FUNCTIONAL GROUP DYNAMICS OF SOIL ORGANIC MATTER DECOMPOSITION IN FOREST AND GRASS ECOSYSTEMS DESCRIBED BY NMR, DIFFERENTIAL UV-VIS AND FT-IR SPECTROSCOPY

摘要

During the process of soil organic matter (SOM) decomposition, dissolved organic carbon (DOC) leached from SOM parent material undergoes structural changes that affect such processes as DOC bioavailability, soil acidity, metal complexation, mineral dissolution, and pollutant transport. During precipitation events, leaching of O horizon material by rainwater transports organic carbon to mineral soil, but in that process soil microbial communities rapidly decompose this carbon, which is used for metabolic substrate, respired as CO_2, generation of biomass, or converted to recalcitrant humic material. In this study we use a combination of spectroscopic approaches, each sensitive to a different set of organic moieties, in efforts to describe the oxidative production of soluble organic carbon derived from decomposing forest and grass organic matter.