张家界女儿寨小流域植被变化驱动力  

Driving forces for cover changes of Nverzhai Watershed,Zhangjiajie:applications of a new AutoLogistic model

作　　者：赵占轻[1,2] 黄玲玲[3] 张旭东[3] 郭志华[1] 张小全[1] 王建力[2] 向洪波[2] 

机构地区：[1]中国林业科学研究院森林生态环境与保护研究所,北京100091 [2]西南大学地理科学学院,重庆400715 [3]中国林业科学研究院林业研究所,北京100091

出　　处：《生态学报》2010年第5期1238-1246,共9页Acta Ecologica Sinica

基　　金：国家"十一五"科技支撑资助项目(2006BAD03A16;2006BAD03A04);国家林业公益性行业专项资助项目(200804001)

摘　　要：选择坡度、海拔、坡向、到道路和河流及居民点的最近距离等作为植被变化的空间驱动因子,分别采用传统Logistic和AutoLogistic回归模型,对比研究湖南张家界女儿寨小流域植被变化的驱动力,并用ROC方法检验这两个模型的解释能力。结果表明:(1)在女儿寨小流域,各类植被变化和空间驱动因子均表现出一定的空间正自相关,且这种空间自相关性随着距离的增加而逐渐减弱。(2)考虑空间自相关性的AutoLogistic模型比传统Logistic模型的精度更高,这说明在分析小流域植被变化的空间驱动力时不能忽略空间自相关性的影响。考虑空间自相关后,显著的空间驱动因子的个数比未考虑空间自相关性的个数少。(3)自然环境和人类活动因子对小流域植被变化的影响力不同:坡度对耕地变化、果园变化、常绿阔叶林变化和针叶林变化等均影响较大;坡向对耕地变化、果园变化、常绿阔叶林变化和灌木林地变化的影响显著;海拔对该小流域各种植被变化类型的影响相对较小;人类活动的影响对落叶阔叶林的变化影响显著。The driving forces analysis is frequently used in conventional multivariate analysis such as multiple linear regression,canonical correlation analysis,principal component analysis and logistic model.These methods,however,assume that the input data are spatially independent regardless of the facts showing otherwise in landscape analysis.To overcome the shortfalls of the conventional methods to address the spatial autocorrelations,we proposed a new model（AutoLogistic）by incorporating the spatial autocorrelations into the conventional logistic model.AutoLogistic model was then applied at the Nverzhai watershed of Zhangjiajie to identify the driving forces for the cover changes.We included spatial variables（slope,altitude,aspect）,distance to the nearest road,stream and residential areas in our new model.Model predictions were validated based on the Relative Operating Characteristics（ROC）method.We found that：（1）the vegetation cover changes and the driving factors appeared positive autocorrelation in space that decreases with distance across the watershed;（2）the AutoLogistic model showed higher accuracy than that of the logistic model,with remarkable reduction in the number of independent variables;（3）the magnitudes of influences from the natural driving forces seemed significantly different from those of the anthropogenic driving forces.Slope was the single most important variable on changes in farmlands,orchards,evergreen broad-leaved stands,and the coniferous stands,while aspect showed its importance for changes of farmlands,orchards,evergreen broad-leaved stands,and the shrub stands.Elevation appeared an unimportant factor driving the cover changes.Interestingly,the changes in deciduous broad-leaves stands seemed to be more influences by anthropogenic activities.

关 键 词：植被动态 驱动力 AutoLogistic回归模型 张家界 

分 类 号：Q948[生物学—植物学]