A Vascular Flora of the Sacatar Trail Wilderness, Sierra Nevada, California

The Sacatar Trail Wilderness in Inyo and Tulare counties, California, encompasses a bioregional transition zone in the southeastern Sierra Nevada. The ca. 233 km 2 (90 mi 2 ) study area, located 32 km (20 mi) northwest of the city of Ridgecrest, ranges from 930 to 2698 m (3051–8851 ft) in elevation. The highly diverse California Floristic Province, Great Basin, and Mojave Desert converge in the region including the Wilderness creating conditions to support a broad spectrum of vegetation assemblages. The Bureau of Land Management has prohibited vehicular activity in this area since its wilderness designation in 1994; consequently, recent human impact has been minimal. Grazing, however, is still permitted throughout most of the wilderness and is a potential threat to the native flora. This area was considered a “botanical black hole” prior to 2022 with limited documentation of the plants that occur there. The primary goal of this project was to better document the vascular flora of the Sacatar Trail Wilderness and generate an annotated checklist supported by herbarium specimens. Over the course of this study in 2022 and 2023, 77 days were spent in the field and a total of 1,505 herbarium specimens were collected. With the addition of 578 historical collections, a vascular plant inventory was produced for the Sacatar Trail Wilderness that includes 507 minimum-rank taxa from 74 plant families. Over half of the checklist (266 minimum-rank taxa) were newly documented within the study area including 21 new county records. Twenty-four special-status (rare) taxa were observed, as well as 32 non-native taxa. Additionally, temperature data loggers were installed, and vegetation surveys were conducted along two transects spanning the study area’s elevational gradient at 305 m (1000 ft) intervals. This was done to associate localized temperature ranges with plant distribution and community composition. Background information about the study area, as well as temperature, vegetation, and floristic results are presented. In the context of climate change, this study is intended to serve as baseline data for future research in plant diversity and distribution shifts.