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.