祁连山南坡不同林地土壤水分及其水源涵养特征研究

发布时间：2018-08-15 14:55

【摘要】：土壤是森林生态系统必不可少的组成部分,森林土壤含水量的多少是土地质量评价的重要指标之一。森林土壤作为林木生存的物质基础,是森林生态系统涵养水源的主要蓄积库,它不仅依赖于森林植被下的特殊生物群落,而且受林木根系和枯落物的影响,具有独特的水文特征。针对祁连山地区的森林水源涵养功能研究主要集中在祁连山北坡,对于青海省境内祁连山南坡水源涵养功能的研究报道很少。本文以祁连山南坡为研究对象,通过野外采样、室内实验和数据处理对祁连山南坡不同林地土壤水分及其水源涵养特征进行研究。主要得出如下研究结果:(1)研究区内不同林地类型土壤含水量变化趋势为:基本上随土层深度的加深而缓慢降低,从不同土层深度看,大致为青海云杉金露梅祁连圆柏,箭叶锦鸡儿介于三者之间变化;从整体上看,表现为青海云杉金露梅祁连圆柏,箭叶锦鸡儿和金露梅林地土壤含水量相差不大。不同林地类型土壤孔隙度基本上都随土层深度的增加而减少,可见土壤表层存在植被及枯落物可以增大土壤的孔隙度,从不同土层深度和整体上看,均为青海云杉祁连圆柏金露梅箭叶锦鸡儿。不同林地类型土壤容重基本上随着土层深度递增,从不同土层深度和整体上看,均为箭叶锦鸡儿金露梅祁连圆柏青海云杉。(2)研究区内土壤含水量在20-40 cm土层处由于存在毛细根,其土壤含水量有不同程度的回升。祁连圆柏由于多生长于阳坡,故而其土壤含水量明显小于其他三种林地土壤含水量。表层土壤植被根系比深层土壤发达,土壤的孔隙度较大,容重较小;到了30cm左右,随土层深度增加土壤孔隙度减小趋势不变,容重的增大趋势也不变。青海云杉和祁连圆柏作为乔木根系较发达与金露梅和箭叶锦鸡儿灌木林相比,孔隙度明显偏大,容重较小,可见根系发达程度以及毛细根的数量决定土壤孔隙度和容重。(3)研究区内影响土壤含水量的主要因素是林地类型,土层深度为次要因素。除祁连圆柏以外的三种林地类型土壤孔隙度、容重与土层深度的相关性较显著,含水量与土层深度的相关性较差,孔隙度、容重与土层深度的相关性几乎一致。(4)研究区内不同林地土壤蓄水量基本上都随土层深度的增加而降低,可见表层土壤存在植被及枯落物可以提升土壤蓄水能力,从不同土层深度和整体上看,均为青海云杉祁连圆柏金露梅箭叶锦鸡儿。不同林地枯落物有效拦蓄量、持水量为箭叶锦鸡儿青海云杉祁连圆柏金露梅,最大持水率为箭叶锦鸡儿祁连圆柏青海云杉金露梅。不同林地土壤总蓄水量为青海云杉祁连圆柏箭叶锦鸡儿金露梅。结果显示,土壤层贮水量占总蓄水量的百分比高达96%,土壤层涵养水源的能力比较强,表明祁连山南坡林地土壤水源涵养功能最强的是青海云杉林。
[Abstract]:Soil is an essential part of forest ecosystem, and the amount of forest soil moisture is one of the important indicators of land quality evaluation. As the material basis of forest survival, forest soil is the main reservoir of water conservation in forest ecosystem. It not only depends on the special biota under forest vegetation, but also is affected by forest roots and litter. It has unique hydrological characteristics. The study on forest water conservation function in Qilian Mountains is mainly focused on the northern slope of Qilian Mountains, but there are few reports on the water conservation function in the southern slope of Qilian Mountains in Qinghai Province. In this paper, the characteristics of soil moisture and water conservation in different forest land on the south slope of Qilian Mountain were studied by field sampling, laboratory experiments and data processing. The main results are as follows: (1) the variation trend of soil water content in different forest land types in the study area is that the soil moisture content decreases slowly with the deepening of soil depth, and from different soil depth, it is roughly about Cypress crassifolia var. crassifolia. The variation of Caragana is between the three factors, and on the whole, it shows that the soil water content of Picea crassifolia var. crassifolia is not different from that of Jilumei Qilian Cypress, and the soil moisture content of Caragana chinensis and Jinlu Plum Forest is not different. Soil porosity of different woodland types decreases with the increase of soil depth. It can be seen that vegetation and litter on the surface of soil can increase the porosity of soil, which can be seen from the depth of different soil layers and the whole soil layer. All for the Qinghai spruce Qilian cypress juniper leaf Caragana. The soil bulk density of different forest land types increases with the depth of soil layer. From the depth of different soil layers and the whole soil layer, they are all spruce of Cypress crassifolia. (2) the soil moisture content in the study area exists in the soil layer of 20-40 cm because of the existence of capillaries. The soil moisture content increased to some extent. The soil water content of Cypress chinensis was obviously lower than that of the other three forest land because it was mostly grown on sunny slope. The root system of surface soil is more developed than that of deep soil, the porosity of soil is larger and the bulk density is smaller than that of deep soil, and the soil porosity decreases with the increase of soil depth, and the increasing trend of bulk density does not change with the increase of soil depth. Picea crassifolia and Phyllostachys chinensis were more developed as Arbor roots, compared with Jilumei and Caragana shrubbery, the porosity and bulk density of Picea crassifolia were obviously larger and their bulk density was smaller. It can be seen that the degree of root development and the number of capillary roots determine soil porosity and bulk density. (3) the main factors affecting soil water content in the study area are forest land type and soil depth is the secondary factor. Soil porosity, bulk density and soil depth were significantly correlated with soil porosity in three types of woodland, except for Cypress chinensis, but the correlation between water content and soil depth was poor, and porosity was significant. The correlation between bulk density and soil depth is almost the same. (4) soil water storage in different forest land decreases with the increase of soil depth. It can be seen that vegetation and litter in surface soil can improve soil water storage capacity. From the depth of different soil layers and the whole, they all belong to Caragana chinensis, Cypress chrysanthemum var. crassifolia. The effective storage capacity of litter in different forest land was Caragana crassifolia, and the maximum water holding rate was Pinus crassifolia, and the maximum water holding rate was Pinus crassifolia var. crassifolia. The total soil water storage of different forest land was Picea crassifolia Qilian cypress leaf Caragana jinlumei. The results showed that the percentage of soil water storage in the total water storage was as high as 96, and the water conservation capacity of soil layer was relatively strong, indicating that the function of soil water conservation in forest land on the south slope of Qilian Mountains was the strongest in Picea crassifolia.
【学位授予单位】：青海师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S714

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