Study On Suitability Division Of Five Main Economic Forest In Shaanxi Province

In this study, guided by ecological principles, according to ecological zoning of the basic principles and methods, the suitable region for main economic forest species in Shaanxi Province were divided using quantitative and qualitative analysis method. By means of clustering, the ecological factors affecting the distribution and growth of tree includes the average temperature, January average temperature, July average temperature, extreme maximum temperature, extreme minimum temperature, annual rainfall, sunshine hours, frost-free period. Each factor weight was obtained by using hierarchical analysis, the fuzzy similarity analysis was employed to divide the suitable region for main economic forest species in Shaanxi Province, as follows:1. The suitable regions for: Xanthoceras sorbifoliaMethod: Euclidean distance fuzzy similarity analysis(1) Suitable regions:north part of shaanxi and the Loess Plateau on the north of Weibei, including 29 counties such as Zichang, Fu, Yichuan, Yanchang, Ganquan, Huanglong.(2) Sub-suitable regions:most parts of Guanzhong Plain, including 29 counties such as Lingyou, Bin, Hengshan, Jingbian, Long.(3) Unsuitable regions: except for the suitable regions and sub-suitable regions owing to the unsuitable climate for Xanthoceras sorbifolia.2. The suitable regions for: Castanea mollissima. BlumeMethod: Hamming distance fuzzy similarity analysis(1) Suitable regions:low hills, middle hills and plain dam in Han river watershed and Dan river watershed on Qinba mountain. The mean altitude is 800～1000, including 31 counties such as shangnan, danfeng, shang, zhashui, zhenan, hanzhong yang, hanyin, baihe and so on(2) Sub-suitable regions:including 37 counties such as Yao, Bin, Tongchuan, Pucheng, Hancheng in the gully regions in Weibei plateau, as well as Jingyang, Liquan, Gaoling, Weinan in the Guanzhong plain.(3) Unsuitable regions: Muusu sand and gully regions of Loess Plateau. The area is rich in sunlight and heat, but little rainfall, poor fit tolerance to drought-resistant plants while unsuitable for Juglans regia L. 3. The suitable regions for: Juglans regia. LMethod: Euclidean distance fuzzy similarity analysis:(1) Suitable regions: low hills and plain dam in Han river watershed and Dan river watershed in Qinba mountain and Guanzhong plain, including 30 counties such as zhashui, shangnan, shanyang, zhuozhi, lantian, fengxiang, meixian, danfeng, wugong, qishan.(2) Sub-suitable regions:including 37 counties such as Yao, Bin, Tongchuan, Pucheng, Hancheng in the gully regions in Weibei plateau, as well as Jingyang, Liquan, Gaoling, Weinan in the Guanzhong plain.(3) Unsuitable regions: Muusu sand and gully regions of Loess Plateau where the climate is unsuitable for Juglans regia. L.4. The suitable regions for: Ziziphus zizyphusMethod: Euclidean distance fuzzy similarity analysis:(1) Suitable regions: including 26 counties such as Fugu, Mizhi, Suide, Jia,Shenmu. Dingbian, Qingjian in Yulin city and Zizhou, Zichang, Ansai, Baota, Ganquan, Wuqi in Yanan city. These regions mostly located at gully regions of Loess Plateau in north of Shaanxi and Weibei.(2) Sub-suitable regions:including 37 counties such as chuanhua, Xianyang, Bin, Linyou, Chengcheng, Baishui, Dali, Pucheng, Qianyang, Long, mostly of which located at Guanzhong plain and Weibei loess plateau.(3) Unsuitable regions: Qinba mountain in south of Shaanxi and south slope in Qinling.5. The suitable regions for: Armeniaca spp. MillMethod: Euclidean distance fuzzy similarity analysis:(1) Suitable regions: including 26 counties such as Fugu, Mizhi, Suide, Jia,Shenmu. Dingbian, Qingjian in Yulin city and Zizhou, Zichang, Ansai, Baota, Ganquan, Wuqi in Yanan city. These regions mostly located at gully regions of Loess Plateau in north of Shaanxi and Weibei.(2) Sub-suitable regions:including 37 counties such as Heyang, Xianyang, Bin, Linyou, Chengcheng, Baishui, Dali, Pucheng, Qianyang, Long and Zhidan, Wuqi in Yanan city, mostly of which located at Guanzhong plain and Weibei loess plateau.(3) Unsuitable regions: south part of Shaanxi province.