Soil heterogeneity and the distribution of native grasses in California: Can soil properties inform restoration plans?

When historical vegetation patterns are unknown and local environments are highly degraded, the relationship between plant species distributions and environmental properties may provide a means to determine which species are suitable for individual restoration sites. We investigated the role of edaphic variation in explaining the distributions of three native bunchgrass species ( Bromus carinatus , Elymus glaucus and Nassella pulchra ) among central California mainland and island grasslands. The relative contribution of soil properties and spatial variation to native grass species abundance was estimated using canonical redundancy analysis, with subsequent testing of individual variables identified in ordination. Soil variables predicted a significant proportion (22–27%) of the variation in species distributions. Abiotic soil properties that drive species distributions included serpentine substrates and soil texture. Biotic properties that correlated with species distributions were ammonium and nitrogen mineralization rates. Spatial autocorrelation also contributed to species presence or absence at each site, and the significant negative autocorrelation suggested that species interactions and niche differentiation may play a role in species distributions in central California mainland and island grasslands. We explored the application of plant‐environment relationships to ecological restoration for species selection at locations where degradation levels are high and historical communities are unclear.