NEPA) of 1969 (42 United States Code [USC] 4321-4347), the Council on Environmental Quality Regulations for Implementing the Procedural Provisions of NEPA (40 Code of Federal Regulations [CFR] 1500-1508), and the BLM NEPA Handbook (H-1790-1). The EA tiers to the 2016 Final Vegetation Treatments Using Aminopyralid, Fluroxypyr, and Rimsulfuron on BLM Lands in 17 Western States PEIS (2016 PEIS) (USDI BLM, 2016). The ROD for this PEIS was signed August 15, 2016. The 2016 PEIS ROD approves three new herbicides: aminopyralid, fluroxypyr, and rimsulfuron. These three new herbicides are integrated into the herbicide treatment activities that were assessed in the 2007 PEIS. The ROD for the 2016 PEIS increased the number of herbicide active ingredients available to the BLM from 18 to 21. The 2016 PEIS incorporates by reference the analyses completed in the 2007 PEIS for all other vegetation treatment activities. Additional information pertaining to the 2016 PEIS and the tiering process are in the BDO Noxious Weed and Invasive Plant Management EA. Noxious weeds are non-native plants with the potential to displace native vegetation at the watershed and local scale. A noxious weed is any plant designated by a Federal, State, or County government to be injurious to public health, agriculture, recreation, wildlife, or any public or private property (Sheley & Petroff, 1999). Idaho currently has 67 different species of weeds that are designated noxious by State law. Appendix A lists noxious weeds in the State of Idaho and identifies those that are known to occur in the BDO. According to Executive Order 13112, invasive plants are defined as non-native plants whose introduction cause or are likely to cause economic or environmental harm, or harm to human health. Non-native invasive plants, such as cheatgrass (Bromus tectorum) and medusahead wildrye (Taeniatherum caput-medusae), have become dominant in portions of the BDO. This dominance has altered fire regimes and, in some cases, resulted in landscape-scale changes in vegetation composition and structure. For example, cheatgrass rapidly invades disturbed areas and acts as a hazardous fuel, increasing the fire frequency and intensity in sagebrush steppe
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 7 ecosystems and other landscapes characteristic of southwest Idaho. Invasive plant species can also include new invaders that are not currently recognized as noxious weeds in the State of Idaho but have the potential to become noxious weeds if not controlled (Appendix A, Table 4). The continued expansion of noxious weeds has been recognized as the single greatest threat to the integrity of native plant communities (Asher, 1998). The rapid expansion of invasive plants across public lands continues to be a primary cause of ecosystem degradation, and control of these species is one of the greatest challenges in land management (USDI BLM, 2007c). Noxious weeds and invasive plants are aggressive and can out-compete native vegetation, especially following a disturbance. Left unchecked, noxious weeds and invasive plants can create monocultures that degrade or reduce soil productivity, water quality and quantity, species diversity and structure of native plant communities, wildlife habitat, wilderness values, recreational opportunities, and livestock forage, and are detrimental to agriculture and commerce of Idaho (USDI BLM, 2007b). Specific guidance regarding the BLM's responsibilities to conserve species that are classified as listed, proposed, and candidate species under the Endangered Species Act (ESA) of 1973, as amended, is provided in BLM Manual 6840 – Special Status Species Management. The BLM is required to follow these guidelines from the manual: ● The BLM shall conserve listed species and the ecosystems on which they depend and shall use existing authority in furtherance of the purposes of the ESA; ● Ensure that all actions authorized, funded, or carried out by the BLM are in compliance with the ESA; ● Cooperate with the U.S. Fish and Wildlife Service (USFWS or the Service) in planning and providing for the recovery of ESA-listed and proposed species. This Biological Assessment (BA) evaluates the effects of noxious weed and invasive plant treatments on animals and plants listed or proposed for listing under the ESA. These effects are determined relative to current conditions for ESA-listed and proposed species. The proposed action contains conservation measures that were adapted from land use plans and the consultations for the 2016 PEIS (USDI BLM, 2015a). Additional conservation measures were developed during BDO Level One Team discussions as part of the ESA section 7 consultation process. The conservation measures are expected to provide long-term benefits and contribute to the recovery of listed species and conservation of proposed species and habitats. In addition to the conservation measures, the proposed action also includes design features, (see Chapter 2, Design Features and Conservation Measures), and standard operating procedures (SOP; Appendix B) to reduce or eliminate potential adverse effects to special status species, including ESA-listed and proposed species. These are consistent with the management direction in BLM Manual 6840. Relationship of the Proposed Action to Future Federal Actions The BDO Integrated Weed Management EA contains a programmatic analysis of vegetation treatments that could occur singly or in combination to treat infestations of noxious weeds and invasive plants to promote land health. Future actions consist of manual, biological control, ground-based broadcast herbicide, small scale aerial application of herbicide, and spot herbicide treatments of new and existing infestations of noxious weeds where immediate and continued actions are required would be implemented with no further NEPA analysis. Estimated annual
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 8 acreages are identified for each treatment type (See Table 1). These acreages are estimates based on past treatments, current noxious weed inventories, and anticipated future needs to control or contain noxious weed populations. Actual treatment acreages could vary from year-to-year. Table 1 – Summary of treatments across BDO
Number of Estimated Number of Treatments Under Annual Treatments Under Treatment Type the No Action the and Size Alternative Action Alternatives Ground-Based Herbicide Less than 0.1 acre 9,200 20,000 0.1 - 0.50 acre 1,200 2,000 0.50 - 5.0 acres 323 1,000 5.0 - 50 acres 5 50 Aerial Herbicide 0.1 - 50 acres 0 5
Consultation History The BLM consulted with the Service for the 2007 and 2016 PEISs (USDI BLM, 2007a; USDI BLM, 2015a). The 2007 consultation was for 20 BLM approved herbicides and the 2016 consultation was for the three new approved herbicides aminopyralid, fluroxypyr, and rimsulfuron. September 17, 2017 The Bureau and Service discussed the Noxious and Invasive Weed Treatment EA at a Level 1 meeting. October 5, 2017 The Bureau and Service discussed the Noxious and Invasive Weed Treatment EA at a Level 1 meeting. February 12, 2018 The Bureau and Service discussed the Noxious and Invasive Weed Treatment EA at a Level 1 meeting. March 27, 2018 The Bureau provided a draft BA to the Service for review. April 2, 2018 The Bureau received comments from the Service on the draft BA May 16, 2018 The Bureau submitted a request for a Letter of Concurrence with the Final BA to the Service. Relationship of Section 7 Consultation for Future Federal Actions of the Proposed Action The proposed action includes conservation measures, design features, prevention measures, herbicide application criteria, and SOPs that combined, reduce or eliminate potential impacts of
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 9 small-scale (less than 50 acres) noxious weed and invasive plant treatments to ESA-listed and proposed species and/or their designated or Proposed Critical Habitat. This BA analyzes the potential direct, indirect, and cumulative impacts from small-scale treatments. Any treatment that falls within the scope of this consultation would not require any further Section 7 consultation. Any treatment that deviates from the proposed action, resulting in potential effects beyond those described in this BA, would require additional Section 7 consultation. Species and Critical Habitats This BA assesses the impacts from noxious weed and invasive plant treatments on two ESA- listed species that occur within the BDO. These species and their ESA status are displayed in Table 2. This list of species was derived from the Idaho BLM Special Status Species List Update (USDI BLM, 2015b). Table 2 - ESA-Listed Species and Critical Habitats Addressed. Species or Critical Habitat ESA Status Bruneau hot springsnail (Pyrgulopsis bruneauensis) Endangered Bruneau hot springsnail Critical Habitat Slickspot peppergrass (Lepidium papilliferum) Threatened Slickspot peppergrass Proposed Critical Habitat
Yellow-billed Cuckoo: No suitable habitat exists on the BDO and there is no Proposed Critical Habitat on the BDO. While this species has been observed on the BDO, occurrences are rare and the birds were most likely migrating through the area when observed. Because there is no suitable habitat and the species only rarely occurs on BDO, the likelihood of either negative or beneficial effects from small scale weed treatments to yellow-billed cuckoo is discountable. Canada Lynx: Lynx primarily inhabit boreal and mesic forests, and are closely associated with its primary prey snowshoe hare (USDA FS, 2007). Across its range, dense horizontal cover, persistent snow, and moderate to high snowshoe hare densities are common attributes of lynx habitat. The elevation at which lynx habitat occurs depends on local moisture patterns and temperatures, and varies across the range of the species. Spruce-fir forests are the primary vegetation type that characterizes lynx habitat in the contiguous United States (Koehler & Brittell, 1990; Koehler et al., 2008; McKelvey et al., 2000; Squires et al. 2010). In Idaho, lynx primarily occur in high elevation, cold forest habitats that support spruce, subalpine fir, whitebark pine, lodgepole pine, or moist Douglas-fir habitat. Canada lynx are associated with mesic forests, and “dry forests” do not provide lynx habitat (USDA FS, 2007). Habitat for Canada lynx in Idaho generally consists of subalpine forests that receive deep snow, and have high-density populations of snowshoe hares. Lands managed by the BDO are generally at lower elevations and is not considered suitable habitat for Canada lynx, there is no critical habitat within the BDO. Lynx have never been documented on BDO managed lands, therefore, the likelihood of effects from small-scale weed treatments is discountable. North American Wolverine: Wolverines prefer areas of high elevation and deep snow that persists into the month of May, which is essential for wolverine reproduction. In the contiguous United States, wolverine year-round habitat is found at high elevations centered near the tree line
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 10 in conifer forests (below tree line) and rocky alpine habitat (above tree-line) and in cirque basins and avalanche chutes that have food sources such as marmots, voles, and carrion (Copeland, 1996; Hornocker & Hash, 1981). Lands managed by the BDO are generally at lower elevations and do not provide suitable habitat for wolverine, although wolverines may rarely travel through BDO managed lands. Based on the fact that the BDO does not have suitable habitat for wolverine and their home ranges are so large, the likelihood of small scale weed treatments having any effect on wolverines is discountable. Northern Idaho Ground Squirrel: Populations of northern Idaho ground squirrels NIDGS have never been documented on BLM lands managed by the BDO. There were two populations documented near BLM lands in the Hornet Creek area northwest of Council, ID, but those populations located on private land are thought to be extirpated. The closest population to BDO managed lands is over three miles away and those BLM lands would not provide suitable habitat. Very little if any of the land managed by the BDO near NIDGS populations would provide suitable NIDGS habitat. Therefore, small-scale weed treatments would not result in any effect to NIDGS or their habitat. Bull Trout and Bull Trout Critical Habitat: No resident bull trout have been documented on the BDO. Further, the only time they are likely present on the BDO is during the winter months when water temperatures would be within the range of preference for bull trout or when they are migrating through waterways that cross BLM managed lands. There is a minimal amount of Critical Habitat on BDO managed lands except for 39 miles of the Bruneau River (Table 3). Although the 39 miles of the Bruneau River are identified as Critical Habitat, no bull trout have been documented. No aerial treatment would occur within 300 feet of the Bruneau River canyon rim to reduce the chance for drift into the river and Critical Habitat or within 300 feet of areas with designated Critical Habitat. Due to the remote and rugged nature of the Bruneau River Canyon very little weed treatments occur, and would not occur during the winter months when bull trout may be present in waterways adjacent to BLM managed lands. Proposed weed treatments are small scale and treatments within riparian areas would follow design features and SOPs to minimize potential impacts to aquatic resources including bull trout. Due to the small scale of the proposed treatments and the design features and SOPS that would be incorporated into the treatments, there would be no effect to bull trout or bull trout Critical Habitat. Table 3 – Miles of Bull Trout Critical Habitat managed by the BDO.
Recovery Unit Core Area Miles of Critical Habitat Mid-Columbia Pine, Indian, and Wildhorse Creeks 4.1 Upper Snake River Anderson Ranch Reservoir 0.5 Upper Snake River Middle Fork Payette River 0.2 Upper Snake River Bruneau River 39.3
Snails: There are two species of endangered snails on the BDO, the Bliss Rapids snail and the Snake River physa. The Bliss Rapids snail is found in the Snake River on the eastern border of the BDO, and there is very little habitat for the Bliss Rapids snail on the BDO. The Snake River physa has spotty distribution in the Snake River within the BDO. Eighty percent of samples
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 11 containing live Snake River physa were located in the middle 50 percent of the river channel. No aerial application would occur within 0.5 miles of the Snake River. There would be no aquatic weed species treated. Due to the small-scale weed treatments, the project design features and SOPs, the potential for impacts to these two species would be insignificant. Therefore, small- scale weed treatments would have no effect on Snake River snails or their habitat.
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Chapter 2 – Proposed Action The proposed action is to utilize three new active ingredients approved for use by the BLM and small-scale aerial application of thirteen active ingredients previous approved only for ground application to control and eradicate noxious weeds and invasive plants through small-scale treatments on the BDO. All active ingredients under the current proposal are presented in Table 4. Active ingredients, registered herbicide trade names approved by the BLM, and general effects to target vegetation are found in Appendix C. Table 4 – Herbicides Proposed for use in BDO. Year PEIS Active Ingredient Authorized 2,4-D 2007 Aminopyralid 2016 Chlorsulfuron 2007 Clopyralid 2007 Dicamba 2007 Diflufenzopyr1 2007 Fluroxypr 2016 Glyphosate 2007 Hexazinone 2007 Imazapic 2007 Imazapyr 2007 Metsulfuron methyl 2007 Picloram 2007 Rimsulfuron 2016 Tebuthiuron 2007 Triclopyr 2007 1 In formulation with dicamba; herbicide trade names Overdrive® and Distinct® Targeted Plant Communities
Noxious Weeds The current Idaho noxious weeds list and those most likely to be found and treated in the BDO are included in Appendix A. They occur in a variety of environments including riparian, upland, and forested sites. These noxious weeds can potentially be moved about by a variety of means including humans, vehicles, livestock, wind, water, and wildlife. Generally, noxious weeds are defined as a plant species designated by Federal or State law as generally possessing one or more of the following characteristics: ● aggressive and difficult to manage;
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● parasitic; ● a carrier or host of serious insects or disease; ● non-native, new, or not common to the United States.
The State of Idaho administrative rules put noxious weeds into three categories that determine how they are managed: ● Statewide Early Detection and Rapid Response. Plants in this category must be reported to the Idaho State Department of Agriculture (ISDA) within 10 days after being identified by the University of Idaho or other qualified authority approved by the ISDA director. Eradication of these weeds must occur in the same growing season they are found. ● Statewide Control. Plants in this list are known to exist in varying populations throughout the State. Concentrations of these plants are at levels where control and/or eradication may be possible. A written plan must be developed by the control authority that specifies active control methods to reduce known populations within 5 years. ● Statewide Containment. Plants in this category are known to exist in varying populations throughout the State. Control efforts may be directed at reducing or eliminating new or expanding weed populations while known and established weed populations, as determined by the weed control authority, may be managed by any approved weed control methodology, as determined by the weed control authority.
Invasive Plants Executive Order 13112 (1999), as amended by Executive Order 13751 (2016), defines invasive species as non-native organisms whose introduction causes, or is likely to cause, economic or environmental harm or harm to human, animal, or plant health. Invasive plants: ● are not part of the native plant community; ● have the potential to become a dominant or co-dominant species on the site if their future establishment and growth is not actively controlled by management interventions; or ● are classified as exotic or noxious plants under State or Federal law. Native species that become dominant for only one to several years (e.g. short-term response to drought or wildfire) are not invasive plants. Douglas-fir, western juniper, and rabbitbrush are not targeted species under the proposed action. Invasive plants compromise the BLM’s ability to manage lands for a healthy native ecosystem. They create a host of environmental and/or economic effects, most of which are harmful to native ecosystem processes, including: ● displacement of native plants, ● reduction in functionality of habitat and forage for wildlife and livestock, ● increased potential for soil erosion and reduced water quality, ● alteration of physical and biological properties of soil, ● loss of long-term riparian area function, ● loss of habitat for culturally significant plants, ● increased economic cost of controlling invasive plants, and Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 14
● increased cost of keeping ecosystems and recreational sites free of invasive species. Invasive plant communities can be the dominant vegetation cover or be a significant component (greater than or equal to10 percent cover) of a stand of native vegetation. Treatment of these native plant communities to reduce the incidence of invasive species can be critical to maintaining or improving key wildlife habitats (e.g., sage-grouse habitat and big game winter ranges). Treatment Planning Use of aminopyralid, fluroxypyr, and rimsulfuron for ground-based broadcast or spot herbicide treatments, or small-scale aerial herbicide application, to new and existing infestations of noxious weeds where immediate and continued actions are required would be implemented with no further NEPA analysis. Estimated annual acreages are identified for each treatment type (Table 1). These acreages are estimates based on past treatments, current noxious weed inventories, and anticipated future needs to control or contain noxious weed populations. Actual treatment acreages could vary from year-to-year.
On-going Actions On-going actions would treat noxious weeds that occur primarily in burned areas or locations with frequent disturbance such as roadways, gravel pits, private/public land interfaces, or high- use recreation sites, including OHV areas, campsites, and trails. Spot herbicide treatments consist of treating individual plants or small patches up to one acre with a hand-held wand attached to a backpack sprayer or vehicle-mounted spray equipment. Ground-based broadcast herbicide treatments are implemented with a boom attached to a vehicle. The ground-based broadcast and aerial methods allow for treatment of larger patches (not greater than 50 acres), such as roadsides. Areas burned by wildland or prescribed fire would be inventoried for noxious weeds post-fire. Noxious weeds detected during the inventory process would be spot-treated with herbicide using a hand-held wand attached to a backpack sprayer or vehicle-mounted spray equipment. Ground- based broadcast and aerial treatments could be used for large patches (not greater than 50 acres). In addition, some areas containing known infestations that cannot be completely eradicated require regular (e.g. annual) treatment for containment and to prevent spread to adjacent areas. These areas would be treated at intervals necessary for containment using ground-based broadcast, or spot herbicide spray methods that may utilize one of the newly approved three herbicides. Anticipated annual acreages for each of the methods are discussed in the individual treatment methods below. As new invaders are discovered, they would be treated the same as an on-going action with appropriate methods, as necessary.
General Site Selection and Treatment Treatment priorities are established and influenced by several factors. These factors include National, State, and local priorities pursuant to current policies, directives, and initiatives. Priorities would also be influenced by the following factors: ● Treatments that will be planned, implemented, and/or monitored using funding from multiple sources, both internal and external.
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● Landscape treatments coordinated across field office or land management boundaries [i.e. Idaho Department of Lands (IDL), U.S. Forest Service (USFS), National Park Service, USFWS, or Military] to improve treatment effectiveness. ● Contracted treatments that support economic opportunities for rural communities and/or high potential to use stewardship contracting authorities. The extent of noxious weed infestations in the BDO requires prioritization of weed treatment efforts for the most efficient use of limited time and resources. The following management situations would be used to prioritize noxious weed and invasive plant treatments in order to focus efforts towards success (USDI BLM, 2007b):
Priority 1: New aggressive infestations in a previously un-infested area or small infestations in areas of special concern (e.g., special management areas, special status species habitat). ● Management Objective: Eradicate. Eliminate all traces of a population (including reproductive propagules) to the point where individuals are no longer detectable. This eliminates the potential for further introduction and spread. Priority 2: Areas of high traffic or sources of infestation and infestations in areas of special concern. ● Management Objective: Control. Reduce the extent and density of a target weed to limit the potential for further introduction and spread. Priority 3: Existing infestations or roadside infestations where spread can be checked or slowed. ● Management Objective: Contain. Prevent weeds from moving beyond the current infestation perimeter. Applying these priorities would result in the following general strategy: ● Keep weed-free areas weed-free. Keeping weed-free areas weed-free is the most biologically and cost-effective approach. Once an area has been taken over by weeds, restoration may be expensive and may not always return an area to its full native community of plants and animals. Thus it is better to maintain the native vegetation than to have to restore it. ● Use BLM-approved herbicides where weeds are establishing in new areas. ● Use aerial application in areas difficult to access or too large to effectively treat by ground methods. ● Assess current vegetation condition to determine site potential to release and increase desirable perennial vegetation through control of invasive annual species (i.e., herbicide application). ● Revegetate areas where the potential native plant community cannot naturally reestablish following noxious weed and invasive plant control. ● Monitor all types of treatment for effectiveness and adjust control methods accordingly. ● Continue education, prevention, and inventory. Cooperative Weed Management Areas and Partnerships A Cooperative Weed Management Area and Partnership (CWMA) is composed of local, private, and Federal interests. CWMAs typically center on a particular watershed or similar geographic area in order to combine resources and management strategies in the prevention and control of
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 16 weed populations. Much of the BLM’s on-the-ground invasive species prevention and management is done directly or indirectly through CWMAs. The BLM partners with all counties in the BDO as well as Southern Idaho Biocontrol, State, and other Federal agencies to control noxious weeds. The BDO would continue utilizing partnerships to control noxious weeds with allowable methods as funding is made available. Prevention
As stated in Partners Against Weeds: An Action Plan for the BLM, prevention and public education are the highest priority weed management activities. Priorities are as follows: Priority 1: Take actions to prevent or minimize the need for vegetation control when and where feasible, considering the management objectives of the site. Priority 2: Use effective non-chemical methods of vegetation control when and where feasible. Priority 3: Use herbicides after considering the effectiveness of all potential methods or in combination with other methods or controls. The proposed action adopts prevention measures included in the 2007 PEIS. Weed free seed, forage, and straw for permitted activities are required on public lands (USDI BLM, 2011a). Treatment Methods Treatment methods would be chosen based on site characteristics. Selection of the most appropriate treatments depends on numerous factors, including specific noxious weeds or invasive plants present on the site, risk of expansion, weed species biology, season, soil type, environmental setting, and objectives. In addition, data regarding past treatment successes or failures would also be considered. Vegetation treatment methods are selected based on several parameters, which may include the following: ● Management program/objective for the site. ● Historic and current conditions. ● Opportunities to prevent future problems. ● Opportunities to conserve native and desirable vegetation. ● Effectiveness and cost of the treatment methods. ● Success of past restoration treatments or treatments conducted under similar conditions or recommendations by local experts. ● Characteristics of the target plant species, including size, distribution, density, life cycle, and life stage in which the plant is most susceptible to treatment. ● Non-target plant species that could be impacted by the treatment. ● Land use of the target area. ● Proximity to communities and private agricultural land. ● Slope, accessibility, and soil characteristics of the treatment area. ● Weather conditions at the time of treatment, particularly wind speed and direction, precipitation prior to or likely to occur during or after application, and season. ● Proximity of the treatment area to sensitive areas, such as wetlands, streams, or habitat for plant or animal species of concern. Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 17
● Potential impacts to humans or terrestrial and aquatic wildlife, including non-game species. ● Need for subsequent re-vegetation and/or restoration. For most vegetation treatment projects, pre-treatment inventories are conducted before selecting one or more treatment methods. These inventories involve the consideration of all feasible treatments, including their potential effectiveness based on previous experience, and best available science, impacts, and costs. Before vegetation treatment or ground disturbance occurs, the BLM consults specialists or databases for information on sensitive resources within the proposed project area. If no current information exists, the proposed treatment area would have to be inventoried for special status species and evidence of cultural or historic sites. Detailed descriptions of the methods and equipment used in proposed vegetation treatment actions can be found in Restoring Western Ranges and Wildlands, Rocky Mountain Research Station General Technical Report 136, (Monsen, Stevens, & Shaw, 2004). Herbicides
The BDO is proposing to use three new herbicides that are approved for use on public lands by the ROD for the 2016 PEIS. Herbicides would be used to control and eliminate areas of noxious weeds and invasive plants expansion and to contain existing infestations. The three active ingredients, registered trade names and use are listed in Appendix C. Additional information concerning the herbicides available for use under the proposed action is included in the 2016 PEIS; a summary of herbicide impacts can be found in Chapter 4, pages 4- 27 through 4-33. Chemical treatment involves the application of herbicides, by a variety of application methods, at certain plant growth stages to kill noxious weeds and invasive plants. Depending on the type of herbicide selected, they can be used for control or complete eradication and may be used in combination with other control treatments. Selection of an herbicide and timing of application would depend on its chemical effectiveness on a particular weed species, habitat types present, proximity to water, and presence or absence of sensitive plant, wildlife, fish or other aquatic species. Herbicide applications also utilize adjuvants to enhance or prolong the activity of an active ingredient (USDI BLM, 2007a). For terrestrial herbicides, adjuvants aid in proper wetting of foliage and absorption of the active ingredient into plant tissue. Adjuvant is a broad term that includes surfactants, selected oils, anti-foaming agents, buffering compounds, drift control agents, compatibility agents, stickers, and spreaders. Adjuvants are not under the same registration guidelines as pesticides; the Environmental Protection Agency (EPA) does not register or approve the labeling of spray adjuvants. Individual herbicide labels contain lists with “label-approved” adjuvants for use with a particular herbicide under specific conditions. Currently more than 200 adjuvants are approved for use on BLM lands. Under the proposed action, only approved adjuvants would be used and all label restrictions would apply. Ecological risk assessments (ERAs) for herbicides analyzed in the 2016 PEIS included the use of adjuvants; results of the ERAs were incorporated into the biological assessments (BAs) for the PEIS. Conservation measures resulting from consultations on the 2016 PEIS address the use of
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 18 adjuvants for sensitive aquatic resources (USDI BLM, 2007a). These conservation measures are incorporated into the Design Features and Conservation Measures section below. Aminopyralid, fluroxypyr, and rimsulfuron would be applied using ground-based low boom or spot treatments, or aerial applications. Ground applications would include vehicle mounted or towed sprayers including OHV, truck, or tractor, as well as spot spraying, backpack spraying, hand spraying, wicking, wiping, dipping, painting or injecting. Aerial applications would be made from helicopter or fixed wing aircraft. Additional targeted herbicide applications that could be used include wiping, brushing, or dabbing of herbicides onto noxious or invasive plant species that have been cut with chain saws or other hand tools. Approximately 10,000-25,000 spot herbicide applications for weed control would occur annually across the BDO. The vast majority of these treatments range in size from a single plant up to 5 acres. Treatments of up to 50 contiguous acres could be completed. There would be fewer than 25 treatments of 50 acres annually. Total acres treated yearly with herbicide would be 1,000 – 10,000 acres. Over the last 10 years, the BDO has averaged 2,000 acres of herbicide treatment annually. There would be 1-10 aerial herbicide applications of less than 50 acres in size annually. Aerial application of liquid and granular forms of herbicides would be made from fixed-wing planes or helicopters. Application of herbicides using aircraft would incorporate all SOPs and required provisions. The BDO estimates that the maximum area for aerial treatment per year would not exceed 500 acres. Herbicide Treatment Standard Operating Procedures
The BLM would adopt Standard Operating Procedures (SOP) from the ROD for the 2016 PEIS to ensure that risks to human health and the environment from herbicide treatment actions are kept to a minimum. The SOPs are the management controls and performance standards intended to protect and enhance natural resources that could be affected by vegetation treatments involving the use of herbicides (Appendix B). Design Features and Conservation Measures Design features were derived from land use plans, conservation plans and agreements, existing NEPA documents, and current ESA Section 7 consultations. In addition, mitigation measures resulting from the RODs for the 2007 and 2016 PEISs were adopted and included as design features, as appropriate. Where multiple design features in different documents addressed the same resource, the most conservative option was chosen for incorporation. Design features identified in Chapter 2 would be included to reduce or eliminate potential adverse impacts. Water Resources and Riparian Conservation Areas (RCAs) The BDO uses the Inland Native Fish Strategy (INFISH) for the Intermountain, Northern, and Pacific Northwest Regions (USDA FS, 1995) to identify areas where management actions may affect aquatic resources, including water quality. The INFISH RCAs are: ● 300 feet for fish bearing streams; ● 150 feet for perennial non-fish bearing streams; ● 150 feet for ponds, lakes, reservoirs, and wetlands greater than one acre;
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● 50 feet for seasonally flowing or intermittent streams, wetlands less than one acre, landslides and landslide-prone areas. ● In non-forested rangeland ecosystems, the interim RCA width for permanently flowing streams in categories 1 and 2 is the extent of the 100 year flood plain.
Figure 1 displays the relationship between the stream channel, riparian vegetation, and upland vegetation within the RCA. The RCA consists of the stream channel and the area on either side of the stream extending from the edges of the active channel (i.e., where high water scours perennial vegetation or deposits debris within the active floodplain) beyond the outer limits of hydric vegetation for a linear distance appropriate for the RCA (i.e., fish-bearing, non-fish bearing, or wetlands). The term hydric vegetation refers to vegetation types that are influenced by surface or subsurface water and include woody (e.g., aspen, dogwood, willow) and herbaceous (e.g., carex, rush, sedge) plant species. Management actions within RCAs, such as noxious weed and invasive plant treatments, are often necessary to meet riparian management objectives for special status aquatic species. The following conservation measures were developed to reduce the potential for noxious weed and invasive plant treatments to have negative effects to RCAs. Additional design features and conservation measures to protect special status aquatic species are listed below. Conservation Measures for Site Access and Fueling/Equipment Maintenance ● Where feasible, access work sites only on existing roads and limit travel on roads when damage to the road surface will result or is occurring. ● Within RCAs, do not use full-sized vehicles for transport or fueling. ● Outside of RCAs, allow driving off of established roads only on slopes of 20% or less. ● Helicopter service landings, fuel trucks, and fueling or storage of fuel would not occur within 300 feet of live water. ● Except in emergencies, land helicopters outside of RCAs. ● Prior to helicopter fueling operations prepare a transportation, storage, and emergency spill plan and obtain the appropriate approvals; for other heavy equipment fueling operations use a slip-tank not greater than 250 gallons; prepare spill containment and cleanup provisions for maintenance operations. Conservation Measures Related to Mechanical Treatments Outside RCAs: ● Conduct soil-disturbing treatments only on slopes of 20% or less, where feasible. Within RCAs: ● Do not use vehicles in perennial channels or in intermittent channels with water, except at crossings that already exist. ● Leave suitable quantities (to be determined at the local level) of excess vegetation and slash on site. Do not completely remove invasive hydric trees and shrubs (e.g. saltcedar, Russian olive) from riparian areas if removal would result in bank destabilization. Phase removal with planting of native riparian shrubs to maintain bank stability.
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Conservation Measures Related to Herbicide Treatments ● The three new herbicides aminopyralid, fluroxypyr, and rimsulfuron would not be used in RCAs. These herbicides can be used for spot treatments in upland vegetation within RCAs, but cannot be used within 15 feet of hydric vegetation. Areas with potential for groundwater for domestic or municipal water use shall be evaluated through the appropriate, validated EPA model(s) to estimate vulnerability to potential groundwater contamination, and appropriate mitigation measures shall be developed if such an area requires the application of herbicides and cannot otherwise be treated with non-chemical methods.
Figure 1 - Relationship between the Stream Channel, Upland, and Riparian Vegetation within an RCA
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Threatened, Endangered, and Proposed (TEP) Species
Applicable conservation measures specific to threatened and endangered aquatic species listed below are from the BAs for the 2016 PEIS and should be used to develop site-specific treatment plans. These would be applied in addition to the design features and conservation measures listed above for RCAs. These conservation measures would apply to treatments occurring in watersheds with TEP aquatic species, as well as Designated and Proposed Critical Habitats. Conservation measures for TEP aquatic species listed below, including protective buffers, should be reviewed and applied as needed to protect TEP species. Additional conservation measures apply to all special status aquatic species (TEP and BLM sensitive), as noted. Conservation Measures for Site Access and Fueling/Equipment Maintenance ● No storage or re-fueling of equipment would occur within RCAs.
Conservation Measures Related to Herbicide Treatments ● No surfactants would be used within 15 feet of streams containing TEP and BLM sensitive aquatic species. The following conservation measures would apply to protect habitats for ESA-listed snails: ● Aerial herbicide treatments would not occur within 0.5 miles of the lower Bruneau River downstream of the wilderness boundary (Bruneau hot springsnail Recovery Area) to protect the Bruneau hot springsnail. ● Aerial herbicide treatments would not occur within 0.5 miles of the Snake River to protect Snake River physa and Bliss Rapids snails. ● No spraying of herbicides would occur within 15 feet of geothermal springs within the Bruneau hot springsnail Recovery Area. Manual treatments and aquatic-approved herbicide applications using wicking, wiping, dipping, painting, or injection are the only treatment methods allowed in these habitats. Additional conservation measures, including protective buffers, could be included in site-specific treatment plans to address conditions such as soil type, rainfall, vegetation type, and herbicide treatment method for protection of TEP aquatic species. Slickspot Peppergrass Design Features The Conservation Agreement (US BLM and FWS 2014) for slickspot peppergrass states the following in regards to herbicide use: “Although non-chemical methods will be the preferred approach in occupied habitat, when appropriate, projects involving the application of pesticides, (including herbicides, fungicides and other related chemicals) in habitat categories for slickspot peppergrass that may affect the species would be analyzed at the project level and designed such that herbicide applications will support conservation and minimize risks of exposure.” Under this proposed action, project planning and implementation of noxious and invasive weed herbicide treatment methods would comply with the applicable conservation measures outlined in the Biological Assessments (USDI BLM 2007 and USDI BLM 2015a). Additional design features specific to slickspot peppergrass are described below. Definitions specific to slickspot peppergrass are in Appendix D.
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Project planning ● Potential project areas would be assessed via BLM GIS and IDFG IFWIS data sets to determine presence or absence of slickspot peppergrass element occurrences (EOs) and/or habitats. These proposed project treatments will be coordinated with BDO Noxious Weed Specialist and BDO Botanist to determine the most appropriate treatment given the condition of the area and slickspot peppergrass habitats involved. If an inventory is necessary it would be performed or overseen by a qualified BLM botanist and conducted per BLM slickspot peppergrass inventory and clearance standards to determine the presence/absence of the species and/or its habitat before implementation. ● An annual report would be provided to the FRFO botanist specifying locations and details of noxious and invasive weed spot treatments in any LEPA Management Areas. ● Where needed and feasible, projects would be coordinated with adjacent landowners and local governments regarding treatment of noxious weeds and invasive plants in upland areas through cooperative weed management programs. ● BLM weed staff, county weed management cooperators, and contractors would be trained annually in slickspot peppergrass plant and slickspot habitat identification. ● Use of full-size vehicles for treatment site access and equipment staging would be limited to existing roads in slickspot peppergrass habitats. ● All ATV and/or UTV operators would be educated and instructed to avoid driving through slickspots in slickspot peppergrass habitat categories. Herbicide Application All Slickspot Peppergrass Habitat Categories ● No Aerial applications of herbicide are included under the current proposed action in any habitat category for slickspot peppergrass. Aerial applications of herbicide in any slickspot peppergrass habitat categories would require additional site specific NEPA and section 7 consultation. ● Aerial application of herbicide would not occur within a ¼-mile buffer of EOs, PCH, or Slickspot Peppergrass Habitat. EOs, PCH and Occupied Habitat ● Develop site-specific stipulations and assure coordination between project manager, BDO Noxious Weed Specialist, and BLM Botanist. ● Evaluate the benefits and risks of vegetation treatment including the following: mode of action, application methods, individual herbicide characteristics, carriers, and surfactants used, necessary treatment buffers, and potential use of non-chemical noxious weed control (e.g., biological control and manual treatment methods). ● Herbicide application treatments would be conducted by BLM staff and/or weed management cooperators or contractors trained annually in slickspot peppergrass plant and slickspot habitat identification.
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● Ground-based low boom application of contact herbicides would not occur within EOs through this proposed action. Ground-based low boom application of contact herbicides in slickspot peppergrass EOs would require additional site-specific consultation. ● Ground-based low boom application of contact herbicides within PCH or Occupied Habitat outside of EOs be overseen by the BLM Noxious Weed Specialist and BLM Botanist, and would be implemented by personnel trained in plant and slickspot identification. These treatments would focus on the control of noxious and invasive plants while promoting the preservation of native forbs through native forb avoidance. ● Application of pre-emergent herbicides would not occur within 100 feet of a slickspot (USDI BLM 2016). Noxious or invasive weeds within this buffer area would be treated using a contact herbicide or manual removal. Pre-emergent herbicides would not be used within active EOs until the effects of the active ingredients are shown to have no effect to slickspot peppergrass seed banks. Occupied Habitat outside of an EO (Pollinator Habitat Buffer) ● Within the Pollinator Habitat Buffer, ground-based low boom application of pre- emergent herbicides would only be applied by a BLM certified pesticide applicator trained in slickspot identification and coordinated with BLM botanist. Monitoring Implementation monitoring of herbicide use is accomplished through the PUP (required by the BLM) and Pesticide Application Records (PAR, required by the State of Idaho). These documents are required in order to track pesticide use annually. The PUP requires the pesticide proposed for use and the maximum application rate as well as the number and timing of applications. Targeted and non-targeted species at the treatment site and other site characteristics are described, sensitive resources and mitigation measures to protect these resources, and a description of the integrated weed management approach to be taken (i.e., the combination of treatments to be used). The NEPA document that analyzes the effects of the treatment must also be referenced. Idaho BLM requires the PUP must be signed by a BLM certified weed applicator, the District Manager, State Weed Coordinator, Branch Chief (Resources) and Deputy State Director before the treatment can go forward. The PAR, which must be completed within 24 hours after completion of the application, documents the actual rate of application and that all the above factors have been taken into account. PARs are used to develop annual state summaries of herbicide use by the BLM. Monitoring of invasive plant treatment effectiveness can range from site visits to compare the targeted population size against pre-treatment inventory data, to comparing pre-treatment and post-treatment photo points, to more elaborate transect work, depending on the species and site- specific variables. Monitoring should provide sufficient information to document the following factors, at a minimum: ● Changes in the distribution, amount, and proportion of invasive plant infestations resulting from treatments ● Reduction in infestation size at the project level ● Success of treatment methods, either separate or in combination for a particular species ● Anticipated or unanticipated effects to non-target species
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● Baseline vegetation inventories would be conducted to determine invasive plant community conditions and to determine the need and scope of treatments to reduce infestations. Post treatment monitoring would occur to evaluate success of the treatments. The methods used to monitor treatments could include monitoring methods such as field observations, photo plots, cover transects, density, and belt transects.
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Chapter 3 – Species Life History Summaries Bruneau Hot Springsnail Listing Status and Recovery Plan The Bruneau hot springsnail (Pyrgulopsis bruneauensis) was listed by the Service as endangered under the ESA on January 25, 1993 (58 FR 5938-5946). However, on December 14, 1993, the U.S. District Court of Idaho set aside the Final Rule listing this species as endangered. On June 29, 1995, the U.S. Court of Appeals for the Ninth Circuit Court ruled that the Service reconsider the ESA listing for this species. On June 17, 1998, the Service reaffirmed the 1993 listing of the Bruneau hot springsnail as endangered (63 FR 32981-32996). The Recovery Plan for the Bruneau hot springsnail was approved by the Service (USDI USFWS, 2002b) on September 30, 2002, and made available to the public on December 9, 2002 (67 FR 72967). The objective of the plan is to recover this species to the point where delisting is warranted. The recovery priority is 2C on a scale of 1 to 18, indicating the Bruneau hot springsnail meets the following criteria (USDI USFWS, 2002b): 1) taxonomically, the snail is a species; 2) the species faces a high degree of threat; 3) the species is rated high in terms of recovery potential; and 4) the species may be in conflict with other economic activities. The recovery area for the Bruneau hot springsnail includes BLM-administered lands in the Jarbidge and Bruneau Field Offices and private land (Figure 2). The recovery area begins at the point where the Bruneau River (flowing south to north) crosses the southern boundary of T08S, R06E, S12 and continues downstream (including Hot Creek from the confluence of the Bruneau River to the Indian Bathtub) to the point where the Bruneau River crosses the northern boundary of T07S, R06E, S35 of Owyhee County, Idaho (USDI USFWS, 2002b). The Recovery Plan (USDI USFWS, 2002b) lists nine strategies or conservation measures needed to achieve recovery of the Bruneau hot springsnail. In general, the strategies include the protection of the geothermal aquifer on which the species depends, monitoring to assess changes in the geothermal aquifer and the survival and recovery of the species and its habitat, habitat restoration, a control program for non-native fish that prey upon the Bruneau hot springsnail within the recovery area, the use of translocation to establish additional Bruneau hot springsnail colonies within the recovery area, and monitoring and evaluation of recovery actions with regard to fulfilling the recovery plan objectives. The Recovery Plan (USDI USFWS, 2002b) included the BLM as having responsibility to not permit any activities on lands under BLM jurisdiction that would jeopardize the survival of endangered or threatened species, or destroy or adversely modify habitat. To this end, the BLM has installed fencing along the east and west sides of the Bruneau River and the Hot Creek watershed to prevent the trampling of riparian vegetation by cattle and the subsequent erosion and siltation of Bruneau hot springsnail habitat. In total, the Bruneau hot springsnail Recovery Area encompasses approximately 471 acres. Of these acres, approximately 259 acres are managed by the BLM BDO- Bruneau Field Office (west side of the Bruneau River) and 212 acres are managed by the Twin Falls District Office – Jarbidge FO (east side of the Bruneau River). Of the 259 acres within the Bruneau FO, only 22 acres are not encompassed by the wilderness or the Lower Bruneau Canyon ACEC. Activities
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Species Description The family Hydrobiidae has a worldwide distribution of freshwater snail that is represented in North America by approximately 285 species in 35 genera (Sada, 2006). In North America, most species occupy springs, and their abundance and diversity is notably high in the Great Basin, where approximately 80 species from the genus Pyrgulopsis occur (Hershler & Sada, 2002). Pyrgulopsis is the most common genus in the family with approximately 131 described species that are considered valid, 61 percent of which occur in the Great Basin (Hershler & Sada, 2002). The Bruneau hot springsnail (Pyrgulopsis bruneauensis) is a small freshwater snail (Gastropoda) in the family Hydrobiidae. Hydrobiids are gill-breathing, aquatic or semi-aquatic mollusks that are restricted to permanent waters, particularly spring-fed waters. Adult Bruneau hot springsnails have a small, globose (short, fat, rounded) to low-conic (short and cone-shaped) shell up to 5.5 millimeters (mm) (0.22 inch) long, less than 2.8 mm (0.11 inch) high, and with 3.75 to 4.25 mm (0.15 to 0.22 inch) whorls. Fresh shells are thin, transparent, and white to clear, appearing black because of underlying pigmentation. Other distinguishing features of this species include a verge (male intromittent organ) with a small lobe bearing a single distal glandular ridge and elongate muscular filament (Hershler, 1990; in: 58 FR 5938-5946). P. bruneauensis is endemic to thermal springs and seeps that occur along eight kilometers (km) (five miles) of the Bruneau River in southwest Idaho (USDI USFWS, 2007). This species has a temperature tolerance between 11oC to 35οC (52 to 95οF) (Mladenka, 1992). Although P. bruneauensis have been observed in the Bruneau River proper (Mladenka & Minshall, 2004), occurrences have been directly associated with geothermal upwelling on the river bottom (Myler, 2004). The occurrence of P. bruneauensis is strongly associated with suitable water temperature (58 FR 5938-5946). In late summer (July to August) water temperatures in the Bruneau River are within the temperature tolerance of P. bruneauensis. However, there are no known surveys that have located P. bruneauensis in cold water or outside of geothermal upwelling zones in the Bruneau River (USDI USFWS, 2007). P. bruneauensis is seldom found in standing or slow-moving water and was shown in the laboratory to tolerate higher current velocities than present in nature (Mladenka, 1992). This species has been observed to drift into the Bruneau River when it is disturbed from its geothermal spring habitat (Myler, 2004). Drift as a mechanism of downstream dispersal is possible for this species. However, it is assumed that since this species has no locomotion abilities in the river current, many drifting individuals that do not settle in geothermal springs will likely perish due to their strict temperature requirements (USDI USFWS, 2007). The dispersal mechanism and long-term exposure to cold river water for this species remains uncertain.
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Figure 2 – BLM BDO Bruneau Hot Springsnail Recovery Area
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Life History and Habitat Characteristics P. bruneauensis are tiny gill-breathing springsnails that are aquatic throughout their life cycle (Hershler & Sada, 2002). Reproduction occurs throughout the year except when limited by high or low water temperatures (USDI USFWS, 2002b). The optimal temperature range for reproduction is between 75oF and 95oF (Mladenka, 1992). Sexual maturity occurs at approximately 2 months of age. P. bruneauensis are dioecious (reproductive organs in separate male and female specimens) and lay single oval eggs on hard surfaces such as rock substrates or other snail shells (58 FR 5938-5946). The Bruneau hot springsnail appears to be an opportunistic feeder, grazing primarily on algae and diatoms (USDI USFWS, 2002b). Springsnail densities are lowest in areas with bright green algal mats and higher in areas supporting periphyton-dominated communities (Mladenka, 1992). Abundance of springsnails generally varies seasonally, and is influenced principally by water temperature, spring discharge, food availability, and food quality as measured by chlorophyll content (Mladenka, 1992; Varricchione & Minshall, 1997). During the winter period of cold ambient temperatures and icing, the springsnails are most often located on the underside of outflow substrates; habitats least exposed to cold temperatures (Mladenka, 1992). A movement study performed in the laboratory showed that P. bruneauensis is capable of crawling one centimeter per minute (0.3 in/min) (Myler & Minshall, 1998). This species prefers to move over wetted substrates and has a propensity to move upstream versus downstream (Myler & Minshall, 1998). Bruneau hot springsnails are found on exposed surfaces of various substrates, including rocks, gravel, sand, mud, algal film, and periphyton communities within geothermal spring habitats (USDI USFWS, 2002b). Current velocity is not considered a significant factor limiting springsnail distribution, since they have been observed to inhabit nearly 100 percent of the available current regimes (USDI USFWS, 2002b). Water temperature is the primary factor influencing this species’ life history and habitat requirements, while water availability is the primary factor limiting this species’ abundance and distribution. Bruneau hot springsnails are found in flowing geothermal springs and seeps with temperatures ranging from 15.7ºC to 36. ºC (60.3ºF to 98.4ºF (Mladenka & Minshall, 1996). The highest springsnail densities (greater than 837 individuals per square yard) occur in springs with temperatures between 22.8ºC to 36.6ºC (73.0ºF and 97.9ºF (Mladenka, 1992). The habitat for Bruneau hot springsnail is vastly different than the habitat used by the other ESA- listed aquatic snails within the BDO. The Bruneau hot springsnail occurs in geothermal springs that either originate from basalt rubble or bedrock cliffs or emerge from consolidated or unconsolidated sediments (sands and silts) in the form of bank seeps (Hopper, Burak, & Hardy, 2013). These geothermal springs drain downslope to the Bruneau River as either well defined creek channels or poorly defined moist banks with little to no pooling. Most of the visible, channelized geothermal spring streams are small, being only centimeters across and no longer than several meters from their source. However there are exceptions to this, with one notable spring being greater than one meter wide, and numerous other springs in excess of 10 meters in length. The Bruneau hot springsnail only occurs within the geothermal springs and are not found within the Bruneau River in areas without geothermal upwelling where stream velocities and water temperatures are not suitable to support Bruneau hot springsnail (D. Hopper, pers.com;
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2016). The geothermal springs can be relatively open or densely vegetated with numerous native species such as cattails, willow, poison ivy, hackberry, juniper, native forbs or grasses, or non- native invasive species, including Russian olive. With the exception of Russian olive, most of the vegetation along the geothermal springs is appropriate for the site.
Status and Species Distribution The Bruneau hot springsnail is only known to occur in a complex of related geothermal springs and their immediate outflows along the Bruneau River and its tributary, Hot Creek, in Owyhee County, southwestern Idaho (58 FR 5938-5946). The geothermal springs are located in the Bruneau hydrologic unit code 17050102 and are outflows of the Bruneau Valley geothermal aquifer (63 FR 32981-32996). No additional historic records exist for this species from the U.S. or elsewhere. Mollusk surveys of other thermal and cold-water springs in southern Idaho have failed to locate additional populations of P. bruneauensis. Little is known about the historic range and distribution of the springsnail in the Bruneau River Basin. There is no recorded information on this species or its distribution prior to the 1950s. However, Hershler (1993) stated the presence of substantial populations of hydrobiid snails at a locality indicates the permanence of a water body and the persistence of habitat, perhaps for millennia (USDI BLM, 2006b). Bruneau hot springsnails were first collected in springflows at the Indian Bathtub in upper Hot Creek by Borys Malkin in 1952 (58 FR 5938-5946). In 1953, J. P. E. Morrison concluded that these specimens represented a previously unknown genus and species of springsnail (USDI USFWS, 2002b). Robert Hershler formally described the species in 1990 from type specimens collected from the Indian Bathtub in Hot Creek as Pyrgulopsis bruneauensis, with a new common name of Bruneau hot springsnail (Hershler, 1990, in 58 FR 5938-5946). Most of the geothermal springs occupied by the Bruneau hot springsnail occur along the Bruneau River at and upstream of the confluence with Hot Creek on public lands administered by the BLM (USDI USFWS, 2002b). BLM-administered lands within this species’ range along the east bank of the Bruneau River (232 acres) are within the BLM Jarbidge Field Office (FO), while those along the west bank (62.1 acres) are within the BLM Bruneau Field Office. Some additional springs occur on 164.5 acres of private land downstream of the Indian Bathtub and Hot Creek. However, most of these springs do not provide suitable geothermal conditions for the P. bruneauensis because of high water temperature (greater than 98.6oF) (USDI BLM, 2006b). Range-wide assessments in 2012 occurred upstream of Hot Creek, on the west and east banks combined, and determined there were 63 total geothermal springs found, of which 43 had springsnails (Hopper et al., 2013). Overall, there was a 25 percent increase in the number of occupied springs in 2012 when compared to similar surveys in 2011. It is speculated these measured increases could reflect the low water year of 2011-2012, resulting in reduced disturbance to springs and river habitats (Hooper et al., 2013). It is assumed that elevated flows in the spring of 2011 may have scoured benthic habitats, which may have negatively impacted springsnail populations, that disturbance being reflected in the large number of springs lacking snails (Hopper et al., 2013). Although it is speculated the high river flows in the spring of 2011 explained the reduced presence of springsnails throughout the recovery area, the opposite trend was observed in 2012
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 30 with lower spring flows and higher snail densities (Hopper et al., 2013). Supportive of this disturbance hypothesis is that the low water years [peak flows < 1000 cubic feet/second (cfs)] in 2004, 2007, and 2012, were all years of relatively high snail abundance (presence at springs). However, the two higher water years in 2005 and 2010 were also high abundance years, making the relationship between spring runoff and snail abundance uncertain.
Conservation Needs The Recovery Plan for the Bruneau hot springsnail (USDI USFWS, 2002b) identifies the following conservation measures for State and Federal agencies as actions that would reduce the threats to the species and its habitat: ● Implement conservation measures to increase water levels in the regional geothermal aquifer. Geothermal spring discharges should be permanently protected within the recovery area. ● Implement a groundwater monitoring program to assess changes in the geothermal aquifer. ● Develop a monitoring program to assess the survival and recovery of the species and habitat. ● Implement a habitat restoration program within the recovery area. ● Develop a non-native fish control program for the Bruneau hot springsnail Recovery Area. ● Manage Federal lands to promote recovery of the Bruneau hot springsnail. ● Implement a groundwater recharge model that stabilizes the geothermal aquifer at the recovery elevation. Determine the feasibility of restoring Upper Hot Creek as suitable Bruneau hot springsnail habitat. Use translocation to establish additional Bruneau hot springsnail colonies within the recovery area. ● Seek funding for implementation of recovery tasks. ● Monitor and evaluate the success of recovery actions with regard to fulfilling the recovery objectives, criteria, actions needed, and removal of threats as outlined in the plan. Conservation measures specific to BLM land management activities include not authorizing actions (e.g. livestock grazing or off-road vehicle travel) on Federal lands that would jeopardize the survival of endangered or threatened species or destroy or adversely modify their habitat. The recovery plan acknowledges the BLM has installed fencing along the east and west side of the Bruneau River and the Hot Creek watershed to prevent grazing impacts to riparian vegetation. More recent changes in management include identification of habitat used by Bruneau hot springsnail as critical suppression areas for wildland fire and specific guidelines for wildfire suppression within the occupied habitats.
Threats to the Species The 5-Year Review for the Bruneau hot springsnail (USDI USFWS, 2007), as described below, identifies the following threats to P. bruneauensis and its habitat: groundwater withdrawals, livestock grazing, surface water withdrawals, recreation, predation by exotic fish, groundwater management and water quality. Groundwater withdrawal for irrigation has resulted in a decline of the geothermal aquifer underlying the Bruneau, Sugar, and Little valleys in north-central Owyhee County, Idaho which
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 31 threatens P. bruneauensis through the reduction or loss of geothermal habitat. The total number of geothermal springs along the Bruneau River upstream of Hot Creek (with and without P. bruneauensis) declined from 1991 to 2006 (Myler, 2006) and there are currently fewer high and low snail density sites with P. bruneauensis compared to 1991 (Myler, 2006). Because the water table has dropped dramatically, much of the geothermal spring habitat previously inhabited by P. bruneauensis is dry, resulting in a reduction in number of habitats, habitat area, and isolation of colonies (USDI USFWS, 2002b; USDI USFWS, 2007). Prior to 1998, livestock grazing was considered a threat factor that impacted some geothermal spring habitats where P. bruneauensis occurred near Hot Creek. In the 1990s, the BLM constructed fences to exclude livestock grazing in this area, and presently, cattle are excluded from Hot Creek and all geothermal spring habitats along the Bruneau River upstream of Hot Creek. Riparian vegetation has rebounded and is providing stream cover as well as defense against instream erosion. Presently, livestock grazing is considered a low-ranking threat factor to P. bruneauensis colonies and the geothermal habitats it occupies in Hot Creek or along the Bruneau River upstream of Hot Creek. Surface water withdrawals and diversions occur along the Bruneau River downstream of Hot Creek. Within the recovery area, which extends approximately 1.2 miles below Hot Creek, there are two major diversions dams; Harris Dam and Buckaroo Dam. These dams divert nearly all of the water from the Bruneau River for irrigation in the Bruneau Valley. It is unknown how P. bruneauensis disperses between geothermal springs; however, they have been observed to drift into the Bruneau River when disturbed (Myler, 2006). Therefore, removing the majority of the flow below Hot Creek may impede the ability of this species to migrate or disperse to other downstream geothermal springs. Surface water diversion is a low-ranking threat that only applies to habitat along the Bruneau River below Hot Creek. The original 1993 listing (58 FR 5938-5946) stated that recreational access also impacts habitats of P. bruneauensis along the Bruneau River (USDI USFWS, 2007). Recreational activities continue to occur at one geothermal spring where small dams have been constructed to form thermal pools for bathing. In 1998, the Service determined that recreational use of thermal springs was not a significant threat to P. bruneauensis or its geothermal spring habitat (63 FR 32981-32996). Presently, only one known geothermal spring in the recovery area is used by recreational bathers, but is above the thermal maximum of 35οC (95οF), that P. bruneauensis can tolerate. Therefore, recreational use of the geothermal springs and seeps is considered a low- ranking threat to P. bruneauensis. Introduced populations of redbelly tilapia (Tilapia zilli), and mosquito fish (Gambusia affinis) thrive in Hot Creek and in the geothermal springs that discharge into the Bruneau River throughout the entire range of P. bruneauensis (Myler, 2004). Recent laboratory studies suggest that Tilapia zilli will use P. bruneauensis as a food source (Myler & Minshall, 1998). In 1999, a controlled fish feeding experiment in enclosures in Hot Creek with T. zilli and P. bruneauensis found that all P. bruneauensis were absent within five days (Myler, 2000). Since T. zilli occur in the geothermal springs along the Bruneau River and in Hot Creek (Myler, 2004) they likely threaten the continued existence of P. bruneauensis through predation. In addition, Mladenka observed G. affinis to eat P. bruneauensis in the laboratory. Future declines in P. bruneauensis habitat increase the likelihood for population declines due to predation from these exotic fish.
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Slickspot Peppergrass
Listing Status Slickspot peppergrass is listed as threatened under the Act, as of September 16, 2016 (81 FR 55057-55084, August 17, 2016, p. 55057). The species was proposed as a candidate for listing under the Act in 1999 (64 FR 57534-57547). In November 2001, the Service was sued by the Committee for Idaho’s High Desert and Western Watersheds Project for failure to issue an emergency rule to list the plant and for failing to proceed with a proposed rule to list the plant as endangered. Pursuant to a settlement agreement, the Service agreed to publish a final listing determination by July 15, 2003. In July 2002, the Service proposed listing the plant as endangered under the Act (67 FR 46441-46450). In July 2003, the Service extended the date for publication of a final listing decision to January 15, 2004, because of disagreement over whether available data for slickspot peppergrass populations were sufficient to indicate a continuing trend of decline towards extinction (68 FR 42666-42668). In 2003, the State of Idaho, BLM, private landowners who were also BLM livestock grazing permittees, and the Idaho Army National Guard finalized a Candidate Conservation Agreement for slickspot peppergrass. In addition, the U.S. Air Force finalized their Integrated Natural Resources Management Plan in January 2004. Based on these conservation efforts, the certainty of their implementation, their effectiveness in reducing risks to the species after implementation, and the then current lack of strong evidence suggesting a negative population trend, the Service withdrew the proposal to list slickspot peppergrass as endangered in January 2004 (69 FR 3094- 3116). In April 2004, the Service was sued by Western Watersheds Project for failure to list slickspot peppergrass as threatened or endangered under the Act. In August 2005, the U.S. District Court for the District of Idaho reversed the decision to withdraw the proposed rule to list slickspot peppergrass as endangered, with directions that the case be remanded to the Secretary of the Department of the Interior for reconsideration of whether a proposed rule listing slickspot peppergrass as either threatened or endangered should be adopted. In October 2005, the Service requested new information for slickspot peppergrass as a result of that court decision. The Service withdrew the proposed determination to list slickspot peppergrass as endangered in January 2007 (72 FR 1622-1644) and efforts to complete section 7 consultation on existing land use plans and on-going actions ceased. The withdrawal of the proposal to list slickspot peppergrass was based on the conclusion that, while its sagebrush-steppe habitat was becoming increasingly degraded, the best available information at the time provided no evidence indicating that this degradation was impacting slickspot peppergrass within its slickspot microsites. On April 6, 2007, Western Watersheds Project filed a lawsuit challenging the decision to withdraw the proposed rule to list slickspot peppergrass. On June 4, 2008, the U.S. District Court for the District of Idaho reversed the Service’s decision to withdraw the proposed rule, with directions that the case be remanded to the Service for further consideration (Western Watersheds Project v. Kempthorne, Case No.CV 07-161-E-MHW [D. Idaho]). After issuance of the court’s remand order, the Service published a public notification of the reinstatement of the July 15, 2002 proposed rule to list slickspot peppergrass as endangered and announced the re-opening of a public comment period on September 19, 2008 (73 FR 54345-54346). Slickspot peppergrass was listed as a threatened species under the Act on October 8, 2009 (74 FR 52014-52064).
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The Service published a proposed rule for the designation of Critical Habitat for slickspot peppergrass and an accompanying 60-day comment period on May 10, 2011 (76 FR 27184- 27215). On July 7, 2011, the public comment period was extended an additional 60 days (76 FR 39807-39808). Currently, the proposed rule for designation of slickspot peppergrass Critical Habitat has yet to be approved. The 2009 listing was challenged under the Administrative Procedures Act and the Act. On August 8, 2012, the listing decision was reversed and remanded to the Service for further consideration on the grounds that the term “foreseeable future” was not adequately defined (Otter v. Salazar, No. 1:11-cv-00358-CWD, 2012 U.S. Dist. LEXIS 111743). The Service addressed the deficiency and published the final rule on August 17, 2016 (81 FR 55058-55084), which reinstated the species as listed threatened under the Act, effective September 16, 2016.
Species Description Slickspot peppergrass is an intricately branched, tap-rooted plant, averaging 2 to 8 inches (in.) high, but occasionally reaching up to 16 in. high. Leaves and stems are covered with fine, soft hairs, and the leaves are divided into linear segments. Flowers are numerous, 0.11 to 0.15 in. in diameter, white, and four-petalled. Fruits (silicles1) are 0.10 to 0.15 in. across, round in outline, flattened, and two-seeded (Moseley 1994, pp. 3, 4; Holmgren et al. 2005, p. 260). The species is monocarpic (it flowers once and then dies) and displays two different life history strategies—an annual form and a biennial form. The annual form reproduces by flowering and setting seed in its first year and dies within one growing season. The biennial life form initiates growth in the first year as a vegetative rosette but does not flower and produce seed until the second growing season. Biennial rosettes must survive generally dry summer conditions, and consequently many of the biennial rosettes die before flowering and producing seed. The number of prior-year rosettes is positively correlated with the number of reproductive plants present the following year (ICDC 2008, p. 9; Unnasch 2008, p. 14; Sullivan and Nations 2009, p. 44). The proportion of annuals versus biennials in a population can vary greatly (Meyer et al. 2005, p. 15), but in general, annuals appear to outnumber biennials (Moseley 1994, p. 12).
Life History and Habitat Characteristics
Seed Production Depending on an individual plant’s vigor, the effectiveness of its pollination, and whether it is functioning as an annual or a biennial, each slickspot peppergrass plant produces varying numbers of seeds (Quinney 1998, pp. 15, 17). Biennial plants normally produce many more seeds than annual plants (Meyer et al. 2005, p. 15). Average seed output for annual plants at the Idaho Army National Guard’s (IDARNG) Orchard Combat Training Center2 (OCTC) was 125 seeds per plant in 1993 and 46 seeds per plant in 1994. In contrast, seed production of biennials
1 In previous documents, the Service described the fruit of slickspot peppergrass as a "silique" based on Rollins 1993 (p. 577) and Moseley 1994 (p. 3). More recently, Holmgren et al. (2005, p. 260) described the fruit of slickspot peppergrass as a “silicle” (which may also be described as a "short silique").
2 The Idaho Army National Guard’s Orchard Combat Training Center (OCTC) was previously named the Orchard Training Area (OTA).
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 34 at this site in 1993 and 1994 averaged 787 and 105 seeds per plant, respectively (Meyer et al. 2005, p. 16). Based on data collected from a 4-year demography study on the OCTC, survivorship of the annual form of slickspot peppergrass was demonstrated to be higher than survivorship of biennials (Meyer et al. 2005, p. 16). Meyer et al. (2005, p. 21) hypothesize that the reproductive strategy of slickspot peppergrass is a plastic response, meaning that larger plants will flower and produce seed in their first season, whereas smaller plants that stand less chance of successfully setting seed in their first season will delay reproduction until the following year. Thus, the biennial life form is maintained, despite the higher risk of mortality. Like many short-lived plants growing in arid environments, above-ground numbers of slickspot peppergrass individuals can fluctuate widely from year to year, depending on seasonal precipitation patterns (Mancuso and Moseley 1998, p. 1; Meyer et al. 2005, pp. 4, 12, 15; Palazzo et al. 2005, p. 9; Menke and Kaye 2006a, p. 8; Menke and Kaye 2006b, pp. 10, 11; Sullivan and Nations 2009, p. 44). Mancuso and Moseley (1998, p. 1) note that sites with thousands of above-ground plants one year may have none the next, and vice versa. Above- ground plants represent only a portion of the population; the seed bank (a reserve of dormant seeds generally found in the soil) contributes the other portion and in many years, constitutes the majority of the population (Mancuso and Moseley 1998, p. 1). Seed banks are adaptations for survival in a “risky environment” because they buffer a species from stochastic (random) impacts, such as lack of soil moisture (Baskin and Baskin 2001, p. 160). Seed Viability and Germination The seeds of slickspot peppergrass are found primarily within the slickspot microsites where the plants are found (Meyer and Allen 2005, pp. 5–6). Slickspots, also known as mini-playas or natric (high sodium content) sites, are visually distinct openings in the sagebrush-steppe created by unusual soil conditions characterized by significantly greater sodium and clay content relative to the surrounding area (Moseley 1994, p. 7). The vast majority of slickspot peppergrass seeds in slickspots have been located near the soil surface, with lower numbers of seeds located in deeper soils (Meyer et al. 2005, p. 19; Palazzo et al. 2005, p. 3). Slickspot peppergrass seeds have been found in slickspots even if no above-ground plants are present (Meyer et al. 2005, p. 22; Palazzo et al. 2005, p. 10). When above-ground plants are present, flowering usually occurs in late April and May, fruit set occurs in June, and the seeds are released in late June or early July. Seeds produced in a given year are dormant for at least a year before any germination takes place. Following this year of dormancy, approximately 6 percent of the initially viable seeds produced in a given year germinate annually (Meyer et al. 2005, pp. 17–18). When combined with an average annual 3 percent loss of seed viability, approximately 9 percent of the original seed cohort per year is lost after the first year. Thus, after 12 years, all seeds in a given cohort will likely have either died or germinated, resulting in a maximum estimated longevity of 12 years for seeds in the seed bank (Meyer et al. 2005, p. 18). Billinge and Robertson (2008, pp. 1005–1006) report that both small and large slickspot peppergrass populations share similar spatial structure, and that spatial structuring within its unique microsite slickspot habitats suggests that both pollen dispersal and seed dispersal are low for this species and occur over short distances (Robertson et al. 2006a, p. 3; Billinge and Robertson 2008, pp. 1005–1006). Dispersal and seed dormancy modeling of desert annual plants predicts that plants with long-range dispersal will have few dormancy mechanisms and quick germination (Venable and Lawlor 1980, p. 272). Contrary to this prediction, however, slickspot
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 35 peppergrass has delayed germination (Meyer et al. 2005, pp. 17–18), and, therefore, according to the model, may not disperse long distances. The primary seed dispersal mechanism for slickspot peppergrass is not known (Robertson and Ulappa 2004, p. 1708), although viable seeds have been found outside of slickspots, indicating that some seed dispersal is occurring beyond slickspot habitat (Palazzo et al. 2005, p. 10). Additionally, beginning in mid-July, entire dried-up biennial plants and some larger annual plants have been observed to break off at the base and are blown by the wind (Stillman, pers. obs., as reported in Robertson et al. 2006b, p. 44). This tumbleweed-like action may have historically resulted in occasional long-distance seed dispersal (Robertson et al. 2006b, p. 44). Ants are not considered a likely disperser despite harvesting an average of 32 percent of fruits across six sites (Robertson and White 2007, p. 11). Slickspot peppergrass seeds located near the soil surface show higher rates of germination and viability (Meyer and Allen 2005, pp. 6–8; Palazzo et al. 2005, p. 10) and the greatest seedling emergence success rate (Meyer and Allen 2005, pp. 6–8). Viable seeds were more abundant and had greater germination rates from the upper 2 in. of soil (Palazzo et al. 2005, pp. 8, 10), while Meyer and Allen (2005, pp. 6–8) observed the upper 0.08 in. as optimal for germination. Deep burial of slickspot peppergrass seeds (average depths greater than 5.5 in.) can entomb viable seeds and may preserve them beyond the 12-year period previously assumed as the maximum period of viability for slickspot peppergrass seeds (Meyer and Allen 2005, pp. 6, 9). However, seeds buried at such depth, even if they remain viable, are unlikely to regain the surface for successful germination. The effects of environmental factors, such as wildfire, on slickspot peppergrass seed dormancy and viability are unknown although slickspot peppergrass abundance is reduced in burned areas. Pollination Slickspot peppergrass is primarily an outcrossing species requiring pollen from separate plants for more successful fruit production and has a low seed set in the absence of insect pollinators (Robertson 2003, p. 5; Robertson and Klemash 2003, p. 339; Robertson and Ulappa 2004, p. 1707; Billinge and Robertson 2008, pp. 1005–1006). Slickspot peppergrass is able to self- pollinate, with a selfing rate (rate of self-pollination) of 12 to 18 percent (Billinge 2006, p. 40; Robertson et al. 2006a, p. 40). In pollination experiments where researchers moved pollen from one plant to another, fruit production was higher when pollen from distant sources was used (4 to 12.4 miles (mi)) between patches of plants) than when pollen from plants within the same patch was used (246 to 330 feet (ft)) between plants within the same patch) (Robertson and Ulappa 2004, p. 1705; Robertson et al. 2006a, p. 3). Fruits produced from fertilized flowers reach full size approximately two weeks after pollination (Robertson and Ulappa 2004, p. 1706). Each fruit typically bears two seeds that drop to the ground when the fruit dehisces (splits open) in midsummer (Billinge and Robertson 2008, p. 1003). Known slickspot peppergrass insect pollinators include several families of bees (Hymenoptera), including Apidae, Halictidae, Sphecidae, and Vespidae; beetles (Coleoptera), including Dermestidae, Meloidae, and Melyridae; flies (Diptera), including Bombyliidae, Syrphidae, and Tachinidae; and others (Robertson and Klemash 2003, p. 336; Robertson et al. 2006b, p. 6). In slickspot peppergrass insect pollinator studies conducted at three study sites, seed set was not limited by the number of pollinators at any study site (Robertson et al. 2004, p. 14). Studies have shown a strong positive correlation between insect diversity and the number of slickspot Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 36 peppergrass plants flowering at a site (Robertson and Hannon 2003, p. 8). Measuring fruit set per visit revealed considerable variability in the effectiveness of pollination by different types of insects, ranging from 0 percent in dermestid beetles to 85 percent in honeybees (Apis mellifera) (Robertson et al. 2006b, p. 15). Population Dynamics Due to its occupancy of patchily distributed slickspots, the habitat of slickspot peppergrass is somewhat naturally fragmented. However, large-scale fragmentation can pose problems for slickspot peppergrass by creating barriers in the landscape that prevent effective genetic exchange between populations. Seed dispersal for slickspot peppergrass likely occurs only over very short distances; thus, pollinators and pollen dispersal are the primary means for reproductive and genetic exchange between slickspot peppergrass sites (Robertson and Ulappa 2004, pp. 1705, 1708; Stillman et al. 2005, pp. 1, 6–8). Research indicates that seeds generated by the pollen of nearby plants have reduced viability, and that slickspot peppergrass seed viability increases as the distance to the contributing pollination source increases (Robertson and Ulappa 2004, pp. 1705, 1708). The ability to exchange pollen with distant populations is therefore an advantage for slickspot peppergrass. Barriers or too much distance between slickspots and pollinating insect habitats can reduce the effective range of insects important to slickspot peppergrass pollination (Robertson et al. 2004, pp. 2–4). Barriers can include agricultural fields, urban development, and large areas of annual and perennial grass monocultures that do not support diversity and suitable floral resources such as nectar or edible pollen for pollinators. Slickspot peppergrass habitats separated by distances greater than the effective range of available pollinating insects (about 0.6 mi. as described in Colket and Robertson in litt. 2006, p. 1) are at a genetic disadvantage and may become vulnerable to the effects of loss of genetic diversity (Stillman et al. 2005, pp. 1, 6–8) and a reduction in seed production (Robertson et al. 2004, p. 1705). A genetic analysis of slickspot peppergrass suggested that populations in the Snake River Plain and Northern Basin and Range3 “may have reduced genetic diversity” (Larson et al. 2006, p. 1).4 Many of the remaining occurrences of slickspot peppergrass, particularly in the Snake River Plain near urban centers, are restricted to small, remnant patches of suitable sagebrush-steppe habitat. When last surveyed, 31 of the 80 EOs (39 percent) each had fewer than 50 plants (Colket et al. 2006, Tables 1–13). Many of these small, remnant EOs exist within habitat that is degraded. Small slickspot peppergrass populations have likely persisted due to their long-lived seed bank, but the potential risk of depleting each population’s seed bank with no new genetic input makes the persistence of these small populations uncertain. Providing suitable nesting and foraging habitats for the species’ insect pollinators is important for maintaining slickspot peppergrass genetic diversity. Small populations are vulnerable to relatively minor environmental disturbances such as wildfire, herbicide drift, and nonnative plant invasions (Given 1994, pp. 66–67) and are subject to the loss of genetic diversity from genetic drift and inbreeding (Ellstrand and Elam 1993, pp. 217–237). Populations with lowered genetic diversity
3 The Northern Basin and Range physiographic unit (Kinter 2016, in litt. entire) was previously called Owyhee Plateau physiographic unit.
4 The Boise Foothills were not analyzed separately in this study.
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 37 are more prone to extirpation (Barrett and Kohn 1991, pp. 4, 28). Smaller populations generally have lower genetic diversity, and lower genetic diversity may lead to even smaller populations by decreasing the species’ ability to adapt, thereby increasing the probability of population extinction (Newman and Pilson 1997, p. 360). Fragmentation (either by development or wildfires) has occurred in 62 of 79 EOs (15 of 16 on the Boise Foothills, 35 of 42 on the Snake River Plain, and 12 of 21 on the Northern Basin and Range), and within 0.31 mi in 78 of the 79 EOs (all except one on the Northern Basin and Range) (Cole 2009, threats table).5 Additionally, several development projects are planned within slickspot peppergrass occupied range that would contribute to further large-scale fragmentation of its habitat, potentially resulting in decreased viability of populations through decreased seed production, reduced genetic diversity, and increased inherent vulnerability of small populations to extirpation.
Status and Species Distribution The range of slickspot peppergrass is restricted to the volcanic plains of southwest Idaho, occurring primarily in the Snake River Plain and its adjacent northern foothills, with a single disjunct population on the Northern Basin and Range (Figure 3). The plant occurs at elevations ranging from approximately 2,200 to 5,400 ft in Ada, Canyon, Gem, Elmore, Payette, and Owyhee Counties (Moseley 1994, pp. 3–9). Based on differences in topography, soil, and relative abundance, we have divided the extant slickspot peppergrass populations into three physiographic regions: the Boise Foothills, the Snake River Plain, and the Northern Basin and Range. The nature and severity of factors affecting the species also vary between the three physiographic regions for the purposes of analysis. For example, urban and rural development, agriculture, and infrastructure development has been substantial in the sagebrush-steppe habitat of the Boise Foothills and the Snake River Plain regions, while very little of these types of development have occurred within the Northern Basin and Range region. Currently there are 109 extant slickspot peppergrass EOs occurring on 15,823 acres range wide. Of that total 87 percent (13,728 acres) of the acreage is managed by the Federal government, 9 percent (1,502 acres) is managed by the State of Idaho, and 4 percent (593 acres) is private land (Kinter 2016). The area actually occupied by slickspot peppergrass is a small fraction of this total range wide acreage since slickspots occupy only a small percentage of the landscape, and slickspot peppergrass occupies only a fraction of those slickspots (USAF 2002, p. 9). Table 5 presents distribution, land ownership and management information for all slickspot peppergrass EOs, in total and by region. The majority of slickspot peppergrass sites are located on Federal lands; most of these Federal lands are administered by the BLM.
5 Habitat information is known for 79 of the 80 extant EOs; habitat information is not known for 1 EO on the Snake River Plain.
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Figure 3. The range of Lepidium papilliferum (slickspot peppergrass) in southwest Idaho, showing its distribution in the Snake River Plain, Boise Foothills, and Northern Basin and Range (previously Owyhee Plateau) physiographic regions.
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Habitat Characteristics Biological soil crust, also known as a microbiotic crust or cryptogamic crust, is one component of quality habitat for slickspot peppergrass. Such crusts are commonly found in semiarid and arid ecosystems and are formed by living organisms, primarily bryophytes, lichens, algae, and cyanobacteria, that bind together surface soil particles (Moseley 1994, p. 9; Johnston 1997, p. 4). Microbiotic crusts play an important role in stabilizing the soil and preventing erosion, increasing the availability of nitrogen and other nutrients in the soil and regulating water infiltration and evaporation levels (Johnston 1997, pp. 8–10). In addition, an intact crust appears to aid in preventing the establishment of invasive plants (Brooks and Pyke 2001, p. 4 and references therein; Serpe et al. 2006, pp. 174, 176). These crusts are sensitive to disturbances that disrupt crust integrity, such as compression due to livestock trampling or off highway vehicle (OHV) use and are subject to damage by fire; recovery from disturbance is possible but occurs very slowly (Johnston 1997, pp. 10–11).
Table 5. Distribution and land management status of slickspot peppergrass extant EOs/Sub EOs6 by physiographic region (IDFG 2017).
Slickspot Federal State Private Total Physiographic Peppergrass EOs Region Number Percent Acres* Percent Acres* Percent Acres* Percent Acres* Percent
Boise Foothills 18 17% 74 0.5% 0 0% 65 0.4% 139 1%
Northern Basin 417 38% 2,564 16% 1338 1% 0 0% 2,697 17% and Range
Snake River 50 46% 11,119 70% 1,3699 9% 527 3.3% 13,016 82% Plain
All Extant EOs 109 100% 13,757 87% 1,502 9% 592 4% 15,852 100%
* All areas are estimates; acreages/percentages may not total exactly due to rounding.
6 SubEOs are only designated for metapopulation EO 16, which is located in the Northern Basin and Range physiographic region.
7 EO 16, in the Northern Basin and Range physiographic region, is represented by 19 individual subEOs in the extant EO/SubEO total. If only extant EOs are considered, a total of 90 extant EOs are described by IDFG as of January 2017.
8 Of these 133 acres of State land located within the Northern Basin and Range physiographic region, about 76 acres (57 percent) are located within SubEO 704 and are managed under the Mountain Home Air Force Base’s INRMP.
9 Of these 1,369 acres of State land located within the Snake River Plain physiographic region, about 1,269 acres (93 percent) are managed under the Orchard Combat Training Center’s INRMP.
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Slickspot peppergrass occurs in slickspot habitat microsites scattered within the greater semiarid sagebrush-steppe ecosystem of southwestern Idaho. On a broad scale, the Snake River Plains and the Northern Basin and Range physiographic regions are volcanic in nature and underlain by Tertiary basalt or rhyolite; the adjacent Boise Foothill sites are underlain by Pliocene/Quaternary lacustrine deposits (Moseley 1994, p. 8). Slickspots are visually distinct openings characterized by natric soils and distinct clay layers; they tend to be highly reflective and relatively light in color, making them easy to detect on the landscape (Fisher et al. 1996, p. 3). Slickspots are distinguished from the surrounding sagebrush matrix by the following characteristics: microsites where water pools when rain falls (Fisher et al. 1996, pp. 2, 4); sparse native vegetation, distinct soil layers with a columnar or prismatic structure, higher alkalinity and clay content, and natric properties (Fisher et al. 1996, pp. 15–16; Meyer and Allen 2005, pp. 3–5, 8; Palazzo et al. 2008, p. 378); and reduced levels of organic matter and nutrients due to lower biomass production (Meyer and Quinney 1993, pp. 3, 6; Fisher et al. 1996, p. 4). Fisher et al. (1996, p. 11) describe slickspots as having a “smooth, panlike surface” that is structureless and slowly permeable when wet, moderately hard and cracked when dry. Although the low permeability of slickspots appears to help hold moisture (Moseley 1994, p. 8), once the thin crust dries out, slickspot peppergrass seedling survival depends on its ability to extend its taproot into the argillic horizon (soil layer with high clay content) to extract moisture from the deeper natric zone (Fisher et al. 1996, p. 13). How long slickspots take to form is unknown, but is hypothesized to take several thousands of years (Nettleton and Peterson 1983, p. 193; Seronko 2006, in litt. p. 2). Climate conditions that allowed slickspot formation in southwestern Idaho are thought to have occurred during a wetter Pleistocene period. Holocene additions of wind-carried salts (often loess deposits) produced the natric soils characteristic of slickspots (Nettleton and Peterson 1983, p. 191; Seronko 2006, in litt., p. 2). Several hundred years may be necessary to alter or lose slickspots through natural climate change or severe natural erosion (Seronko 2006, in litt. p. 2). However, some researchers hypothesize that new slickspots are no longer being created given current climatic conditions (Nettleton and Peterson 1983, pp. 166, 191, 206). As slickspots in southwest Idaho appear to have formed during the Pleistocene and current climate conditions may not allow for the formation of new slickspots, the loss of slickspot microsites appears to be permanent. Some slickspots subjected to past light disturbance may be capable of reforming (Seronko 2006, in litt. p.2). However, disturbances that alter the physical properties of the soil layers, such as deep disturbance and the addition of organic matter, may lead to the destruction and permanent loss of slickspots. For example, deep soil tilling and adding organic matter and gypsum have been recommended for eliminating slickspots from agricultural lands in Idaho (Peterson 1919, p. 11; Rasmussen et al. 1972, p. 142). Slickspot soils are especially susceptible to mechanical disturbances when wet (Rengasamy et al. 1984, p. 63; Seronko 2004, in litt. pp. 1–2). Such disturbances disrupt the soil layers important to slickspot peppergrass seed germination and seedling growth and alter hydrological function. Meyer and Allen (2005, p. 9) suggest that if sufficient time passes following the disturbance of slickspot soil layers, the slickspot soil layers may regain their pre-disturbance configuration yet not support the species. Thus, while the slickspot appears to have regained its former character, some essential component required to sustain the life history requirements of slickspot peppergrass has apparently been lost, or the active seed bank is no longer present. Most slickspots are between 10 and 20 square feet (ft2) in size although some are as large as 109 ft2 (Mancuso et al. 1998, p. 1). Slickspots cover a relatively small cumulative area within the
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 41 larger sagebrush-steppe matrix, and only a small percentage of slickspots are known to be occupied by slickspot peppergrass. Slickspot peppergrass has infrequently been documented outside of slickspots on disturbed soils, such as along graded roadsides and badger mounds. However, the vast majority of plants documented over the past 19 years of surveys and monitoring for the species were observed within slickspot microsite habitats (USFWS 2006, p. 20). For example, in 2002, a complete census of an 11,070-ac area recorded approximately 56,500 slickspots (USAF 2003, in litt. p. 15), of which approximately 2,450 (about 4 percent) were occupied by slickspot peppergrass plants (Bashore, pers. comm. 2003, p. 1). Of the approximately 11,300 slickspot peppergrass plants documented during the survey effort, only 11 plants (less than 1 percent) were documented outside of slickspots (USAF 2002, summary attachment). Not all potential slickspot peppergrass habitats in southwest Idaho have been surveyed, and additional slickspot peppergrass sites may be found outside of areas known to be occupied. In 2008, a high-quality, predictive-distribution model of slickspot peppergrass to identify Potential Habitat was developed (Colket 2008, p. 1). The BLM defines Potential Habitat as areas within the known range of slickspot peppergrass that have certain general soil and elevation characteristics that indicate the potential for the area to support slickspot peppergrass, although the presence of slickspots or the plant is unknown (Bureau 2009, p. B–2). Although surveys were conducted in 2008 in some areas identified as previously unsurveyed habitat with potential to contain the species, these surveys did not result in any new locations of the species (Colket 2008, pp. 4–6). Slickspot peppergrass has also been surveyed for in eastern Oregon, but the species has never been found there (Findley 2003, in litt. p. 1). We have no historical records indicating that slickspot peppergrass has been found anywhere outside of its present range in southwestern Idaho. The Idaho Natural Heritage Program (INHP) uses an EO ranking system for assessing the status of slickspot peppergrass. This system ranks slickspot peppergrass occurrences based on measures of habitat quality and species abundance. EO ranks are useful for assessing estimated viability or probability of persistence and helping prioritize conservation planning or actions (NatureServe 2002). The ranks are defined as follows (Colket et al. 2006, pp. 3–4): A-Rank— SIZE: Greater than 1,000 detectable genets. CONDITION: Native plant community is intact with trace introduced plant species cover. Slickspots have zero or trace introduced weed cover and/or livestock disturbance. Zero or few minor anthropogenic disturbances are present. EO is unburned. LANDSCAPE CONTEXT: Surrounding landscape less than 0.6 mi away has not been fragmented by agricultural lands, residential or commercial development, introduced annual grasslands, or drill seeding projects.
B-Rank— SIZE: 400–999 detectable genets. CONDITION: Native plant community is intact with low introduced plant species cover. Slickspots have low introduced weed cover and/or livestock disturbance. Zero or few minor anthropogenic disturbances present. EO is predominantly unburned.
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LANDSCAPE CONTEXT: Surrounding landscape less than 0.6 mi away is minimally to partially fragmented by agricultural lands, residential or commercial development, introduced annual grasslands, or drill seeding projects.
C-Rank— SIZE: 50–399 detectable genets. CONDITION: Native plant community is partially intact with low-to-moderate introduced plant species cover. Slickspots have low-to-moderate introduced weed cover and/or livestock disturbance. Few or several minimally to moderately severe anthropogenic disturbances are evident. EO has partially burned. Portions of EO may have been drill seeded, but slickspots are largely intact. LANDSCAPE CONTEXT: Surrounding landscape less than 0.6 mi away is partially to predominantly fragmented by agricultural lands, residential or commercial development, introduced annual grasslands, or drill seeding projects. D-Rank— SIZE: 1–49 detectable genets. CONDITION: Few components of the native plant community remain and introduced plant species cover is high. Slickspots have high introduced weed cover and/or livestock disturbance. Few or several moderately severe anthropogenic disturbances are evident. EO has been predominantly to completely burned. Portions of EO may have been drill seeded, and slickspot soils have been altered by drill seeding. LANDSCAPE CONTEXT: Surrounding landscape less than 0.6 mi away is moderately to completely fragmented by agricultural lands, residential or commercial development, introduced annual grasslands, or drill seeding projects. E-Rank (Extant)— EO has been verified extant, but population size, condition, and landscape context have not been assessed. F-Rank (Failed to find)— EO has been surveyed by experienced individuals who failed to find any slickspot peppergrass individuals, despite searching under conditions appropriate for the element at a location where it was previously recorded. Only one visit is required for this rank designation, but the survey should cover the entire extent of the EO. The F- rank was first standardized by NatureServe (2002) and not implemented for slickspot peppergrass before 2006.
H-Rank (Historical)10— An EO that has not been observed since 1970. These are historical EOs indicating where slickspot peppergrass was reported, often based on older herbarium records. Locations associated with these herbarium records are typically geographically vague and may be simply indicated by the name of a town. X-Rank (Extirpated)— EO has been extirpated. Extirpation is based on: 1) agricultural conversion, commercial or residential development, or other documented habitat destruction where slickspot
10 No G-rank exists in the INHP EO ranking system for slickspot peppergrass.
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peppergrass has been previously recorded, or 2) when an EO has consistently received an F-rank five times within a 12-year time period.
X?-Rank (Probably Extirpated)— EO Has probably been extirpated. The”?” qualifier is used with the most appropriate rank (i.e. X?) if there is incomplete information on the EO size, condition, and/or landscape context factors. As described above and updated in Kinter (2016), there are 109 extant slickspot peppergrass EOs/sub-EOs encompassing about 15,823 acres rangewide. No A-ranked EOs for slickspot peppergrass exist and the most common range wide EO ranks for slickspot peppergrass are C and D (Kinter and Miller 2016, p. 61). In addition, 10 EOs are ranked as X or X? and seven EOs are ranked as H (Kinter and Miller 2016, p. 61). EO ranks also vary by physiographic region. A little over half of the extant EO area in the Boise Foothills physiographic region is C-ranked (75 out of 139 total acres (53 percent) in the Boise Foothills). In contrast, approximately 74 percent of the total EO area in the Snake River Plain is B-ranked (9,577 acres of the 12,984 total acreage of the Snake River Plain physiographic region), the majority of which is located within the IDARNG’s OCTC (about 7,173 acres). About 84 percent of the total EO area in the Northern Basin and Range physiographic region is also B-ranked (2,287 acres of the 2,696 total acreage of the Northern Basin and Range physiographic area, the majority of which is located on the Air Force’s Juniper Butte Range). Population Trends Extreme variability in annual plant counts makes detecting significant population trends in slickspot peppergrass difficult. However, the best scientific and commercial evidence available collected over the past 18 years from the rough census areas on the OCTC shows a significant downward density trend in the abundance of slickspot peppergrass plants during the past two decades (74 FR 52025, October 8, 2009). Furthermore, we believe it is reasonable to infer that this negative trend may be similar or possibly even greater range wide in areas outside the high- quality habitat of the OCTC, and this trend appears to be independent of any precipitation trend. Uncertainties associated with both the data and the model, used by Sullivan and Nations (2009, entire) in their analysis of slickspot peppergrass density and abundance on the OCTC over time, preclude our ability to project future population trends for slickspot peppergrass. These uncertainties include, but are not limited to, great annual variability in plant numbers; the confounding influence of the long-lived seed bank; complications associated with annual variability in both precipitation and temperature; and inconsistent results between the special-use plots and the rough census areas on the OCTC (see Sullivan and Nations 2009, pp. 28–33 for an explanation of these two OCTC survey methodologies). The evaluation by Sullivan and Nations (2009, pp. 1–278) was based on a simple model of slickspot peppergrass abundance or density as a linear function of time and intended only to discern whether there was any general population trend (74 FR 52025, October 8, 2009). The authors acknowledge that the dynamics are complicated, and note their model is not intended to describe (nor explain) the details of the temporal pattern of abundance or density of slickspot peppergrass (Sullivan and Nations 2009, p. 38).
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In addition, we do not have any models for slickspot peppergrass based on multivariate analyses, which would simultaneously consider additional variables such as precipitation to potentially allow for the prediction of abundance or density of slickspot peppergrass over time based on projected conditions. As stated in our listing rule, although the available descriptive model is helpful for interpreting the population information available to date and indicates that slickspot peppergrass has likely been trending downward for all of the reasons outlined above, it would be inappropriate to rely on this model to predict any future population trajectory for slickspot peppergrass (74 FR 52025, October 8, 2009). Previous Consultations and Conservation Efforts
The Service has completed several consultations under section 7 of the Act for programs and individual actions located within the range of slickspot peppergrass. Some of these were completed as letters of concurrence/conference reports [Normal Fire Emergency Stabilization and Rehabilitation Plan (01EIFW00-2013-FE-0103; USFWS 2013, in litt. entire; 14420-2006- IC-0975, USFWS 2006a, in litt. entire); Noxious Weed Management Plan (14420-2006-IC-0918; USFWS 2006b, in litt. entire)] as they were determined to be unlikely to adversely affect listed/proposed species, including slickspot peppergrass. Following listing of the species in 2009, conference reports for slickspot peppergrass were converted to letters of concurrence, at the request of the Bureau, to ensure continued compliance under section 7 of the Act (14420-2010- TA-0103; USFWS 2009, in litt. entire). A similar process occurred when slickspot peppergrass was re-listed again in 2016 (01EIFW00-2017-TA-0072; USFWS 2016, in litt. entire). The Service has completed formal consultations with the Bureau on the Kuna Management Framework Plan (MFP), the Cascade Resource Management Plan (RMP), Jarbidge RMP, and the Snake River Birds of Prey National Conservation Area RMP (11420-2010-F-0019; USFWS 2009, entire and 01EIFW00-2015-F-0545; USFWS 2015a, entire). Formal consultation or conference on the effects of multiple projects on slickspot peppergrass have been completed, including Bureau on-going livestock grazing activities on 27 Allotments (14420-2010-F-0025; USFWS 2010, entire), Bureau authorization of rights-of-way associated with the M3 Development in northwest Ada County (14420-2011-F-0148; USFWS 2011, entire), reauthorization of livestock grazing activities on the Mountain Home Subunit Allotment #00813 (01EIFW00-2012-F-0183; USFWS 2012b, entire), construction of the Kinyon Road Fuel Breaks Project (01EIFW00-2012-F-0040; USFWS 2012d, entire), reauthorization of the existing Williams Northwest Pipeline Right-of-Way (01EIFW00-2013-FC-0040; USFWS 2012c, entire), rights-of-way authorizations for the Gateway West Transmission Line Project (06E1 3000-2013- F-0033; USFWS 2013a, entire), construction of the Jarbidge Fuel Breaks Project (01EIFW00- 2014-FC-0767; USFWS 2014b, entire), construction of the Paradigm Fuel Breaks Project (01EIFW00-2015-FC-0260, USFWS 2015b, entire), the Service’s sage steppe improvement actions at the Orchard Project near the Orchard Combat Training Center (01EIFW00-2017-F- 0002, USFWS 2017a, entire), and the Noxious Weeds and Invasive Plant Treatment Program on Twin Falls District BLM (01EIFW00-2017-F-0231, USFWS 2017b, entire). For actions that are underway, standing concurrences and consultations will remain in effect as long as the actions are carried out as proposed and no new information becomes known and indicates the species will be affected in unanticipated ways. As described in the Jarbidge RMP consultation, the Bureau committed to implement conservation measures for slickspot peppergrass that would avoid or minimize effects associated
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 45 with Bureau actions planned under their LUPs (USFWS 2015b, entire). Conservation measures in the RMP are an update of those in the CA and its earlier versions (Bureau and USFWS 2014, entire; Bureau and USFWS 2013, entire; Bureau and USFWS 2009, entire; Bureau and USFWS 2006, entire). The conservation measures and associated implementation actions for on-going BLM LUP programs provide overall guidance for avoiding or minimizing direct and indirect effects to the habitat of slickspot peppergrass and restoring and maintaining that habitat. Conservation measures and implementation actions for slickspot peppergrass include conducting species inventories on BLM lands, exchanging location information with agency partners, completing site-specific section 7 consultation on both on-going and new actions, and avoiding or minimizing potential adverse impacts of site-specific projects covered under LUP programs. Site-specific implementation and effectiveness monitoring, including annual reporting requirements, will also be completed to track progress toward achieving conservation objectives. All conservation measures in the CA will be implemented until such time that new LUPs or amendments are approved with completed consultations and signed Records of Decision. The CA provides goals for inventories of slickspot peppergrass as well as direction for completing section 7 consultations on all on-going and proposed activities on BLM lands that may affect this species. The State of Idaho is also implementing conservation measures defined in the Candidate Conservation Agreement (CCA) signed between the State of Idaho, the BLM, the IDARNG, and nongovernmental cooperators (private landowners who also hold livestock grazing permits on BLM lands) (State of Idaho et al. 2003, entire and 2006, entire). The majority of the individual conservation efforts being implemented for slickspot peppergrass that are applicable to individual projects are contained in the CCA, which was originally drafted in 2003 and updated in 2006. The CCA represents an important milestone in the cooperative conservation of slickspot peppergrass given its range wide scope and coordinated management across lands managed by Federal agencies and the State of Idaho. The CCA includes range wide efforts that are intended to address the need to maintain and enhance slickspot peppergrass habitat; reduce intensity, frequency, and size of natural- and human-caused wildfires; minimize loss of habitat associated with wildfire-suppression activities; reduce the potential of nonnative plant species invasion after wildfire; minimize habitat loss associated with rehabilitation and restoration techniques; minimize the establishment of invasive nonnative species; minimize habitat loss or degradation from OHV use; mitigate the negative effects of military training and other associated activities on the IDARNG’s OCTC; and minimize the impact of ground disturbances caused by livestock penetrating trampling11 when soils are saturated (State of Idaho et al. 2006, p. 3). As a signatory of the CCA (State of Idaho et al. 2003, 2006), the State of Idaho is responsible for implementing applicable conservation actions for slickspot peppergrass on their lands. State lands constitute approximate 9 percent of EO acreage for the species range wide. Although the majority of the conservation measures identified in the CCA have been implemented to date, relatively few of these measures have been determined at this time to be measurably effective for conserving slickspot peppergrass. For example, many of the
11 Penetrating trampling is defined by the CCA as breaking through the restrictive layer (i.e., the middle layer of slickspot soil that supports slickspot peppergrass, as described by Meyer and Allen 2005, p. 3) under the silt surface area of a slickspot during saturated conditions (State of Idaho et al. 2006, p. 9).
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 46 implemented measures include conducting surveys, monitoring, or providing for public outreach and education, which have limited direct or long-term conservation benefits to the species. With the exception of several conservation efforts implemented at the IDARNG’s OCTC that have been successful in controlling wildfire effects on slickspot peppergrass habitats, many of the remaining conservation efforts and adaptive management provisions identified in the CCA have not been implemented over a long enough period of time to demonstrate their effectiveness in reducing threats to the species. Furthermore, the conservation measures identified in the CCA are concentrated on slickspot peppergrass EOs. While this focus is helpful, effectively controlling the most significant threats to slickspot peppergrass (wildfire and invasive nonnative plant species) requires efforts that extend well beyond the boundaries of the EOs since these threats are naturally expansive and occur throughout the Great Basin. We recognize the conservation efforts identified in the CCA have a conservation benefit for slickspot peppergrass, but their effectiveness in reducing or eliminating the most significant range wide threats to the species has not been demonstrated at this time. Conservation measures identified for slickspot peppergrass are either specific measures designed to reduce impacts to the species and its habitat at the local level, or general measures designed to improve the ecological condition of native sagebrush-steppe vegetation at a landscape scale, inclusive of areas supporting slickspot peppergrass. Specific measures include management actions such as varying the timing or season of livestock grazing or trailing and moving water or supplements away from EOs. General measures include management actions designed to maintain or increase native forb and grass cover, protect sagebrush through fire protection or suppression, and restore degraded habitats to improve connectivity between sites. General conservation measures and implementation actions within the CCA include direction to prioritize slickspot peppergrass EOs for fire protection and weed control across the range of the species. For example, the CCA indicates that fire suppression efforts will be conducted, as possible, to protect slickspot peppergrass habitat; protecting slickspot peppergrass habitat will be a high priority. The CCA also promotes diversity, richness, and health of native plant communities to support pollinators and habitat for slickspot peppergrass, including conducting weed control activities compatible with slickspot peppergrass conservation. The Service expects the State of Idaho’s continued implementation of these general conservation measures will reduce effects from wildfire and nonnative invasive plants across the range of the species.
Conservation Needs Although recovery planning has not been completed for slickspot peppergrass, the Service anticipates that providing for its survival and recovery will entail reducing the threats that are the basis for its being listed: habitat loss, degradation, and fragmentation primarily caused by increased fire frequencies and the invasion of exotic plants; lack of sufficient gene flow between populations; and reduced viability of seed banks. The Service anticipates that the following factors will be important for survival and recovery of the species: ● Protection, restoration, and maintenance of suitable habitat conditions for all life stages of slickspot peppergrass; ● Reduction and mitigation of negative effects caused by increased fire frequencies and invasive nonnative plants on slickspot peppergrass;
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● Establishment of vegetation management goals and objectives that are compatible with slickspot peppergrass recovery; ● Identification of what is necessary to conserve genetic diversity and gene flow among populations of slickspot peppergrass; and monitoring to ensure that this diversity and gene flow are being maintained; ● Implementation of an adaptive management based research and monitoring program that uses feedback from implemented, site-specific recovery tasks to implement and evaluate slickspot peppergrass recovery activities; ● Use of all available conservation programs and regulations to protect and conserve slickspot peppergrass and sagebrush-steppe habitats, including slickspot microsites; and ● Development of a management area-based recovery program that relies on adaptive management to implement and revise, as appropriate, recovery actions for slickspot peppergrass. Slickspot peppergrass survival and recovery depends on maintaining and enhancing Wyoming big sagebrush–steppe habitat and the slickspot microsites located within this ecosystem in southwestern Idaho. The long-term conservation of slickspot peppergrass is dependent upon the maintenance or improvement of ecological function of the higher quality (C- through A-ranked) EOs range wide, including maintaining or improving connectivity within and between EOs, which may involve the maintenance or enhancement of currently lower ranked EOs (D- through F-ranked) as necessary to facilitate pollinator activity; the maintenance of genetic diversity; and limiting the establishment of invasive non-native plant species. Key to maintaining quality habitat includes preserving existing Wyoming big sagebrush stands by avoiding or minimizing adverse effects of wildfire and invasive nonnative plants, such as cheatgrass and Taeniatherum caput-medusae (medusahead). The Service has identified the modified wildfire regime in the Great Basin and subsequent proliferation of invasive nonnative plants as the primary threats to slickspot peppergrass. Adequate resources should be made available to reduce the wildfire risk in remaining sagebrush stands, and efforts to maintain and restore native shrubs, grasses, forbs, and biological soil crust should be identified as a priority in areas that have burned in or nearby slickspot peppergrass population strongholds. Plant species that may invade slickspots and compete with slickspot peppergrass should be avoided for use in emergency stabilization and rehabilitation or habitat restoration seedings in areas that support slickspot peppergrass and its habitat. Native forb cover should be maintained or restored to levels that would encourage diverse insect pollinators available for slickspot peppergrass seed production. Activities that could cause direct plant mortality should be minimized. Ground disturbance that could cause decreased suitability of microsites to support slickspot peppergrass should be avoided or minimized. When soils are saturated, ground disturbing activities should be minimized to reduce the likelihood of directly affecting plants and burying seeds too deep to successfully germinate and emerge. Conservation measures should be implemented to mitigate the effect of actions that create conditions conducive to both unseeded and seeded invasive non- native plants within and adjacent to slickspot habitat. Secondary threats, such as commercial and residential development, seed predation by Owyhee harvester ants (Pogonomyrmex salinus), habitat fragmentation and isolation, and climate change, were identified in the Federal Register notice for listing of slickspot peppergrass as factors that
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 48 could impact slickspot peppergrass throughout a significant portion of its range. Other factors, including livestock grazing, fire rehabilitation activities, military training, and recreational use, were discussed as not having significant impacts that would lead to slickspot peppergrass becoming endangered in the foreseeable future. However, both secondary threats and these other factors have been identified as aggravating degraded habitat conditions caused by the modified wildfire regime and associated invasion of non-native plants. While not identified as range wide issues, secondary threats and other factors may adversely affect individual slickspot peppergrass plants at the physiographic regional or local level. In areas containing high-quality sagebrush- steppe habitats, conservation measures should be implemented to avoid or minimize the impacts of habitat loss on slickspot peppergrass. Actions that could degrade slickspots to the point that they can no longer provide the essential functions to support slickspot peppergrass should be avoided as losing habitat represents a permanent loss for the species. Using pesticides near EOs should also be minimized to avoid impacts to individual slickspot peppergrass plants or insect pollinators. The maintenance or improvement of moderate to high conservation value EOs (i.e., those currently ranked C through B by INHP, and including any EOs that may be A-ranked in the future) will be an important component of the range wide conservation strategy for slickspot peppergrass. We anticipate the enhancement of higher-quality EOs will effectively offset the relatively low contribution made by the lower-ranked EOs of lesser conservation value to the species. In general, small populations of slickspot peppergrass in degraded and fragmented habitat are at high risk of extirpation and are unlikely to significantly contribute to the conservation of the species.
Effects of Climate Change on Slickspot Peppergrass Survival and Recovery Needs Warmer temperature regimes associated with global climate change represent another potentially significant risk factor for slickspot peppergrass. Researchers confirmed “experimentally in an intact ecosystem that elevated carbon dioxide may enhance the invasive success of Bromus spp. in arid ecosystems,’’ and suggest that this enhanced success will then expose these areas to accelerated fire cycles (Smith et al. 2000, p. 81). Chambers and Pellant (2008, p. 32) also suggest that higher carbon dioxide levels are likely increasing cheatgrass fuel loads due to increased productivity, with a resulting increase in fire frequency and extent. Based on the best available information, we therefore expect continuing production of atmospheric carbon dioxide at or above current levels, as predicted, to increase the threat posed to slickspot peppergrass by cheatgrass and from more frequent, expansive, and severe wildfires (Smith et al. 1987, p. 143; Smith et al. 2000, p. 81; Brown et al. 2004, p. 384; Neilson et al. 2005, pp. 150, 156; Chambers and Pellant 2008, pp. 31-32). Thus, under current climate-change projections, we anticipate future climatic conditions will favor further invasion by cheatgrass, continued increase in fire frequency, and an increase in the extent and severity of fires. Current projections for the Pacific Northwest region are that precipitation will increase in the winter but decrease in the summer months (Karl et al. 2009, p. 135). The survivorship of slickspot peppergrass rosettes to flower the following spring is favored by greater summer precipitation (Meyer et al. 2005, p. 15; CH2MHill 2007, p. 14; Sullivan and Nations 2009, pp. 33, 41), and increased winter precipitation appears to decrease survivorship (Meyer et al. 2005, pp. 15-16; Sullivan and Nations 2009, pp. 39, 43-44). As the projected rainfall pattern under climate change would follow the opposite pattern, this alteration in seasonal precipitation could
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 49 result in decreased survivorship of slickspot peppergrass. Alterations in precipitation patterns, however, are more uncertain than predicted changes in temperature for the Great Basin region (Neilson et al. 2005, p. 153). According to climate change models the temperature within the Snake River Plain has been increasing and is expected to continue to increase at least through the middle of the 21st century (Klos et al. 2012, p. 1). Precipitation patterns within the Snake River Plain have been shifting to increased winter rain and less snow, increased intensity for spring rain events, and decreased summer precipitation than was received historically (Nayak et al. 2010, pp. 9-10, 15; Klos et al. 2012, pp. 2-4). Models predict that by mid-century, the largest portion of the precipitation within the Snake River Plain will come in December and January (Klos et al. 2012, p. 11). Using data collected from numerous field studies, Meyer et al. (2006, p. 896) found that slickspot peppergrass biennial persistence is reliant on high summer and low early winter rain fall. Meyer et al. (2006, p. 896) determined that while a constant percentage of the seed bank germinates each year, the proportion that survives to emergence is reliant on high levels of precipitation in February and March. Higher April and May precipitation is positively correlated with number of plants that make it to the flowering and fruiting stage (Meyer et al. 2006, p. 896). Precipitation trends shifting as a result of climate change could negatively affect slickspot peppergrass by decreasing the number of first year biennials that survive over the winter and into the following summer to flower and fruit. Annual forms of slickspot peppergrass could also be negatively affected if growing season precipitation (February through May) decreases. As described above, increased temperatures and carbon levels could also result in an increase in cheatgrass throughout the Snake River Plain. The consequences of climate change, if current projections are realized, are therefore likely to exacerbate the existing primary threats—modified wildfire regime and invasive nonnative plants, particularly cheatgrass—to slickspot peppergrass conservation. Because the Intergovernmental Panel on Climate Change (IPCC) projects changes to the global climate system in the twenty- first century will likely be greater than those observed in the twentieth century (IPCC 2007, p. 45), we anticipate that these effects will continue and likely increase into the future. Due to the uncertainty associated with climate change projections, we did not consider climate change in and of itself to represent a significant range wide threat to slickspot peppergrass in our 2009 listing decision. However, we acknowledge that climate change will likely play a potentially important supporting role in intensifying the most significant current threats to the species in the foreseeable future. The severity and scope of the primary threats of changing wildfire regime and invasive nonnative plants to slickspot peppergrass are likely to be magnified, depending on the realized outcome of climate change. Habitat conservation and restoration efforts are likely to be further complicated by these climatic changes. Additional conservation measures may be needed to mitigate the effects of habitat degradation that are aggravated by climate change. For a more detailed discussion of climate change and slickspot peppergrass, refer to the final listing rule (74 FR 52014, October 8, 2009).
Status of the Species in the Action Area The action area for the proposed action is all BLM-managed land within the BLM BDO including Bureau of Reclamation (BOR) lands which are surface-managed by the BLM. The action area encompasses the Boise Foothills and Snake River Plain physiographic regions of slickspot peppergrass. These two physiographic regions make up 63% of the extant EOs and
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70.5% of the acres within slickspot peppergrass EOs range-wide on all land management designations. On BLM-managed land within the action area there are 57 extant slickspot peppergrass EOs; 15 are ranked B, 1 ranked BC, 21 ranked C, 5 ranked CD, and 15 ranked D (Table 6). Table 6. Extant slickspot peppergrass EOs within the BDO12. Highest 2016 EO LEPA Count1 rank 2006 rank BLM acres 2 117 C C 2.5 8 2730 B B 983.1 10 7 D D 3.9 15 177 C D 119.6 18 21905 B C 1705.2 20 597 C C 1.9 21 ~100 (1998) 2 C C 19.4 24 799 C C 89.9 25 1453 B C 38.5 26 1341 B B 708.4 27 26423 B B 5890.2 28 5 (2005) 2 C D 0.5 29 460 C C 104.6 30 2460 BC B 539.7 31 51 D C 37.9 32 1618 C C 590.6 42 9 (2000) 2 D F 2.1 43 17 (2000) 2 CD D 0.9 48 560 C C 1.8 49 325 (1993) 2 C F 3.9 50 630 C C 4.3 51 227 D BC 3.8 52 1529 B C 27.3 53 2100 B C 40.4 54 2 (2003) 2 D F 1.4 56 19 D D 3.2 57 Unk # (2004) 2 CD D 0.5 58 Unk # (1989) 2 CD D? 1.9 60 1 (2006) D D 7.2 61 850 C C 15.8 62 67 D C 5.8 63 342 C D 7.9
12 Table modified from Kinter and Miller 2016. Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 51
Highest 2016 EO LEPA Count1 rank 2006 rank BLM acres 664 1995 B C 7.8 67 2935 B B 9.6 68 2813 B C 6.9 69 94 C D 4.2 70 5675 B B 2.1 72 1729 B C 64.5 76 4995 B C 18.5 77 1 C C 0.35 102 ~10 (2004) 2 C D 2.4 103 8 D D 0.57 104 3059 B C 88.2 105 40 D unknown3 0.54 106 Unk # (2001) 2 CD unknown3 0.48 108 45 D unknown3 3.9 111 1 D unknown3 0.27 112 2 D unknown3 0.02 113 257 D unknown3 0.03 114 53 C unknown3 0.07 115 385 C unknown3 0.09 116 7 C unknown3 0.03 117 30 D unknown3 0.03 118 443 B unknown3 0.12 119 1 CD unknown3 0.03 120 ~500 C unknown3 0.71 121 126 C unknown3 0.48
1 Highest number seen since 2010 as per Kinter and Miller 2016. 2 No plants were observed in the Kinter and Miller 2016 assessment; numbers reported here are approximate as they were from pre-2010, year in parentheses indicates last year individuals were actually observed in the EO not last year of site visit. 3 Not previously ranked. 4 New sub- EO located (incidental observation) in 2017 with unknown number of plants and acreage. Report has been given to IDFG and FWS. Within the BDO on BLM-managed lands there are 71,270 acres of Occupied Habitat which includes individual EOs plus a surrounding 0.5 mile radius buffer for pollinator habitat (Pollinator Buffer). There are 25,022 acres of PCH, a subset of Occupied habitat, on BLM- managed lands (Table 7, Figure 4). All potential habitat within the BDO has been surveyed at least once with the exception of 29,963 acres within the Impact Area in the Orchard Combat Training Center (OCTC) and 160 acres of small isolated parcels. Approximately 18,913 acres have had two years of surveys and 14,816 acres have had three years of surveys. As a result of the surveys of Potential habitat, 266,517 acres of Slickspot Peppergrass habitat has been identified on BLM-managed lands within the BDO (Table 7.)
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It is unlikely that any of the 160 acres of potential habitat on isolated parcels would be treated for noxious and invasive weeds, but in the event that these parcels would need treatment a thorough potential habitat inventory would be performed as specified in the design features for slickspot peppergrass (Chapter 2). Potential Habitat within the Impact Area on the OCTC has not been surveyed by the Idaho Army National Guard, and is not treated for noxious weeds due to the danger presented from unexploded ordinances (UXOs), due to the heavy artillery use the Impact Area has experienced, and is expected to experience, these acres have been eliminated as Potential Habitat. Table 7. Habitat acres within the BDO project area on all land management designations
Habitat Acres Habitat Category BLM BOR State Private Military Other1 Occupied Habitat 70,121 1,148 8,224 31,518 49 0 Proposed Critical Habitat 52,364 366 4,641 3929 1 0 Slickspot Peppergrass Habitat 260,352 6,165 640 0 149 0 Potential Habitat 30,007 117 41,492 123,819 1,309 30
1 Includes Corp of Engineers, US Forest Service, Idaho Historic Waters
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Figure 4- Slickspot peppergrass Occupied and Potential Habitats and Proposed Critical Habitat. These habitats only occur in the Four Rivers Field Office portion of the action area.
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Factors Affecting the Species in the Action Area Wildfire and invasive non-native plants were identified in the Service’s 2009 Federal Register Notice as the two primary reasons for slickspot peppergrass decline and loss of habitat. When Wyoming big sagebrush is burned, natural re-establishment can take between 20 to 50 years, and only occurs when an available seed source is nearby. Whisenant (1990, p. 4) estimated historic fire return intervals for Wyoming big sagebrush communities to actually be between 60 to 110 years. Invasive non-native annual grasses and forbs, especially cheatgrass, are widespread and contribute to the fine fuels that result in repeated wildland fires in lower elevations throughout the range of slickspot peppergrass. An exponential increase in the density of invasive annual species is typical following a fire when these species occur within or near a burned area, creating a continuous, fine wildfire fuel load. Balch et al. (2013, pp. 179-180) found that fires were more likely to start in cheatgrass than in other vegetation types, and that cheatgrass is associated with increased fire frequency, size, and duration. Fire return intervals in cheatgrass-dominated areas in the Project area are commonly between 5 and 10 years and sometimes shorter. Invasive nonnative annual plants are common understory components in some perennial vegetation types and often occur at cover levels of less than 50 percent, but can still dominate an area following fire. Fire has likely resulted in a significant decrease in Wyoming big sagebrush and native bunchgrass habitat within the Project area and throughout most of the species’ range. Native rangeland within and near the Project area was historically predominantly Wyoming big sagebrush with an array of perennial grasses and forbs. However, since the late 1890s the Intermountain West has experienced an increase in invasive non-native annual grasses and forbs, such as cheatgrass, medusahead, Russian thistle (Salsola kali), and tall tumblemustard (Sisymbrium altissimum). These invasive annual plant species are now widely distributed and in some areas dominate the plant community. Where invasive annual species dominate, large-scale areas and ecosystem function have been altered to the point of transitioning to a new steady but depleted state. Changes to an ecosystem caused by invasive annual grasses and forbs can occur in just a few years. Invasive annual species rapidly fill available open spaces and provide an abundance of continuous fine fire fuel. Once established, these plants compete with native vegetation for water, nutrients, and space; invade and degrade sensitive plant and animal habitats; and increase wildfire frequency. Conversion from this depleted state back to a native perennial shrub-steppe plant community is unlikely without human intervention, which requires money, time, and favorable weather patterns. The Owyhee harvester ant has been identified as a slickspot peppergrass seed predator. Harvester ants have become more common in areas where sagebrush has been removed by fire due to greater availability of nest sites and seed sources used for food (Robertson, 2011). Owyhee harvester ants remove mature, seed-bearing fruits and carry them to nests outside of slickspots. Harvester ants can remove up to 90 percent of slickspot peppergrass fruits and seeds, either directly from the plant or by scavenging seeds that drop to the ground. Seventy-five percent of slickspots with flowering slickspot peppergrass located within 66 feet of a harvester ant nest showed evidence of seed predation; research suggests that this is the maximum foraging distance for the Owyhee harvester ant (White and Robertson, 2009).
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Additional threats that can exacerbate degraded habitat conditions resulting from wildfire and non-native invasive plants include residential and commercial development, agricultural conversions, livestock use, recreational activities such as off-road vehicle use, military training, factors associated with climate change, wildfire management including ground disturbing activities such as establishment of fire lines, and post-wildfire rehabilitation treatments. The latter may use mechanical seedbed preparation and seeding methods that disturb the soil surface. These may injure or kill plants and disrupt the silt and clay layers in slickspots, resulting in habitat modification and seed burial too deep for germination. In addition, chemical herbicides can also result in damage or mortality of plants or seed. Within the LEPA Consideration Zone (LCZ) that was created in 2003 for the then, slickspot peppergrass Candidate Conservation Agreement, there are 22 documented noxious weed species (Figure 5). Within Occupied habitat for slickspot peppergrass there are 11 documented noxious weed species; 3 of these species fall within actual EO boundaries. Species found within the LCZ and therefore also in Occupied habitat and EOs are listed in Table 8 below.
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Figure 5- Weeds within the LEPA Consideration Zone.
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Table 8. Idaho State Noxious Weeds found in Slickspot Peppergrass EOs and Occupied Habitat.
Common Name Scientific Name Family Nearby EOs Black Henbane1 Hyoscyamus niger Solanaceae 72, 77, 103 Camelthorn2,3 Alhagi maurorum Fabaceae 10 Canada Thistle1 Cirsium arvense Asteraceae 10, 48, 68, 104 Linaria dalmatica ssp. Dalmatian Toadflax4 dalmatica Schrophulariacea 49 Diffuse Knapweed1 Centaurea diffusa Asteraceae 8, 26, 66, 68, 69 Field Bindweed Convolvulus arvensis Convolvulaceae 26, 54, 64, 101 Houndstongue Cynoglossum officinale Boranginaceae > 15 km from EO Jointed Goatgrass Aegilpos cylindrical Poaceae > 15 km from EO Leafy Spurge Euphorbia esula Euphorbiaceae > 5 km from EO Mediterranean Sage2 Salvia aethiopis Lamiaceae 662 Perennial Pepperweed1 Lepidium latifolium Brassicaceae 24 Poison Hemlock Conium maculatum Apiaceae 26, 66, 68, 69 Puncturevine1 Tribulus terrestris Zygophyllaceae 24 Purple Loosestrife Lythrum salicaria Lythraceae > 15 km from EO 8, 10, 15, 20, 30, 31,54, 56, Rush Skeletonweed1 Chondrilla juncea Asteraceae 60, 68, 69, 112, 118 Russian Knapweed1 Acroptilon repens Asteraceae 76 Russian Olive3 Elaeagnus angustifolia Elaegnaceae 61 Saltcedar, Tamarisk1 Tamarix sp. Tamaricaceae 43, 66 81, 18, 24, 271, 28, 29, 32, 50, 53, 661, 68, 69, 70, 104, Scotch Thistle1 Onopordum acanthium Asteraceae 115, 116, 117 Spotted Knapweed Centaurea stoebe Asteraceae 112 Squarrose Knapweed Centaurea trimfetti Asteraceae 106 18, 24, 25, 26, 321, 43, 48, Whitetop1 Cardaria draba Brassicaceae 72, 77, 102, 103, 105,
1 Noxious weed found within pollinator buffer of Occupied Habitat but not within the EO itself. 2 Noxious Weed found within EO boundary and therefore also Occupied habitat. 3 Invasive plants that are considered potential new invaders and/or may be on noxious weed lists in adjacent States but are not currently on the Idaho State Noxious Weed list. 4 Noxious Weed found on private land with potential to move into slickspot peppergrass habitat categories.
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Slickspot Peppergrass Proposed Critical Habitat Legal Status
Critical Habitat was proposed for Slickspot Peppergrass on May 10, 2011. On February 12, 2014, the Service amended the original May 10, 2011 Critical Habitat proposal to include recently discovered slickspot peppergrass locations that met Critical Habitat designation criteria. Final designation of Critical Habitat has not yet occurred. Conservation Role and Description of Proposed Critical Habitat
The conservation role of slickspot peppergrass Critical Habitat is to support the various life history needs and provide for conservation of the species (76 FR 27190). Four CHUs encompassing a combined total of 61,301 acres within Ada, Elmore, Payette, and Owyhee Counties have been identified as being important to the survival and recovery of slickspot peppergrass. All CHUs currently proposed as Critical Habitat are located within the geographical area occupied by slickspot peppergrass at the time of listing, and are currently occupied by the species. These units proposed as Critical Habitat contain the physical and biological features essential to the conservation of slickspot peppergrass. Physical and Biological Features (PBFs) of Critical Habitat are essential to the conservation of the species, and include, but are not limited to: (1) space for individual and population growth, and for normal behavior; (2) food, water, air, light, minerals, or other nutritional or physiological requirements; (3) cover or shelter; (4) sites for breeding, reproduction, rearing of offspring, germination, or seed dispersal; and (5) habitats that are protected from disturbance or are representative of the historic geographic and ecological distributions of a species [Act §3(5)(A)(i), 50 CFR §424.12(b)]. In determining which areas to propose as Critical Habitat, the Service considered the physical and biological features that are essential to the conservation of slickspot peppergrass and that may require special management considerations or protection. These PBFs need to be laid out in the appropriate quantity and spatial arrangement for conservation of the species. PBFs of slickspot peppergrass PCH are: PBF 1. Ecologically-functional microsites or ‘‘slickspots’’ that are characterized by: ● A high sodium and clay content, and a three-layer soil horizonation sequence, which allows for successful seed germination, seedling growth, and maintenance of the seed bank. The surface horizon consists of a thin, silty, vesicular, pored (small cavity) layer that forms a physical crust (the silt layer). The subsoil horizon is a restrictive clay layer with an abruptic (referring to an abrupt change in texture) boundary with the surface layer, that is natric or natric-like in properties (a type of argillic (clay- based) horizon with distinct structural and chemical features) (the restrictive layer). The second argillic subsoil layer (that is less distinct than the upper argillic horizon) retains moisture through part of the year (the moist clay layer); and ● Sparse vegetation with low to moderate introduced invasive nonnative plant species cover. PBF 2. Relatively-intact native Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) vegetation assemblages, represented by native bunchgrasses, shrubs, and forbs, within 250 m (820 feet) of slickspot peppergrass EOs to protect slickspots and slickspot
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 59 peppergrass from disturbance from wildfire, slow the invasion of slickspots by nonnative species and native harvester ants, and provide the habitats needed by slickspot peppergrass’ pollinators. PBF 3. A diversity of native plants whose blooming times overlap to provide pollinator species with sufficient flowers for foraging throughout the seasons and to provide nesting and egg-laying sites; appropriate nesting materials; and sheltered, undisturbed places for hibernation and overwintering of pollinator species. For genetic exchange of slickspot peppergrass to occur, pollinators must be able to move freely between slickspots. Alternative pollen and nectar sources (other plant species within the surrounding sagebrush vegetation) are needed to support pollinators during times when slickspot peppergrass is not flowering, when distances between slickspots are large, and in years when slickspot peppergrass is not a prolific flowerer. PBF 4. Sufficient pollinators for successful fruit and seed production, particularly pollinator species of the sphecid and vespid wasp families, species of the bombyliid and tachnid fly families, honeybees, and halictid bee species, most of which are solitary insects that nest outside of slickspots in the surrounding sagebrush-steppe vegetation, both in the ground and within the vegetation. The space for individual and population growth is provided by PBFs 1, 2, and 3; the need for food, water, air, light, minerals, or other physiological requirements is provided by PBFs 1 and 2; the need for cover and shelter is met by PBFs 1 and 2; sites for reproduction, germination, and seed dispersal are provided by PBFs 1, 2, 3, and 4; and habitat free from disturbance is met by PBF 2 (76 FR 27191). Activities that cause adverse effects to Critical Habitat are evaluated to determine if they are likely to “destroy or adversely modify” Critical Habitat by no longer serving the intended conservation role for the species or retaining those PBFs that relate to the ability of the area to at least periodically support the species. Activities that may destroy or adversely modify Critical Habitat are those that alter the PBFs to such an extent that the conservation value of Critical Habitat is appreciatively reduced. The Service’s evaluation must be conducted at the scale of the entire Critical Habitat area designated, unless otherwise stated in the final Critical Habitat rule (USFWS and NMFS 1998, p. 4-39). Thus, PCH for slickspot peppergrass is evaluated at the scale of the entire area proposed for designation, which includes the four CHUs described above. All four CHUs contain features or areas essential to the conservation of slickspot peppergrass. Therefore, if a proposed or on-going action would alter the physical or biological features of PCH to the extent that appreciably reduces the conservation function of one or more CHUs for slickspot peppergrass, a finding of adverse modification for the entire PCH area may be warranted.
Current Range Wide Condition of Proposed Critical Habitat The condition of slickspot peppergrass PCH varies across the range from poor to good. While some areas contain intact sagebrush-steppe habitat, other areas have been fragmented by wildfires and both unseeded and seeded invasive non-native plants such as cheatgrass and Agropyrum cristatum (crested wheatgrass). The modified wildfire regime and spread of invasive nonnative plants continues to degrade slickspot microsites and associated sagebrush-steppe habitat across the range of slickspot peppergrass (76 FR 27186).
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Many factors have impacted slickspot peppergrass and its habitat, and continue to do so. Among the factors that contribute to degraded PBFs, those which appear to be particularly significant and have resulted in degraded habitat conditions within areas proposed for Critical Habitat designation are as follows: ● Current Wildfire Regime (i.e., increasing frequency, size, and duration). The result of this altered wildfire regime has been the conversion of vast areas of the former sagebrush-steppe ecosystem to nonnative annual grasslands, resulting in loss or reduction in cover of sagebrush, native grasses, and native forbs available for insect pollinator foraging and/or shelter. Frequent wildfires can also promote soil erosion and sedimentation (Bunting et al. 2003, p. 82) in arid environments such as the sagebrush- steppe ecosystem. Increased sedimentation can result in a silt layer that is too thick for optimal slickspot peppergrass germination (Meyer and Allen 2005, pp. 6–7). The altered wildfire regime is one of the primary causes of reduced quality of PBFs 1, 2, 3, and 4 of PCH for slickspot peppergrass.
● Invasive Nonnative Plant Species. Invasive, nonnative plants can alter various attributes of ecosystems including geomorphology, wildfire regime, hydrology, microclimate, nutrient cycle, and productivity (for a summary see Dukes and Mooney 2003, entire). Additionally, these invasive nonnative plants can negatively affect native plants, including rare plants like slickspot peppergrass, through competitive exclusion, niche displacement, hybridization, and competition for pollinators; examples of these negative effects are widespread among different taxa, locations, and ecosystems (D’Antonio and Vitousek 1992, pp. 63–87; Olson 1999, p. 5; Mooney and Cleland 2001, p. 1). Recent analyses have revealed a significant, negative association between the presence of weedy species and the abundance or density of slickspot peppergrass, to the point that the species may be excluded from slickspots (Sullivan and Nations 2009, pp. 109–112). Although the specific mechanisms are not well understood, some of these plants, such as Agropyrum cristatum (crested wheatgrass) and cheatgrass, are strong competitors in this arid environment for such limited resources as moisture, which tends to be concentrated in slickspots (Pyke and Archer 1991, p. 4; Moseley 1994, p. 8; Lesica and DeLuca 1998, p. 4), at least in the subsurface soils (Fisher et al. 1996, pp. 13–16). Invasive nonnative plants are one of the primary causes of reduced quality of PBFs 1, 2, 3, and 4 of PCH for slickspot peppergrass.
● Livestock Grazing. Livestock trampling of water-saturated slickspot soils that breaks through the restrictive layer (referred to as ‘‘penetrating trampling’’ (State of Idaho et al. 2006, p. 9)) has the potential to alter the soil structure and the functionality of slickspots (Rengasamy et al. 1984, p. 63; Seronko 2004, in litt.). Penetrating trampling that occurs when slickspots are wet also has the potential to affect the seed bank for slickspot peppergrass by pushing the seeds below a depth where they can germinate (i.e., below 3 cm (1.5 in.)) (Meyer and Allen 2005, pp. 9–10; Meyer et al. 2006, pp. 891, 901–902). Livestock grazing may also locally reduce native forb cover available for insect pollinators. In contrast, with careful management, livestock grazing may be used as a tool to select for certain native plant species, or even to control cheatgrass (Frost and Launchbaugh 2003, p. 43). Therefore, livestock grazing may result in localized reductions in the quality of PBFs 1, 2, 3, and 4; current livestock management (including
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continued implementation of conservation measures to avoid or minimize impacts) is not considered to pose a significant threat to PCH of slickspot peppergrass. Other factors that may result in localized reduced quality of PCH PBFs include rangeland revegetation projects, wildfire management practices, and recreational use.
Effects of Climate Change on Proposed Critical Habitat for Slickspot Peppergrass Similar to potential effects of climate change on the species, we also recognize that climate change may cause changes in slickspot peppergrass PCH. As described above for the species, climate change models show that the temperature has been increasing (Klos et al. 2012, p. 1); precipitation patterns within the Snake River Plain have been shifting to increased winter rain and less snow, increased intensity for spring rain events, and decreased summer precipitation than was received historically (Nayak et al. 2010, pp. 9-10, 15; Klos et al. 2012, pp. 2-4). Under projected future temperature conditions, the cover of sagebrush in the Great Basin region is anticipated to be dramatically reduced (Neilson et al. 2005, p. 154). Warmer temperatures and greater concentrations of atmospheric carbon dioxide create conditions favorable to cheatgrass, and perpetuate the positive feedback cycle between annual grasses and fire frequency that poses a significant threat to the sagebrush habitat (Chambers and Pellant 2008, p. 32; Karl et al. 2009, p. 83) where slickspot peppergrass occurs. The direct, long-term impact from climate change to Critical Habitat of slickspot peppergrass is yet to be determined. As discussed above, we anticipate that future climatic conditions will favor further invasion by cheatgrass, that fire frequency will continue to increase, and that the extent and severity of fires may increase as well, further changing the species composition of southwest Idaho’s sagebrush-steppe habitat. Over a period of decades, climate change may directly threaten the integrity of PBFs 1, 2, 3, and 4. Climate change may exacerbate habitat degradation impacts both physically (i.e., degradation or loss of slickspot microsites) and biologically (i.e., reduction of insect pollinators due to habitat degradation as well as increased competition with invasive nonnative plants). Protecting slickspot peppergrass strongholds and remaining intact sagebrush- steppe habitat from the effects of the modified wildfire regime and associated spread of invasive nonnative plants as well as ensuring connectivity among populations are important considerations in addressing the potential impacts of climate change. Previous Conference on the Effects of Actions on Slickspot Peppergrass Proposed Critical Habitat
On-going or proposed actions with formal conferencing completed for slickspot peppergrass PCH include emergency conference on effects of 2011 and 2012 wildfire suppression actions on the BLM’s Boise District (01EIFW00-2012-EF-0073; USFWS 2012a, entire and 01EIFW00- 2013-FE-0103; USFWS 2013b, entire), BLM authorization of rights-of-way associated with the M3 Development in northwest Ada County (14420-2011-F-0148; USFWS 2011, entire); reauthorization of livestock grazing activities on the Mountain Home Subunit Allotment #00813 (01EIFW00-2012-F-0183; USFWS 2012b, entire), rights-of-way authorizations for the Gateway West Transmission Line Project (06E1 3000-2013-F-0033; USFWS 2013a, entire), reauthorization of the existing Williams Northwest Pipeline Right-of-Way (01EIFW00-2013-FC- 0040; USFWS 2012c, entire), on-going livestock grazing activities on eight BLM Allotments on the Boise District (14420-2010-F-0025-R001; USFWS 2014a, entire), construction of the Jarbidge Fuel Breaks Project (01EIFW00-2014-FC-0767; USFWS 2014b, entire), construction
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 62 of the Paradigm Fuel Breaks Project (01EIFW00-2015-FC-0260, USFWS 2015b, entire), the Service’s sage steppe improvement actions at the Orchard Project near the Orchard Combat Training Center (01EIFW00-2017-F-0002, USFWS 2017a, entire), and the Noxious Weeds and Invasive Plant Treatment Program on Twin Falls District BLM (01EIFW00-2017-F-0231, USFWS 2017b, entire). As described above, section 7 consultation/conference has occurred on the effects of multiple actions and plans on the species itself. It is anticipated that section 7 conference or consultation, as appropriate, will be completed regarding the potential effects of additional on-going and new actions on proposed and designated Critical Habitat for slickspot peppergrass. Section 7 conference and consultation are expected to include some actions that may degrade the environmental baseline over the short-term in many cases. However, existing conservation measures are intended to minimize habitat degradation for the species; these conservation measures also are expected to minimize short-term impacts to PBFs of slickspot peppergrass Critical Habitat.
Status of Slickspot Peppergrass Proposed Critical Habitat in the Action Area Critical Habitat receives protection under section 7 of the Endangered Species Act through the prohibition against Federal agencies carrying out, funding, or authorizing the destruction or adverse modification of Critical Habitat. Critical Habitat designations identify, to the extent known using the best scientific data available, habitat areas that provide essential life-cycle needs of listed species. PCH is habitat that has been proposed in the Federal Register to be designated as Critical Habitat, or habitat proposed to be added to an existing Critical Habitat designation, under Section 4 of the Act for any listed or proposed species [50 CFR §402.02]. PCH within the BDO is located in Payette County (Unit 1), Ada County (Subunits 2a, 2b, 2c, and 2d), and Elmore County (Subunits 3a, 3b, and 3c), Idaho. Range wide there are 61,301 acres of PCH; 52,730 acres of located on BLM-managed lands, 1 acre occurring on military lands, 4,641 acres occurring on State lands, and 3,929 acres occurring on private land (Table 7). Of the 52,730 acres of PCH located on BLM-managed lands, 25,022 or approximately 47 percent are within the BDO; the remaining acreage is within the BLM Twin Fall District, Jarbidge Field Office.
Factors Affecting Slickspot Peppergrass Proposed Critical Habitat in the Action Area On-going threats to PBFs of slickspot peppergrass range-wide PCH include modified wildfire regime, invasive nonnative plants, urban and agricultural development, recreation, habitat fragmentation, and livestock use. These same factors affecting the PBFs of proposed Critical Habitat have been previously described in detail for their effects on the species above. The primary threats of modified wildfire regime and invasive nonnative plants have significantly impacted the functionality of PBFs of PCH within the action area, and may continue to impact Critical Habitat PBFs in the future. Threats to PCH within the Project area include wildfire, presence of invasive nonnative plants, pesticide use and livestock grazing. Several threat factors are negatively affecting slickspot peppergrass across the range of the species. The sagebrush-steppe habitat of the Great Basin, where slickspot peppergrass occurs, is becoming increasingly degraded due to the impacts of multiple threats, including increased fire frequency and the subsequent invasion of nonnative annual grasses, such as cheatgrass. Effects of the modified wildfire regime and the invasive nonnative plants were identified as the primary threats identified in the Service’s decision to list
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 63 slickspot peppergrass as threatened. Cheatgrass can impact slickspot peppergrass directly through competition but also indirectly by providing continuous fine fuels that contribute to the increased frequency and extent of wildfires. Frequent wildfires have numerous negative consequences in the sagebrush-steppe system, which is adapted to much longer fire-return intervals, ultimately resulting in the conversion of the sagebrush community to nonnative annual grasslands with associated losses of native species diversity and natural ecological function.
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Chapter 4 – Description of the Action Area Actions (common to all alternatives) would take place on the approximately 4.2 million acres of public land managed by the BDO which consists of three field offices: Bruneau Field Office (BFO), Four Rivers Field Office (FRFO) including the Morley Nelson Snake River Birds of Prey National Conservation Area (MNSRBOP), and Owyhee Field Office (OFO); in southwest Idaho. Figure 1.1 shows the location of the field offices within the BDO. These lands also include approximately 8,000 acres of public land in Elko County, Nevada13. The counties (or portions of counties) occurring within the bounds of the BDO are Ada, Adams, Boise, Canyon, Elmore, Gem, Owyhee, Payette, Valley, and Washington Counties, Idaho and Elko County, Nevada. The BDO includes the Treasure Valley which supports the densest population of people in Idaho, which includes Boise, the State Capital. There are a variety of natural landscapes within this area, differing in elevation and precipitation. Elevation ranges from a low of 2,200 feet at the Snake River to more than 8,000 feet in the Owyhee Mountains. Average annual precipitation varies from 6 inches or less on the Snake River plain to 22 inches or more in high elevation areas. The majority of precipitation falls during the winter and spring months. Mean temperatures vary from 15°F in January to 95°F in July. Temperature extremes of -20°F and greater than 100°F occur for short periods.
Soils Soils in the BDO are affected by several physical properties, including topography, and parent materials. The following soil orders are found within the BDO: Aridisols, Mollisols, Entisols, Vertisols, Inceptisols, Alfisols, Andisols and Histosols. The two most commonly occurring soil orders are Ardisols and Mollisols which are briefly described below. 1) Aridisols are semi-desert and desert soils. They tend to be coarse textured and are susceptible to wind erosion. Sandy and loamy soils, types of Aridisol soils, are susceptible to accelerated wind erosion when vegetation cover is removed. Sandy loam soils have a moderate to high wind erosion potential, but will usually not erode readily unless the surface is disturbed and the vegetation is sparse. Water erosion can occur on steeper slopes. 2) Mollisols are generally found in grasslands, shrub-steppe, mountain shrublands, and along riparian zones; within a wide range of precipitation zones. They are finer grained than Aridisols and are subject to water erosion and soil compaction when wet. The finer textured soils on steeper slopes have a moderate to high water erosion potential when disturbed. They are also subject to wind erosion when their surfaces are exposed.
Biological crusts have a significant influence on soil quality in the arid and semi-arid lands that comprise much of the BDO. Biological crusts consist of a variety of cyanobacteria, green algae, lichens, mosses, microfungi, and other bacteria. They positively affect the soil environment by reducing erosion (both wind and water), fixing atmospheric nitrogen, retaining soil moisture, and providing a living organic surface mulch (Belnap and Phillips, 2001). Annual invasive plant
13 The 8,000 acres are managed under a Memorandum of Understanding (MOU) with the BLM Elko District Office.
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 65 expansion and associated increased fire frequency reduces biological soil crust, which in turn affects cycling, water infiltration, and potential soil erosion.
Water Resources The Snake River is the primary river within the BDO, however there are four other rivers within the BDO including, the Boise, Bruneau, Owyhee and Payette Rivers that are major tributaries to the Snake River. Peak flows of the Snake River and its tributaries occur between mid-April and mid-June as a result of snowmelt and rainfall. Spring and early summer run off may be 20 to 50 times greater than base flows. During the summer, high intensity and widely dispersed thunderstorms produce sporadically high discharges of precipitation for short durations; however, overland flow and runoff are generally insufficient to sustain flows for an extended period of time. Base flows are maintained during the remainder of the year by ground water and spring discharges. Stream flows in the Snake River are managed by a series of dams within and upstream of the BDO managed lands. The BDO contains a variety of stream types and floodplains, from very small spring-fed creeks to medium and large rivers. Streams and their floodplains occur in a wide variety of landscapes, from high elevation slow-moving headwater meadow reaches to mid- and low elevation fast- flowing basalt canyon reaches. Stream and river conditions vary from undisturbed river and vegetative communities in inaccessible rocky canyons to deep, erodible soil banks in the lower elevations. Other surface waters include shoreline and open water habitat on lakes, reservoirs, ponds, and natural groundwater fed springs. Playas are also present and provide a water source to livestock and wildlife during some times of the year. Playas collect water from small basins and have no external drainage. Playas typically lack water from late June to December. Riparian areas and wetlands are generally associated with streams, rivers and springs/seeps and are broadly distributed across the BDO. Riparian areas provide cover and food for wildlife and fish as well as water quality benefits by filtering out nutrients from runoff, maintaining stream temperature by providing shade and controlling erosion. Wetlands are commonly associated with riparian areas but are also found in upland areas in association with springs and seeps. Wetlands associated with springs/seeps often provide surface and subsurface water to downslope streams and rivers.
Vegetation
Vegetation in the BDO is primarily classified as Semi-Desert Shrubland and Grassland with dry coniferous forests to the north and juniper woodlands to the south. These broad vegetation types are further divided into 13 sub-divisions, per BLM national vegetation classification standards (USDI BLM, 2013; Table 9). Vegetation mapping of plant communities is based on on-the- ground inventory, remote imagery with field verification, and vegetation treatment data. Plant communities were aggregated into sub-divisions and macrogroups. Acreages of some vegetation types are dynamic and may vary year-to-year dependent on acres burned in wildland fire, vegetation treatments implemented, and rates of natural recovery and seeding establishment. Therefore, Table 9 shows general proportions for plant communities throughout the BDO.
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Table 9 – Plant Communities in the BDO
Vegetation Division Vegetation Sub-Division BLM Acres Native Shrubs and Low-Elevation Shrub Steppe 2,441,330 Perennial Species Perennial Grass 86,005 Mid-Elevation Shrub Steppe 1,615 Salt Desert Shrub 298,618 Forest and Woodland Dry Conifer 43,241 Species Aspen/Conifer 49,231 Juniper Woodlands 201,220 Other Woodlands1 22,516 Wetlands and Riparian Wetland and Riparian Vegetation 96,851 Noxious Weeds and Non-Native Annual Grasses 602,805 Invasive Plants Noxious Weeds and Other Invasive Plants 77,227 Non-Native Perennial Grasses and Forbs 25,050 Other Other (urban, agricultural, etc.) 183,970 Total Acreage BDO 4,129,679 1The Other Woodlands category includes Inter-Mountain Basins Curl-leaf Mountain Mahogany Woodlands, Inter-Mountain Basins Greasewood Flats and Mountain Shrub.
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Chapter 5 – Effects Analysis and Determinations Common Effects of Herbicide Treatments to Listed Species This BA incorporates by reference the supplemental information on the effects of herbicide use on BLM lands from the Final BA for Vegetation Treatments Using Aminopyralid, Fluroxypyr, and Rimsulfuron on BLM Lands in 17 Western States (USDI BLM, 2015a). This BA included Ecological Risk Assessments (ERAs) that summarized the ecological risks to both plants and animals from applications of aminopyralid, fluroxypyr, and rimsulfuron. The ERAs were created by an interagency group that was established to identify uncertainties about effects of herbicides on listed species and to develop information for completing Endangered Species Act (ESA) consultations (USDI BLM, 2002; ID-2002-027). The purpose of this effort was to gather, in one place, the known information on direct and indirect effects, and in particular, sub-lethal effects, on ESA-listed and proposed species. These documents are intended to compile the best available information on the fate and transport for each of the herbicides approved for use on BLM land. The methodology used in creating the ERAs and their findings for each of the identified herbicides can be found in their entirety in Appendix C of the BA for the 2016 PEIS (USDI BLM, 2015a; AECOM, 2014). The findings of the ERAs were fully considered in the development of the design features and conservation measures that will be applied to herbicide treatments in the BDO in habitats containing ESA-listed and proposed species. Effects of Use of Spray Adjuvants and Surfactants
Under the proposed action, spray adjuvants and surfactants would be used to improve the effectiveness of herbicide treatments. Examples of adjuvants include compatibility agents for mixing herbicides, drift retardants, suspension aids, and spray buffers to change the spray solution acidity. Surfactants are a type of adjuvant designed to improve the dispersing, emulsifying, absorbing, spreading, sticking and/or penetrating properties of the spray mixture. Herbicide effectiveness improves with the use of adjuvants and surfactants and reduces the need for increased amounts of active ingredient or additional treatments to control undesirable vegetation (USDI BLM, 2007a). The ERAs for the herbicides analyzed in the 2007 and 2016 PEISs included the use of adjuvants and surfactants and the results of the ERAs were incorporated into the BAs for the PEISs. The potential direct and indirect effects from using these agents were fully considered in the effects analysis of herbicide treatments for each of the ESA-listed and proposed species in this BA. Effects of Accidental Spills
For all herbicide treatments, the potential exists for an accidental spill during the process of mixing herbicides or during the transport of herbicides to or within the treatment area. The ERAs from the BA for the 2016 PEIS assessed the potential risks to ESA-listed and proposed species from an accidental spill of the three newly approved herbicides (USDI BLM, 2015a). The severity of the effects from an accidental spill would vary by treatment method, location, quantity and type of herbicide spilled, amount of plant material affected, timing of the spill, and distance from the occupied habitat. The proposed action includes species specific design features and conservation measures to reduce or eliminate the potential for direct or indirect effects from
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 68 accidental spills. The potential direct and indirect effects from accidental spills were fully considered in the effects analysis of herbicide treatments for each of the ESA-listed and proposed species. Effects of Surface Runoff of Herbicides:
The BA for the 2016 PEISs (USDI BLM, 2007a; USDI BLM, 2015a) identified surface runoff of herbicides as a source of potential impact to ESA-listed and proposed species or habitats. The proposed action includes design features and conservation measures that would avoid the potential for herbicides to run-off the identified treatment area (e.g., no spray if precipitation is expected within 24 hours of treatment). In addition, herbicide application rates would be consistent with manufacture label requirements and would not exceed the identified maximum rate. The potential direct and indirect effects due to surface runoff were fully considered in affects analysis for herbicide treatments for each of the ESA-listed and proposed species. Bruneau Hot Springsnail Direct and Indirect Effects
This effects analysis focuses on noxious weed and invasive plant treatments within the Bruneau hot springsnail Recovery Area using the three newly approved herbicides. Treatments that occur outside of the Recovery Area would have no direct or indirect effects to Bruneau hot springsnail or its habitat. The use of design features and conservation measures were fully considered when determining if an action may affect or would have no effect on Bruneau hot springsnail or its habitat. Actions Determined to Have No Effect
Several noxious weed and invasive plant treatment methods were determined to have no potential for short- or long-term, direct or indirect effects to Bruneau hot springsnail and its habitat. The no effect determination was reached because the treatment method would not be applied in occupied RCAs or the distance between the treatment and the occupied RCA was sufficient to avoid any potential for direct or indirect effects. The treatments determined to have no effect to Bruneau hot springsnail or its habitat and the rational for the no effect determination is provided in Appendix E. Actions That May Affect Bruneau Hot Springsnail and Its Habitat
This analysis identifies the potential for on-going (small-scale) noxious weed and invasive plant treatments to have short- or long-term, direct or indirect effects to Bruneau hot springsnail and its habitat. In general, the may affect determinations were made because the treatment methods had the potential for effects to Bruneau hot springsnail individuals or to water quality or hydric vegetation in occupied RCAs. All noxious weed and invasive plant treatments within the Bruneau hot springsnail Recovery Area would be designed using the INFISH RCA widths as described above in the Design Features and Conservation Measures section. The potential direct and indirect effects for “may affect” treatment methods and the rationale for those determinations are discussed below and summarized in Appendix E.
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Effects of Herbicide Treatments The proposed action allows for using the three newly approved herbicides approved for use on public lands by the ROD for the 2016 PEIS (USDI BLM, 2016). Herbicide treatments would include both aerial and ground-based methods. Ground-based methods would include spraying from all-terrain vehicles (e.g., ATV, UTV, truck, or tractor) or on foot (e.g., backpack or horse). Aerial methods from a helicopter or fixed wing aircraft would be used for treatments up to 50 acres in size and would include area restrictions for sensitive resources. Aerial treatments are restricted within 0.5 mile from the Bruneau hot springsnail Recovery Area. Additional conservation measures are identified in the proposed action (Chapter 2). The proposed action does not allow for broadcast spraying of terrestrial herbicide formulations in areas with hydric vegetation (i.e., aminopyralid, fluroxypyr, rimsulfuron) within RCAs containing Bruneau hot springsnail or its habitat. These upland herbicides can be used for spot treatments (manual methods) in upland vegetation types within RCAs, but cannot be used within 15 feet of areas with hydric vegetation (Figure 1). On-going, small-scale treatments would be used on a limited basis to control or eradicate existing or new infestations in upland vegetation types in RCAs. The effects analysis below focuses on the potential direct and indirect effects from ground-based and aerial herbicide treatments using upland and riparian herbicides in or adjacent to RCAs containing Bruneau hot springsnail or its habitat. Ground-based and aerial herbicide treatments consistent with the design features and conservation measures would be effective in reducing or removing noxious weeds and invasive plants from areas in and adjacent to occupied RCAs. Actions to control or eliminate noxious weeds and invasive plants from adjacent upland areas would reduce the risk for the noxious and invasive plants to alter suitable habitat adjacent to Bruneau hot springsnail populations and suitable habitat. This would result in a beneficial effect to Bruneau hot springsnail and its habitat in the long-term. Herbicide treatments in upland vegetation types that are outside of (not adjacent to) occupied RCAs would have no direct or indirect effects to Bruneau hot springsnail or Bruneau hot springsnail habitat. Effects Common to all Ground-based Herbicide Treatments Ground-based herbicide treatments would occur in and adjacent to occupied RCAs within the Bruneau hot springsnail Recovery Area and would include measures to improve riparian conditions to meet the recovery objectives for ESA-listed aquatic species. Design features and conservation measures (e.g., no mixing of herbicides or fueling in occupied RCAs, limitations on herbicide use and treatment methods in RCAs) would be applied to all on-going treatments. These measures would reduce the potential for direct or indirect effects to Bruneau hot springsnail and its habitat to the extent possible. However, the potential exists for some treatments to result in localized, short-term direct or indirect effects to Bruneau hot springsnail or its habitat where treatments occur in or adjacent to occupied RCAs. Ground-based herbicide treatments consistent with the design features and conservation measures would be effective in reducing or removing noxious weeds and invasive plants from areas in and adjacent to RCAs with geothermal springs containing Bruneau hot springsnail. Actions to control or eliminate noxious weeds and invasive plants from adjacent upland areas
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 70 would reduce the risk for noxious and invasive plants to invade occupied RCAs and alter habitat conditions suitable for Bruneau hot springsnail. This would have a beneficial effect to Bruneau hot springsnail and its habitat in the long-term. Herbicide treatments adjacent to occupied geothermal springs could potentially result in direct adverse effects to listed Bruneau hot springsnail individuals if they were to come into contact with herbicide contaminated water. With the inclusion of the design features and conservation measures (Chapter 2), and SOPs (Appendix B), the on-going (small-scale) and noxious weed and invasive plant treatments adjacent to occupied geothermal springs would have a low potential for direct effects to individual Bruneau hot springsnail. Direct or indirect effects to Bruneau hot springsnail individuals from herbicide treatments using a low boom sprayer method are expected to be insignificant and discountable because treatments would not occur within 50 feet of occupied geothermal springs. Herbicide treatments using hand methods would pose the greatest risk for direct effects to Bruneau hot springsnail individuals because treatments could occur within 15 feet of occupied waters. However, with the limitations on treatment method (i.e., spot treatments, hand methods, no spraying of herbicides within 15 feet of occupied geothermal springs), the potential for direct herbicide contact to individual snails would be discountable. Herbicides that unintentionally come into contact with hydric vegetation may indirectly affect Bruneau hot springsnail habitat by reducing or removing woody or herbaceous hydric plants in occupied RCAs. The potential short and long-term effects of removing hydric vegetation from these habitats include a localized loss of overhead cover, streamside shading, and a source of nutrients that supports the food base. These effects are likely to be localized in scale, but could be short- or long-term depending on the type and quantity of herbicide coming into contact with hydric vegetation (USDI BLM, 2007a; pg. 5-58, 5-64). However, the limitations on treatment method (i.e., spot treatments, hand methods, no spraying of herbicides within 15 feet of occupied geothermal springs) and herbicide use (aquatic approved herbicides only) would reduce the potential for effects to hydric vegetation to the extent possible. Potential effects to Bruneau hot springsnail due to accidental herbicide effects to hydric vegetation are likely to be insignificant but not completely discountable because treatments could occur in areas with hydric vegetation within 15 feet of occupied geothermal springs. The proposed action allows the use of terrestrial (upland) herbicide formulations in upland vegetation types in RCAs within the Bruneau hot springsnail Recovery Area. These herbicides can be applied as spot treatments using hand methods and direct application only (no broadcast spraying) but cannot be used closer than 15 feet of hydric vegetation. With the design features and conservation measures for RCAs, the potential indirect effects to hydric vegetation from these on-going spot treatments would occur at the transition zone between upland and hydric vegetation. Potential effects would be due to herbicide drift and are likely to be insignificant and discountable. Therefore, treatments using upland herbicides in and adjacent to occupied RCAs may affect, but are not likely to adversely affect Bruneau hot springsnail and its habitat. No direct or indirect effects to Bruneau hot springsnail or its habitat would occur from applying these herbicides in upland vegetation types outside of (not adjacent to) occupied RCAs. Effects of Herbicide Treatments using Low Boom Methods Riparian herbicides could be applied using a low boom sprayer mounted on an ATV or UTV in upland vegetation types 50 feet from hydric vegetation in occupied RCAs. Treatments using a low boom sprayer have a low potential for herbicide drift onto hydric vegetation because of the Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 71 low boom height on the sprayer (20 inches and below). Applying the conservation measures (i.e., weather conditions, herbicide use and handling) would reduce the potential for short-term direct and indirect effects to hydric vegetation and surface water in the Bruneau hot springsnail Recovery Area to the extent possible. Because treatments may occur up to 50 feet from occupied waters, the potential for localized, short-term direct or indirect effects to hydric vegetation and water quality cannot be completely discounted, but will likely be insignificant. Therefore, treatments using low boom methods from to within 50 feet from hydric vegetation for occupied geothermal springs may affect, but are not likely to adversely affect Bruneau hot springsnail and its habitat. Effects of Herbicide Treatments using Hand Methods Riparian herbicides could be applied in occupied RCAs using hand methods which include spot spraying of individual plants using a backpack sprayer or ATV/UTV mounted spray equipment to within 15 feet of occupied waters. These treatments pose an increased risk for direct or indirect effects to Bruneau hot springsnail and its habitat due to accidental direct chemical exposure or due to herbicide drift. Because hand methods are highly controllable, the potential for herbicides to come in direct contact with surface water in occupied geothermal springs is low. Applying the conservation measures (i.e., wind velocity, herbicide use and handling) would reduce the potential for short-term direct and indirect effects to hydric vegetation and surface water in the Bruneau hot springsnail Recovery Area to the extent possible and will likely be insignificant. Because localized, short-term direct or indirect effects to hydric vegetation and water quality cannot be completely discounted, treatments using hand methods within 15 feet from occupied waters may affect, but are not likely to adversely affect Bruneau hot springsnail and its habitat. Treatments using riparian herbicides from 15 feet up to the water’s edge would pose the most risk for direct exposure of herbicides to Bruneau hot springsnail and its habitat. To reduce the potential for adverse effects due to accidental direct spray or off-site drift, treatments would be limited to spot treatments using hand methods only (i.e., wicking, wiping, dipping, painting, or injecting) of only riparian herbicides with no adjuvants or surfactants. These conservation measures would avoid the potential for direct effects to Bruneau hot springsnail and its habitat due to accidental spray or herbicide drift. The “no spray” design feature, combined with the methods for wicking, wiping, dipping, painting, or injecting, would reduce the potential for herbicides to accidentally enter occupied geothermal springs to the extent possible. Although herbicide treatments may occur up to the water’s edge, the potential for localized, short-term direct or indirect effects to hydric vegetation and water quality due to accidental direct exposure would be insignificant but not completely discountable. Therefore, treatments using hand methods to within 15 feet of occupied geothermal springs may affect, but are not likely to adversely affect Bruneau hot springsnail and its habitat. Herbicide treatments using hand methods (i.e., spot spray, wicking, wiping, dipping, painting, or injecting) in upland vegetation types more than 50 feet from hydric vegetation in occupied RCAs would have no direct or indirect effects to Bruneau hot springsnail or its habitat. This distance is sufficient to prevent direct or indirect herbicide exposure to surface waters or hydric vegetation in occupied RCAs.
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Determination – Effects of Ground-based Herbicide Treatments Ground-based herbicide treatments to reduce or eliminate noxious weeds and invasive plants in and adjacent to occupied RCAs may affect, but are not likely to adversely affect Bruneau hot springsnail and its habitat. Herbicide treatments have the potential for localized, short-term direct and indirect effects to Bruneau hot springsnail or its habitat from direct accidental exposure or due to herbicide drift into areas with hydric vegetation or surface water. The design features and conservation measures reduce the potential for effects to insignificant, but all potential effects may not be discountable. Ground-based herbicide treatments would have a long- term beneficial effect to Bruneau hot springsnail and its habitat by reducing the potential for noxious weeds and invasive plants to invade occupied geothermal springs and alter suitable habitat conditions for Bruneau hot springsnail. Interrelated and Interdependent Effects
Interrelated and interdependent actions include those activities that would not occur if not for the proposed action. No interrelated or interdependent effects to Bruneau hot springsnail and its habitat have been identified for the proposed action. Cumulative Effects
The implementing regulations for Section 7 of the ESA define cumulative effects to include those effects of future State, Tribal, local, or private actions that are reasonably certain to occur in the action area. The cumulative effect assessment considered the potential for effects to Bruneau hot springsnail and its habitat from on-going and predicted future uses and activities on private lands in and adjacent to the Bruneau hot springsnail Recovery Area. There are no State lands in or adjacent to the Bruneau hot springsnail Recovery Area. The primary private land uses within or adjacent to the Bruneau hot springsnail Recovery Area include but may not be limited to cropland irrigation and associated diversion of surface water, livestock grazing, noxious weed treatments or a lack thereof, road use and maintenance, maintenance of private land infrastructure (e.g., fences, roads, diversions or irrigation equipment), and operation and maintenance of geothermal developments. Private land uses also include a boat ramp and access road that is used as a take-out by both commercial and private whitewater rafters. All of these activities and uses have resulted in direct or indirect adverse effects to Bruneau hot springsnail and its habitat in the past and is expected to continue to have similar levels of impact into the future. The cumulative effects to Bruneau hot springsnail and its habitat from private land uses and activities would include impacts to water quality due to sediment, nutrients, or chemical contamination. There also is the potential for adverse effects to the quantity of water within the geothermal seeps and springs from geothermal development on private land. Geothermal development is considered the primary threat to Bruneau hot springsnail and its habitat (USDI USFWS, 2002b). There are more than 50 wells on private lands within 7.5 miles of the Indian Bathtub site that use geothermal water to irrigate private land that have contributed to the reduction or elimination of geothermal spring habitat. These developments are expected to continue to reduce geothermal flows and result in a potential loss of habitat available or suitable for Bruneau hot springsnail in the future. The potential for impacts to Bruneau hot springsnail and its habitat from private land activities are expected to continue to have cumulative effects to
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Bruneau hot springsnail habitat on private land and indirectly on the adjacent Federal lands in the future. Another threat to Bruneau hot springsnail and its habitat includes competition with aquatic nuisance species (IISC, 2007). For Bruneau hot springsnail, the current greatest threat from invasive aquatic plants species is due to hydrilla, which is known to be present in the lower Bruneau River. Idaho Department of Agriculture is working to prevent the spread of this invasive plant using hand-pulling methods. Other invasive plants known to be present in or adjacent to the Bruneau hot springsnail Recovery Area include saltcedar (Tamarix sp.) and purple loosestrife (Lythrum salicaria). Non-native fish, such as guppies (Poecilia reticulate) and tilapia (Oreochromis niloticus) are also known to be present in geothermal spring habitat of the lower Bruneau River (USDI USFWS, 2002b). Aquatic invasive mollusks within the BDO include Asian clam (Corbicula fluminea) and New Zealand mudsnail (Potamopyrgus antipodarum), both of which occur in the Snake River. Zebra mussels (Dreissena polymorpha) and Quagga mussel (D. bugensis) are not yet in Idaho, but the potential exists for these species to accidentally be introduced to waters within the BDO in the future through recreational activities such as boating or whitewater rafting. The risk for any of these invasive aquatic species to be introduced into the Bruneau hot springsnail Recovery Area, either accidentally or deliberately, poses an increasing risk to Bruneau hot springsnail and its habitat in the future. The analysis of direct or indirect effects discloses the potential effects of noxious weed and invasive plant treatments on Bruneau hot springsnail and its habitat incorporates design features, conservation measures, and SOPs to reduce the potential for effects. These measures are not likely to be applied on private land and therefore similar actions may have a greater effect to the listed species and its habitat than would occur on the Federal land. In addition, herbicide treatments on private lands are not limited to 20 herbicides that can be used on the Federal land. A lack of noxious weed and invasive plant treatments on State and private lands would increase the influx of these plants on Federal lands, increasing the necessity and frequency of treatments on the Federal land. Slickspot Peppergrass Direct and Indirect Effects
Design features would be incorporated into every project implemented under this Program to reduce or eliminate potential direct and indirect adverse effects to slickspot peppergrass and PCH due to spot and small-scale ground and aerial broadcast treatment of noxious and invasive weeds.
This effects analysis considers the potential for short- and long-term direct, indirect effects to slickspot peppergrass and its PCH from spot and small-scale broadcast treatment of noxious and invasive weeds. This analysis focuses on treatments within slickspot peppergrass EOs, PCH, Occupied, and Slickspot Peppergrass Habitats (Figure 4). Spot herbicide treatments in Potential Habitat would not occur until slickspot peppergrass inventories were completed and the habitat designation was changed to either Occupied Habitat, Slickspot Peppergrass Habitat, or Non- Habitat depending on the findings of the inventory. Effects determinations were made assuming strict adherence to all design features listed in Chapter 2.
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Actions that May Affect Slickspot Peppergrass Effects of Herbicide Treatments Noxious weed and invasive plant treatments using the proposed herbicides would use spot and small-scale ground and aerial broadcast application. Damage or death of slickspot peppergrass plants could occur due to accidental direct spray or drift. Therefore, design features to eliminate this risk include no aerial spraying within ¼- mile of any slickspot peppergrass habitat category, and education of weed treatment personnel regarding slickspot peppergrass plant and habitat identification and methods that avoid drift. These, in combination with SOPs and small scale of treatments are expected to make the potential for accidental direct spray or drift discountable. Over the long-term, control or containment of noxious weeds and invasive plants due to ongoing spot treatments in and adjacent to EOs and its habitats would reduce competition to slickspot peppergrass and other native vegetation, including plants that support pollinator species. Spot treatments could also reduce the density of noxious weeds and/or invasive plants in slickspot microsites and the potential for sediment entrapment that could modify slickspot structure (Meyer & Allen, 2005). Control of noxious and invasive weeds within Slickspot Peppergrass Habitat would improve habitat corridors for slickspot peppergrass pollinators and potentially improve conditions for germination and emergence of dormant slickspot peppergrass seed within slickspots in this habitat type.
Pollinators in the vicinity of slickspot peppergrass EOs have been observed utilizing noxious weed species such as Scotch thistle. However, it is unlikely that all species supporting pollinators would be impacted and this effect would be insignificant. Effects of spot spraying to pollinators for slickspot peppergrass would be short-term, and population-level effects are not anticipated when all design features are incorporated into project design. Ground-based broadcast herbicide treatment using a low boom would be used where noxious and invasive weeds are too dense and widespread for spot treatments. Therefore, these treatments would occur in areas with low abundance of forbs and shrubs. These treatments would only occur in areas where Stage 3 surveys for slickspot peppergrass have been completed and no plants have been found. Broadcast herbicide application would be used primarily in areas dominated by noxious weeds and invasive plants, and therefore, where native forb abundance is low. As described in design features, these treatments would also focus on the control of noxious and invasive plants while promoting the preservation of native forbs through native forb avoidance. Effects of low boom herbicide treatment would be short-term and population-level effects are not anticipated when all design features are incorporated into project design. Because these treatments would occur in areas with low abundance of forbs and shrubs (pollinator habitat), and avoidance techniques would be employed, potential effects to would be insignificant. Slickspot peppergrass would not be directly affected because it will not be present where this activity occurs. Small-scale aerial application of herbicide will not occur within any slickspot peppergrass habitat categories nor within a ¼- mile buffer of any of these habitat categories. No more than five aerial applications of 50 acres or less would occur on the entire BDO within a given year and would mostly occur in areas where the native vegetation is in a depleted state. Aerial application near slickspot peppergrass habitat categories may impact native pollinator habitat but due to the
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 75 small scale, buffer distance to slickspot peppergrass habitats, and degraded quality of the sites the impacts would be insignificant or discountable. Off-site movement (drift) is a risk associated with herbicide application and may impact non•target vegetation, including slickspot peppergrass and native pollinator forbs. This could result in inhibition of seed germination, reduced vigor, stunted growth, or plant mortality. Adherence to design features in combination with SOPs (Appendix B) would make adverse impacts associated with these projects insignificant or discountable. Beneficial effects resulting from application of herbicides for control of noxious weeds and invasive plants could, when done in conjunction with treatments to enhance resident native vegetation and/or seeding or planting to re-establish perennial grasses, forbs, and shrubs, have the long-term effect of maintaining or improving slickspot peppergrass habitats. Herbicide application would reduce or eliminate noxious weed and invasive plant seed sources and thus competition with native plants in and adjacent to slickspot peppergrass habitats. This could, over the long-term, provide more stable and diverse habitat for slickspot peppergrass and its pollinators. Removal of noxious weeds and invasive plants from within slickspots would reduce plant densities and subsequent sediment entrapment. In addition, control or elimination of invasive plants that create fine fuels in and around slickspot peppergrass habitats would reduce the potential for wildfire ignition and spread, and habitat degradation that could occur post-fire.
Determination – Impacts of Herbicide Treatments Spot and ground-based broadcast herbicide treatment of noxious and invasive weeds may affect, but are not likely to adversely affect slickspot peppergrass. Implementation of design features and SOP would make adverse impacts due to accidental spray or drift insignificant or discountable. Reduced competition from noxious weeds and invasive plants to slickspot peppergrass and other native plants, including those that support pollinator species, would result in both short- and long-term beneficial effects to slickspot peppergrass. Slickspot Peppergrass Proposed Critical Habitat The action area includes PCH for slickspot peppergrass which is located in Payette County (Unit 1), Ada County (Subunits 2a, 2b, 2c, and 2d), and Elmore County (Subunits 3a, 3b, and 3c), Idaho. There 25,022 acres of PCH on BLM-managed land within the action area, this represents 47% of the total PCH on BLM-managed land (52,730 acres) and 41% of the total PCH range wide (61,301 acres). PCH is a subset of the total Occupied Habitat in the action area.
Physical or biological features (PBFs) define attributes of Critical Habitat that are essential to the conservation of a species. Four PBFs were defined for slickspot peppergrass PCH (see 76 FR 27190-27191). Effects to PBFs from each treatment type are described below Table 11.
Direct and Indirect Effects of the Proposed Action
Similar to effects to the species, both positive and negative direct and indirect effects to Proposed Critical Habitat for slickspot peppergrass may result from herbicide spot and ground-based broadcast treatment methods of noxious and invasive weed species.
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PBFs of slickspot peppergrass PCH and potential effects of the proposed treatments are displayed in Table 11.
Summary of Impacts to Slickspot Peppergrass Proposed Critical Habitat Table 11 - Direct and indirect effects to PBFs for slickspot peppergrass Proposed Critical Habitat
Direct and Indirect Effects to PBFs PBF # PBFs (Maintain, Improve, or Degrade) 1 Ecologically-functional microsites or Soil layers within slickspots could be ‘‘slickspots’’ that are characterized by: disturbed due to ATV, UTV, and full-sized vehicle traffic or foot traffic from noxious a) A high sodium and clay content, and a and invasive weed herbicide spot and three-layer soil horizonation sequence, ground-based broadcast treatments methods. which allows for successful seed Any damage to slickspot soil layers could germination, seedling growth, and also result in occupation of the slickspot by maintenance of the seed bank. The species not normally found within slickspots, surface horizon consists of a thin, silty, both native and non-native. vesicular, pored (small cavity) layer that forms a physical crust (the silt Design features such as no ground-based layer). The subsoil horizon is a broadcast treatments in EOs, limiting full- restrictive clay layer with an abruptic sized vehicles to existing roads, and (referring to an abrupt change in educating and instructing ATV and UTV texture) boundary with the surface operators to avoid driving through slickspots layer, that is natric or natric-like in in combination with SOPs, would result in properties (a type of argillic (clay- insignificant or discountable adverse effects based) horizon with distinct structural to PBF 1. and chemical features) (the restrictive layer). The second argillic subsoil layer Treatments would have beneficial effects on (that is less distinct than the upper PBF 1 by reducing or eliminating noxious argillic horizon) retains moisture and invasive weeds in and around through part of the year (the moist clay slickspots. layer); and Therefore, PBF 1 would be maintained b) Sparse vegetation with low to moderate or improved. introduced invasive non-native plant species cover.
2 Relatively-intact native Wyoming big sagebrush Aerial application of herbicide would not occur vegetation assemblages, represented by native within ¼ mile (1,320 feet) of any slickspot bunchgrasses, shrubs, and forbs, within 250 m peppergrass habitat categories. This will help to (820 feet) of slickspot peppergrass EOs to protect any relatively-intact native habitat protect slickspots and slickspot peppergrass surrounding slickspot peppergrass EOs from from disturbance from wildfire, slow the negative effects of herbicide to non-target invasion of slickspots by non-native species and vegetation from accidental direct spray or drift. native harvester ants, and provide the habitats needed by slickspot peppergrass’ pollinators. Because ground-based broadcast treatments would occur in areas with low abundance of forbs and shrubs, and avoidance techniques would be employed, potential effects to native vegetation would be insignificant.
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Direct and Indirect Effects to PBFs PBF # PBFs (Maintain, Improve, or Degrade) Noxious and invasive weed herbicide spot and small-scale broadcast treatments methods using hand and ground broadcast application methods, in combination with design features and SOPs, would result in insignificant impacts to PBF 2 in the short-term Treatments would beneficially affect PBF 2 by reducing or eliminating competition to native vegetation. Therefore, PBF 2 would be maintained or improved.
3 A diversity of native plants whose blooming A long-term effect of control or containment of times overlap to provide pollinator species with noxious and invasive weeds would be decreased sufficient flowers for foraging throughout the competition to native pollinator plants and to seasons and to provide nesting and egg-laying improve habitat corridors for slickspot sites; appropriate nesting materials; and peppergrass pollinators. sheltered, undisturbed places for hibernation and overwintering of pollinator species. In order Noxious and invasive weed herbicide spot and for genetic exchange of slickspot peppergrass to ground-based broadcast treatments methods occur, pollinators must be able to move freely using hand and ground broadcast application between slickspots. Alternative pollen and methods, in combination with design features nectar sources (other plant species within the and SOPs, would result in insignificant effects surrounding sagebrush vegetation) are needed to to PBF3. support pollinators during times when slickspot Treatments would beneficially affect PBF 3 by peppergrass is not flowering, when distances reducing competition from noxious weeds and between slickspots are large, and in years when invasive plants to native plants. Overall, PBF 3 slickspot peppergrass is not a prolific flowerer. would be maintained or improved. 4 Sufficient pollinators for successful fruit and Pollinators in the vicinity of slickspot seed production, particularly pollinator species peppergrass EOs have been observed utilizing of the sphecid and vespid wasp families, species noxious weed species such as Scotch thistle. of the bombyliid and tachnid fly families, Removal of this noxious weed species could honeybees, and halictid bee species, most of have a short-term negative effect on slickspot which are solitary insects that nest outside of peppergrass pollinators. However, it is unlikely slickspots in the surrounding sagebrush-steppe that all species supporting pollinators would be vegetation, both in the ground and within the impacted and this effect would be insignificant. vegetation. Noxious and invasive weed herbicide spot and ground-based broadcast treatments methods using hand and ground broadcast application methods, in combination with design features and SOPs, would result in insignificant or discountable effects to PBF4. Reduction or elimination of noxious weeds and invasive plants in areas adjacent to PCH would support slickspot peppergrass pollinators on a landscape scale. Therefore, PBF 4 would be maintained or improved.
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Actions that May Affect Slickspot Peppergrass Proposed Critical Habitat Effects of Herbicide Treatments Noxious weed and invasive plant treatments using the proposed herbicides would use spot and small-scale ground and aerial broadcast application. Damage or death of slickspot peppergrass plants could occur due to accidental direct spray or drift. The design features include no aerial spraying in or within a ¼-mile buffer of any slickspot peppergrass habitat category, and education of weed treatment personnel regarding slickspot peppergrass plant and habitat identification and methods that avoid drift. These, in combination with SOP and small treatment scale, are expected to make the potential for accidental direct spray or drift discountable. Over the long-term, control or containment of noxious weeds and invasive plants due to on-going spot treatments in and adjacent to EOs and its habitats would reduce competition to slickspot peppergrass and other native vegetation, including plants that support pollinator species. Spot treatments could also reduce the density of noxious weeds and/or invasive plants in slickspot microsites and the potential for sediment entrapment that could modify slickspot structure (Meyer & Allen, 2005). Control of noxious and invasive weeds within Slickspot Peppergrass Habitat would improve habitat corridors for slickspot peppergrass pollinators and potentially improve conditions for germination and emergence of dormant slickspot peppergrass seed within slickspots in this habitat type.
Pollinators in the vicinity of slickspot peppergrass EOs have been observed utilizing noxious weed species such as Scotch thistle. Removal of this noxious weed species could have a negative effect on slickspot peppergrass pollinators. However, it is unlikely that all species supporting pollinators would be impacted and this effect would be insignificant. Effects of spot spraying to pollinators for slickspot peppergrass would be short-term, and population-level effects are not anticipated when all design features are incorporated into project design. Ground-based broadcast herbicide treatment using a low boom would be used where noxious and invasive weeds are too dense and widespread for spot treatments. It would be used in areas dominated by noxious weeds and invasive plants, and therefore, where native forb abundance is low. These treatments would focus on the control of noxious and invasive plants while promoting the preservation of native forbs through native forb avoidance. Because these treatments would occur in areas with low abundance of forbs and shrubs and avoidance techniques would be employed, impacts to native forbs that support pollinator insects would be insignificant. Aerial application near slickspot peppergrass habitat categories may impact native pollinator habitat but due to the small scale, buffer distance to slickspot peppergrass habitats, and degraded quality of the sites the impacts would be discountable. Off-site movement (drift) is a risk associated with herbicide application and may impact non• target vegetation, including slickspot peppergrass and native pollinator forbs. This could result in inhibition of seed germination, reduced vigor, stunted growth, or plant mortality. Adherence to design features in combination with SOPs (Appendix B) would make adverse impacts associated with offsite movement (drift) discountable. Application of herbicides for control of noxious weeds and invasive plants could, when done in conjunction with treatments to enhance resident native vegetation and/or seeding or planting to
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 79 re-establish perennial grasses, forbs, and shrubs, have the long-term effect of maintaining or improving slickspot peppergrass habitats. Herbicide application would reduce or eliminate noxious weed and invasive plant seed sources and thus competition with native plants in and adjacent to slickspot peppergrass habitats. This could, over the long-term, provide more stable and diverse habitat for slickspot peppergrass and its pollinators. Removal of noxious weeds and invasive plants from within slickspots would reduce plant densities and subsequent sediment entrapment. In addition, control or elimination of invasive plants that create fine fuels in and around slickspot peppergrass habitats would reduce the potential for wildfire ignition and spread, and habitat degradation that could occur post-fire.
Determination - Impacts of Spot Herbicide Treatments Spot and ground-based broadcast herbicide treatment may affect, but are not likely to adversely affect slickspot peppergrass Proposed Critical Habitat. Herbicide treatments would reduce noxious weeds and invasive plants in and around slickspots (PBF 1). This would maintain sparse vegetative cover in slickspots (PBF 1) and reduce competition to native plants that provide habitats for slickspot peppergrass pollinators (PBF 3). PBF 1 through 4 would be maintained or improved as a result of herbicide treatments in and adjacent to PCH. Summary of Potential Effects of the Action to Slickspot Peppergrass Proposed Critical Habitat PBF 1 is likely to be maintained or improved by reducing or eliminating noxious and invasive weeds in and around slickspot microsites. PBF 2 would be maintained or improved by reducing or eliminating competition to native vegetation. PBF 3 would be maintained or improved by reducing competition from noxious and invasive plants to native pollinator forbs and nesting habitat. PBF 4 would be maintained or improved by reducing competition from noxious and invasive weeds in areas adjacent to PCH to native pollinator forbs, nesting habitat and habitat corridors. In the long-term, PBFs 1, 2, 3 and 4 would be maintained or improved as a result of the proposed action.
Interrelated and Interdependent Effects
Interrelated and interdependent actions include those activities that would not occur if not for the proposed action. No interrelated or interdependent effects to slickspot peppergrass or slickspot peppergrass PCH have been identified for the proposed action.
Cumulative Effects Livestock grazing, fire suppression actions, post-fire seeding treatments, urban and agricultural development, recreational off-road vehicle use, and chemical treatments for weed or insect control that may directly or indirectly affect slickspot peppergrass can occur on State and private lands in the vicinity of the Project area. The Service recognizes that some actions on non-Federal lands may have beneficial and adverse effects on the slickspot peppergrass at the individual plant or EO level. Some non-Federal lands
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 80 within the region are known to contain slickspot peppergrass, although adequate surveys to determine presence of the species have not occurred to date. Within the entire 15,582-acres of habitat identified as slickspot peppergrass EOs, only 2,095 acres of non-Federal lands are documented to contain portions of EOs. Of these 2,095 acres, about 1,269 acres (61 percent) are managed under the OCTC’s INRMP; conservation implementation and effectiveness for slickspot peppergrass is considered high within the OCTC INRMP area. The remaining 826 non- Federal acres located outside of the OCTC INRMP area constitute only about 6 percent of the total EO acreage within the Snake River Plain Plateau physiographic region and about 5 percent of the total EO acreage rangewide. Any cumulative effects occurring on non-Federal lands are not likely to significantly alter habitat conditions for slickspot peppergrass within the Foothills or Snake River Plains physiographic region or rangewide because they constitute a small percentage of total habitat for the species. Actions by the State of Idaho on State-managed lands or by private land owners that affect slickspot peppergrass or its habitat would constitute cumulative effects. These actions would include treatment of noxious weeds and invasive plants using methods similar to those described under the proposed action; treatment of noxious weeds and invasive plants using methods not described in the proposed action, including additional herbicides or other methods not authorized by use on public lands, or use of plant materials that compete with slickspot peppergrass; livestock grazing and trampling; OHV use; mineral and utility development; development and operation of renewable energy facilities; and road development. Slickspot peppergrass cumulative impacts on non-Federal lands may also include the lack of management actions to maintain occupied and potential habitat. For example, non-Federal lands may be less likely to have habitat restoration and weed control treatments, and habitat burned by wildfire is typically not reseeded. As a result, these areas could be dominated by noxious weeds and invasive plants. In addition, these lands can be seed sources for noxious weed and invasive plant seeds that could spread to adjacent Federal lands, increasing the need for continued on- going and larger-scale treatments. Maintenance and installation of fences, pipelines, water developments, and trailing routes on State lands in occupied or potential habitats would not have the same oversight and restriction as on BLM lands and could result in additional cumulative effects to slickspot peppergrass. Noxious weed and invasive plant control on State and private lands would not be subject to use restrictions, SOPs, design features, and conservation measures that are part of the proposed action. In addition, herbicides used on State and private lands would not be limited to the three included in the proposed action. Therefore, damage to or destruction of slickspots, plants, or seedbanks could occur as a result of these actions. In the long-term, the proposed action provides for conservation and restoration of slickspot peppergrass and its habitat. The proposed action is expected to offset actions occurring on non- Federal lands; therefore, there will be no adverse cumulative effect.
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Appendices
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Appendix A - State of Idaho Noxious Weeds and Boise District Invasive Plants List
The following lists included in this appendix identify species identified by Idaho Department of Agriculture as Noxious Weeds as of 2017. This list is annually reviewed and updated based upon new information. The BDO will update this list in accordance with the State of Idaho. For the most current list of species identified as noxious weeds in the BDO, please see http://invasivespecies.idaho.gov/noxious- weed-program/ for the most current listing of Noxious weeds in the State of Idaho.
Table A-1. State of Idaho Noxious Weeds: Statewide Early Detection Rapid Response List Known Counties of Common Name1 Scientific Name Occurrence in the BDO Brazilian Elodea (A) Egeria densa None Common European Frogbit (A) Hydrcharis morsus-ranae None Fanwort (A) Cobomba caroliniana None Feathered Mosquito Fern (A) Azolla pinnata None Giant Hogweed (T) Heracleum mantegazzianum None Giant Salvinia (A) Salvinia molesta None Iberian Starthistle (T) Centaurea iberica None Hydrilla (A) Hydrilla verticillata Ada, Owyhee Policeman’s Helmet (T) Impatiens glandulifera None Purple Starthistle (T) Centaurea calcitrapa None Squarrose Knapweed (T) Centaurea trimfetti Elmore Syrian Beancaper (T) Zygophyllum fabago Washington Tall Hawkweed (T) Hieracium piloselloides None Variable-Leaf-Milfoil (A) Myriophyllum heterophyllum None Water Chestnut (A) Trapa natans None Water Hyacinth (A) Eichhornia crassipes None Yellow Devil Hawkweed (T) Hieracium glomeratum None Yellow Floating Heart (A) Nymphoides pelata Gem
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Table A-2. State of Idaho Noxious Weeds: Statewide Control List Known Counties of Common Name1 Scientific Name Occurrence in the BDO Black Henbane (T) Hyoscyamus niger Ada, Adams, Elmore, Owyhee, Bohemian Knotweed (T) Polygonum bohemicum Ada, Adams, Boise, Washington Buffalobur (T) Soalnum rostratum Ada, Adams, Gem, Owyhee, Washington Common Crupina (T) Crupina vulgaris Washington Common Reed (A) Phragmites australis Ada, Canyon, Elmore, Owyhee, Payette Dyer’s Woad (T) Isatis Tinctoria Ada, Adams, Boise, Elmore, Owyhee, Washington Eurasian Watermilfoil (A) Myriophyllum spicatum Ada, Boise, Canyon, Gem, Owyhee, Valley, Washington Giant Knotweed (T) Polygonum None sachalinense Japanese Knotweed (T) Polygonum cuspidatum Ada, Adams, Gem, Payette, Washington Johnsongrass (T) Sorghum halepense None Matgrass (T) Nardus stricta None Meadow Knapweed (T) Centaurea debeauxii None Mediterranean Sage(T) Salvia aethiopis Adams, Boise, Payette Musk Thistle (T) Carduss nutans Boise, Gem, Owyhee, Payette Orange Hawkweed (T) Hieracium aurantiacum Adams, Boise, Elmore, Valley, Washington Parrotfeather Milfoil (A) Myriophyllum Ada, Gem, Payette aquaticum Perennial Sowthistle (T) Sonchus arvensis None Russian Knapweed (T) Acroptilon repens Ada, Adams, Canyon, Elmore, Gem, Owyhee, Payette, Washington Scotch Broom (T) Cytisus scoparius None Small Bugloss (T) Anchusa arvensis None Vipers Bugloss (T) Echium vulgare None Yellow Hawkweed (T) Hieracium caespitosum Adams
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Table A-3. State of Idaho Noxious Weeds: Statewide Containment List Known Counties of Common Name1 Scientific Name Occurrence in the BDO Canada Thistle (T) Cirsium arvense Ada, Adams, Boise, Canyon, Elmore, Gem, Owyhee, Payette, Valley, Washington Curlyleaf Pondweed Potamogeton crispus Ada, Boise, Canyon, Elmore, Gem, (A) Owyhee, Payette, Valley, Washington Dalmatian Toadflax (T) Linaria dalmatica ssp. Ada, Adams, Boise, Canyon, Dalmatica Elmore, Gem, Owyhee, Payette, Valley, Washington Diffuse Knapweed (T) Centaurea diffusa Ada, Adams, Boise, Elmore, Gem, Owyhee, Payette, Valley, Washington Field Bindweed (T) Convolvulus arvensis Ada, Adams, Boise, Canyon, Elmore, Gem, Owyhee, Payette, Valley, Washington Flowering Rush (A) Butomus umbelltus None Hoary Alyssum (T) Berteroa incana Adams, Boise, Valley Houndstongue (T) Cynoglossum officinale Ada, Adams, Boise, Elmore, Gem, Owyhee, Payette, Valley, Washington Jointed Goatgrass (T) Aegilpos cylindrical Ada, Adams, Boise, Canyon, Elmore, Gem, Owyhee, Payette, Valley, Washington Leafy Spurge (T) Euphorbia esula Ada, Adams, Boise, Elmore, Gem, Owyhee, Valley, Washington Milium (T) Milium vernale None Oxeye Daisy (T) Leucanthemum vulgare Adams, Boise, Gem, Valley, Washington Perennial Pepperweed Lepidium latifolium Ada, Adams, Boise, Canyon, (T) Elmore, Gem, Owyhee, Payette, Washington Plumeless Thistle (T) Carduus acanthoides None Poison Hemlock (T) Conium maculatum Ada, Adams, Boise, Canyon, Elmore, Gem, Owyhee, Payette, Washington
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Known Counties of Common Name1 Scientific Name Occurrence in the BDO Puncturevine (T) Tribulus terrestris Ada, Adams, Boise, Canyon, Elmore, Gem, Owyhee, Payette, Valley, Washington Purple Loosetrife (T) Lythrum salicaria Ada, Adams, Boise, Canyon, Elmore, Gem, Owyhee, Payette, Washington Rush Skeletonweed (T) Chondrilla juncea Ada, Adams, Boise, Canyon, Elmore, Gem, Owyhee, Payette, Valley, Washington Saltcedar (T) Tamarix spp. Ada, Adams, Canyon, Elmore, Gem, Owyhee, Payette, Washington Scotch Thistle (T) Onopordum acanthium Ada, Adams, Boise, Canyon, Elmore, Gem, Owyhee, Payette, Washington Spotted Knapweed (T) Centaurea stoebe Ada, Adams, Boise, Canyon, Elmore, Gem, Owyhee, Payette, Valley, Washington Tansy Ragwort (T) Senecio jacobaea Boise White Bryony (T) Bryonia alba Ada, Owyhee Whitetop (T) Cardaria draba Ada, Adams, Boise, Canyon, Elmore, Gem, Owyhee, Payette, Washington Yellow Flag Iris (A) Iris psudocorus Ada, Adams, Canyon, Elmore, Gem, Owyhee, Payette, Washington Yellow Starthistle (T) Centaurea solstitialis Ada, Adams, Elmore, Gem, Owyhee, Payette, Washington Yellow Toadflax (T) Linaria vulgaris Ada, Adams, Boise, Gem, Payette, Valley, Washington 1 (A)= Aquatic Species, (T) = Terrestrial Species
The Table A-4 presents invasive species in addition to cheatgrass and medusahead that are not currently recognized as noxious weeds in the State of Idaho. Invasive plants are species of concern that are very limited in extent or not yet known to occur on the BDO but are documented on adjacent lands or States. This list is not exclusive as new species are constantly identified as posing a threat to public lands. Management of new invaders would be a high priority for treatment. Treatments would focus on eradicating newly identified species before they become established on the BDO.
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Table A-4. Potential New Invaders that Threaten the BDO Primary Common Name Scientific Name Habitat Rangea Camelthorn Alhagi maurorum Upland Rare Sulfur Cinquefoil Potentilla recta Riparian Restricted Siberian Elm Ulmus spp. Riparian Restricted Tree of Heaven Ailanthus altissima Riparian Restricted Ventenata Ventenata dubia Upland Numerous Indigo Bush Amorpha fruticosa Riparian Numerous African Rue Peganum harmala Upland Adjacent Bull Thistle Cirsium vulgare Riparian Numerous Clary Sage Salvia sclarea Riparian Adjacent Burdock Arctium spp. Riparian Numerous Giant Reed Arundo donax Riparian Adjacent Myrtle Spurge Euphorbia myrsinites Upland Restricted Eggleaf Spurge Euphorbia oblongata Upland Adjacent Italian Thistle Carduus pycnocephalus Upland Adjacent Bur Chervil Anthriscus caucalis Riparian Restricted Russian Olive Elaeagnus angustifolia Riparian Widespread Bouncingbet Sapanaria officianalis Upland Restricted Common tansy Tanacetum vulgare Riparian Restricted a Range: Adjacent – species found adjacent to District or State; Rare – species known only in one or two locations; Restricted – species limited to few areas; Numerous – species found in numerous areas; Widespread – species found over large areas Sources: http://plants.usda.gov/ and BLM. The list shown above was compiled by BLM staff based on observations in the field.
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Appendix B – Standard Operating Procedures for Applying Herbicides Resource Treatment Protection Measures Authority/ Type Source
General Herbicide ● Prepare operational and spill contingency plan in advance of treatment. BLM Handbook H-9011- Treatment ● Conduct a pretreatment survey before applying herbicides. 1 (Chemical Pest ● Select herbicide that is least damaging to the environment while providing the Control); and BLM desired results. Manuals 1112 (Safety), ● Select herbicide products carefully to minimize additional impacts from 9011 (Chemical Pest degradants, adjuvants, inert ingredients, and tank mixtures. Control), 9012 ● Apply the least amount of herbicide needed to achieve the desired result. (Expenditure of Rangeland Insect Pest ● Follow herbicide product label for use and storage. Control Funds), 9015 ● Have licensed applicators apply herbicides. (Integrated Weed ● Use only BLM-approved herbicides and follow product label directions and Management), and 9220 “advisory” statements. (Integrated Pest ● Review, understand, and conform to the “Environmental Hazards” section on the Management); BLM herbicide product label. This section warns of known pesticide risks to the 2007 PEIS; BLM 2016 environment and provides practical ways to avoid harm to organisms or to the PEIS. environment. ● Consider surrounding land use before assigning aerial spraying as a treatment method and avoid aerial spraying near agricultural or densely populated areas. ● Minimize the size of application area, when feasible. ● Comply with herbicide-free buffer zones to ensure that drift will not affect crops or nearby residents/landowners. ● Post treated areas and specify reentry or rest times, if appropriate. ● Notify adjacent landowners prior to treatment. ● Keep a copy of Safety Data Sheets (SDSs) at work sites. SDSs are available for review at http://www.agrian.com. ● Keep records of each application, including the active ingredient, formulation, application rate, date, time, and location. ● Avoid accidental direct spray and spill conditions to minimize risks to resources. ● Avoid aerial spraying during periods of adverse weather conditions (snow or rain imminent, fog, or air turbulence). ● Make helicopter applications at a target airspeed of 40 to 50 miles per hour (mph), and at about 30 to 45 feet above ground.
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Resource Treatment Protection Measures Authority/ Type Source ● Do not apply herbicides when winds exceed >10 mph (>6 mph for aerial applications), or a serious rainfall event is imminent. ● Conduct pre-treatment surveys for sensitive habitat and special status species within or adjacent to proposed treatment areas. ● Consider site characteristics, environmental conditions, and application equipment in order to minimize damage to non-target vegetation. ● Use drift reduction agents, and low volatile formulations as appropriate, to reduce the drift hazard to non-target species. ● Turn off applied treatments at the completion of spray runs and during turns to start another spray run. ● Refer to the herbicide product label when planning revegetation to ensure that subsequent vegetation would not be injured following application of the herbicide. ● Clean OHVs to remove seeds. ● Prior to helicopter fueling operations prepare a transportation, storage, and emergency spill plan and obtain the appropriate approvals; for other heavy equipment fueling operations use a slip-tank not greater than 250 gallons; prepare spill containment and cleanup provisions for maintenance operations. ● Where feasible, access work sites only on existing roads, and limit all travel on roads when damage to the road surface will result or is occurring. ● Refer to the herbicide label when planning revegetation to ensure that subsequent vegetation would not be injured following application of the herbicide. ● Use weed-free feed for horses and pack animals. Use weed-free straw and mulch for revegetation and other activities. ● Clean all vehicles and equipment prior to entering the area, to minimize the introduction of undesirable and/or invasive plant species. ● Take into account the different types of application equipment and methods, where possible, to reduce the probability of contaminating non-target food and water sources for wildlife, livestock and wild horses. ● Contain and clean up spills and request help as needed. ● Secure containers during transport. ● Dispose of unwanted herbicides promptly and correctly.
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Resource Treatment Protection Measures Authority/ Type Source
Herbicide ● Minimize treatments in areas where herbicide runoff is likely, such as steep BLM Manual 7000 (Soil, Soils slopes when heavy rainfall is expected. treatments Water, and Air ● Minimize use of herbicides that have high soil mobility, particularly in areas Management); BLM where soil properties increase the potential for mobility. 2007 PEIS; BLM 2016 ● Do not apply granular herbicides on slopes of more than 15% where there is the PEIS. possibility of runoff carrying the granules into non-target areas. Herbicide ● Consider climate, soil type, slope, and vegetation type when developing BLM manual 7000 (Soil, Surface Water herbicide treatment programs. Quality treatments Water, and Air ● Select herbicide products to minimize impacts to water. This is especially Management); BLM important for application scenarios that involve risk from active ingredients in a 2007 PEIS; BLM 2016 particular herbicide, as predicted by risk assessments. PEIS. ● Conduct mixing and loading operations in an area where an accidental spill would not contaminate an aquatic body. ● Do not rinse spray tanks in or near water bodies. Do not broadcast pellets where there is danger of contaminating water supplies. ● Maintain buffers between treatment areas and water bodies. Buffer widths should be developed based on herbicide- and site-specific criteria to minimize impacts to water bodies. ● Minimize the potential effects to surface water quality and quantity by stabilizing terrestrial areas as quickly as possible following treatment. Herbicide ● Select proper application equipment (e.g., spray equipment that produces 200- to BLM Manual 7000 (Soil, Air Quality 800-micron diameter droplets [spray droplets of 100 microns and less are most treatments Water, and Air prone to drift]). Management) BLM 2007 ● Select proper application methods (e.g., set maximum spray heights, use PEIS; BLM 2016 PEIS. appropriate buffer distances between spray sites and non-target resources). Wetlands and Herbicide ● Use a selective herbicide and a wick or backpack sprayer BLM 2007 PEIS; BLM ● Use appropriate herbicide-free buffer zones for herbicides not labeled for aquatic 2016 PEIS. Riparian Areas Treatments use based on risk assessment guidance, with minimum widths of 100 feet for aerial, 25 feet for vehicle, and 10 feet for hand spray applications. Use a selective herbicide and a wick or backpack sprayer
See Figure D1 and Table D1 for details of riparian and wetland zones
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Resource Treatment Protection Measures Authority/ Type Source
Vegetation Herbicide ● Establish appropriate (herbicide-specific) buffer zones (see Tables 4-12 and 4- BLM Handbook H-4410- Treatments 14 in the 2007 PEIS) around downstream water bodies, habitats, and 1 (National Range species/populations of interest. Consult the ecological risk assessments (ERAs) Handbook), and manuals prepared for the PEIS for more specific information on appropriate buffer 5000 (Forest distances under different soil, moisture, vegetation, and application scenarios. Management) and 9015 (Integrated Weed Management); BLM 2007 PEIS; BLM 2016 PEIS.
Pollinators Herbicide ● When feasible, complete vegetation treatments seasonally before pollinator Fish and Other Aquatic Treatments foraging plants bloom. Organisms ● When feasible, time vegetation treatments to take place when foraging See manuals 6500 pollinators are least active both seasonally and daily. (Wildlife and Fisheries ● Design vegetation treatment projects so that nectar and pollen sources for Management) and 6780 important pollinators and resources are treated in patches rather than in one (Habitat Management single treatment. Plans); BLM 2007 PEIS; ● Minimize herbicide application rates. Use typical rather than maximum BLM 2016 PEIS. application rates where there are important pollinator resources. ● Maintain herbicide free buffer zones around patches of important pollinator nectar and pollen sources and nesting habitat and hibernacula. ● Make special note of pollinators that have single host plant species, and minimize herbicide spraying on those plants (if invasive species) and in their habitats. Wildlife Herbicide ● Use herbicides of low toxicity to wildlife, where feasible. BLM 2007 PEIS; BLM Treatments ● Use spot applications or low-boom broadcast operations where possible to limit 2016 PEIS. General the probability of contaminating non-target food and water sources, especially non-target vegetation over areas larger than the treatment area. ● Use timing restrictions (e.g., do not treat during critical wildlife breeding or staging periods) to minimize impacts to wildlife. ● Use appropriate buffer zones (see Table 4-12 and 4-14 in Chapter 4 of the 2007 PEIS) to limit contamination of off-site vegetation, which may serve as forage for wildlife.
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Resource Treatment Protection Measures Authority/ Type Source
Special Status Herbicide ● Survey for special status species before treating an area. Consider effects to Treatments special status species when designing herbicide treatment programs. BLM Manual 6840 Species General ● Avoid treating vegetation during time-sensitive periods (e.g., nesting and (Special Status Species); migration, sensitive life stages) for special status species in area to be treated. BLM 2007 PEIS; BLM ● Implement all conservation measures for special status plant and animal species 2016 PEIS. presented in the 2007 and 2016 PEIS BAs. Fish and Site Access for all ● Where threatened/endangered/proposed aquatic species occur, consider ground- BLM 2007 PEIS; BLM treatment methods disturbing activities on a case by case basis, and implement SOPs to ensure 2016 PEIS. Aquatic species minimal erosion or impact to the aquatic habitat. Bull Trout and Redband Trout
Wild Horses Herbicide ● Minimize using herbicides in areas grazed by wild horses and burros. BLM Handbook H-4120- and Burros Treatments ● Use herbicides of low toxicity to wild horses and burros, where feasible. 1 (Grazing ● Remove wild horses and burros from identified treatment areas prior to herbicide Management); BLM application, in accordance with herbicide product label directions for livestock. 2007 PEIS; BLM 2016 ● Minimize potential risks to wild horses by applying glyphosate, hexazinone, and PEIS. tebuthiuron at the minimum application rate, where feasible, in areas associated with wild horse use. ● Minimize the treatment area to the extent necessary to meet objectives when making applications of 2,4-D, dicamba, Overdrive®, and picloram in order to reduce potential impacts to wild horses. ● Apply herbicide label grazing restrictions for livestock to herbicide treatment areas that support populations of wild horses. ● Do not apply 2,4-D in the HMA during the peak foaling season (March through June, and especially in May and June). Native Herbicide ● Consult with tribes to locate any areas of vegetation that are of significance to BLM 2007 PEIS; BLM Treatments the tribe and that might be affected by herbicide treatments. 2016 PEIS. American ● Work with tribes to minimize impacts to these resources. Traditional ● Follow guidance under Human Health and Safety in the PEIS in areas that may Uses be visited by Native peoples after treatments. ● Do not exceed the typical application rate when applying 2,4-D, hexazinone, and tebuthiuron in known traditional use areas.
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Resource Treatment Protection Measures Authority/ Type Source ● Avoid applying tebuthiuron aerially in known traditional use areas. Human Health Herbicide ● Establish a buffer between treatment areas and human residences based on BLM Manual 8120; guidance given in the HHRA, with a minimum buffer of ¼ mile for aerial and Safety Treatments BLM Handbook H-8120- applications and 100 feet for ground applications, unless a written waiver is 1; BLM 2007 PEIS; granted. BLM 2016 PEIS. ● Use protective equipment as directed by the herbicide product label. ● Use the typical application rate, where feasible, when applying 2,4-D, hexazinone, and tebuthiuron to reduce risk to occupational and public receptors. ● Do not apply hexazinone with an over-the-shoulder broadcast applicator. Wilderness Herbicide ● Encourage backcountry pack and saddle stock users to feed their livestock only BLM 2007 PEIS; BLM Treatments weed-free feed for several days before entering a wilderness area. 2016 PEIS. Areas ● Encourage stock users to tie and/or hold stock in such a way as to minimize soil disturbance and loss of native vegetation. ● Re-vegetate disturbed sites with native species if there is no reasonable expectation of natural regeneration. ● Provide educational materials at trailheads and other wilderness entry points to educate the public on the need to prevent the spread of weeds. ● Use the “minimum tool” to treat noxious and invasive vegetation, relying primarily on the use of ground-based tools, including backpack pumps, hand sprayers, and pumps mounted on pack and saddle stock. ● Use chemicals only when they are the minimum method necessary to control weeds that are spreading within the wilderness or threaten lands outside the wilderness. ● Give preference to herbicides that have the least impact on non-target species and the wilderness environment. ● Implement herbicide treatments during periods of low human use, where feasible. ● The use of motorized or mechanized vehicles and equipment will be evaluated through a Minimum Requirements Analysis (MRA) for the purpose of protecting and preserving wilderness character. The MRA will determine whether the proposal is consistent and compatible with requirements of the Wilderness Act, the OPLMA, House Report 101-405.
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Resource Treatment Protection Measures Authority/ Type Source
All Treatments ● Vegetation treatment activities within Wilderness and Wild and Scenic River BLM Handbook H-8560- Wilderness corridors would be applied following the management considerations and Areas 1 (Management of vegetation treatment guidelines approved in the final DR of the Owyhee Designated Wilderness WSAs Canyonlands Wilderness and Wild and Scenic Rivers MP and EA (DOI-BLM- Study Areas); BLM 2007 ID-B000-2011-0001-EA), signed April 10, 2015. PEIS; BLM 2016 PEIS.
Herbicide ● Encourage backcountry pack and saddle stock users to feed their livestock only Treatments weed-free feed for several days before entering a wilderness area. ● Encourage stock users to tie and/or hold stock in such a way as to minimize soil disturbance and loss of native vegetation. ● Re-vegetate disturbed sites with native species if there is no reasonable expectation of natural regeneration. ● Provide educational materials at trailheads and other wilderness entry points to educate the public on the need to prevent the spread of weeds. ● Use the “minimum tool” to treat noxious and invasive vegetation, relying primarily on the use of ground-based tools, including backpack pumps, hand sprayers, and pumps mounted on pack and saddle stock. ● Use chemicals only when they are the minimum method necessary to control weeds that are spreading within the wilderness or threaten lands outside the wilderness. ● Give preference to herbicides that have the least impact on non-target species and the wilderness environment. ● Implement herbicide treatments during periods of low human use, where feasible. ● Address wilderness and special areas in management plans. WSAs All Treatments ● Vegetation treatments in wilderness study areas (WSAs) would be designed BLM Handbook H 8550- consistent with BLM Manual 6330–Management of Wilderness Study Areas 1 (Management of Wild and Scenic (BLM, 2012). Wilderness Study Areas Rivers (WSAs); BLM 2007 PEIS; BLM 2016 PEIS.
Herbicide ● Maintain adequate buffers for aerial treatments near Wild and Scenic Rivers (¼ Treatments mile on either side of river).
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Resource Treatment Protection Measures Authority/ Type Source
All Treatments ● Vegetation treatment activities within Wilderness and Wild and Scenic River BLM Manual 8351 (Wild Wild and Scenic corridors would be applied following the management considerations and Rivers and Scenic Rivers); BLM vegetation treatment guidelines approved in the final DR of the Owyhee 2007 PEIS; BLM 2016 National Canyonlands Wilderness and Wild and Scenic Rivers MP and EA (DOI-BLM- PEIS. ID-B000-2011-0001-EA), signed April 10, 2015. Historic Trails
All Treatments ● Use different ingress and egress routes when using off-road vehicles for BLM Manual 8100 (The Travel and treatment application (e.g. spraying noxious weeds) or transporting supplies (e.g. Transportation Foundations for shrub seedlings for large planting projects) to avoid route creation. Managing Cultural Management ● Utilize hardened or previously disturbed areas for staging equipment. Resources); Programmatic Agreement among the Bureau of Land Management, the Advisory Council on Historic Preservation, and the National Conference of State Historic Preservation Officers Regarding the Manner in Which BLM Will Meet Its Responsibilities Under the National Historic Preservation Act; BLM 2007 PEIS; BLM 2016 PEIS.
Recreation Herbicide ● Schedule treatments to avoid peak recreational use times, while taking into BLM Manual 8270 Treatments account the optimum management period for the targeted species. (Paleontological ● Notify the public of treatment methods, hazards, times, and nearby alternative Resource Management); recreation areas. BLM Handbook H- 8270-1 (General Procedural Guidance for Paleontological Resource Management); BLM
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Resource Treatment Protection Measures Authority/ Type Source 2007 PEIS; BLM 2016 PEIS.
Social and Herbicide ● When proposing aerial application, notify the public of the project to improve BLM Handbook H-1601- coordination and avoid potential conflicts and safety concerns during Economic Treatments 1 (Land Use Planning implementation of the treatment. Handbook, Appendix C); Values ● To the degree possible within the law, hire local contractors and workers to assist BLM 2007 PEIS; BLM with herbicide application projects and purchase materials and supplies, 2016 PEIS. including chemicals, for herbicide treatment projects through local suppliers. ● To minimize fears based on lack of information, provide public educational information on the need for vegetation treatments and the use of herbicides in an integrated pest management program for projects proposing local use of herbicides. Rights-of-way Herbicide ● Coordinate vegetation management activities where joint or multiple use of a BLM 2007 PEIS; BLM Treatments ROW exists. 2016 PEIS. ● Notify other public land users within or adjacent to the ROW proposed for treatment.
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Appendix C - Three Newly Approved Herbicides for Use on BLM Lands The following tables list the three newly approved herbicides that may be used on BLM lands in Idaho at this time, and their general affects to vegetation. The BLM would also be able to use new active ingredients that are developed in the future if: 1) they are registered by the EPA for use on one or more land types (e.g., rangeland, aquatic, etc.) managed by the BLM; 2) the BLM determines that the benefits of use on public lands outweigh the risks to human health and the environment; and 3) they meet evaluation criteria to ensure that the decision to use the active ingredient is supported by scientific evaluation and NEPA documentation. The BLM maintains a BLM approved herbicide list that is updated annually. To see most current list of herbicides, formulations and manufacturers contact the BLM. Registered Aerial Ground Active Ingredient Trade Names Application Application General Effects to Target Vegetation Aminopyralid Milestone, Yes Yes Aminopyralid is a post emergence, selective herbicide that is Milestone VM used to manage invasive annual, biennial, and perennial species. It is a plant growth regulator that binds to receptor sites normally used by the plant’s natural growth hormones, causing death of the plant.
The BLM has identified this herbicide for its activity on difficult-to-control species in rangelands, among other uses. It is an alternative to other growth regulator herbicides that are commonly used on broadleaf weeds, such as picloram, clopyralid, 2,4-D, and dicamba Species targeted include: Knapweeds, yellow starthistle, thistles, and rush skeletonweed Aminopyralid + Grazon Next, Yes Yes See Aminopyralid and 2,4-D for effects of these chemicals. 2,4-D ForeFront HL, ForeFront R&P Aminopyralid + Opensight Yes Yes See Aminopyralid and Metsulfuron Methyl for effects of these Metsulfuron chemicals. Methyl
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Registered Aerial Ground Active Ingredient Trade Names Application Application General Effects to Target Vegetation Aminopyralid + Milestone VM Yes Yes See Aminopyralid and Triclopyr for effects of these chemicals. Triclopyr Plus Chlorsulfuron Telar DF; Yes Yes An ALS‐inhibitor (acetolactate synthase herbicides inhibit Alligare growth) that is especially effective on broadleaf plants such as Chlorsulfuron; whitetop, perennial pepperweed, Mediterranean sage, and thistles. It is often mixed with 2,4‐D to reduce the likelihood of developing plant resistance and to deter seed production.
Areas where registered use is appropriate include rangelands, ROW, recreation and cultural resources, and oil, gas and minerals Clopyralid Reclaim; Yes Yes Clopyralid is a selective herbicide most effectively used post- Stinger; emergence for the control of broadleaf weeds. Clopyralid is a Transline; plant growth regulator that is rapidly absorbed across leaf Spur; Pyramid surfaces, and acts as a synthetic auxin hormone, causing a R&P; proliferation of abnormal growth that interferes with the Clopyralid 3; transport of nutrients, which can then result in substantial Cody damage to the plant, or death. Herbicide; Clopyralid targets many of the same species as picloram, but is CleanSlate more selective. It is particularly effective on knapweeds and Canada thistle, while minimizing risk to surrounding desirable brush, grass, and trees. Areas where registered use is appropriate include rangelands, forestlands, ROW, recreation and cultural resources, and oil, gas and minerals Clopyralid + 2,4-D Curtail; Yes yes See 2,4-D and clopyralid for effects of these chemicals. Commando; Cutback; Cody Herbicide
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Registered Aerial Ground Active Ingredient Trade Names Application Application General Effects to Target Vegetation 2,4-D HardBall; Yes Yes 2,4-D is a plant growth regulator and acts as a synthetic auxin Unison; Clean hormone. 2,4‐D is effective on a wide range of broadleaf Amine; Low invasive plants while not affecting most grasses. 2,4‐D can help Vol 6 Ester inhibit seed production, prevent herbicide resistance, and Weed Killer; effectively treat multiple invasive plant species when a variety Saber; Salvo; are encountered in a particular treatment area. Savage DS; Aqua-Kleen; In addition, adding a small amount of 2,4‐D to a tank mix can Esteron 99C; often improve the effectiveness of the other herbicides and Weedar 64; reduce the likelihood of a population developing herbicide Weedone LV- resistance. The amount of 2,4‐D used in combination with other 4; Weedone herbicides would vary based on these factors. LV-4 Dicamba Dicamba Yes Yes A growth-regulating herbicide readily absorbed and DMA; Vision; translocated from either roots or foliage. This herbicide Cruise produces effects similar to those found with 2,4-D. Used Control; primarily for control of knapweeds, thistles, and whitetop. Banvel; Clarity; Rifle; Diablo; Vanquish Herbicide; Vanquish; Sterling Blue; Kam-Ba Dicamba + 2,4-D Range Star; Yes Yes See Dicamba and 2,4-D for effects of these chemicals. Weedmaster; Brush-Rhap; Latigo; Rifle- D;
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Registered Aerial Ground Active Ingredient Trade Names Application Application General Effects to Target Vegetation KambaMaster; Veteran 720; Brash; Outlaw; Dicamba + 2,4-D DMA Fluroxypyr Comet, Yes Yes Fluroxypyr is a selective, post-emergent herbicide that is used Fluroxypyr to manage broadleaf species in rangelands and other areas and Herbicide, disrupts plant cell growth by inducing auxin-like responses. It Vista, Vista is often used in industrial sites, along roads and railroads, and XRT along ROWs. Fluroxypyr would be used at locations where complete removal of vegetation is desired. In these situations, non-target plants would not be present within the treatment area. Fluroxypyr + Truslate Yes yes See Fluroxypyr and Clopyralid for effects of these chemicals. Clopyralid Fluroxypyr + Surmount, Yes yes See Fluroxypyr and Picloram for effects of these chemicals. Picloram Trooper Pro Fluroxypyr + PastureGard, Yes Yes See Fluroxypyr and Triclopyr for effects of these chemicals. Triclopyr PastureGard HL Glyphosate Aqua Star; Gly Yes Yes Glyphosate is a non-selective systemic herbicide that can Star Plus; damage all groups or families of non-target plants to varying Rodeo; degrees. Glyphosate inhibits the production of aromatic amino Showdown; acids and certain phenolic compounds. This leads to a variety Mirage Plus; of toxic effects in plants, including the inhibition of Aquamaster; photosynthesis, respiration, and nucleic acid synthesis, thereby Honcho Plus; resulting in cellular disruption, decreased growth, and death at Roundup sufficiently high levels of exposure. PROMAX;
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Registered Aerial Ground Active Ingredient Trade Names Application Application General Effects to Target Vegetation Rattler; Because of its non-selective nature, glyphosate may be highly Buccaneer effective in spot applications or in areas where a variety of Plus; Mirage invasive species dominate and where very few non-target plants Herbicide; exist. Glyphosate is best used in areas where bare ground is Mirage Plus desired (e.g., around fences and structures); however, it has low Herbicide; residual activity, so it would not be effective for an extended Agrisolutions period of time. Glyphosate may also be used in riparian and Rascal Plus; aquatic habitats on shoreline and floating-leaved species such KleenUp Pro; as purple loosestrife, phragmites, and yellow flag iris. Mad Dog Plus; Roundup Custom Glyphosate + 2,4- Landmaster Yes Yes See 2,4-D and glyphosate for effects of these chemicals. D BW; Campaign; Imitator Plus D Hexazinone Velpar ULW; Yes Yes Hexazinone is an “s-triazine” herbicide that inhibits Velpar L; photosynthesis and the synthesis of RNA, proteins, and lipids. Velpar DF; Although some foliar absorption may occur, the major route of Velossa; exposure involves hexazinone moving from the soil surface to Pronone MG; the root system of plants, where, in most species, it is readily Pronone 10G; absorbed and translocated throughout the plant. The differential Pronone 25G; toxicity of hexazinone to plants is based on variations in the Pronone Power ability of different plants to absorb, degrade, and eliminate the Pellet; Velpar herbicide. DF VU; A foliar-or soil-applied herbicide with soil activity. It is used Velpar L VU for broadleaf weed, brush, and grass control in non-cropland, ROWs and adjacent to facilities. Imazapic Plateau; Yes Yes This is a selective, systemic herbicide that can be applied both Panoramic pre-emergence and post-emergence for the management of
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Registered Aerial Ground Active Ingredient Trade Names Application Application General Effects to Target Vegetation 2SL; Nufarm selective broadleaf and grassy plant species. Its mode of action Imazapic 2SL is associated with the synthesis of branch-chained amino acids. Imazapic, an ALS-inhibitor, is a selective, systemic herbicide used on annual and perennial broadleaf weeds and grasses. Due to its activity, imazapic may be highly effective, particularly in spot applications, at controlling aggressive invasive species that have not responded to other herbicides or treatment methods. Imazapic is used on leafy spurge, white top and perennial pepperweed. Imazapic + Journey Yes Yes See imazapic and glyphosate for effects of these chemicals. Glyphosate Imazapyr Imazapyr 2 Yes Yes Imazapyr is an ALS-inhibiting herbicide used in the control of SL; Arsenal a variety of grasses, broadleaf weeds, vines, and brush species. Railroad Although post-emergence application is more effective than Herbicide; pre-emergence application, toxicity can be induced either Chopper; through foliar or root absorption. Due to its activity, imazapyr Arsenal may be highly effective in controlling aggressive invasive Applicators species that have not responded to other herbicides or treatment Conc.; Stalker; methods. The strength of this herbicide is in the management of Habitat; saltcedar in riparian zones. In addition, imazapyr may also be Polaris; SSI used in riparian and aquatic habitats on shoreline and floating- Maxim Rotary leaved species such as purple loosestrife, phragmites, and 2 SL yellow flag iris. Imazapyr + Mojave 70 EG; Yes Yes See imazapyr and diuron for effects of these chemicals. Diuron Sahara DG; Imazuron E- Pro; SSI Maxim Topsite 2.5G
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Registered Aerial Ground Active Ingredient Trade Names Application Application General Effects to Target Vegetation Imazapyr + Lineage Yes Yes See imazapyr and metsulfuron methyl for effects of these Metsulfuron Clearstand chemicals. methyl Metsulfuron MSM 60; Yes Yes Metsulfuron methyl is a selective ALS-inhibiting herbicide methyl AmTide MSM used pre- and post-emergence in the control of many annual 60DF and perennial weeds and woody plants. Due to its potency, Herbicide; metsulfuron methyl may be highly effective in controlling Escort DF; aggressive invasive species that have not responded to other Escort XP; herbicides or treatment methods. Metsulfuron methyl can be used for the management of wildlife habitat and for the control of invasive plant species such as hoary cress, perennial pepperweed, biennial thistles (musk, and Scotch), and yellow starthistle. Metsulfuron methyl is a selective herbicide used pre- and post- emergence in the control of many annual and perennial weeds and woody plants. Metsulfuron Cimarron X- Yes Yes See metsulfuron methyl and chlorsulfuron for effects of these methyl + tra; Cimarron chemicals. Chlorsulfuron Plus Metsulfuron Cimarron Yes Yes See metsulfuron methyl, dicamba, and 2,4-D for effects of these methyl + Dicamba MAX chemicals. + 2,4-D Picloram Triumph K; Yes Yes Picloram is a pyridine herbicide that acts as a plant growth Triumph 22K; regulator. It mimics naturally occurring plant auxins or Picloram K; hormones in a manner that leads to uncontrolled and abnormal Picloram 22K; growth that can in turn lead to gross signs of toxicity or death Grazon PC; (SERA 2003b). Picloram is more toxic to broadleaf and woody OutPost 22K; plants than grains or grasses (Extension Toxicology Network Tordon K; 1996c, SERA 2003b). Picloram is effective on knapweeds,
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Registered Aerial Ground Active Ingredient Trade Names Application Application General Effects to Target Vegetation Tordon 22K; toadflax, Mediterranean sage, rush skeletonweed, leafy spurge, Trooper 22K and thistles, and provides good residual control.
Picloram is more toxic to broadleaf and woody plants than grains or grasses. Picloram + 2,4-D Graslan L; Yes Yes See Picloram, and 2,4-D for effects of these chemicals. GunSlinger; Picloram + D; Tordon 101 M; Tordon 101 R Forestry; Tordon RTU; Grazon P+D; HiredHand P+D; Pathway; Trooper 101; Trooper P + D Picloram + 2,4-D Trooper Extra Yes Yes See Picloram, 2,4-D and dicamba for effects of these + Dicamba chemicals. Rimsulfuron Matrix, Matrix Yes Yes Rimsulfuron is a selective, ALS-inhibiting herbicide that SG, Matrix controls target weeds by inhibiting the biosynthesis of certain FNV amino acids. It is applied both pre- and post-emergence, and is active in both the xylem and the phloem of the plant. Invasive plants targeted by this active ingredient include cheatgrass, medusahead rye, and other annual grasses that have invaded public lands in the western U.S. Tebuthiuron Alligare Yes Yes Tebuthiuron is a relatively non-selective herbicide absorbed by Tebuthiuron plant roots through the soil for use against broadleaved and 80 WG; woody weeds and grasses. Tebuthiuron disrupts photosynthesis
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Registered Aerial Ground Active Ingredient Trade Names Application Application General Effects to Target Vegetation Alligare by blocking electron transport and the transfer of light energy. Tebuthiuron Because of its non-selectivity, tebuthiuron should be used in 20 P; SpraKil areas dominated by invasive species, particularly woody S-5 Granules invasives, such as in rangelands or ROWs invaded by shrubs, trees, and other undesirable species. A soil-applied herbicide used for control of woody plants and vegetation. Tebuthiuron has a two to four year residual on dry sites depending on application rates. Triclopyr Garlon 3A; Yes Yes Triclopyr is a selective, systemic herbicide used on broadleaf Garlon 4; and woody species. Triclopyr mimics auxin, a plant growth Garlon 4 Ultra; hormone, thus disrupting the normal growth and viability of Remedy; plants. Triclopyr could be used to manage woody riparian and Remedy Ultra: aquatic species of interest, including saltcedar, broadleaf weeds Pathfinder II; and thistles. It is effective in riparian areas as a treatment for Tahoe 3A; purple loosestrife because it does not damage native grasses Tahoe 4E; and sedges. Tahoe 4E A growth-regulating herbicide for control of woody and Herbicide; broadleaf perennial weeds in non-cropland, forest lands, and lawns. Triclopyr + 2,4-D Everett; Yes Yes See triclopyr and 2,4-D for effects of these chemicals. Crossbow; Aquasweep; Candor Triclopyr + Prescott Yes Yes See triclopyr and clopyralid for effects of these chemicals. Clopyralid Herbicide; Redeem R&P; Brazen
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Appendix D - Definitions for terms used in the slickspot peppergrass analysis Element Occurrence (EO): Area where a species or community is, or was, present (NatureServe 2002). EOs are typically represented by mapped areas of land and/or water, and are usually created for native species or communities of conservation interest based on current or historically known occurrences, though they may also be created for extirpated occurrences. EOs are defined primarily to aid in conservation of the species or community represented (NatureServe 2002).
Habitat Integrity and Population (HIP) Monitoring: A monitoring protocol developed by Idaho Fish and Game’s Natural Heritage Program, and approved by the Service and Bureau, to study trends and conditions of slickspot peppergrass plants and associated habitat. HIP monitoring provides the bulk of the available information used for management decisions involving slickspot peppergrass.
Potential Habitat: Areas within the known range of slickspot peppergrass that have certain general soil and elevation characteristics that indicate the potential for the area to support slickspot peppergrass, although the presence of slickspots or the plant is unknown. These areas meet the following criteria: ● Natric and natric-like soils forming “slickspots,” and associated soil series, or phases thereof, which support loamy 7-13-inch Wyoming big sagebrush Ecological Sites (Major Land Resource Areas 11—Snake River Plains and 25—Owyhee High Plateau) ● an aridic bordering on xeric soil moisture regime ● 2,200 to 5,400 feet elevation. Proposed Critical Habitat (PCH): A specific geographic area which contains the physical or biological features essential to the conservation of an endangered or threatened species that may require special management and/or protection. Proposed Critical Habitat is different from designated Critical Habitat (formally designated/finalized) in that is has not been through public review and economic analysis. Federal agencies conference with the Service when Critical Habitat is proposed and consult with the Service when formally designated/finalized.
Occupied Habitat: (EO plus 0.5-mile buffer) An EO (area occupied by slickspot peppergrass) plus the area encompassing a 0.5-mile buffer around it. Occupied Habitats are important to maintain or improve habitat integrity and pollinator populations necessary for species conservation. This area identified as occupied habitat may or may not include additional slickspots or slickspot peppergrass plants beyond the EO. Further refinement of Occupied Habitat may be accomplished through field surveys considering existing resource conditions as well as specific habitat quality and integrity.
Slickspot Peppergrass Habitat: Areas with Wyoming big sagebrush ecological site conditions that, through Stage 1 surveys, have documented slickspot microsites (natric and natric-like soil
Boise District Noxious Weed and Invasive Plant Management EA-BA Page - 120 types) between 2,200 feet and 5,400 feet elevation in southwest Idaho. Slickspot Peppergrass Habitat includes areas with slickspots of unknown occupancy, and in some cases may be dominated by non-native vegetation such as annual grasses or crested wheatgrass. In addition, to maintain ecological continuity, if there is less than 0.5 miles between areas defined as Slickspot Peppergrass Habitat, the entire area is considered Slickspot Peppergrass Habitat. Surveyed potential habitat not meeting these criteria is considered non-habitat for slickspot peppergrass.
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Appendix E - Summary of Effects Tables Table E-1: Summary of Effects and Determinations for Noxious Weed and Invasive Plant Treatments: Bruneau hot springsnail
Potential Direct and Conservation Measures Indirect Effects to Potential Effects Rationale for the for Avoiding or Treatment Method Bruneau hot Cumulative Determination by Effects Reducing Adverse springsnail and its Effects Treatment Method Determination Effects Habitat
Ground Based See Design Features and Conservation Measures for Aquatic Species (Chapter 2). Herbicide Treatments: Including Adjuvants, Surfactants, Accidental spills, and Herbicide runoff
Herbicide treatments in Potential for localized, Potential for Apply the design features, NLAA – Short-term Treatments using RCAs in upland short-term indirect cumulative effects conservation measures, BE-Long-term upland herbicides in vegetation types using effects to hydric to water quality or prevention measures, occupied RCAs may
upland herbicides (spot vegetation in occupied hydric vegetation herbicide application have indirect effects to treatment, hand method RCAs due to herbicide from similar on- criteria, and SOPs for hydric vegetation due to only) drift. Design features going and future Special Status Species to all herbicide drift that are and conservation treatments, or a treatments (BA Chapter 2; insignificant and measures would reduce lack of treatment, Appendix B). discountable. potential effects to on State and/or Treatments would Upland herbicides would not insignificant and private land. benefit Bruneau hot be broadcast sprayed in discountable. Measures to reduce springsnail and its RCAs; No spraying of Treatments would potential effects to habitat in the long-term herbicides would occur benefit Bruneau hot Bruneau hot by removing noxious within 15 feet of geothermal springsnail and its springsnail may or weeds and invasive springs in the Recovery habitat in the long-term may not be applied plants from occupied Area. by removing noxious on State or private RCAs. weeds and invasive land. plants from occupied RCAs.
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Potential Direct and Conservation Measures Indirect Effects to Potential Effects Rationale for the for Avoiding or Treatment Method Bruneau hot Cumulative Determination by Effects Reducing Adverse springsnail and its Effects Treatment Method Determination Effects Habitat
Herbicide treatments in Potential for localized, Potential for Apply the design features, NLAA – Short-term Design features and RCAs using low boom short-term direct and cumulative effects conservation measures, BE-Long-term conservation measures methods to within 50 indirect effects to to water quality or prevention measures, would reduce the feet of hydric hydric vegetation or hydric vegetation herbicide application potential for direct and vegetation using water quality due to from similar on- criteria, and SOPs for indirect effects to riparian herbicides herbicide drift. Design going and future Special Status Species to all hydric vegetation and features and treatments, or a treatments (BA Chapter 2; water quality to conservation measures lack of treatment, Appendix B). insignificant, but would reduce potential on State and/or potential effects may Herbicide treatments using effects to insignificant private land. not be discountable. high boom methods would but may not be Measures to reduce Treatments would not be used within 50 feet of discountable. potential effects to benefit Bruneau hot hydric vegetation. Only Treatments would Bruneau hot springsnail and its aquatic approved herbicides benefit Bruneau hot springsnail may or habitat in the long-term would be used. springsnail and its may not be applied by removing noxious habitat in the long-term on State or private weeds and invasive by removing noxious land. plants from occupied weeds and invasive RCAs. plants from occupied RCAs.
Herbicide treatments in Potential for localized, Potential for Apply the design features, NLAA – Short-term Design features and RCAs using hand short-term direct and cumulative effects conservation measures, BE-Long-term conservation measures methods (spot spray or indirect effects to to water quality or prevention measures, would reduce the
direct application) to hydric vegetation or hydric vegetation herbicide application potential for direct and within 15 feet from water quality due to from similar on- criteria, and SOPs for indirect effects to occupied waters using accidental direct going and future Special Status Species to all hydric vegetation and riparian herbicides exposure or herbicide treatments, or a treatments (BA Chapter 2; water quality to drift (indirect). Design lack of treatment, Appendix B). insignificant, but features and on State and/or potential effects may Herbicides would not be conservation measures private land. not be discountable. broadcast sprayed within 50 would reduce the Measures to reduce Treatments would feet of areas with hydric potential for effects to potential effects to benefit Bruneau hot
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Potential Direct and Conservation Measures Indirect Effects to Potential Effects Rationale for the for Avoiding or Treatment Method Bruneau hot Cumulative Determination by Effects Reducing Adverse springsnail and its Effects Treatment Method Determination Effects Habitat insignificant but may Bruneau hot vegetation. Spot application springsnail and its not be discountable. springsnail may or may occur. Only aquatic habitat in the long-term Treatments would may not be applied approved herbicides would by removing noxious benefit Bruneau hot on State or private be used. weeds and invasive springsnail and its land. plants from occupied habitat in the long-term RCAs. by removing noxious weeds and invasive plants from occupied RCAs.
Herbicide treatments in Potential for localized, Potential for Apply the design features, NLAA – Short-term Design features and RCAs using hand short-term direct and cumulative effects conservation measures, BE-Long-term conservation measures methods only (direct indirect effects to to water quality or prevention measures, would reduce the application, no hydric vegetation or hydric vegetation herbicide application potential for direct and spraying) within 15 feet water quality due to from similar on- criteria, and SOPs for indirect effects to of occupied geothermal accidental direct going and future Special Status Species to all hydric vegetation and springs using riparian exposure. Design treatments, or a treatments (BA Chapter 2; water quality to herbicides only (no features and lack or treatment, Appendix B). insignificant, but adjuvants or conservation measures on State and/or potential effects may Herbicide treatments in surfactants) would reduce potential private land. not be discountable. RCAs within 15 feet of effects to insignificant Measures to reduce Treatments would occupied geothermal springs but may not be potential effects to benefit Bruneau hot would use direct application discountable. Bruneau hot springsnail and its (no spraying) and riparian Treatments would springsnail may or habitat in the long-term herbicides only (no benefit Bruneau hot may not be applied by removing noxious adjuvants or surfactants). springsnail and its on State or private weeds and invasive habitat in the long-term land. plants from occupied by removing noxious RCAs. weeds and invasive plants from occupied RCAs.
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Table E-2: Summary of Effects and Determinations for Noxious Weed and Invasive Plant Treatments: Slickspot Peppergrass
Potential Direct and Potential Design Features for Effects Rationale for the Indirect Effects to Treatment Method Cumulative Avoiding or Reducing Determination for Effects Slickspot Effects Adverse Effects Treatment Method Determination Peppergrass
Herbicide Treatments Damage or death of Non-Federal lands Conservation measures NLAA – Short-term Design Features in slickspot peppergrass are less likely than include education of weed BE – Short- and long- combination with SOP On-going Spot plants could occur due Federal to be treatment personnel term and small treatment to accidental direct treated for noxious regarding slickspot scale, are expected to spray or drift. Control weed and invasive peppergrass identification make the potential for or containment of plant control and and methods that avoid drift. accidental direct spray noxious weeds and restoration. These or drift discountable. invasive plants due to areas could be seed Reduced competition to on-going spot sources for noxious slickspot peppergrass treatments in and weeds and invasive and other native plants, adjacent to occupied plants that could including those that and potential habitats spread to adjacent support pollinator would reduce Federal lands, species, from noxious competition to slickspot increasing the need weeds and invasive peppergrass and other for continued on- plants would result in native vegetation, going treatments. short- and long-term including plants that Herbicides used on beneficial effects to support pollinator non-Federal lands slickspot peppergrass. species. Spot treatments might not be could also reduce the limited to the active density of noxious ingredients weeds and/or invasive currently approved plants in slickspot by the BLM. In microsites and the addition, design potential for sediment features, entrapment that could conservation modify slickspot measures, and other structure. use constraints contained in the proposed action may not be part of
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Potential Direct and Potential Design Features for Effects Rationale for the Indirect Effects to Treatment Method Cumulative Avoiding or Reducing Determination for Effects Slickspot Effects Adverse Effects Treatment Method Determination Peppergrass
treatments applied to non-Federal lands. Therefore, damage or destruction of slickspots, plants, or seedbanks could occur as a result of these actions.
Herbicide Treatments Ground-based herbicide Non-Federal lands Ground-based broadcast NLAA – Short-term Design Features in treatments could result are less likely than herbicide treatment up to 50 BE – Long-term combination with SOP Ground-based in damage or death to Federal to be acres would be used where and small treatment Broadcast plants and seed banks. treated for noxious noxious and invasive weeds scale, are expected to Implementation of weed and invasive are too dense and make the potential for conservation measures plant control and widespread for spot accidental direct spray (Chapter 2) and SOP restoration. These treatments. Therefore these or drift discountable. (Appendix B), areas could be seed treatments would occur in Reduced competition to including temporal and sources for noxious areas with low abundance of slickspot peppergrass spatial adjustments, weeds and invasive forbs and shrubs. These and other native plants, could result in short- plants that could treatments could result in including those that term adverse, but long- spread to adjacent damage or death to slickspot support pollinator term beneficial effects. Federal lands, peppergrass and/or its seed species, from noxious These beneficial effects increasing the need banks. Effects of ground- weeds and invasive would include reduced for larger-scale based broadcast herbicide plants would result in competition to slickspot treatments. treatment would be short- short- and long-term peppergrass and other Herbicides used on term and population-level beneficial effects to native plants from non-Federal lands effects are not anticipated slickspot peppergrass. noxious weeds and might not be when all design features are invasive plants. Control limited to the active incorporated into project or elimination of ingredients design. invasive plants that currently approved create fine fuels in and by the BLM. In Ground-based broadcast around slickspot addition, design herbicide treatment up to 50
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Potential Direct and Potential Design Features for Effects Rationale for the Indirect Effects to Treatment Method Cumulative Avoiding or Reducing Determination for Effects Slickspot Effects Adverse Effects Treatment Method Determination Peppergrass
peppergrass habitats features, acres could also affect non- would reduce the conservation target vegetation, including potential for wildfire measures, and other native forbs that support ignition and spread and use constraints pollinator insects. habitat degradation that contained in the Broadcast herbicide could occur post-fire. proposed action application would be used may not be part of primarily in areas dominated treatments applied by noxious weeds and to non-Federal invasive plants and therefore lands. Therefore, where native forb abundance damage or is low. Because these destruction of treatments would occur in slickspots, plants, areas with low abundance of or seedbanks could forbs and shrubs impacts occur as a result of would be insignificant. these actions.
Summary of Effects Treatments to reduce Non-Federal lands Apply all design features, NLAA - Short-term Design features and the occurrence and are less likely than conservation measures, BE - Long-term SOPs would be applied extent of noxious weeds Federal to be prevention measures, to all treatments for and invasive plants in treated for noxious herbicide application noxious weeds and slickspot peppergrass weed and invasive criteria, and SOPs (BA invasive plants. These occupied and potential plant control and Chapter 2; Appendix B). features are expected to habitat could have restoration. These reduce but not eliminate short-term adverse areas could be seed the potential for short- effects to slickspot sources for noxious term adverse effects to peppergrass or its weeds and invasive slickspot peppergrass. habitat. Over the long- plants that could Treatments may result term, slickspot spread to adjacent in unavoidable short- peppergrass and its Federal lands, term adverse effects. pollinators would increasing the need Removing noxious benefit from restoration for larger-scale weeds and invasive treatments. plants from slickspot Herbicides used on peppergrass habitats
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Potential Direct and Potential Design Features for Effects Rationale for the Indirect Effects to Treatment Method Cumulative Avoiding or Reducing Determination for Effects Slickspot Effects Adverse Effects Treatment Method Determination Peppergrass
of occupied and non-Federal lands and applying re- potential habitats. might not be vegetation treatments limited to the active would have long-term ingredients beneficial effects to currently approved slickspot peppergrass by the BLM. In and its pollinators. addition, design features, conservation measures, and other use constraints contained in the proposed action may not be part of treatments applied to non-Federal lands. Therefore, damage or destruction of slickspots, plants, or seedbanks could occur as a result of these actions.
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