Piute Mountains Jewel-flower (Streptanthus cordatus var. piutensis)

Transcription

1 PLANTS Piute Mountains Jewel-flower (Streptanthus cordatus var. piutensis) Piute Mountains Jewel-flower (Streptanthus cordatus var. piutensis) Legal Status Taxonomy State: S1.2 1 California Rare Plant Rank: 1B.2 2 Federal: Bureau of Land Management Sensitive Critical Habitat: N/A Recovery Planning: N/A Piute Mountains jewel-flower (Streptanthus cordatus var. piutensis) is a perennial herb in the mustard family (Brassicaceae) (Jepson Flora Project 2011). Thomas Nuttall first described Streptanthus cordatus in 1838, with the type locality from the forests of the Rocky Mountains (as provided by the Jepson eflora [Jepson Flora Project 2011]). John Thomas Howell described the variety piutensis in the Leaflets of Western Botany in 1963 (IPNI 2011) based on the collections of D. E. Breedlove (Tropicos 2011). Jepson s A Flora of California, written between 1909 and 1940 (with one update in 1979), notes that there may be some disagreement about the identification of the California Streptanthus cordatus as compared to the Streptanthus cordatus originally described from type specimens collected in the Rocky Mountains (Jepson Flora Project 2011). However, this taxonomic uncertainty does not appear to be a present-day concern and does not concern the validity of the variety piutensis. Greene and Sanders (2006) discuss discrepancies between accounts of Streptanthus cordatus in The Jepson Manual (Hickman 1996) and in The Cruciferae of Continental North America (Rollins 1993, cited in Greene and Sanders 2006), specifically related to the intraspecific identity of specimens collected in eastern Tulare County, which is outside of the Plan Area. Greene and Sanders (2006) cite difficulty in identifying differences between var. cordatus, var. 1 S1: Critically Imperiled. X.2: Threatened. 2 1B: Rare, threatened, or endangered in California and elsewhere. X.2: Fairly endangered in California. 1

2 Distribution General piutensis, and the intermediate var. duranii. They hypothesize this could be a result of clinal variation (where varieties intergrade where their ranges overlap), or hybridization between var. cordatus and var. piutensis resulting in the intermediate var. duranii (Greene and Sanders 2006). However, no changes to the taxonomy of these varieties have been offered in the updated Jepson Manual (Jepson Flora Project 2011). This species generally stands from 3 to 9 decimeters (1.0 to 3.0 feet) tall (Jepson Flora Project 2011). Descriptions of the species physical characteristics can be found in Greene and Sanders (2006), and on the Jepson eflora (Jepson Flora Project 2011). Piute Mountains jewel-flower is restricted to the southern Sierra Nevada in Kern County (CDFG 2012a; CCH 2011; Jepson Flora Project 2011) although Greene and Sanders (2006) note that there appear to be specimens matching this species taken from near Chimney Peak in eastern Tulare County. No further information about the identification of these individuals is available and they are located outside of the Plan Area. There are four element occurrences in the California Natural Diversity Database (CNDDB) (CDFG 2012a) and 28 records from the Consortium of California Herbaria (CCH) (2011) of this species. Most, but not all, of the CCH records appear to be geographically distinct from the CNDDB records, but geographic location is not mapped and therefore is difficult to compare with CNDDB data. All CNDDB records are presumed extant (CDFG 2012a). Element Occurrence #1 (CDFG 2012a), containing eight separately mapped occurrence areas, is by far the largest of the four occurrences. It is outside of the Plan Area. Figure SP-P25 shows the range of Piute Mountains jewel-flower in California. 2

3 Distribution and Occurrences within the Plan Area Historical Within the Plan Area, one element occurrence of Piute Mountains jewel-flower was observed in 1966 within the Cache Peak area north of the City of Mojave. It was observed on the northwest flank of Cache Peak at Champagne Spring. It was noted as a scattered colony growing in sheltered metamorphic rock at the base of a high cliff (CDFG 2012a). Recent Natural History Within the Plan Area, one element occurrence of Piute Mountains jewel-flower was last observed in 2010 within the Cache Peak area north of the City of Mojave. It was observed at the north end of Sweet Ridge, southeast of Cache Peak, growing on and around rock outcrops within dense Tucker oak chaparral (CDFG 2012a). This occurrence record is located on lands in private ownership. Figure SP-P25 provides the known distribution of Piute Mountains jewel-flower, with these occurrences overlaid (CDFG 2012a). Habitat Requirements Piute Mountains jewel-flower has been documented in broadleafed upland forests, closed-cone coniferous forest, and pinyon-juniper woodlands (CDFG 2012a). According to Greene and Sanders (2006), most occurrences are associated with Bodfish Piute cypress (Cupressus nevadensis) and California juniper (Juniperus californica) in the Piute Mountains. The Cache Peak occurrence at Champagne Spring (Occurrence #3; CDFG 2012a) was observed growing in association with canyon live oak (Quercus chrysolepis). Plants have been found growing at elevations of between 1,095 and 1,825 meters (3,592 to 5,988 feet) (CNPS 2011). Collections have been made at elevations of 3,600 to 7,000 feet according to Greene and Sanders (2006). Within the Plan Area, the two known occurrences are found at 5,700 feet and 6,200 feet (CDFG 2012a). However, the 3

4 entire documented elevation range for the species was applied when modeling potential habitat within the Plan Area. One occurrence within the Plan Area is associated with metamorphic rock. Other substrates include reddish clay-like soils (CDFG 2012a), heavy clay (Rollins 1993, cited in Greene and Sanders 2006), stony gabbro substrate, and very dark brown-red soil and rock (Greene and Sanders 2006). A population at Chimney Creek Canyon was recorded as occurring on a sandy slope (Greene and Sanders 2006). Table 1. Habitat Associations for Piute Mountains Jewel-Flower Land Cover Type Broadleafed upland forests, closed-cone coniferous forests, and pinyon-juniper woodlands Habitat Designation Habitat Parameters Supporting Information Primary habitat 3,592 to 7,000 feet elevation CDFG 2012a; Greene and Sanders 2006 Reproduction Piute Mountains jewel-flower blooms from June to July and produces 20 to 38 (occasionally as many as 46) small, broadly oblong to slightly round seeds (Jepson Floral Project 2011). Very little work has been done on the reproductive biology of Piute Mountains jewel-flower, but Preston (1994) studied a related mountain jewel-flower (Streptanthus tortuosus) with similar flower morphology (Greene and Sanders 2006). Preston (1994) found that bees are the most common and consistent floral visitors, but wasps, flies, butterflies, and beetles were also observed visiting the flowers foraging for pollen and nectar. These observations may not apply directly to Piute Mountains jewel-flower, but given the similarities of flower form, the pollinators are probably similar or identical (Greene and Sanders 2006). Ecological Relationships Very little is known about the ecological relationships of Piute Mountains jewel-flower. Like many other species, the success of Piute Mountains jewel-flower is strongly dependent upon relationships 4

5 with the soil, animal pollinators, adjacent habitat, and climactic processes, such as rainfall patterns. Any changes in soil condition, viability of known pollinators, or of the habitats in which this species occurs will affect this rare plant. Population Status and Trends Global: G5T1, Critically Imperiled (CDFG 2012b) State: S1.2, Critically Imperiled (CDFG 2012b) Piute Mountains jewel-flower is classified as a 1B.2 rare plant species by the California Rare Plant Rank (CRPR) system. Species with the 1B rank are rare, threatened, or endangered in California and elsewhere. The X.2 threat rank indicates that this species is fairly threatened (20% 80% occurrences threatened or moderate degree and immediacy of threat) in California. Population trends are difficult to establish due to the small number of verified records of this species (CDFG 2012a) and the fact that the plant is a short-lived perennial herb. Its known range in Kern County is poorly explored, but populations or hybrids could extend into eastern Tulare County (Greene and Sanders 2006). Population counts in the CNDDB records are limited to the largest occurrence (Element Occurrence #1), in which 30 plants were reported in 1992 and 75 in 1995 (CDFG 2012a). This variation could easily be attributed to yearly fluctuations in population size and may not indicate long-term trends. Threats and Environmental Stressors Within the Plan Area, the two known occurrences of Piute Mountains jewel-flower are on private lands and potentially threatened by maintenance of wind energy facilities (Hare 1995, cited in Greene and Sanders 2006; CDFG 2012a). Off-highway vehicle (OHV) use also has the potential to adversely affect this species. Linton (2009) describes a number of potential direct and indirect impacts to special-status plant species occurring in the Sequoia National Forest, including Piute Mountains jewel-flower, resulting from roads and OHV use. Direct impacts include, but are not limited to, crushing of the foliage, root systems, and seedlings by the wheels; uprooting; and disruption of root systems of larger plants. Indirect impacts can include reductions 5

6 in photosynthetic capacity, poor reproduction, increases in bare ground, diminished litter cover, and a reduction in the overall cover and frequency of plant species. These impacts can lead to the eventual replacement of native plant species with non-native species better adapted to frequent disturbances and altered soil conditions, such as invasive non-native species (Linton 2009). Moreover, soil erosion and changes to the physical and chemical properties of soil resulting from OHV use pose potential threats to Piute Mountains jewel-flower. Linton (2009) discusses how OHV use can result in a loss of cohesion and lateral displacement of soils, while repeated use leads to compaction. This in turn, can lead to decreased moisture available for plant growth, which is especially problematic in arid areas, where soil moisture is frequently a strong limiting factor for plant productivity and reproductive success (Linton 2009). The two occurrences within the Plan Area, located on private land, are also potentially threatened by any future construction, cattle grazing, logging, or mining, by both destruction of individual plants and reduction and/or elimination of their habitat (Greene and Sanders 2006). In addition, any reduction of the habitat or threat to the longterm survival of the plant s pollinators poses a significant threat. Conservation and Management Activities Piute Mountains jewel-flower was part of the original 98 plant and animal species initially addressed in the West Mojave Plan (BLM 2005). However, this species was later dropped due to insufficient information, according to Appendix Y of Volume 2 of the Plan (BLM 2005). In addition, the Bureau of Land Management (BLM) manages sensitive plants, including Piute Mountains jewel-flower, on lands it administers. Management priorities are consistent with BLM s principles of multiple use and include, but are not limited to, the following: developing and implementing range-wide and/or sitespecific management plans for sensitive plant species that include specific habitat and population management objectives designed for recovery; ensuring that BLM activities affecting the habitat of sensitive plant species are carried out in a manner consistent with the objectives for managing those species; and monitoring populations 6

7 and habitats of candidate plant species to determine whether management objectives are being met (BLM 2003). Data Characterization There are considerable data gaps for this species, including questions about the true range of the plants meeting the description of variety piutensis both because of the presence of questionable records in eastern Tulare County and because of limited sampling in the remote areas where it has been documented in Kern County. There is also a limited amount of information on microhabitat requirements (e.g., soil types, how alluvial processes affect the plant), reproductive processes (e.g., requirements for seed germination, how long seeds remain viable in the soil), and interactions with climatic forces (e.g., how long plants can survive dormancy, what rainfall amounts are required for plants to set seeds). Management and Monitoring Considerations Species protection activities should focus on CNDDB occurrences known to occur in the Plan Area (CDFG 2012a), as well as modeled habitat for the species. Protection of known occurrences is made more difficult because these occurrences are located on private land. The long-term viability of populations may also rely on the protection of habitat corridors between these populations. Because so little is known about the abundance and distribution of Piute Mountains jewel-flower in California, focused surveys for this species should be conducted within appropriate habitat in high rainfall years in the Plan Area. Absent the acquisition of, or conservation easement on, private lands where these occurrences are located, long-term management and monitoring of the two known populations within the Plan Area may be difficult. Predicted Species Distribution in Plan Area There are 99,736 acres of modeled suitable habitat for Piute Mountains jewel-flower in the Plan Area. Modeled suitable habitat occurs in the Tehachapi-Piute Mountains from 3,500 to 7,000 feet in elevation. Modeled suitable habitat includes forest and woodland 7

8 Literature Cited vegetation communities. Appendix C includes specific model parameters and a figure showing the modeled suitable habitat in the Plan Area. BLM (Bureau of Land Management) Special Status Plant Management. BLM-California Manual Supplement Last revised January 3, Accessed November 21, pdfs/pa_pdfs/biology_pdfs.par.428edb73.file.pdf/ supplement.pdf. BLM Final Environmental Impact Report and Statement for the West Mojave Plan: A Habitat Conservation Plan and California Desert Conservation Area Plan Amendment. Vol. 1, ES SCH no Moreno Valley, California: BLM. January Accessed November st/en/fo/cdd/wemo.html. CCH (Consortium of California Herbaria) Accession results for Streptanthus cordatus var. piutensis. Accessed November CDFG (California Department of Fish and Game). 2012a. Streptanthus cordatus var. piutensis. Element Occurrence Query. California Natural Diversity Database (CNDDB). RareFind, Version 4.0 (Commercial Subscription). Sacramento, California: CDFG, Biogeographic Data Branch. Accessed February CDFG. 2012b. Special Vascular Plants, Bryophytes, and Lichens List. California Natural Diversity Database (CNDDB). January Accessed. cnddb/plants_and_animals.asp. CNPS (California Native Plant Society) Streptanthus cordatus var. piutensis. Inventory of Rare and Endangered Plants. Online ed. Version 8-01a. Sacramento, California: CNPS. Accessed November 23,

9 Greene, J. A., and A.C. Sanders Piute Mountain Jewel-Flower. West Mojave Plan. U.S. Department of the Interior, Bureau of Land Management. January Accessed December 13, medialib//blm/ca/pdf/pdfs/cdd_pdfs.par.41e75f64.file.pdf/ piutemtn1.pdf. Hickman, J.C., ed The Jepson Manual: Higher Plants of California. 3rd printing, with corrections. Berkeley, California: University of California Press. IPNI (International Plant Names Index) Plant Name Details: Streptanthus cordatus var. piutensis. Accessed November 23, Jepson Flora Project Streptanthus cordatus var. piutensis. I.A. Al-Shehbaz. Jepson eflora [v. 1.0]. Berkeley, California: University of California. Accessed November 23, Linton, F Biological Evaluation for Sensitive Plants Sequoia National Forest Travel Management Project. In Travel Management Final Environmental Statement Sequoia National Forest. August Accessed November 23, travel-management-eis/tm_botany_final_be.pdf. NatureServe Streptanthus cordatus var. piutensis. NatureServe Explorer: An Online Encyclopedia of Life. Version 7.1. Arlington, Virginia: NatureServe. Last update July Accessed November 21, Preston. R.E Population Biology of Streptanthus tortuosus (Brassicaceae). Madrono 41(2): Tropicos Streptanthus cordatus var. piutensis. Accessed November 23, Name/

10 Species Range in California Utah Nevada!( Current Occurrence Point!( Historic and Unknown Occurrence Point Note: Occurrence point size graphically represents the precision level code for the data point but is not scaled geographically.!( Arizona Z:\Projects\CEC\j6668_DRECP\MAPDOC\MAPS\BaselineBioReport\SpeciesProfiles I January 15, Miles P a c i f i c O c e a n Sources: DRECP Species Occurrence Database (2011), CWHR (2008), CEC (2010), USGS (2010), ESRI (2010) Desert Renewable Energy Conservation Plan (DRECP) Baseline Biology Report MEXICO FIGURE SP-P25 Piute Mountains Jewel-flower in the Plan Area (N=2)