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作 者 ：邓艳,蒋忠诚,覃星铭,祁晓凡,蓝芙宁,吴华英

期 刊 ：生态学报 2009年 29卷 6期 页码：3307~3315

关键词：岩溶生态系统；枯落物；土壤理化性质；表层岩溶泉；岩溶效应；

Keywords:karst ecosystem, litter, soil physical and chemical properties, epikarst spring, karst effect,

摘 要 ：对广西弄拉岩溶生态系统中60a成熟林、20a乔幼林和10a灌丛的枯落物、土壤理化性质和岩溶效应进行了研究。研究表明：（1）成熟林、乔幼林和灌丛调落物储量分别为18.4、16.9、1.9 t/hm2，通过凋落物归还土壤的营养元素(N、P、K、Ca、Mg、Si、Al、Fe、Zn、Cu、Na 、Mn)的年归还总量依次为：乔幼林(4.657 t/hm2)>成熟林(4.068 t/hm2)>灌丛（0.193 t/hm2）。弄拉成熟林的枯落物储量是灌丛的10倍，枯落物12种元素的归还量是其21倍。（2）成熟林枯落物有效拦蓄量是灌丛的11倍，保障了土壤的持水能力。（3）随着土壤的加深，枯落物对其影响减弱。深层土壤的理化性质主要受母岩的影响，化学性质比较稳定，而表层土受枯落物和植被影响大，枯落物的储量、分解程度和组分等控制着表层土有机质、有效N/P/K、有效锰、有效锌等有效态的含量，对元素的全量分布影响不大，影响土壤元素全量空间分布的因子主要是母岩。枯落物可以促进碳酸盐岩的成土速率。植被的发育程度越高，其涵养的表层岩溶泉的溶质含量越多。枯落物的存在增加了水在表层岩溶动力系统中的滞留时间，同时给岩溶生态系统注入更多的有机质和CO2，加速表层岩溶动力系统的运行。

Abstract:In forested karst ecosystems,the effects of litter on soil properties are not fully understood.We conducted a study in 60 years old mature forest(S1),20 years old earlier arbor forest(S2) and 10 years old shrub(S3) in the Nongla karst ecosystem of Guangxi,China. Physical and chemical properties of Litter and soil ware examined to understand the effects of litter on soil properties.Our data showed that the reserves of litters in S1,S2 and S3 were 18.4、16.9、1.9 t/hm2,respectively.The total nanual nmounts of nutrient elements((N、P、K、Ca、Mg、Si、Al、Fe、Zn、Cu、Na and Mn) returning to soil from the litters at S1,S2 and S3 were 4.657, 4.068 t/hm2 and 0.193 t/hm2, respectively.The reserves of litters at S1 were ten times greater than that at S3. The effective water holding depth of litter layer at S1 were 11 times greater than that of S3, enhancing the eco-hydrological function of forest soil. Properties of deeper soils are less influenced by litter than shallower ones.Properties of deeper soils are more influenced by the rock,while the upper soils are more influenced by plants and litter.Nutrient behavior in the upper soil,including contents of organic matter, available N/P/K,were controlled by the reserves,content and decomposition of litters.Litter can speed up the formation of limestone soil in karst area.Litter can improve water storage in the epikarst dynamic system.At the same time,it can imputs more organic matter and CO2 to the karst ecosystem,accelerating its evolution.

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