FINAL REPORT ◦ SEPTEMBER 2019 Special-Status Plant Surveys for the McKay Community Forest Trail Plan Implementation Project Humboldt County, California PREPARED FOR PREPARED BY Humboldt County Stillwater Sciences Department of Public Works 850 G Street, Suite K 1106 Second Street Arcata, CA 95501 Eureka, CA 95501 Stillwater Sciences Special-Status Plant Surveys for the McKay Community Forest Trail Plan Implementation Project Suggested citation: Stillwater Sciences. 2019. Special-status Plant Surveys for the McKay Community Forest Trail Plan Implementation Project. Final Report. Prepared by Stillwater Sciences, Arcata, California for Humboldt County Department of Public Works, Eureka, California. Cover photos (clockwise from upper left): Dense forest understory vegetation within Mid-McKay trail planning unit (May 2019), dispersed trail near Ryan Creek to be incorporated into the trail system (July 2019), special-status plant Pleuropogon refractus (nodding semaphore grass) observed within the South-McKay trail planning unit (May 2019), and Picea sitchensis (Sitka spruce) in the Mid-McKay trail planning unit (July 2019). September 2019 Stillwater Sciences i Special-Status Plant Surveys for the McKay Community Forest Trail Plan Implementation Project Table of Contents 1 PROJECT DESCRIPTION ................................................................................................... 1 1.1 Background .................................................................................................................. 1 1.2 Project Location and Survey Area ............................................................................... 1 1.3 Purpose of the Special-status Plant Survey .................................................................. 2 2 METHODS .............................................................................................................................. 4 2.1 Establishing the List of Species that Could Occur in the Survey Area ........................ 4 2.2 Pre-field Review ........................................................................................................ 10 2.3 Field Surveys ............................................................................................................. 10 2.3.1 Vegetation mapping ............................................................................................ 10 2.3.2 Special-status plant surveys ................................................................................. 10 3 RESULTS .............................................................................................................................. 12 3.1 Vegetation Mapping .................................................................................................. 12 3.1.1 Sequoia sempervirens Forest Alliance ................................................................ 18 3.1.2 Riparian forest (Acer macrophyllum and Alnus rubra Forest Alliances) ............ 19 3.1.3 Holcus lanatus-Anthoxanthum odoratum Semi-natural Herbaceous Alliance .... 19 3.2 Special-status Plant Surveys ...................................................................................... 20 3.2.1 Carex lyngbyei (Lyngbye’s sedge) ...................................................................... 21 3.2.2 Pleuropogon refractus (Nodding semaphore grass) ............................................ 23 3.2.3 Chrysosplenium glechomifolium (Pacific golden saxifrage) ............................... 25 4 REFERENCES ...................................................................................................................... 27 Tables Table 1. Special-status plant species with potential to occur in the Survey Area. ........................ 5 Table 2. Vegetation cover types and acreage in the Survey Area. .............................................. 12 Table 3. Special-status plant occurrence in the Survey Area. ..................................................... 20 Figures Figure 1. Survey Area and trail units within the MCF Trail. ......................................................... 3 Figure 2. Vegetation communities documented within the Survey Area (Tile 1 of 5). ................ 13 Figure 3. Vegetation communities documented within the Survey Area (Tile 2 of 5). ................ 14 Figure 4. Vegetation communities documented within the Survey Area (Tile 3 of 5). ................ 15 Figure 5. Vegetation communities documented within the Survey Area (Tile 4 of 5). ................ 16 Figure 6. Vegetation communities documented within the Survey Area (Tile 5 of 5). ................ 17 Figure 7. Mapped populations of Carex lyngbyei (CRPR 2B.2) in the Survey Area. .................. 22 Figure 8. Mapped populations of Pleuropogon refractus (CRPR 4.2) in the Survey Area. ......... 24 Figure 9. Mapped populations of Chrysosplenium glechomifolium (CRPR 4.3) in the Survey Area. .............................................................................................................................. 26 Appendices Appendix A. Special-status Plant and CDFW Sensitive Natural Communities Scoping Lists Appendix B. Comprehensive List of Vascular Plant Species Observed in the Survey Area Appendix C. CNDDB Forms for Special-status Plant Species Observed in the Survey Area September 2019 Stillwater Sciences ii Special-Status Plant Surveys for the McKay Community Forest Trail Plan Implementation Project 1 PROJECT DESCRIPTION 1.1 Background In August 2014, Humboldt County acquired 1,000 acres of forestland from the Green Diamond Resource Company as the first phase of developing the McKay Community Forest (MCF) located southeast of Eureka, California (Figure 1). Humboldt County Department of Public Works is proposing to construct a system of trails in the MCF that will include hiking trails, mountain biking trails, multi-use trails, and multi-use roads. Multi-use roads will be utilized as trails but will also serve as roads and hauling routes to support timber harvesting that will be conducted in the future as part of the overall management of the MCF. The first portion of the trail system is proposed to be implemented in 2019/2020 (Project), additional trail construction will be planned for and implemented in the future. In support of this phased trail implementation, Stillwater Sciences (Stillwater) conducted protocol-level special-status plant surveys along the proposed trail alignments throughout a portion of the MCF. 1.2 Project Location and Survey Area The MCF is located southeast of the city of Eureka adjacent to the unincorporated communities of Cutten, Myrtletown, and Ridgewood Heights within Humboldt County within the Freshwater Creek watershed of the Eureka Plain hydrologic unit, which includes Ryan Creek and Ryan Slough (Figure 1). The Project is located in Sections 31 and 36 of Township 5 North, Range 1 West and Sections 1, 2, 11, 12, and 13 of Township 4 North, Range 1 West of the Eureka, Fields Landing, and Arcata South U.S. Geological Survey (USGS) 7.5-minute topographic quadrangles. Elevations range from approximately 10 feet [ft] to 310 ft above mean sea level. The special-status plant survey area (Survey Area) includes the following trail units within the MCF (Figure 1): Redwood Acres (all trail segments except RA-18, RA-19, and RA-20) Northridge (all trail segments) Mid-McKay (all trail segments) South McKay (SM-01 and SM-02) September 2019 Stillwater Sciences 1 Special-Status Plant Surveys for the McKay Community Forest Trail Plan Implementation Project 1.3 Purpose of the Special-status Plant Survey The purpose of the survey was to document the presence of any special-status plant species or sensitive natural communities within the Survey Area. Special-status plant species are defined as those listed, proposed, or under review as threatened or endangered under the federal Endangered Species Act of 1973 (FESA) and/or the California Endangered Species Act (CESA); designated as rare under the California Native Plant Protection Act (CNPPA); and/or taxa that meet the criteria for listing as described in Section 15380 of the California Environmental Quality Act of 1970 (CEQA) Guidelines, including species listed on California Department of Fish and Wildlife’s (CDFW’s) Special Vascular Plants, Bryophytes, and Lichens List (CDFW 2018a), plants with a California Rare Plant Rank (CRPR) of 1, 2, 3, or 4, and/or considered a locally significant species (i.e., rare or uncommon in the county or region). Sensitive natural communities are defined as those natural community types (i.e., legacy natural communities in CDFW’s California Natural Diversity Database [CNDDB], vegetation alliances and/or associations) with a state ranking of S1 (critically imperiled), S2 (imperiled), or S3 (vulnerable) on CDFW’s California Sensitive Natural Communities List (CDFW 2018b) or in the CNDDB (CDFW 2019). September 2019 Stillwater Sciences 2 Special-Status Plant Surveys for the McKay Community Forest Trail Plan Implementation Project Figure 1. Survey Area and trail units within the MCF. September 2019 Stillwater Sciences 3 Special-Status Plant Surveys for the McKay Community Forest Trail Plan Implementation Project 2 METHODS 2.1 Establishing the List of Species that Could Occur in the Survey Area A list of special-status plants and sensitive natural communities that may occur in the Survey Area was developed by querying the following resources: The U.S. Fish and Wildlife Service (USFWS) online Information for Planning and Consultation (IPaC) (USFWS 2019), The California Native Plant Society’s