退耕还林政策对山地植被空间格局变化的驱动分析  

Mountain Vegetation Spatial Pattern Changes Affected by Slope Land Conservation Program(SLCP)

作　　者：张志明[1] 孙长青[1] 欧晓昆[1] 

机构地区：[1]云南大学生态学与地植物研究所,云南昆明650091

出　　处：《山地学报》2009年第5期513-523,共11页Mountain Research

基　　金：国家重点基础研究发展计划资助项目(2003CB415102);比利时弗莱芒省大学联合会(批准号:VLIR ZEIN2002PR264-886)项目资助~~

摘　　要：政策是引起土地利用和土地覆盖变化的重要驱动力之一。分析退耕还林工程实施对山地景观格局变化的影响,可以为土地的可持续利用和退耕还林的后续工作提供参考。利用人工智能神经网络变化测定技术产生2000至2003年间研究区植被变化图,由此产生两时期的植被图并结合景观指数定量分析和比较两时期植被景观格局的空间动态变化,并重点关注25°坡度以上的区域。研究结果表明,在2000年至2003年间,有部分松树林(约1757hm2)转变成农业用地,混交林(约2718hm2)转变成灌草丛,同时有部分灌草丛(约181hm2)转变成松树林;农业用地(约1915hm2)转变成疏生林,其中有65.4%的变化是发生在坡度为25°以上的区域。此外根据景观指数结果显示,云冷杉林、松树林、混交林和农业用地的面积有不同程度的增加,而疏生林和灌草丛面积明显减少。结合野外调查该结果表明,在退耕还林的政策驱动下部分农业用地被种植成松树林,有些农业用地自然转变成疏生林和灌草丛。但是同时也有些疏生林和灌草丛被开垦成农业用地。在景观水平方面,发现蔓延度和集合指数都有所减小,表明该区域景观破碎化程度有所增加。而景观的丰富度指数和均一性指数都有所增加,表明该区域内景观类型的优势度有所增加。In order to analyze the effects of slope land conservation program （SLCP）, the changes of vegetation spatial pattern between 2000 and 2003 were detected by using artificial neural networks （ANN） change detection technique. Landscape metrics were used to quantify the vegetation changes. In this study, the slope lands more than 25° were focused on. The results showed that about 1 757 hm^2 pine forest changed into agriculture land, about 2 718 hm^2 mixed forest transferred into dwarf shrub and meadow, about 181 hm^2 dwarf shrub and meadow changed into pine forest from 2000 to 2003. In addition, in the span of three years about 1 915 hm^2 agriculture land changed into low density and tall shrubs. 65.4% of this change occurred in steep slope land （more than 25°）. In class level, the area of fir and spruce forest, pine forest, mixed forests, agriculture land increased obviously, while low density forest and tall shrubs, dwarf shrub and meadow decreased dramatically. It indicates that some SLCP droved some agriculture land change into forest or low density forest in the span of three years. However, part of low density forest and tall shrubs, dwarf shrub and meadow were opened for farm land during the three years （2000 - 2003）. In landscape level, the fragmentation degree of the whole research area had decreased and many of landscape types＇ shape became more regular, meanwhile the relationship between patch types became closer. It indicates that the landscape fragmentation is increased. The diversity and evenness are increased. It means that the dominance of landscape is increased.

关 键 词：退耕还林政策 景观空间格局 FRAGSTATS 景观指数 土地覆盖类型 坡度 

分 类 号：P901[天文地球—自然地理学] Q948[生物学—植物学]