华南典型树种凋落叶的野外分解和溶解性有机质溶出动态  

Field decomposition and dissolved organic matter release dynamics in leaf litter of typical trees in South China

作　　者：蔡丹[1] 杨秀虹[2] 雷秋霜 方志文[1] 王诗忠[1,3] 仇荣亮[1,3] 杨燕花[3] 

机构地区：[1]中山大学环境科学与工程学院,广州510275 [2]中山大学珠海校区实验教学中心,广东珠海519082 [3]中山大学广东省环境污染控制与修复技术重点实验室,广州510275

出　　处：《应用生态学报》2016年第9期2823-2830,共8页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41001322);中央高校基本科研业务费专项资金项目(11lgpy98)资助~~

摘　　要：选用华南亚热带地区常见阔叶树种木荷和针叶树种湿地松的新近凋落叶,在野外分解0、30、60、90、150、210、240、365 d,分析溶出的溶解性有机质(DOM)浓度、组成和性质的变化,以及对土壤可溶性有机碳(DOC)的影响.结果表明:随着分解的进行,尽管木荷叶片的DOM浓度高于松针,但是2种凋落叶DOM浓度、性质和物质组成变化规律一致;2种凋落叶的DOM浓度均呈下降趋势,芳香化程度和分子量增大,富里酸、腐殖酸类物质逐渐增多,可降解的简单芳烃蛋白(如酪氨酸)逐渐减少.在分解初期,DOM主要由亲水中性和酸性部分组成,易分解、易迁移,对表层土壤DOC影响不显著;在分解后期,DOM主要为腐殖酸和富里酸类物质,吸附性强,表层土壤DOC浓度显著下降.Leaf litters of Pinus elliottii （needle-leaved） and Schima superba （ broad-leaved）, which are commonly found in subtropical regions of South China, were decomposed in a field for 0, 30, 60, 90, 150, 210, 240 and 365 d to evaluate changes in concentrations, compositions and proper- ties, and amount of dissolved organic matter （DOM） released and dissolved organic carbon （DOC） in soil. Although the concentrations of DOM derived from S. superba were higher than those from P. elliottii, similar variation patterns of DOM characteristics （ e.g., concentrations, composition and properties） were observed between the two types of litter during decomposition. The concentrations of DOM showed a downward trend. Upward trends were obtained for the aromatization and molecular mass of DOM, as well as fulvic acid and humic acid levels in DOM, while a downward trend was found for levels of simple aromatic proteins, such as tyrosine, in DOM. During the initial phase of decomposition, DOM was generally composed of hydrophilic neutral and acidic components, which were easily decomposed and transferred, and their effects on surface soil DOC were not significant. At later stages, DOM was mainly composed of humic and fulvic acid and other aromatic, complex structure substances, which could easily adsorb on soil, and decreased the DOC concentration of surface soil.

关 键 词：森林凋落物 溶解性有机质 土壤有机碳 

分 类 号：S714[农业科学—林学]