Surface heat exceeds air temperature regulates topsoil quality over the arid-cold regions

Abstract

Transpiration cooling, induced by vegetation greening in a warming climate, controls changes in soil quality, which affects plant productivity, establishing a positive feedback. However, this feedback mechanism for soil quality is largely unknown. Here we analyze empirical data from microbial, soil, plant and climatic properties (all n=30), to explore the determinants of soil quality and build a its mechanism framework over broad environmental gradients. We find high topsoil quality (significantly different at P<0.01) is associated with high nutrient content, microbial biomass, and physico-chemical protection under low sensible heat flux release. Physiochemical mechanisms play an extremely key role in regulating the topsoil quality than biological mechanisms. Models suggest that vegetation greening, which could lead to a decrease in sensible heat and an increase in latent heat. The dependence of topsoil quality on surface energy dynamic changes should be considered in Ecological Meteorological Models to accurately predict land-atmosphere feedbacks in changing environments.