| This paper is based on the vegetation and soil for vegetation under mountain forests-the arid valley of ecotone in the upper reaches of Minjiang River.According to the altitude it is divided into:the typical dry valley areas,ecotone and mountain forest areas.And were selected in each of lots 2-3 samples,sampling survey on the vegetation and soil in kind of selected areas,researching on the distribution patterns of vegetation and soil moisture,analyzing the variability of soil moisture in different vegetation in different environmental factors,exploring mountain forests-the arid valley of ecotone vegetation restoration and management of the adjustment mechanism.To improve the ecotone of ecological evolution theory,better understand soil moisture changes in the region and similar areas,and provide a theoretical basis on vegetation restoration in mountain forests-the arid valley of ecotone and complex ecosystem management.The results are as follows:1.There are 36 section 104 genera and 131 kinds of plant species in study area,and vegetation community level is a single in each sample area.there are shrub layer,herb layer, and the tree-scarce layer.The average height of the shrub layer is 60～130 cm,the average coverage is 40%to 65%.Average height of the herb is 60 cm below,and the average coverage is 10%to 35%.2.A variety of soil physical properties have been studied,soil bulk density is 0.96～1.65 g. cm-3,with the deepening and increasing soil depth.Surface soil porosity situation is good,soil porosity and the total gross porosity of the soil is reducing with deepening of the depth,the soil mechanical is composed of the main particle of class d＜0.25mm and d = 0.25～0.5mm mainly, the Shili content of 0～20 cm soil layer is high in each soil profile.3.Soil moisture changes in laws and the local precipitation is basically the same in the arid valley of the upper reaches of Minjiang River.During the rainy season soil moisture is good in various types of vegetation,and is little difference in the elevation gradient;in dry season soil moisture differences in the entire study area is larger,with an elevation rise of soil moisture has increased;soil moisture during the dry season is in a serious deficit in,and it is the main reason for restrictions on plant growth in the dry season;in high-altitude ecotone edge of the plantation site,which soil moisture conditions is between ecotone's and typical dry valley's,as surface layer covering a large number of herbal and large forest canopy density,to curb the surface of the soil moisture loss a large extent,so that is better than low-lying areas.4.Soil moisture vertical changes of various vegetation types generally have seasonal, surface water in the rainy season is higher than the lower-layer,called lower-type.Surface soil moisture variation is large,soil water of 10～20cm layer is above surface(0-10 cm),and with better soil moisture decreases,was first and then decreased.Surface soil coefficient of variation is higher than lower-layer,with the constant deepening of the soil,soil moisture is gradually stabilizing trend.Coefficient of variation of the soil is small in rainy season,is big during the dry season,with the increasing trend of a rise in elevation.5.The soil moisture conditions where staggered into the mountain forest edge and staggered Xia margin of Plantation Lot during the rainy season and dry season are better than the arid valley's,especially obvious in the dry season,therefore,we should consider the elevation of the impact of soil moisture in the process of restoration of vegetation.Along with ecotone down gradually restore vegetation,to lower the timberline,eventually reached the purpose of restoring vegetation in the arid valley,which is an effective way to restoration of vegetation of the arid valley area,promotion when resumption vegetation in the arid valley area.
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