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

Abstract

Abstract. 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.

What can local and geographic population limits tell us about distributions?

“…Belowground niche factors or axes of variation can be critical to plant success ( Janssens et al, 1998 ;Turnau and Haselwandter, 2002 ;Potthoff et al, 2006 ;Heneghan et al, 2008 ;Huff ord et al, 2014 ). At our M. leptaleus site, no obvious factors (e.g., herbivory or plant competition) were observed that could explain the inability of plants to develop seeds.…”

Spatial patch structure and adaptive strategy for desert shrub of Reaumuria soongorica in arid ecosystem of the Heihe River Basin

“…As a consequence, in the groundwater-dominant sites, R. soongorica was motivated to expand its mean individual size and biomass to resist drought stress by maintaining consistent water availability, while in precipitation-dominant sites, net "facilitation-competition" interactions could be balanced by R. soongorica due to its flexible water use pattern. The heterogeneity of soil physicochemical properties determines vegetation patch dynamics (Hufford et al, 2014). Patch size increased with decreasing MAP on both sand and loam soils but declined slightly on clay soil (Ludwig et al, 1999).…”

Heterogeneity-diversity Relationships in Natural Areas of Yunnan, China

“…To deal with this dilemma, some researchers have proposed dealing with systematic conservation planning by coupling environmental variables (e.g., topography, climate, soil) with biodiversity surrogates (Hufford et al, 2014;Heller et al, 2015;Tukiainen et al, 2017). The essence of idea is that conserving environmentally heterogeneous landscapes supports diverse species and communities in a region, which is consistent with niche theory (MacArthur 1970;Ricklefs 1977;Stein et al, 2014).…”