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| Effects of environment on soil water in dry-hot valleys of Panzhihua |
| Jiang Junming1,2,Zhang Xudong2,Fei Shimin1,Zhou Jinxing2,Cai Xiaohu1 |
| 1.Sichuan Academy of Forestry,610081,Chengdu;2.Institute of Forestry,Chinese Academy of Forestry,100091,Beijing:China |
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Abstract The deficiency of soil water in dry season was the main limited factor for restoration of vegetation in dry-hot valleys.In this paper,focusing on the water environment,some key approaches for the restoration of vegetation in the area of Panzhihua were advanced according to four aspects with the regional climate,water-holding capacity of soil,the water-consuming feature of vegetations and dynamics of soil water,and some main conclusions were also made as follows.(1) The difficulty in restoration of vegetation mainly owed to non-synchronization between water and temperature in the dry season.The climate difference of microenvironments,such as amount of evaporation determines distribution and type of vegetation.(2) The water-holding capacity of the red soil with more gravel is poor owing to bad soil structure and thin depth of soil layer.Saturated storage and infiltration ratio of soil are respectively 3.8-5.0 mm with every centimeter soil layer and 0.77-4.72 mm/min,but amount of the available water is only 50% of saturated water in soil layer.(3) Because of its particularity possessed by this soil,saturated storage and infiltrative ratio f parent material layer were both less than soil layer,and there were the same amount of available water in two layers.(4) The water in deeper soil,especially in parent material layer played a crucial role in maintaining existence of the vegetation in dry season.Therefore,to add he thickness of soil layer and improve infiltrative ratio of parent material layer were important technical measures for the restoration of vegetation in the red soil.(5) The dayly water-consuming amount in dry season was considerable difference among tree species for forestry,and the rational structure collocation of tree species was a key for restoration of vegetation.Presently,plants practically afforested such as Jatropha curcas,Pinus caribaea,Dodonaea viscosa,Acacia dealbata,India neem,Lantana camara,Broussonetia papyrifera have strong capacity of tolerance to drought.
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Received: 10 December 2007
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