SPECIES: Scientific [common] Erigeron humilis [Arctic-alpine fleabane; low fleabane] Forest: Salmon–Challis National Forest Forest Reviewer: Jessica M Dhaemers; Brittni Brown; John Proctor Date of Review: 09/26/2017; 15 February 2018; 13 March 2018 Forest concurrence (or YES recommendation if new) for inclusion of species on list of potential SCC: (Enter Yes or No)
FOREST REVIEW RESULTS:
1. The Forest concurs or recommends the species for inclusion on the list of potential SCC: Yes_X__ No___
2. Rationale for not concurring is based on (check all that apply): Species is not native to the plan area ______Species is not known to occur in the plan area ______Species persistence in the plan area is not of substantial concern ______
FOREST REVIEW INFORMATION:
1. Is the Species Native to the Plan Area? Yes_X__ No___
If no, provide explanation and stop assessment.
2. Is the Species Known to Occur within the Planning Area? Yes_X__ No___
If no, stop assessment. Table 1. All Known Occurrences, Years, and Frequency within the Planning Area Year Number of Location of Observations (USFS Source of Information Observed Individuals District, Town, River, Road Intersection, HUC, etc.) 1991 800 Lost River Ranger District IDFG Element Occurrence Kane Lake Cirque EO Number: 1 The Kane Lake Cirque proposed EO_ID: 2532 Special Interest Botanical Area is located at the northern end of Moseley, R.K., and S. Bernatas. the Pioneer Mountains, 1992. Vascular flora of Kane Lake approximately 13 miles Cirque, Pioneer Mountains, Idaho. northeast of The Great Basin Naturalist, 335- Ketchum 343. 1997 200 Lost River Ranger District IDFG Element Occurrence Meadow Canyon Research EO Number: 2 Natural Area EO_ID: 665
Year Number of Location of Observations (USFS Source of Information Observed Individuals District, Town, River, Road Intersection, HUC, etc.) Bell Mountain is along the crest of the Lemhi Range east of the Little Lost River Valley; north side of Bell Mountain 1979 No data Lost River Ranger District IDFG Element Occurrence Peak 10,358 EO Number: 3 Approximately 2.5 miles EO_ID: 2774 southeast of Sunset Peak and east of Elbow Canyon; 0.25 mile north of Peak 10,358 on ridge, Lost River Range 1950 50+ Challis Ranger District IDFG Element Occurrence West Fork Pahsimeroi River EO Number: 4 Headwaters EO_ID: 2055 Lost River Range, northwest base of Leatherman Peak, on a small bench below (north side of) Leatherman Pass 1979 No data Challis Ranger District IDFG Element Occurrence Lake 9682 East Fork Pahsimeroi EO Number: 5 River EO_ID: 3299 Headwaters East Fork Pahsimeroi River, edge of Lake 9682 1979 No data Lost River Ranger District IDFG Element Occurrence Upper Lake Castle Peak EO Number: 6 East slope Lost River Range, EO_ID: 1070 uppermost lake above and south of Castle Peak 1987 400 Lost River Ranger District IDFG Element Occurrence Rock Creek Cirque EO Number: 7 Rock Creek Cirque proposed EO_ID: 2634 Special Interest Botanical Area is located below the north face of Borah Peak in the central Lost River Range, approximately 17 miles northwest of Mackay 1997 None found Challis Ranger District IDFG Element Occurrence Merriam Lake Basin Research EO Number: 8 Natural Area EO_ID: 2405 Upper Merriam Lake Basin, 1.2 miles southeast of Borah Peak, Lost River Range 1994 400 Lost River Ranger District IDFG Element Occurrence
Year Number of Location of Observations (USFS Source of Information Observed Individuals District, Town, River, Road Intersection, HUC, etc.) Boulder Creek Cirque EO Number: 9 984 feet south of Boulder Lake EO_ID: 3247 at the head of Boulder Creek, Wildhorse drainage, Pioneer Mountains
a. Are all Species Occurrences Only Accidental or Transient?
Yes___ No_X__
If yes, document source for determination and stop assessment.
b. For species with known occurrences on the Forest since 1990, based on the number of observations and/or year of last observation, can the species be presumed to be established or becoming established in the plan area?
Yes__X_ No___
If no, provide explanation and stop assessment
c. For species with known occurrences on the Forest predating 1990, does the weight of evidence suggest the species still occurs in the plan area?
Yes___ No___
Provide explanation for determination
N/A. Occurrences have been recorded since 1990.
If determination is no, stop assessment
d. Map 1, Arctic alpine fleabane range in Idaho (NRCS 2017)
NRCS (United States Department of Agriculture, Natural Resources Conservation Service). 2017. Erigeron humilis Graham. Arctic alpine fleabane. Internet website: https://plants.usda.gov/core/profile?symbol=ERHU. Accessed on September 1, 2017.
e. Map 2, Arctic alpine fleabane occurrences on the Salmon–Challis National Forest (Idaho Fish and Wildlife Information System [January 2017])
3. Is There Substantial Concern for the Species’ Capability to persist Over the Long-term in the Plan Area Based on Best Available Scientific Information?
Table 2. Status summary based on existing conservation assessments
Entity Status/Rank Global Rank G5—Secure (Common; widespread and abundant)1 State Rank S2—Imperiled (At high risk of extinction due to very restricted range, very few populations [often 20 or fewer], steep declines, or other factors)1 USDA Forest Region 1: Not listed2 Service Region 4: Not listed3 USDI FWS Not listed as a candidate species4 Other Idaho Native Plant Society: 2016 – on list, not yet ranked5; 2011 – State Monitor (Taxa common within a limited range in Idaho, as well as those which are uncommon, but have no identifiable threats)6
BLM: Not listed7 1. Idaho Natural Heritage Program. 2016. IDNHP Tracked Plant Species 2016. Accessed January 12, 2018 2. USFS Region 1. 2011. 2011 Sensitive Species List Idaho and Montana. Website: http://fsweb.r1.fs.fed.us/wildlife/wwfrp/TESnew.htm. Accessed January 10, 2017. 3. USFS Region 4. 2016. Proposed, Endangered, Threatened, and Sensitive Species List. On file. Accessed January 11, 2017. 4. USFWS. 2017. Candidate species believed to or known to occur in Idaho. Website: https://ecos.fws.gov/ecp0/reports/species-listed-by-state-report?state=ID&status=candidate. Accessed January 12, 2018. 5. Idaho Native Plant Society. 2016. INPS Rare Plant List May 2016. https://idahonativeplants.org/rare-plants-list/ Accessed January 10, 2018. 6. Idaho Native Plant Society. 2011. Results of the twenty-fifth Idaho Rare Plant Conference – The Idaho Native Plant Society rare plant list. Website: https://idahonativeplants.org/rpc/pdf/2011_Results_IRPC_v2.2.pdf. Accessed on January 11, 2018. 7. BLM. 2016. Bureau of Land Management Idaho Special Status Plants List Aug 2016. On file. Accessed 15 January, 2018.
Table 3. Status summary based on best available scientific information.
Species (Scientific and Common Name): Erigeron humilis (Arctic alpine fleabane) Criteria Rank Rationale Literature Citations 1 A2 E. humilis is known from nine occurrences on the SCNF, all in the Lost IDFG. 2017. Idaho Fish and Wildlife Distribution on River and Challis Ranger Districts (IDFG 2017). Although, a floristic Information System, Species Diversity Salmon–Challis inventory of the SCNF took place (Irwin 2014), targeted systematic Database, Idaho Natural Heritage National Forest surveys have not been conducted. Potential habitat for this species (see Data. Accessed on February 27, 2017. Criterion 6) is patchy and often isolated on the Forest (Rank A). Irwin, J. J. 2014. “A Floristic Inventory
of East-Central Idaho, U.S.A.” Master’s Confidence in Rank: High, Medium, or Low thesis, University of Wyoming, Laramie. 2 C E. humilis is a circumpolar species. In North America, it extends south to Fertig, W. 2000. Erigeron humilis Low Distribution in high elevations in the Rocky Mountains, including: southern British fleabane. State Species Abstract. surrounding Columbia, northwest Montana, northern Wyoming, and Colorado (Fertig Wyoming Natural Diversity Database. geographic area 2000). In Idaho, the only known occurrences are on the SCNF. Surveys have been conducted in adjacent Targhee National Forest in the Moseley, R.K. 1989. Field investigations of seven rare alpine southern Lemhi Range and Beaverhead Mountains, but populations were plant species in the southern Lemhi not discovered (Moseley 1989). Due to the wide distribution of E. humilis Range and Beaverhead Mountains, in Canada and other circumpolar countries, a criterion of C is given. Dubois Ranger District, Targhee National Forest. Idaho Department of Confidence in Rank: High, Medium, or Low Fish and Game. 3 B E. humilis is a perennial, rhizomatous plant with wind dispersed seeds FNA (Flora of North America) Editorial Dispersal (FNA 2006). The species is known to flower from June to August Committee, eds. 1993+. Erigeron Capability depending upon conditions. Little else is known regarding the humilis Graham, Edinburgh New reproductive ecology of the species, but it likely is only capable of Philos. J. Flora of North America North dispersing through suitable habitat (Rank B). of Mexico. 20+ vols. New York and Oxford. vol. 20, 2006; pg. 326. Internet
website: Confidence in Rank: High, Medium, or Low http://www.efloras.org/florataxon.asp x?flora_id=1&taxon_id=250066612. Accessed on September 8, 2017. 4 B On the SCNF, there are nine known occurrences of E. humilis. In the IDFG. 2017. Idaho Fish and Wildlife known occurrences of E. humilis, populations are relatively small; the Information System, Species Diversity
Species (Scientific and Common Name): Erigeron humilis (Arctic alpine fleabane) Criteria Rank Rationale Literature Citations Abundance on the largest populations recorded are 200-800 individuals (IDFG 2017; Database, Idaho Natural Heritage Salmon–Challis Moseley 1989). The current abundance is likely large enough that Data. Accessed on February 27, 2017. National Forest demographic stochasticity is not likely to lead to rapid local extinction, but, in combination with highly variable environmental factors, could pose a threat, this criterion is given a B ranking. Since no occurrences have been recorded since 1997, confidence for this ranking is low.
Confidence in Rank: High, Medium, or Low 5 B Species specific monitoring has not been conducted for this species. IDFG. 2017. Idaho Fish and Wildlife Population Trend However, site revisits have occurred at four EOs; three populations (EOs Information System, Species Diversity on the Salmon– 1, 2, 4) appear stable, while the population at EO 8 was not relocated Database, Idaho Natural Heritage Challis National (IDFG 2017). A number of EOs note populations were fruiting. No site Data. Accessed on February 27, 2017. Forest visits have been documented on EO records since 1997. Given current information, populations are presumed stable (Rank B).
Confidence in Rank: High, Medium, or Low 6 B E. humilis is found in moist alpine meadows above 9,600 feet elevation. Fertig, W. 2000. Erigeron humilis Low Habitat Trend on Habitat is near snowbanks, rivulets fed by melting snow, and areas with a fleabane. State Species Abstract. the Salmon–Challis high-water table that keeps the soil moist through the growing season Wyoming Natural Diversity Database. National Forest (Moseley 1989). It is often associated with Poa alpine, Poa rupicola, Deschampsia cespitosa, Thalictrum alpinum, Erigeron simplex, Salix Google Earth. 2017. Salmon–Challis National Forest. Internet website: nivalis, and Carex nova. This habitat is rare and restricted in the arid http://google.com/earth/. Accessed mountain ranges of east-central Idaho (Moseley 1989). Fertig (2000) on October 15, 2017. notes that habitat in Wyoming is often montane granite and limestone cliff faces, talus slopes, alpine meadows, and tundra – frequently in IDFG. 2017. Idaho Fish and Wildlife mossy, moist microsites. Information System, Species Diversity Database, Idaho Natural Heritage
Data. Accessed on February 27, 2017. Approximately 1.2% (~ 51,000 acres) of vegetation on the Forest is classified as alpine (based on Landfire biophysical settings) (USFS 2017). IDFG (Idaho Department of Fish and Within these alpine systems, approximately 13% (6,000 acres) of the Game). 2017b. Idaho State Wildlife vegetation is considered mesic meadows. On the SCNF, alpine plant Action Plan, 2015. Boise, ID.
Species (Scientific and Common Name): Erigeron humilis (Arctic alpine fleabane) Criteria Rank Rationale Literature Citations communities tend to be dry and largely dominated by graminoids (Mancuso and Lehman 2016). Although these systems are rare and Mancuso, M., Lehman, R. 2016. Alpine unique, they are well represented on the Forest (USFS 2017). plant community sampling and stewardship assessment in the Sheep Because alpine vegetation mainly occur in designated wilderness, Mountain Research Natural Area, Lemhi Mountains, Idaho. Caribou- roadless, or remote areas where human interference disturbance is Targhee National Forest, Idaho Falls, minimal, alpine communities of the Salmon–Challis are considered to ID and Salmon-Challis National Forest, exhibit good integrity and relatively stable (IDFG 2017b; USFS 2017). In Salmon, ID. 2016, Mancuso and Lehman resampled plots from a 1992 study on alpine community types on Sheep Mountain. Comparisons between the two Moseley, R. K. 1989. Field dates indicate no substantial change in vegetative composition or species investigations of seven rare alpine represented in the intervening 24 years (Mancuso and Lehman 2016). plant species in the southern Lemhi Range and Beaverhead Mountains, There have not been any recorded disturbances to the habitat of this Dubois Ranger District, Targhee species (IDFG 2017). Aerial imagery was evaluated for each EO to assess National Forest. Idaho Department of the impact of local disturbances, such as wildfire, invasive infestation, Fish and Game.
grazing, mining, and roads and trails (Google Earth 2017, USFS 2016). USFS (United States Department of There appears to be no considerable disturbances among any Agriculture Forest Service). 2017. occurrences, which is in agreement with the threat descriptions within Salmon-Challis National Forest Plan EO records. Revision Assessments. Topics 1& 2: Terrestrial Ecosystems, Aquatic While some populations do lie within active grazing allotments, the Ecosystems, Watersheds, Air, Soil, general remoteness and ruggedness of suitable habitat for this species Water. likely precludes livestock grazing. In addition, some occurrences have been documented in proposed Special Botanical Interest Areas and USFS. 2016. SDE RMU Range Research Natural Areas, offering some supplementary protections. Allotments. GIS Database Information. Data source: S_R04_SCF.rmu_unit. Last updated March 30, 2016. There appears to be a stable amount of good condition and minimally
disturbed habitat on the Forest, thus it is likely there has been no change in suitable habitat for this species (Rank B).
Species (Scientific and Common Name): Erigeron humilis (Arctic alpine fleabane) Criteria Rank Rationale Literature Citations Confidence in Rank: High, Medium, or Low 7 B Suitable habitat for E. humilis is particularly vulnerable to climate change. Ash, J.D., Givnish, T.J., Waller, D.M. Vulnerability of 2016. Tracking lags in historical plants Habitats on the To project the future climate and impacts to resources in the species’ shifts in relation to regional Salmon–Challis Intermountain Region including the Salmon-Challis, the Intermountain climate change. Global Change National Forest Adaptation Partnership (IAP) used Representative Concentration Biology, doi: 10.1111/gcb.13429.
Pathway [RCP] 4.5 and 8.5, which capture a moderate and high future Behrens, P.N., R.E. Keane, D.L. warming, respectively (Halofsky et al. 2018). Although pathways Peterson, and J.J. Ho. 2018. Chapter 6: predicting lower warming exist, the 4.5 and 8.5 pathways were chosen by effects of climatic variability and the IAP because they are, in comparison, well studied providing a large change on forest vegetation. In set of projections that enhance our understanding of the possible range Halofsky, J.E., D.L. Peterson, J.J. Ho, in future climate. Thus, this represents best available science for our N.L. Little, L.A. Joyce, editors. 2018. Forest with regard to a warming climate. Climate change vulnerability and adaptation in the Intermountain Although uncertainty exists about the magnitude and rate of climate Region. Gen. Tech. Rep. RMRS-GTR- change (For a discussion of this see Behrens et al. 2018), warming XXX. Fort Collins, CO: US Department temperatures are the most certain consequence of increased CO2 in the of Agriculture, Forest Service, Rocky Mountain Research Station. atmosphere. By 2100, median minimum temperature in the Middle
Rockies subregion, which includes the Salmon-Challis, is projected to rise Dirnbock, T., F. Essl, and W. Rabitsch. about 5˚F under the moderate warming scenario and about 10˚F under 2011. Disproportional risk for habitat the high warming scenario. Regardless of scenario, the greatest loss of high-altitude endemic species departure from historical seasonal minimum temperatures occurs in the under climate change. Global Change summer. Annual precipitation projections are highly variable with no Biology, 17:990-996. discernible trend under moderate warming and a slight increasing trend with high warming (Joyce and Talbert 2018). Halofsky, J.E., D.L. Peterson, J.J. Ho, N.L. Little, L.A. Joyce, editors. 2018. Alpine habitat may be vulnerable to climatic factors and have low Climate change vulnerability and adaptive capacity to climate change. Climate change is expected to cause adaptation in the Intermountain Region. Gen. Tech. Rep. RMRS-GTR- increasingly warmer and wetter conditions, with worsening summer xxx. Fort Collins, CO: US Department of drought, and alpine areas may transition from snow-dominated to rain- Agriculture, Forest Service, Rocky dominated (Halofsky et al. 2018; IDFG 2017). An extended growing Mountain Research Station.
Species (Scientific and Common Name): Erigeron humilis (Arctic alpine fleabane) Criteria Rank Rationale Literature Citations season is projected to occur in the alpine which can result in interspecific competition for resources, changes in plant community composition and Hatfield, R., Jepsen, S., Mader, E., displacement of rare plant populations where they currently occupy Black, S.H., Shepherd, M. 2012. specific niches. The amount of surface water flow and timing of peak Conserving bumble bees: guidelines runoff may also be impacted. Such changes may reduce the ranges of for creating and managing habitat for America’s declining pollinators. The high-elevation species. Xerces Society for Invertebrate Conservation. Alpine systems are dependent on snowfields and gradual snowmelt to maintain moisture for vegetation, and thus warming temperatures, IDFG (Idaho Department of Fish and increased drought, and changes in the depth and persistence of Game). 2017. Idaho State Wildlife snowpack is projected to greatly affect this habitat in the Intermountain Action Plan, 2015. Boise ID. Region (Halofsky et al. 2018; IDFG 2017). While the extent of snowfields, as measured on April 1 and modeled under the RCP emissions scenario Joyce, L.A. and M. Talbert. 2018. 8.5 (a severe scenario), is projected to remain similar on the Salmon- Chapter 3: Historical and projected Challis into the 2080’s, warmer conditions will markedly reduce their climate. In Halofsky, J.E., D.L. Peterson, persistence and depth. In addition, losses will be greater than projected J.J. Ho, N.L. Little, L.A. Joyce, editors. 2018. Climate change vulnerability and because this modeling provides an overestimate of precipitation at high adaptation in the Intermountain elevations. This is because it uses the Global Climate Model (GCM), which Region. Gen. Tech. Rep. RMRS-GTR- does not account for local orographic effects (Halofsky et al. 2018). xxx. Fort Collins, CO: US Department of Agriculture, Forest Service, Rocky Summer precipitation is also very important for subalpine and alpine Mountain Research Station. vegetative communities and the RCP8.5 model projects a 20% decrease in summer precipitation for the SCNF. However, cooler soil temperature Miller-Struttmann, N.E., Geib, J.C., at higher elevation may moderate effects to alpine species (Halofsky et Franklin, J.D., Kevan, P.G., Holdo, R.M., al. 2018). Ebert-May, D., Lynn, A.M., Kettenbach, J.A., Hedrick, E., Galen, C. 2015. Some loss of alpine vegetation communities, especially mesic meadows, Functional mismatch in a bumble bee pollination mutualism under climate attributed to upslope migration of trees and shrubs may occur change. Science, 349(6255): 1541- (Alexander et al. 2015 in Halofsky et al. 2018). Some, subalpine 1544. communities may have potential to migrate higher in elevation as a response to changing conditions, but this may be limited by
Species (Scientific and Common Name): Erigeron humilis (Arctic alpine fleabane) Criteria Rank Rationale Literature Citations underdeveloped soils at higher altitudes. Furthermore, the rate of climatic change in alpine communities may outpace the ability of species to shift their distribution (Ash et al. 2016; Dirnbock et al. 2011). Other communities may already exist at the highest elevations in the SCNF and, therefore, may have limited upward migration potential.
Rare plant populations that may be small, isolated, tied to snowpack abundance and distribution timing changes of spring thaw and fall frost cycles, and/or have limited dispersal capacity, are highly vulnerable to impacts from environmental change including reductions in pollination.
Changes in temperature and precipitation may lead to greater variability in forb flowering, which could create an asynchronistic effect with native pollinator emergence (Halofsky et al. 2018; Miller-Struttmann et al. 2015), leading to decreased reproduction in native plants. As pollinators are critical for successful reproduction and seed set for approximately 85% of flowering species globally (Hatfield et al. 2012), this asynchronistic effect may have profound implications.
Alpine vegetation communities are considered exceptionally vulnerable to anthropogenic disturbances including impacts from herbivory/trampling by native ungulates and/or unrestricted livestock grazing, infrastructure development (trails and com sites), increased recreational activities at high elevation sites, and associated trampling. Given potential changes and stressors in alpine communities with regard to climate, it is assumed that the impacts of anthropogenic disturbances may be an additional threat to alpine species.
The degree to which both populations and habitats are vulnerable to loss or disturbance on the Forest are dependent upon variability in severity of
Species (Scientific and Common Name): Erigeron humilis (Arctic alpine fleabane) Criteria Rank Rationale Literature Citations impacts from climate change (Rank B).
Confidence in Rank: High, Medium, or Low 8 B E. humilis is a perennial herbaceous plant with rhizomatous roots (FNA FNA (Flora of North America) Editorial Life History and 2006). Rhizomatous shoots become independent of its parent. Committee, eds. 1993+. Erigeron Demographics Individuals typically only produce one inflorescence with numerous humilis Graham, Edinburgh New fruits. Flowers are insect pollinated and also presumed to be self- Philos. J. Flora of North America North pollinated. Müller et al. (2011) found that E. humilis has poor of Mexico. 20+ vols. New York and Oxford. vol. 20, 2006; pg. 326. Internet germination rates in the field, but higher germination rates in captivity. website: As a result, it is presumed that this species has a low reproductive rate. http://www.efloras.org/florataxon.asp x?flora_id=1&taxon_id=250066612. A study on responses to native grazers found that E. humilis is tolerant to Accessed on September 8, 2017. pika grazing (McIntire and Hik 2002). Native grazers do not pose a significant threat to this species. No information is available regarding McIntire, E.J., and D.S. Hik. 2002. the effect of disease or competition on mortality rates. Grazing history versus current grazing: leaf demography and compensatory Due to poor in situ germination rates, but no indication that the species growth of three alpine plants in suffers a high mortality rate, a criterion ranking of B is given. response to a native herbivore (Ochotona collaris). Journal of Ecology, 90(2), 348-359. Confidence in Rank: High, Medium, or Low
Müller, E., E.J. Cooper, and I.G. Alsos. 2011. Germinability of arctic plants is high in perceived optimal conditions but low in the field. Botany, 89(5), 337-348. Summary and recommendations: Erigeron humilis is globally secure (G5) and locally imperiled in the state of Idaho Date: 9/8/2017 (S2). There are nine occurrence records on the Salmon-Challis National Forest, the only place where the species has been recorded in the state.
E. humilis is a rhizomatous perennial that is assumed to have low reproductive capacity and limited dispersal. Habitat is patchy and isolated and is described as moist alpine meadows above 9,600 feet elevation, near
Species (Scientific and Common Name): Erigeron humilis (Arctic alpine fleabane) Criteria Rank Rationale Literature Citations snowbanks, rivulets fed by melting snow, and areas with a high-water table that keeps the soil moist through the growing season. Both habitat and population trends for the species appear stable. Alpine communities are generally considered stable on the SCNF, but are considered exceptionally vulnerable to long-term threats related to climate change compared to other vegetative communities.
There is substantial concern for the capability of Erigeron humilis to persist over the long-term on the Salmon- Challis, therefore, it is recommended as a SCC.
Evaluator(s): Mary Patterson