土壤中水溶性有机质及其对重金属化学与生物行为的影响

土壤水溶性有机质是陆地生态系统和水生生态系统中一种重要的、很活跃的化学组分，已成为环境科学、土壤学和生态学等学科的研究热点．土壤DOM对重金属化学与生物行为有重要影响。但其机理尚不清楚．文中从土壤性质、环境条件、人为因素等方面阐述了土壤DOM产生及影响因素，总结评述了DOM对重金属化学行为和生物有效性的影响，将DOM对重金属的影响机制归纳为络合机制、竞争吸附机制、酸碱缓冲机制．在此基础上，提出了DOM研究存在的问题及其展望．

Soil dissolved organic matter and its effect on chemical and biological behaviors of soil heavy metals

Dissolved organic matter (DOM) is an important and active component in both terrestrial and aquatic ecosystems,while soil DOM plays an important role in the pedogenesis,mineral weathering,and translocation of pollutants in soils.It has become a hotspot in environment science,soil science and ecology.Soil DOM has important effects on the chemical and biological behaviors of heavy metals in soil plant system,but its mechanism is not identified.The study on soil DOM in China was still in its initial stages,and most studies only reported that the activity of heavy metals in soils was affected by the DOM produced from organic fertilizer.This review is to summarize the recent literatures regarding the formation of soil DOM and its affecting factors,and the effect of soil DOM on the chemical and biological behaviors of heavy metals in soils.The main affecting mechanisms of soil DOM on behaviors of soil heavy metals were summarized as complexing with heavy metals,competing with metals for adsorption sites,and affecting soil pH value.