农林交错区景观特征梯度时空变化分析

农林交错区是具有明显环境梯度的生态敏感区,其景观特征的变化主要受坡度、高程梯度和人类活动的影响。以黑龙江省农林交错区——牡丹江地区为例,以GIS和RS为技术手段,结合趋势面分析方法和景观格局分析方法,分析农林交错区景观特征在高程和坡度梯度上的时空分布变化特征。结果表明:牡丹江地区农林用地的动态过程直接影响着研究区景观特征梯度变化的速率和方向。其景观水平上的景观斑块个数、破碎度和多样性指数在高程梯度上具有峰值,且峰值均出现在小于800m梯度范围内;在坡度梯度上,除斑块个数有一较小的峰值外,其他指数均随坡度的增加而减少。对景观生态潜力进行趋势面分析可以看出1976~1988年研究区景观梯度变化主要集中在低海拔、高坡度的梯度上,1988~2000年则主要集中在了高海拔、低坡度的趋势。因此,可以判定研究区景观特征的梯度变化明显的区域恰恰是人类活动频繁的区域。

Analysis on Gradient Change of Landscape Characteristics in Farm-Forest Ecotone

Farm-forest ecotone proves to be ecologically sensitive areas,where there is obvious change from environmental gradient.The landscape characteristics is mainly influenced by height,gradient and human activities.Taking Mudanjiang in Heilongjiang Province as an example,this paper analyzes spatial-temporal distribution of landscape characteristics in height and gradient by the technology of GIS and RS,and the method of trend surface analysis and landscape pattern analysis.The results showed that dynamic process of land for agriculture and forestry had a direct impact on the change rate and direction of landscape characteristics in Mudanjiang.Landscape patch number,fragmentation and diversity index had a peak value in height gradient,and the value appeared in those whose height was less than eight hundred meters;other indices gradually decreased with the slope increasing except patch number,which had a lesser peak value.Trend surface analysis on landscape ecological potential can conclude that gradient change of landscape was concentrated in low-altitude and high-slope region from 1976 to 1988,on the contrary,mainly concentrated in the high-altitude and low-slope region from 1988 to 2000.Thus,the prominence of landscape gradient change distributed in the regions where there are frequent human activities.