云南糯扎渡自然保护区植被沿坡向空间分异研究

A study on spatial distribution of vegetation in relation to the slope orientation in Nuozhadu Nature Reserve of Yunnan

为了探索糯扎渡自然保护区植被沿坡向的空间分布规律和植被分布与坡向的相关关系,基于数字地形图,使用Ar-cView和ERDAS软件制作了数字高程模型;基于数字高程模型,使用ArcMap软件提取了植被类型沿东、西、南、北、东北、东南、西北和西南8个坡向的分布图层和植被类型按13个海拔带沿8个坡向分布的图层,并结合植被图制作了植被类型按8个坡向分布的三维立体植被图;用EXCEL软件统计了9个自然植被类型沿8个坡向的分布面积和按13个海拔带沿8个坡向的分布面积;用SPSS统计分析软件计算了坡向与植被分布的相关关系。结果为:①9个自然植被类型中除河谷稀树灌木草丛分布在东、东南、南、西南和西5个坡向外,其他8个植被类型在8个坡向均有分布。②8个坡向的优势植被类型均是季风常绿阔叶林。③坡向对季节雨林和河谷稀树灌木草丛的分布影响较大,对落叶季雨林和暖温性针叶林的分布有一定影响,对山地雨林、热性竹林和暖热性稀树灌木草丛的分布影响较小,对季风常绿阔叶林和暖热性针叶林的分布无影响。④确定了9个自然植被类型的适生坡向。

To study the vegetation distribution pattern in relation to slope orientation in Nuozhadu Nature Reserve, a digital elevation model was developed from a digital map by using ArcView and ERDAS; layers of vegetation by slope orientations of east, south, west, north, northeast, southeast, northwest and southwest and layers for the 8 slope orientation by 13 altitude classes were obtained from the digital elevation model by using ArcMap, and a 3D digital vegetation distribution map for vegetation of 8 slope orientations was made based on data from a vegetation map, then areas of the 9 natural vegetation types were calculated by 8 slope orientations , and areas of the 8 slope orientations were further calculated by 13 altitude classes with the aid of EXCEL; and the correlation between vegetation distribution and slope orientation was analyzed by using SPSS. The results were as follows： （1） Of the 9 natural vegetation types, 8 were found in all 8 slope orientation classes with the valley savanna as the only exception found in east, southeast, south, southwest and west orientations.（2） The dominant vegetation for all 8 slope orientation classes was the same. monsoon evergreen broadleaved forest. （3） Slope orientation showed very significant impact on vegetation distribution for seasonal rain forest and valley savanna, moderate impact for deciduous seasonal rain forest and warm temperate conifers, minor impact for mountain rain forest, tropical bamboo forest and warm hot savanna, and no impact for monsoon evergreen broadleaved forest and warm hot conifers. （4） Adaptable slope orientations for the 9 natural vegetation types had been confirmed.