Land use type dominates soil microbial element limitations in a subtropical plateau, China

Abstract

Land use type, vegetation type (artificial or natural) and microbes play a key role in flux of soil matter and energy in subtropical ecosystems. However, microbial element limitations in these ecosystems have been largely unexplored. Here, microbial element limitations under four representative land uses grouped into two vegetation types (artificial or natural) were characterized using enzymatic vector analysis, their drivers were deciphered using redundancy analysis in a subtropical region, Southwestern China. Enzymatic vector analysis showed that soil microbes suffered from carbon (C) & nitrogen (N) limitations in cropland and forestland related to artificial vegetation, but C, N & phosphorus (P) limitations in grassland and shrub land related to natural vegetation. Two-way ANOVA showed land use type and vegetation type (artificial/natural) were the major forces driving C and NP limitations. Redundancy analysis identified that soil total N was the major factor affecting soil microbial C limitation, soil total P was the major factor affecting soil microbial NP limitations. This study implied that conversion of natural vegetation to artificial vegetation would shift microbial element limitations from C, N & P limitation to C & N limitation, and exacerbate N limitation.