黄土高原林(草)生态工程作用机理及模型验证  

The mechanism and model validation of ecological engineering of forestry(grass) in Loess Plateau

作　　者：韩新辉[1] 杨改河[1] 徐丽萍[1] 张笑培[1] 杜英[1] 

机构地区：[1]西北农林科技大学资源环境学院

出　　处：《西北农林科技大学学报（自然科学版）》2008年第7期118-126,共9页Journal of Northwest A&F University(Natural Science Edition)

基　　金：国家重大基础预研项目(2005CCA05300)

摘　　要：【目的】分析林(草)生态工程对生态环境影响的作用机理,提出生态退化和治理的因子触发-响应机制模型,为黄土高原植被修复和生态重建提供理论参考。【方法】根据生态恢复的相关原则、方法与理论,结合近年来的研究与实践经验,提出黄土高原生态环境退化形成与治理的因子触发-响应机制模型,分析黄土高原生态系统与干扰因子的相互作用机制和生态退化机理,并对该模型进行初步验证。【结果】通过构建黄土高原生态退化的因子触发-响应机制模型,认为黄土高原本身维持生态系统自我发展的主导力脆弱,系统演变过程受干扰因子作用而偏离生态演替顶级的趋势提前。严重退化的黄土高原生态系统通过适时、适宜的人为设计,可使治理措施与生态系统产生良性触发,促进植被的正向演替,将生态系统导入良性循环。模型验证结果表明,黄土高原植被恢复措施总体上使该地区生态系统处于良性触发态势,明显提高了地表植被覆盖度,改善了土壤的理化性质,提高了生物多样性。但良性触发的主导因子是封山禁牧,人工造林短期内由于耗竭土壤水分、生物多样性低等原因而处于恶性触发态。【结论】黄土高原生态修复应充分考虑"生态系统-干扰因子"的响应机制,使治理措施与生态系统产生良性触发,充分发挥封山禁牧的良性触发作用,以修复退化的生态环境、减小人工造林的负面影响。[Objective] The effect mechanism of forestry （grass） ecological engineering on environment in Loess Plateau was analyzed and triggering factor-ecological response model for degradation and control of ecology was proposed,which provided academic reference for restoration of vegetation and ecological reconstruction in Loess Plateau. [Method] According to relevant principles, ways and theories of ecological restoration and experiences from practices and experiments in recent years, the triggering factor-ecological response model for degradation and control of ecology were brought forward in our research, which could explain interaction between ecological system and interferential factors during the succession and mecha- nism of ecological degradation. The model was preliminarily validated with experiment as well. [Result] The model indicated that ecological dominant force of Loess Plateau ecosystem was weak to maintain is development, and deviation of the climax of ecological succession from its preconcerted status was ahead of time. Feasible and timing design by human for seriously deteriorated ecosystem of Loess Plateau could form a benign triggering between control measures and ecosystem,which promoted positive succession of vegetation and brought ecosystem into a benign circle. The results from the model validation showed that measures of vegetations recovery in Loess Plateau made its ecosystem at a benign triggering state as a whole, which could significantly increase surface vegetation coverage and diversity of plant, and improved the physical and chemical properties of soil. However,dominant factor of the state was closing land and grazing prohibition,and the artificial afforestation was at malignant triggering state in short-term because of decreasing species diversity and exhausting soil water. [Conclusion] The interacting mechanism between ecological system and interferential factors should be taken full consideration in ecological reconstruction of Loess Plateau,and made a benign triggering between co

关 键 词：因子触发-响应机制模型 黄土高原 生态恢复 林(草)生态工程 

分 类 号：X171.4[环境科学与工程—环境科学]