退耕坡地系统生态综合评价中几个景观生态学问题

退耕坡地系统属于退化土地生态系统,大部分是毁林(草)开荒形成的,是人为加速了自然生态系统的逆行演替而形成的低产脆弱的生态系统。对退化生态系统进行综合整治与恢复,以及人工生态系统的重建的理论基础是生态演替和人为设计理论。退耕还林(草)是通过一定的社会物质和能量的投入定向加速景观生态系统的演替过程。评价退耕地的生态经济效益是退耕还林(草)工程的重要组成部分,重点评定项目是否实现预期目标、项目的产出、效果和影响。本文应用景观生态学的理论:景观尺度与等级理论、景观空间格局与异质性理论、景观演化与干扰理论探讨了退耕地生态评价的内容、方法和应注意的问题,从而为退耕还林(草)工程的顺利进行提供有力的保障。

Synthetically Appraisal of Returning Sloping Farming Land to Forest Project on the Basis of Landscape Ecology Theories

The sloping farming land system belongs to a degraded land ecosystem,and is a low-yield and fragile ecosystem resulting from destroying forests,and artificially accelerating the converse succession of nature ecosystem.Basic theories include ecology succession and artificial design theory which synthetically renovate and rehabilitate the degradated ecosystem and artificial ecosystem.Converting sloping land to forest directionally can quicken up the succession processes of landscape ecosystem.Evaluating sloping land's ecosystem and economic benefits is a part of returning sloping farming land to forest project,particularly focusing on assessing the expected objects,outputs and effects of the project.This article deals with appraisal of contents and methods with regard to ecology and economy in returning sloping farming land for forest project by landscape ecology theories: landscape scale and hierarchy theory,landscape spatial pattern and spatial heterogeneity theory,landscape succession and disturbance theory,thereby affording trenchant guarantee for implementing returning sloping land to forest project.