Botanical Resources Report Gemini Solar Project N-84631 Clark County, Nevada Prepared for: Arevia Power & Solar Partners XI, LLC (a wholly owned subsidiary of Valley of Fire, LLC) Prepared by: Phoenix Biological Consulting July 2018 Table of Contents Introduction .................................................................................................................................................. 1 Project Description ................................................................................................................................... 1 Environmental Setting .............................................................................................................................. 4 Methods ........................................................................................................................................................ 6 Pre-project Review ................................................................................................................................... 6 Reconnaissance Visits ............................................................................................................................... 8 Identification of Native Plant Communities and Soils .............................................................................. 8 Reference Site Visits ................................................................................................................................. 8 Vegetation Sampling Survey Methodology ............................................................................................ 10 Special-status Plant Inventory Methodology ......................................................................................... 11 Cacti/Yucca, Invasive Weeds, and Biocrust/Desert Pavement Sampling Survey Methodology ............ 14 Results ......................................................................................................................................................... 18 Native Plant Communities ...................................................................................................................... 18 Vegetation Sampling ............................................................................................................................... 24 Special-status Plant Inventory ................................................................................................................ 33 Cacti and Yucca, Invasive Weeds, and Biocrust and Desert Pavement Sampling .................................. 41 Discussion.................................................................................................................................................... 66 Special-status Plant Species .................................................................................................................... 66 Native Plant Communities ...................................................................................................................... 68 Cacti/Yucca and Biocrust/Desert Pavement ........................................................................................... 68 Impact Analysis ........................................................................................................................................... 69 Special-status Plant Species .................................................................................................................... 69 Native Plant Communities ...................................................................................................................... 69 Cacti/Yucca and Biocrust/Desert Pavement ........................................................................................... 69 Surveyor Qualifications ............................................................................................................................... 72 References .................................................................................................................................................. 75 Figures Figure 1. Gemini Solar Project Location ........................................................................................................ 2 Figure 2. Gemini Solar Project Study Area .................................................................................................... 3 Figure 3. Nevada Natural Heritage Program Results in the Gemini Study Area. .......................................... 7 Figure 4. BLM Weed Inventory Data (BLM 2014) ....................................................................................... 17 Figure 5. Vegetation Communities in the Study Area ................................................................................. 22 Figure 6. Soils in the Study Area ................................................................................................................. 23 Figure 7. Special-status Plant Populations Identified in the Study Area ..................................................... 35 Figure 8. Threecorner Milkvetch Population Distribution in the Study Area ............................................. 38 Figure 9. Cacti and Yucca, Invasive Weeds, and Biocrust and Desert Pavement Sampling Transects in the Study Area ................................................................................................................................................... 43 Figure 10. Belt Transect Cacti Sampling - Cylindropuntia echinocarpa ...................................................... 47 Figure 11. Belt Transect Cacti Sampling - Cylindropuntia ramosissima ...................................................... 48 Figure 12. Belt Transect Cacti Sampling - Echinocactus polycephalus ........................................................ 49 Figure 13. Belt Transect Cacti Sampling - Echinocereus engelmannii ......................................................... 50 Figure 14. Belt Transect Cacti Sampling - Opuntia basilaris ....................................................................... 51 Figure 15. Belt Transect Results - Areas with Biocrust ............................................................................... 53 Figure 16. Belt Transect Results - Areas with Desert Pavement ................................................................. 54 Figure 17. Weed Sampling Results - Brassica tournefortii .......................................................................... 56 Botanical Resources Report Phoenix Biological Consulting Gemini Solar Project July 2018 i Figure 18. Weed Sampling Results - Halogeton glomeratus ...................................................................... 57 Figure 19. Weed Sampling Results - Strigosella Africana ........................................................................... 58 Figure 20. Weed Inventory Data and Vectors (Northern Area) .................................................................. 63 Figure 21. Weed Inventory Data and Vectors (Southern Area) .................................................................. 64 Figure 22. Weed Inventory Data and Vectors (Central Area) ..................................................................... 65 Figure 23. Plan of Development Features................................................................................................... 71 Tables Table 1. Average monthly precipitation and temperature from Valley of Fire State Park. .......................... 4 Table 2. Precipitation from Valley of Fire State Park CNRFC, September 2017-June 2018. ......................... 6 Table 3. Special-status plant inventory survey dates and rare plant species identified............................. 13 Table 4. Size and proportion of vegetation communities in the Study Area areas A-G, B1 and B 2 and the approximate linear distance of transects needed to capture a representative sample from each community. ................................................................................................................................................. 14 Table 5. Weed inventory species mapped by the BLM in the vicinity of the Study Area (BLM 2014). ...... 15 Table 6. Area and proportion of each vegetation community in the Study Area. ...................................... 18 Table 7. Soil units identified in the Study Area (NRCS 2018). ..................................................................... 21 Table 8. Percent cover, density, average species richness, and total number of species for each vegetation alliance recorded during AIM sampling. ................................................................................... 24 Table 9. Percent cover estimates by species in the Creosote-White Burrobush Shrubland Alliance......... 25 Table 10. Plant density by species in the Creosote-White Burrobush Shrubland Alliance......................... 26 Table 11. Percent cover estimates by species in the Shadscale Shrubland Alliance. ................................. 27 Table 12. Plant density by species in the Shadscale Shrubland Alliance. ................................................... 28 Table 13. Percent cover estimates by species in the Big Galleta Herbaceous Alliance. ............................. 29 Table 14. Plant density by species in the Big Galleta Herbaceous Alliance. ............................................... 30 Table 15. Percent cover estimates by species in the Catclaw Acacia Shrubland Alliance. ......................... 31 Table 16. Plant density by species in the Catclaw Acacia Shrubland Alliance. ..........................................