Vertigo N. Sp. Conservation Assessment
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Conservation Assessment For Vertigo n. sp., Hoko Vertigo Originally issued as Management Recommendations February 1999 John S. Applegarth Revised October 2005 Nancy Duncan USDA Forest Service Region 6 and USDI Bureau of Land Management, Oregon and Washington TABLE OF CONTENTS EXECUTIVE SUMMARY ......................................................................................................... 4 I. NATURAL HISTORY .....................................................................................................5 A. Taxonomic/Nomenclatural History ........................................................................5 B. Species Description .................................................................................................5 1. Morphology ................................................................................................5 2. Reproductive Biology .................................................................................6 3. Ecology .......................................................................................................6 C. Range, Known Sites ................................................................................................6 D. Habitat Characteristics and Species Abundance .................................................... 7 II. CURRENT SPECIES SITUATION ................................................................................8 A. Status History ......................................................................................................... 8 B. Major Habitat and Viability Considerations .......................................................... 8 C. Threats to the Species ............................................................................................ 9 D. Distribution Relative to Land Allocations ............................................................. 9 III. MANAGEMENT GOALS AND OBJECTIVES ...........................................................9 IV. HABITAT MANAGEMENT ...........................................................................................9 A. Lessons from History ..............................................................................................9 B. Identification of Species Habitat Areas ................................................................10 C. Management Within Species Habitat Areas .........................................................10 D. Other Management Issues and Considerations .....................................................11 V. RESEARCH, INVENTORY, AND MONITORING OPPORTUNITIES .................11 A. Data Gaps and Information Needs ........................................................................12 B. Research Questions ...............................................................................................12 C. Monitoring Needs and Recommendations ............................................................12 VI. REFERENCES ................................................................................................................13 2 Preface: Converting Survey and Manage Management Recommendations into Conservation Assessments Much of the content in this document was included in previously transmitted Management Recommendations developed for use with Survey and Manage Standards and Guidelines. With the removal of those Standards and Guidelines, the Management Recommendations have been reconfigured into Conservation Assessments to fit Special Status/Sensitive Species Program (SSSSP) objectives and language. Changes include: the removal of terminology specific to Survey and Manage Standards and Guidelines, the addition of Oregon Natural Heritage Information Center ranks for the species, and the addition of USDA Forest Service and USDI Bureau of Land Management (BLM) Special Status/Sensitive Species status and policy. Habitat, range, and taxonomic information have also been updated to be current with data gathered since the Management Recommendations were initially issued. The framework of the original document is maintained in order to expedite getting this information to field units. For this reason this document does not entirely conform to recently adopted standards for the Forest Service and BLM for Conservation Assessment development in Oregon and Washington. Assumptions about site management In the Final Supplemental Environmental Impact Statement (FSEIS) and Record of Decision (ROD) to Remove or Modify the Survey and Manage Standards and Guidelines (USDA and USDI 2004), assumptions were made as to how former Survey and Manage species would be managed under Agency Special Status/Sensitive Species policies. Under the assumptions in the FSEIS, the ROD stated “The assumption used in the final SEIS for managing known sites under the Special Status Species Programs was that sites needed to prevent a listing under the Endangered Species Act would be managed. For species currently included in Survey and Manage Categories A, B and E (which require management of all known sites), it is anticipated that only in rare cases would a site not be needed to prevent a listing…. Authority to disturb special status species sites lies with the agency official who is responsible for authorizing the proposed habitat-disturbing activity”. This species was in Category A at the time of the signing of the ROD, and the above assumptions apply to this species’ management under the agencies’ SSSSP. Management Considerations Within the following Conservation Assessment, under the “Management in Species Habitat Areas” section, there is a discussion on “Management Considerations”. “Management Considerations” are actions and mitigations that the deciding official can utilize as a means of providing for the continued persistence of the species’ site. These considerations are not required and are intended as general information that field level personnel could utilize and apply to site-specific situations. Management of the species covered in this Conservation Assessment follows Forest Service 2670 Manual policy and BLM 6840 Manual direction. (Additional information, including species specific maps, is available on the Interagency Special Status and Sensitive Species website.) 3 EXECUTIVE SUMMARY Species: Vertigo n. sp., the Hoko Vertigo Taxonomic Group: Mollusks (Phylum Mollusca: Class Gastropoda, Order Pulmonata, Family: Pupilladae, Subfamily Vertigininae) Management Status: This unnamed species is on the Washington State Monitor Species List, is a Tracking Species for WA BLM, and a Forest Service Region 6 Sensitive Species. The Washington Natural Heritage Program gives this species Global ranking G1, State ranking S1, “critically imperiled because of extreme rarity or because it is somehow especially vulnerable to extinction or extirpation”. Range: This species is only known from 2 sites on the Hoko River in the northwestern part of the Olympic Mountains. These locations are on non-Federal lands, but are within 10 km (6 mi) of the Soleduck Ranger District (Olympic National Forest), and 20 km (12 mi) from parcels of Bureau of Land Management land along the Soleduck River in Clallam County. This species is suspected to occur in Clallam County in the Olympic National Forest. Its range may also extend into Vancouver Island, British Columbia and other islands in the region. Specific Habitat: The Hoko Vertigo seems to be an old growth riparian associate. The 2 known locations are on bases of wooded slopes near streams at low elevations of roughly 12 and 90 meters (40 and 300 feet). It is unknown if the species could occur at considerably higher elevations. The habitat seems to be characterized by old trees, riparian hardwoods, and mesic conditions. This species is arboreal and has been found on trunks and lower limbs of deciduous trees, mainly alders. They are most easily detected on the undersides of limbs and leaning trunks of young alders that have relatively smooth bark. Threats: When a species is known from only a few locations, any modification of the environment could be a potential threat to its survival. Habitat factors that seem to be vulnerable include late-successional stands of riparian hardwoods and the associated microclimate, the stream stability, and the diverse community of native plants and animals. Threats to these habitats include silvicultural treatments (especially hardwood conversion for fish habitat improvement) and timber harvest in riparian areas, special forest product harvesting, recreation, and road construction. Management Considerations: If this rare species were to be found on Federal lands, the long-term survival of any newly discovered colonies should be favored by managing for late-successional riparian conifer-hardwood forest stand heterogeneity to provide the interior microclimate needs of the species. Within identified Species Habitat Areas, consider avoiding the use of fire or chemicals, as well as concentrated recreation, road construction or other activities that could compact the ground or mechanically injure old hardwood trees. Research, Inventory and Monitoring Opportunities: The range and relative abundance of this apparently rare species need to be explored. More information on its habitat needs to be collected. Its ecology and tolerance to disturbance are largely unknown. The only known sites are on State land, which suggests that discovery of additional managed sites on federal land would greatly improve the chances of species persistence. 4 I. NATURAL HISTORY A. Taxonomic/Nomenclatural History The genus Vertigo is