植物多样性与生态系统土壤保持功能关系及其生态学意义  

THE RELATIONSHIP OF PLANT SPECIES DIVERSITY TO ECOSYSTEM FUNCTION IN RELATION TO SOIL CONSERVATION IN SEMI-HUMID EVERGREEN FORESTS, YUNNAN PROVINCE,CHINA

作　　者：王震洪[1] 段昌群[2] 侯永平[2] 杨建松[1] 

机构地区：[1]贵州大学生命科学学院,贵阳550025 [2]云南大学生命科学学院,昆明650091

出　　处：《植物生态学报》2006年第3期392-403,共12页Chinese Journal of Plant Ecology

基　　金：贵州大学人才基金(2003F00bs002);国家科技攀登计划(国科基字2000(026));云南省自然科学基金重点项目(2000C0001P)

摘　　要：测定物种丰富度呈梯度变化的半湿润常绿阔叶林不同次生演替阶段小区地表径流、土壤侵蚀和总磷流失及影响这些过程的植物群落郁闭度、个体密度、胸高断面积、植物叶吸附水,分析物种多样性与生态系统土壤保持功能、稳定性及直接影响土壤保持功能的群落结构、树冠截留间的关系。结果表明,在降雨、坡度、坡向、坡位、土壤类型等水土保持影响因子相同条件下,随着各小区物种多样性的增加,地表产流次数不断下降;在3个降雨季节,物种多样性最低的小区产生地表径流77次,而物种多样性最高小区产生地表径流才9次;系列小区地表径流、土壤侵蚀和总磷流失随着物种多样性增加呈幂指数下降;物种多样性最低的小区地表径流、土壤侵蚀和总磷流失分别为960.20m3·hm-2·a-1,11.4t·hm-2·a-1,127.69kg·hm-2·a-1,而物种多样性最高的小区为75.55m3·hm-2·a-1、0.28t·hm-2·a-1、4.71kg·hm-2·a-1,分别相差12、50和25倍;地表径流、土壤侵蚀和总磷流失变异系数也呈幂指数下降,物种多样性最高的小区地表径流、土壤侵蚀和总磷流失的变异系数分别为57.93、187.94和59.2,而物种多样性最低的小区变异系数高达287.6、534.21、315.47,分别相差4、3和5倍。物种多样性与影响土壤保持功能的群落郁闭度、密度和胸高断面积呈正相关关系。不同演替阶段植物叶吸附水量差异显著,吸附水量最高的演替阶段是次生半湿润常绿阔叶林,为12.28t·hm-2·a-1,最低是云南松(Pinusyunnanensis)林,为4.15t·hm-2·a-1。“植物多样性_土壤保持功能相关群落结构因子及树冠截留效应_生态系统土壤保持功能”的耦合关系表明了植物多样性通过植物群落结构削弱了降雨动能,减少了地表径流,减轻了土壤及营养元素的流失,以间接方式调控生态系统土壤保持功能,维持系统营养的持续性,在不同尺度上实现生态系统生产力。�In recent years, the relationship of biodiversity to ecosystem stability, productivity and other ecosystem functions have been researched by using theoretical approaches, experimental investigations and observations in natural ecosystems, however, results have been controversial. For example, simple systems were more stable than complex systems in theoretical studies, higher productivity was observed in man-made ecosystems with poorer species composition than in natural ecosystems with more diverse assemblages, etc. The role of biodiversity in ecosystem functioning, such as its influence on sustainability, stability, and productivity, still is not understood. Because accelerated soil erosion in various ecosystems has caused a decrease in ecosystem primary productivity, a logical way to study the relationship between biodiversity and ecosystem function will be to study the relationship between plant species diversity and soil conservation. In addition, biodiversity is a product of evolutionary history and soil erosion is a key factor controlling the evolution of the modern environment on the surface of the Earth. A study on the relationships between biodiversity and soil erosion processes could help to understand the environmental evolution of Earth and predict the future changes. To test this, fifteen 10 m×40 m standard runoff plots were established to measure surface runoff, soil erosion and total P leaching in different secondary communities of semi-humid evergreen broad-leaved forests that varied in composition, diversity and level of disturbance and soil erosion. The following five communities were studied： AEI （Ass. Elsholtzia fruticosa ＋ Imperata cylindrical ）, APMO （Ass. Pinus yunnanensis ＋ Myrsine africana ＋ Oplismenus compsitus ）, APLO （Ass. Pinus yunnanensis ＋ Lithocarpus dealbatus ＋ Oplismenus compsitus ）, AEME （Ass. Eucalyptus smith ＋ Myrsine africana ＋ Eupatorium enophorum ） and ACKV （Ass. Cyclobalanopsis glaucoides ＋ Keteleeria evelyniana ＋ Viola duelouxii �

关 键 词：植物多样性 土壤保持功能 稳定性 树冠截留 群落结构 

分 类 号：Q948[生物学—植物学]