A survey of vascular plant species in paired shrub and open microsites in southern California drylands

We conducted vegetation surveys across several sites in southern California drylands in early spring 2023 to identify patterns in plant diversity across habitat types and an aridity gradient. Locations sampled include sites in Carrizo Plains National Monument, Cuyama Valley, and sites near Tecopa and Semitropic. Surveys were conducted at two spatial scales - 1m x 1m2 paired quadrats and 1m x 10m transects. All plants in 1m2 quadrats and 10m2 transect were identified to species. In quadrats, all individuals were counted, while in transects total percent cover was estimated. Quadrats were placed under randomly selected shrubs and a paired open plot in shrub habitats, and randomly selected paired locations in open habitats. The dominant shrub species was Ephedra californica at most sites. This survey continues long-term vegetation tracking in California drylands aimed at understanding how foundational species influence regional plant diversity.