Dynamic Changes Of Forest Landscape Pattern In Huanglong Mountainof Northern Shaanxi Provice

Based on the forest management inventories in Huanglong Mountain in1986,1997and2006, we analyzed the changes of landscape types and landscape structure.The results show that:(1)Classification of forest landscape was based on data of secondary investigation of forest resources and DEM.ArcGIS was used as technical supporting systems for data processing. As a result,distribution maps of forest landscape of the study area of3years and they were will be used for the base data for further studying on forest landscape of study region.(2)With the support of ArcGIS, the areas of study region of3years were calculated. The result indicated, The landscape had changed greatly in the11years. The area of forest land continuously increased, while that of the shrub land and wasteland gradually decreased, the area of the cultivated land and immature forest land increased from1986to1997, however, decreased from1997to2006, and the cypressus funebris forest land and nursery land accounted only a small part of the entire landscape.(3) It can be seen from Markov forecasts:the forest landscape increasing amount comed from cultivated land and shrubland, meanwhile, a part of the forest landscape had been changed into cultivated land and shrubland. So, the forest land wa transformed between cultivated land and shrubland, moreover, the area of transformation into the forest land was more than out.(4) With the support of ArcGIS,the slope and aspect were extracted from DEM,then the distribution maps of forest landscape of the study area of3years were overlay with DEM. The result indicated:The landscape types were mainly distributed in the slope of5℃～25℃, and the proportion exceeds87%; the area of each landscape was almost the same in all slopes. As a whole, the landscape area on the shade slope and semi-shady slopes were larger.(5)At the landscape type features level, the land area of hard broad-leaved forest and coniferous forest had continuously increased by40%from1986to2006; the area of cypressus funebris forest land was relatively stable at about2000hm2during the three periods, while the soft broad-leaved forest land area continuously decreased. Moreover, age-class structure of the major species had significant changed as well. (6)Through the calculation results of Fragstats3.3, at the class level, the dominance of hard broad-leaved forest land and coniferous forest land increased, and the LPI was much greater than that of other landscape types in each period; The shrub land, soft broad-leaved forest land and wasteland had become more fragmented accompanied the more dispersive distribution; the cultivated land and immature forest land increased at first then decreased at an growing rate; the indexes of cypressus funebris forest land and nursery land had not changed obviously; at the landscape level, the diversity decreased, while the heterogeneity, fragmentation of landscape and landscape dominance increased, and the patch types tended to distribute as aggregation state.