Simulation Of Forest Landscape Dynamic Change Based On Landis In Xishui Forestry Station

LANDIS-II is a spatially explicit landscape model with pixel-based and developed by University of Wisconsin at Madison.In this paper,a spatially explicit landscape model LANDIS-II was applied to simulate the dynamic natural succession of forests in XishuiForestry Station,Gansu within 300 years(2013-2313a).The landscape statistical software Fragstats4.3 was used to calculate the landscape pattern index such as area percentage of dominant tree species,the aggregation index reflecting the spatial patterns of species,the fractal dimension index,shannon's diversity and shannons' s evenness index of landscape.Variation tendency of all landscape pattern index during simulation time were analyzed.On this basis,we can provide a scientific basisto guiding the rational allocation of forest resources,managing forest,maintaining forest landscape and improving the quality of the forest.The results indicated:(1)PLAND:In the study zone,Picea crassifolia always kept a larger proportion of patches percentage,and as time goes by,no change of patches percentage.Sabina przewalskii and populus davidiana presented a tendency which slightly increased.(2)AI:The aggregation index of research area remained at a highvalue,andwiththe passageof time,the change in value is not obvious.(3)FRAC:Picea crassifolia's fractal dimension index was1.4901,no change;Sabina przewalskii's fractal dimension indexpresented a tendency which slightly increased;populus davidiana'sfractal dimension indexpresented a tendency which fastly increased.(4)SHDI and SHEI:The landscape's shannon'sdiversityindex showed a trend of slow growth;shannon'sevenness index to rise in small incrementsat first,then down,finally slowly rising.For the analysis of the results the following conclusios can be drawn:In the dynamic natural succession of XishuiForestry Stationwithin 300 years,Picea crassifoliahas been the dominant,Sabina przewalskii and populus davidiana are in the vulnerable position,The effects of landscape pattern in the studied area is small.The patches of Xishui forest's landscape have higheraggregation degree and good connectivity,but the landscape diversity is low,uneven distribution.