Study On Landscape Diversity Of The East Slop Of Helan Mountain

Helan mountain(φ（N）38°21’-39°22’, λ(E)105°49’-106°41’） lies in the junctionpoint of Ningxia and Inner Mongolia, between the Yinchuan Plain and Alashan Plain, it playsan important role as ecological barrier of western China, which is also vulnerable to humanactivities. For this reason, it is important to place for the protection and research ofbiodiversity.With the aid of GIS tool Arc Info, based on the vegetation map and topographic map ofthe east slope of Helan mountain, we chose appropriate landscape metrics to study the pathcharacteristics of vegetation landscape pattern of the east slope of Helan mountain. The resultshowed as follows:There are9vegetation landscape types, deciduous broad leaved shrubs and open foreststeppe constitute the main landscape types. Due to the light and heat conditions, the impact ofslope, distinct vegetation vertical zones are distributed in the district, and the light and heatconditions is the amajor influence factor in determining the elements and their distribution inthis area. Area and perimeter of landscape elements showed similar changes in trend is highlysignificant correlation.The diversity of landscape elements in this area is comparably low, while the dominanceis very high. It is key reason for the low diversity that the difference in areas of elements israther the great and only a few elements are dominant. the shape index tends to grow with theincrease of area, it indices that the herbage and shrub landscape are large in distribution. Onthe whole the medium patch is the main patch type in this area, which means it has a greatpotential for touring industry.The mean fractal dimension of all vegetation types were low, and the consistent value is1.394. All of the characters emphasized in this area seem to be in low fragmentation degree,suggesting they are less disturbed by human activities, both fractal dimension andfragmentation degree of deciduous broad leaved forest are higher than other types, reflect itsdistribution is more dispersed and was affected by lots of human activities.In the past12years landscape pattern changed a lot. There is a sharp increase in theproduction of construction land, landscape dominance reduced, the diversity of landscapeincreased, heterogeneity weakened, but also the shape of plaque is getting more complex. the evolution of vegetation landscape are influenced a lot by the national protection policy of theHelan Mountain...