Chemodiversity\nof Soil Dissolved Organic Matter

Abstract

Dissolved\norganic matter (DOM) plays a key role in many biogeochemical\nprocesses, but the drivers controlling the diversity of chemical composition\nand properties of DOM molecules (chemodiversity) in soils are poorly\nunderstood. It has also been debated whether environmental conditions\nor intrinsic molecular properties control the accumulation and persistence\nof DOM due to the complexity of both molecular composition of DOM\nand interactions between DOM and surrounding environments. In this\nstudy, soil DOM samples were extracted from 33 soils collected from\ndifferent regions of China, and we investigated the effects of climate\nand soil properties on the chemodiversity of DOM across different\nregions of China, employing a combination of Fourier transform ion\ncyclotron resonance mass spectrometry, optical spectroscopy, and statistical\nanalyses. Our results indicated that, despite the heterogeneity of\nsoil samples and complex influencing factors, aridity and clay can\naccount for the majority of the variations of DOM chemical composition.\nThe finding implied that DOM chemodiversity is an ecosystem property\nclosely related to the environment, and can be used in developing\nlarge-scale soil biogeochemistry models for predicting C cycling in\nsoils.