降雨季节亚热带常绿阔叶林透冠雨对土壤可溶性有机质的迁移作用  

Effects of Throughfall on the Migration of Soil Dissolved Organic Matter in Subtropical Evergreen Broad-leaved Forest During Rainfall Season

作　　者：王宏宇 吴福忠 张耀艺 郑旭灵 吴捷录 张雪 张欣影 WANG Hongyu;WU Fuzhong;ZHANG Yaoyi;ZHENG Xuling;WU Jielu;ZHANG Xue;ZHANG Xinying(School of Geographical Sciences,Fujian Normal University,Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education,Fuzhou 350117,China;Fujian Sanming Forest Ecosystem National Observation and Research Station,Sanming,Fujian 365002,China)

机构地区：[1]福建师范大学地理科学学院,湿润亚热带生态-地理过程教育部重点实验室,福州350117 [2]福建三明森林生态系统国家野外科学观测研究站,福建三明365002

出　　处：《水土保持学报》2024年第4期181-189,197,共10页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(32171641,32101509,32271633)。

摘　　要：[目的]作为森林土壤中活性最高的组分,可溶性有机质(DOM)不仅可以直接被微生物利用,还是生态系统中C、N、P等元素迁移的主要载体,其迁移过程受到透冠雨驱动的水力作用和溶解过程的影响。[方法]通过野外原位控制透冠雨输入试验,以亚热带常绿阔叶林的砂质红壤为对象,对照林窗降雨,分析降雨季节森林透冠雨对不同土层土壤可溶性有机碳(DOC)、可溶性有机氮(DON)和可溶性有机磷(DOP)动态变化的影响。[结果](1)相对于林窗降雨,整个降雨季节以透冠雨为载体输入到土壤的DOM显著增加(p<0.01),DOC、DON和DOP浓度分别增加37.00%,93.47%,85.12%,DOC、DON和DOP通量分别增加20.76%,49.93%,61.55%,但通过40 cm深土壤后,其输出通量差异并不显著,表明土壤对透冠雨中DOM具有较强的吸收能力。(2)相较于林窗降雨,透冠雨显著降低土壤表层输入C/N的29.19%,C/P的26.00%,而无明显改变N/P,而经过40 cm深土壤后,透冠雨显著降低土壤40 cm深度输入C/N的19.35%,C/P的13.35%和N/P的7.45%。表明透冠雨DOM增加主要是因为吸收冠层中的DON与DOP,而在土壤中DOM减少部分主要集中在DOC与DOP。(3)土壤DOC与DOP表现为截留减少,而DON表现为富集增加。相较于林窗降雨,透冠雨显著增加0—40 cm土壤对DOC截留量的39.93%和DOP截留量的72.42%,显著减少对DON释放量的32.37%。[结论]研究结果充分证明亚热带常绿阔叶林透冠雨能促进DOM的输入,有利于土壤各层次对DOM的吸收,对于生态系统可持续经营和管理具有一定的科学意义。[Objective]As the most active component in forest soil,dissolved organic matter(DOM)can not only be directly utilized by microorganisms,but also be the main carrier for the migration of C,N,P and other elements in the ecosystem.The migration process is influenced by the hydraulic interactions and dissolving processes driven by throughfall.[Methods]Using soil column microcosm in situ culture to analyze the effects of forest throughfall on the dynamics of dissolved organic carbon(DOC),dissolved organic nitrogen(DON),and dissolved organic phosphorus(DOP)across varying layers of sandy red soil during the rainy season.The study focused on a subtropical evergreen broad-leaved forest with rainfall as a control.[Results](1)During the rainfall season,the DOM input of throughfall into soil increased significantly compared with rainfall(p<0.01).The concentrations of DOC,DON and DOP increased by 37.00%,93.47%,and 85.12%,respectively,and the fluxes of DOC,DON and DOP also increased by 20.76%,49.93%,and 61.55%,respectively.However,there was no significant difference in output fluxes after passing through the 40 cm deep soil,indicating a strong capacity of the soil to absorb DOM from throughfall.(2)Compared to rainfall,throughfall reduced the C/N and C/P ratios of the soil surface by 29.19%and 26.00%,respectively,without significantly affecting N/P ratios.After passing through 40 cm of soil,throughfall reduced the input C/N,C/P and N/P ratios of the soil by 19.35%,13.35%and 7.45%,respectively.The increase in DOM in throughfall was mainly due to the absorption of DON and DOP in the canopy,while the decrease in soil DOM was mainly concentrated in DOC and DOP.(3)Soil DOC and DOP showed a reduction in interception,while DON showed an increase in enrichment.Throughfall increased the interception of DOC and DOP in the 0-40 cm soil by 39.93%and 72.42%,respectively,and significantly reduced the release of DON by 32.37%.[Conclusion]These results demonstrate that throughfall in a subtropical evergreen broad-leaved forest can promote the

关 键 词：亚热带森林 砂质红壤 可溶性有机质 林冠截留 林窗降雨 

分 类 号：S715.3[农业科学—林学]