【作者】 李双权；

【导师】 香宝； 苏德；

【作者基本信息】 内蒙古师范大学 ， 人文地理学， 2008， 硕士

【摘要】 森林生态系统是分布最广,结构最复杂,类型最丰富的陆地生态系统。繁茂的林冠层、疏松的枯枝落叶层和深厚的土壤层,构成了森林生态系统截持和蓄储大气降水的良好环境,从而能够对大气降水进行重新分配和有效调节,发挥着其特有的水源涵养功能。随着森林资源的持续减少和森林生态系统的不断破坏,森林生态系统的多功能性的作用愈显重要,特别是1998年的洪水灾害发生以后,人们对长江上游森林生态系统水源涵养功能更是达到了前所未有的关注。本论文以长江上游地区为研究区域,根据其森林类型将研究区域分为21个评估单元,并建立评估单元指标体系。通过现有文献和野外取样、实验获取各森林类型林冠层系统、枯枝落叶层系统和土壤层系统的指标数据,建立长江上游森林水源涵养数据库。利用Arcgis等地理信息系统软件,以栅格(大小为500m×500m)为单位,研究一确定点(网格)上截流、保持和储存的水量,从而对整个长江上游森林各子生态系统水源涵养能力及综合水源涵养能力进行研究。结果表明:(1)森林生态系统综合水源涵养能力中土壤系统和枯落物系统涵养水源量占了绝大部分比例,土壤非毛管孔隙对森林水源涵养能力具有决定性作用。长江上游森林生态系统综合水源涵养总量为324.12×108t。在长江上游各种森林植被类型中,林冠层一次性降水最大截留量平均值为1.07mm,截留总量为3.97×108t,占综合水源涵养总量的1.22%;枯落物层降水最大截留平均值为2.00mm,涵养水源总量为7.55×108t,占综合水源涵养总量的2.33%;土壤层涵养水源能力平均值为80.38mm,涵养水源总量为312.62×108t,占综合水源涵养总量的96.45%。(2)综合涵养水源能力最强的森林植被类型是亚热带山地冷杉林146.60mm,其次是亚热带山地云杉林132.41mm,温带亚热带落叶阔叶杨桦林最小,为21.37mm。综合涵养水源总量最大的是常绿针叶灌丛78.35×108t,其次是常绿阔叶灌丛61.52×108t,亚热带山地落叶松最小,为0.28×108t。(3)森林植被涵养水源能力空间格局表现为岷江上游、横断山区、四川盆地北山地最强,四川西南部高原山区次之,嘉陵江、乌江相对较弱。更多还原

【Abstract】 Forest ecosystem is a kind of terrestrial ecosystems which has the most wildly distribution, the most complex structure and the richest types. Composing of the flourish canopy layer, loose litter layer and thick soil layer, the forest ecosystem has an ideal capacity to hold and store atmospheric precipitation, and so that the atmospheric precipitation can be redistribute and regulated effectively by its specific water retention capacity. The effects of forest ecosystem’s multifunction become more and more important to us as the forest resources lasting reducing and being destroyed, especially after the flood disaster in 1998, the water retention function of forest ecosystems in the upper Yangtze River has been concerned unprecedented.We took the upper Yangtze River region as study areas, and divided them into 21 evaluating units according to their forest types, and built up the evaluating units’index system. Through literature survey and field sampling and experiment, we obtained the index data from the canopy, litter and soil layers of each forest type, and built up the upper Yangtze River forests’water retention database. By using GIS software such as Arcgis, we evaluated the intercepting, holding and storing water capacity of each certain grid (500m×500m), and then studied each water retention capacity of forest sub-ecosystem and the comprehensive water retention in the whole upper Yangtze River region. The results of study express:(1) Among comprehensive water retention capacity of forest ecosystem, water retentions in soil and litter layers account for the most proportion. Soil non-capillary porosity plays the key role in the determination of water retention capacity of ecosystem. The total comprehensive water retentions of forest ecosystems in the upper Yangtze River region are 324.12×108t. Of each forest vegetation type in the upper Yangtze River region, the canopy layer’s average one-off maximal precipitation interception is 1.07mm and the total interception is 3.97×108t, accounting for 1.22% of the total comprehensive water retentions; the litter layer’s average one-off maximal precipitation interception is 2.00mm and the total water retentions are 7.55×108t, accounting for 2.33%; the soil layer’s average water retention capacity is 80.38mm and the total water retentions are 312.62×108t, accounting for 96.45%.(2) Among all the forest vegetation types, the subtropical mountain fir forest has the maximal comprehensive water retention capacity which is 146.60mm, the second one is subtropical mountain spruce forest 132.41mm and the minimum is temperate-subtropical deciduous broad-leaved poplar-birch forest 21.37mm. According to the total comprehensive water retentions, the evergreen needle-leaved shrub land is the strongest one 78.35×108t, the second one is evergreen broad-leaved shrub land 61.52×108t and the last one is subtropical mountain deciduous pine forest 0.28×108t.(3) The spatial distribution expression for forest vegetation water retention capacity is: Mingjiang River, Hengduan mountainous, north mountainous of Sichuan Basin are strongest, next is plateau mountainous in Sichuan Southwest, and the Jialingjiang River, Wujiang River are comparatively weak.更多还原