Threat-Based Land Management in the Northern Great Basin

Threat-Based Land Management in the Northern Great Basin

23. Understanding Threats Threat-Based Land Juniper Juniper Expansion Threat Dual Management in the • Generally above 5,500 ft. • Enough moisture for juniper Dual Threat • Cool enough to suppress invasive IAG annual grasses • Generally 4,000 - 5,000 ft. Northern Great Basin: • Mountain big sagebrush is the • Enough moisture for juniper dominant shrub • Warm enough to risk invasion by invasive annual grasses Exotic Annual Grass • Mountain and Wyoming sagebrush are Invasion Threat the dominant shrubs • Generally below 4,000 ft. A Field Guide • Too dry for juniper • High risk of invasion by invasive annual grasses • Wyoming big sagebrush is the dominant shrub Juniper Exp ansion T hreat Ex oti c A nnu al G rass In vasion Threat 32. Understand States: See Back 42. Choose Map Unit Scale & Delineate States Now it’s time to delineate states. Use the back of this guide to determine states and the examples in this panel to help decide at which scale to map. The appropriate scale for mapping states depends on your management objectives – there is no perfect answer. Map units should be small enough to feasibly manage, and large enough for management to matter in meeting objectives. A Tale of Two Pastures: An Example Comparing Management and Mapping Identify States Pasture 1 Objective: Manage pasture for Pasture 2 Objective: Improve maximum forage yield by containing pasture for sage-grouse habitat Managing a complex world at juniper and aggressively controlling annual by removing encroaching grasses. Maintaining sagebrush cover is a juniper and maintaining secondary priority to improving forage. sagebrush cover. feasible, relevant scales Address Consider Objectives Scale Mapping is an iterative process. Consider Juniper objectives, site and scale collectively. Use remote sensing to estimate map units and dedicate field time to important or Pasture 1: Only the densest stand of juniper ambiguous units. is mapped as State C-Dual because diffuse juniper are not currently impacting forage quality. Pasture 2: A much larger State C-Dual unit is mapped to include all diffuse juniper, as any juniper is a problem for C-Dual sage-grouse. Invasive Pasture 1 Annual Grasses C-Dual Before Using this Guide You Should Know A Pasture 1: Small stands of State D-IAG are mapped within a State A matrix. The high-priority D-IAG Sagebrush ecosystems in the Northern Great With this method, users map simplified ecological A placed on controlling annuals justifies Basin face existential threats from invasive states and estimate future trend. Broad ranges of Pasture 2 the time and effort to map small units. annual grasses and expanding conifers. Land vegetation and environmental conditions can be managers need to work at large spatial scales to mapped with the same state if faced with similar C-IAG Pasture 2: As in the other pasture there are small annual grass patches, but they are address these two ecological threats, but have threats. Understanding plant communities and included together in a larger State C-IAG limited resources to do so. tracking true change over time requires detailed and because sage-grouse can tolerate small areas repeated monitoring. of annual grasses if most of the habitat is This guide provides a framework for land otherwise suitable. managers to efficiently identify, discuss and This decision-support system directly supports address landscape-level threats. This guide is a management objectives. Establishing your objectives decision-support system. It is not an instruction is the first step to using this guide. manual. 54. Determine Apparent Trend Steps for State Classification and Management Use these factors collectively to determine the apparent trend of a site. Apparent trend will help you determine what monitoring or actions are needed, if any. Decide if the trend is Upward, Stable, Downward, or Unclear. Unclear trends will likely require addition monitoring. Establish your management objectives: Do this Understand states: Use the decision tree, 0 before using this guide, all other steps follow photographs, and illustrations on the back of this from your objectives. Clearly stated objectives 3 guide to understand and differentiate states. will help you make key scale and management Recognize that reality will be more complex than Indicators Indicators Estimating Apparent Trend Apparent decisions. the detail used in this framework. of of Stable (Consider all factors together downward Downward Management objectives specify the overall Choose the appropriate scale and delineate or Upward to determine trend) trend Trend desired outcome achieved by addressing a 4 states: Mapping is difficult and subjective. The Trend threat. The Bureau of Land Management size of an individual map unit depends on the provides a good resource to begin writing total scale of your specific landscape and on your management objectives - a QR link is at the management objectives. Choose map units that Factor 1 bottom right of this guide. are large enough to matter, but small enough to Large perennial If shrubs are present, what Invasive annual manage. There is no perfect answer. bunchgrasses grasses Familiarize yourself with functional groups: functional group occupies the 1 This guide uses plant functional groups and Determine apparent trend: Assess the apparent shrub interspaces? simplified vegetation patterns to identify states. 5 trend of each state as upward, downward, stable OR or unclear. Consider all factors together. Apparent Understand threats and states: Environmental trend is a snapshot estimate of how the plant If shrubs are largely absent, Invasive annual factors drive juniper encroachment and annual community may change in the future. Bare ground, litter, what occupies the interspaces 2 grasses grass invasion. The resistance and resilience of desired forbs between bunchgrasses? a site will change how threats are expressed. Identify management actions: Assign management actions to each state based on its 6 apparent trend. Be sure to describe how management actions will achieve management Factor 2 objectives. No Are juniper seedlings present? Yes (If juniper threat is present) 1 Factor 3 1. Relevant Ecology Assess apparent recruitment: Yes Are multiple age classes of No desired vegetation present? Using functional groups improves monitoring efficiency, reduces observer error and eases sampling timing. Functional groups make visually evaluating vegetation state and apparent trend feasible over large areas. We include seven functional groups in our models based on southeastern Oregon, but these groupings may vary across the range of this Factor 4 vast biome. Assess potential bunchgrass No wildfire mortality: Are most LPBG Yes underneath shrub canopies? Large Perennial Small Perennial Bunchgrasses Bunchgrasses (LPBG) are the (SPBG) primarily refers to Factor 5 glue that holds the western Yes – Forage demand No – Forage demand Sandberg’s bluegrass, a low-stat- Does timing, intensity and sagebrush steppe together. ured and early-growing species is in balance with consistently duration of grazing promote LPBG root masses bind soil in common across the western supply exceeding supply desirable vegetation? place, effectively compete with sagebrush steppe. SPBG can annual grasses and provide dominate in harsh, shallow soil forage and habitat for wildlife. sites or where heavy continuous Key species include bluebunch grazing has reduced other wheatgrass, Idaho fescue, bunchgrasses. Despite often needlegrasses and squirreltail. occurring at high densities, SPBG have shallow root systems and do 6 not compete as effectively with 5. Management Actions annual grasses. Annual Forbs (AF) are generally small-statured plants with highly Select and prioritize management actions for each site based on the state, apparent trend, and management objectives. variable productivity depending on The example below shows how a user might manage for increasing the resistance and resilience of a site. year and site conditions. Common Perennial Forbs (PF) are a large, species include blue-eyed Mary diverse and variable group and (Collinsia sp.) and alyssum are important for wildlife habitat (Alyssum sp.). Large amounts of and forage. The aster family, as AF, especially of introduced well as lupines and paintbrushes A B B C C D E species can indicate a depleted are particularly abundant. understory. This category does not Stable Upward Downward Stable Downward Downward Downward include weeds such as yellow star-thistle which should be mapped and managed on a Prioritized for Recovery is very difficult Sagebrush includes several species-specific basis. Protection and and may require multiple species and subspecies. Two subspecies of big sagebrush are Maintenance and repeated actions the most abundant - Wyoming and mountain. Identifying Invasive Annual Grasses (IAG), subspecies of sagebrush can Protect and maintain bunchgrasses including cheatgrass, help understand site potential, medusahead and ventenata, are resilience and restoration species that can fundamentally practices. Other shrub species alter vegetation communities by can help identify past land use Prevent fire replacing native grasses, history and site potential. For dramatically increasing fire example, a high proportion of frequency and leading to a loss of rabbitbrush may indicate past sagebrush and perennial cover. disturbance, or greasewood may Address improper grazing indicate saline soil conditions. Conifers include tree species that Revegetate are encroaching on historically sagebrush treeless sagebrush steppe.

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