Correlation Analysis Between Topography And Dominate Tree Species Groups Based On Digital Elevation Model In Lingnan Forest-farm

With the assistance of ArcGIS software in data collection and analysis, the thesis studies Lingnan forest farm in Xiuning County, Anhui Province, acquiring the contour information and vector data on forest resources based on the topographic map with 1:10000 scale. Meanwhile, SPOTS remote sensing images in the same period in 2009 are used in building interpretation signals to carry out geometric rectification on stand data. The results are to be tested by Geoway3.5, a type of home-developed software, in data quality. Following the test, data will be imported into ArcGIS in the format of SHP, then with contour data, digital elevation model (DEM) is set up. In addition, on the basis of surveyed forest resources data and forest second type inventory data in local region in 2009, the stand attribute database is established. The thesis, then, analyzes topographical factors and forest resources structure with ArcGIS, figuring out and studying the spatial data association between topographical factors and dominant species so as to provide reliable foundation for forest resources operation and management.Results are as follows:The Lingnan forest farm covers 3657.35 hm2 with Conifer,Cunninghamia lanceolata and Quercusbe the major species. Such three forest categories as protection forest, timber forest and economic forest account for 62.46%,32.79% and 4.75% respectively. While forest land, shrub land and immature forest land take up 91.24%,5.6% and 3.16%. In the forest farm,53.08% is natural forest and the rest, which is 46.92%, is artificial forest.Hills with altitude over 800 meters occupy 91.60% of the total area and the rest 8.40% are lower than 800 meters, all of them locate in hilly and lower mountainous areas. Around 73.72% slopes of hill are steep with distinctive rise and fall, tending to cause water and soil loss and making it difficult for afforestation and operation. South-facing slope covers 13.14% of the aspect area while the smallest ones, namely, north-facing and northeast-facing slopes cover 8.66% and 9.74%.Forest resources in Lingnan forest farm concentrate in the altitude range between 300 meters to 800 meters, amounting to 74.05% of the total forestry area. Artificial forests mainly grow below the elevation of 800 meters while above that altitude hills are almost occupied by natural forests. Natural Pinus taiwanensisand natural Quercus forests are distributed above the 800 meters altitude level yet Natural hard broadleaved forest below the height level. Cunninghamia lanceolata, Liquidambar formosanaandCamellia sinensis in general are artificial ones and planted below the 800 meters altitude.Forest resources could be found in steep and abrupt slopes generally, accounting to 77.48% of the total area. Artificial forests mostly grow on the flat slope but the area of natural forests and artificial ones on gentle slope and steep slope is about the same. Conifer and quercus forests are standing at slopes above 25 degrees, natural Liquidambar formosanaforest mainly distribute on steep and abrupt slopes and the most common see forest on the steep slope is natural Phyllostachys heterocycla.Forests cover more areas on the sunny slope than any other slopes, amounting to 893.80 hm2,24.44% of the total area. Forests on the half sunny slope and half shady slope are about the same while the flat slope covers the smallest forestry area. Conifer in general concentrate on the sunny and half sunny slopes while shady and half shady slope holds Natural hard broad-leaved, Quercus Liquidambar formosana.Cunninghamia lanceolata forestsis plant in both sunny and shady slopes.