20世纪末期大兴安岭北段林地变化研究

大兴安岭北段是我国唯一的寒温带针叶林带。本文以MSS和TM影像为基本数据源，采用人机交互的方法提取该区1976年和2000年土地利用信息，分析了林地变化的特征和原因。研究结果表明：与林地相关的土地利用变化类型是该区土地利用变化类型的主体；伴随着有林地的快速减少、灌木林地的大体平衡，疏林地和其他林地快速增加；林地动态变化呈现明显的区域性，灌木林地的区域差异最大；在林地整体变化的整体强度上，呼玛县处于较低水平；内蒙古部分及漠河县居中，塔河县相对较高。该区林地动态变化的原因包括自然原因、人类活动和森林火灾，是驱动力和约束力共同作用的结果。本文最后提出全球变化研究的两种基本模式：根据全球变化的特征分析全球变化的动力机制；根据全球变化的动力机制和动力要素的发展状态来预测全球变化的趋势。

Forestland Change in North Part of Daxinganlin Mountain over the Late Period of the Twentieth Century

By the end of October 2005 the Land Use and Cover Change(LUCC) core project co-sponsored by IGBP and IDHP concluded its work.In the mean time global land project(GLP) initiated and case studies on global comparison of land system among regions were conducted.As one of the cases,this paper analyzed forestland change in north part of Daxinganlin Mountain over the late periods of the twentieth century.Using MSS and TM images and land use information during periods of 1976's and 2000's in the region based on the man-computer interaction method,This paper analyzed characters and reasons of forest land change through LUCC indexes and grid sampling.The results showed that the change of forest land are dominant in types of land use change,associated with a rapid woodland decrease and shrubbery land balances in general and sparse-forest land and others forest land increase sharply from 1976 to 2000;There is a obvious change among regions in forest land and the change of shrubbery are the biggest among regions.As for the change intensity Huma County is the lowest,the part of Inner Mongolia and Mohe County are middle and Tahe County is the highest.The reasons of forestland change include nature factors,human actions and forest fire disaster.Forestland change resulted from the conjunct of driving forces and restriction forces.This paper suggested two modes for global research on land use change:analyzing dynamics of global change according characters of global change;forecasting trend of global change according dynamics of global change and dynamical factors.It's partial to research dynamics of global change from driving-forces.If only we analyze contrary movement of interior and exterior factors of human-environment system fully,we can explain dynamics of global change more accurately.It should be regard as a thinking method to decompose whole force that human-environment system is forced.