Lithological and bioclimatic impacts on soil phosphatase activities in California temperate forests

Abstract Organic phosphorus (Po) biogeochemical cycling is known to be impacted by soil forming factors, however, little is known about interactions among soil forming factors on the drivers of Po cycling, activities of phosphatase in soils. A comprehensive assessment of lithological and bioclimatic impacts on soil phosphatases was conducted using lithological and vegetation-constrained climatic (i.e., bioclimatic) gradients in the California areas. We hypothesized that lithology and bioclimate would impact phosphatase activities interactively. Soils (0–5, 5–15 cm depth) from twelve combinations of three lithologies (andesite, basalt, granite) and four bioclimatic zones (blue oak, ponderosa pine, red fir, white fir) encompassing a wide range of MAP (330–1400 mm) and MAT (5.0–17.0 °C) were analyzed for resin P (Presin), Po, microbial biomass P and total P (Pt), activities of three phosphatase types, and soil properties (e.g., organic carbon [OC], pedogenic minerals). Across soil depths, lithology influenced phosphomonoesterase (ACP, ALP) activities more than bioclimate, whereas the opposite occurred for phosphodiesterase (PDE). Correlations of phosphatases with edaphic (e.g., pedogenic minerals, clay content) and climatic variables (MAP, MAT) varied by lithology (e.g., ACP and OC, Rbasalt = 0.61, p