可溶性有机碳在米槠天然林土壤中的淋溶特征  

Movement of Dissolved Organic Carbon in Natural Forest Soil of Castanopsis carlesii

作　　者：熊丽[1,2] 杨玉盛[1,2] 王巧珍[3] 杨智杰[1,2] 黄惠[2] 司友涛[1,2] 

机构地区：[1]福建省湿润亚热带山地生态重点实验室省部共建国家重点实验室培育基地,福州350007 [2]福建师范大学地理科学学院,福州350007 [3]福建农林大学莘口教学林场,福建三明365009

出　　处：《亚热带资源与环境学报》2014年第1期46-52,共7页Journal of Subtropical Resources and Environment

基　　金：国家自然科学青年基金项目(31100467);国家自然科学基金重点项目(31130013);福建省自然科学青年基金项目(2011J05105);福建师范大学优秀青年骨干教师培养基金(fjsdky2012008)

摘　　要：以中亚热带米槠天然林为研究对象，通过挖剖面法，按0～10 cm、10～20 cm、20～30 cm、30～40 cm、40～50 cm、50～60 cm、60～70 cm、70～80 cm、80～90 cm、90～100 cm分层采集原状土柱，并用米槠叶片制备的可溶性有机碳（ dissolved organic carbon ， DOC）溶液进行逐层淋溶试验，以阐明DOC在米槠天然林土壤中的淋溶特征。结果表明，在淋溶过程中DOC浓度逐渐下降， DOC最大截留量出现在50～60 cm土层，而且60～100 cm各土层的截留量要小于0～60 cm各土层。淋溶过程中DOC的芳香性和腐殖化程度随土层深度均逐渐下降。红外光谱表明， DOC溶液在土壤淋溶过程中，芳香类、羧酸类等大分子物质会被优先吸附，并且通过0～30 cm土层时土壤中的醇类、酚类小分子物质会发生解吸附， DOC在30～100 cm土层中淋溶时小分子物质的比例明显增加。说明DOC在土壤淋溶过程中会优先吸附芳香化合物和大分子物质，到达底层土壤的DOC溶液中小分子物质所占比例增加，因此DOC对土壤的亲和力降低，减少了土壤的截留量，表明DOC本身的化学性质要比土壤的理化性质更能影响其吸附行为。To reveal dynamics of dissolved organic carbon （ DOC） transporting through soils and bet-ter understand carbon sequestration potential in mid-subtropical China , intact soil cores were sampled from 0 to 100 cm, at a 10 cm increment, from each of the three profiles in a natural Castanopsis car-lesii forest.After extracting DOC from the leaves of the same Castanopsis carlesii stand with ultrapure water, we leached the DOC through the ten successive layers in the laboratory .The result shows that DOC concentration of the leachates decrease with depth , with a maximum retention of DOC occurring＆amp;nbsp;in the 50~60 cm horizon.And, the retention amount of DOC in 60~100 cm layers is smaller than that in 0~60 cm layers.The aromaticity and humification index also gradually decrease with soil depth when DOC transports through soils .Infrared spectrum suggests macromolecular substances bearing aro-matic and carboxylic groups can be absorbed by soil preferentially , the indigenous simple molecules such as phenols and alcohols can be desorbed from soils of 0~30 cm layers, and the content of this sort of simple molecules increases significantly when DOC transporting through 30 ~100 cm layers. Because of preferential absorption of complex and aromatic DOC molecules by topsoils , the subsoils can only receive more simple molecules , which have a weak affinity to deep soils , and reduce the ca-pacity of DOC retention , indicating that chemical properties of DOC have greater effects on adsorption than soil properties .

关 键 词：可溶性有机碳 (DOC) 淋溶 吸附 光谱 dissolved ORGANIC CARBON (DOC) 

分 类 号：S718.5[农业科学—林学]