【作者】 陈玉生；

【导师】 张卓文；

【作者基本信息】 华中农业大学 ， 园林植物与观赏园艺， 2005， 硕士

【摘要】 本文通过对三峡库区巴东县区段的气候特征及森林资源的现状调查,采用分割森林水文生态作用过程的研究方法,将森林水文过程分为林冠截留、凋落物持水、林地土壤蓄水等几个过程,并对其进行了深入的研究分析。 文章在收集巴东县1993年至2003年降雨资料的基础上,对巴东县的降雨特征进行了分析,认为巴东县年降雨量变化较大,年平均降雨量达978.6mm,属雨水丰富区域;年内雨量集中,中雨、大雨和暴雨比较多,主要分布在5—8月;其日最大降水量变化范围为39.9—106.7mm,大多大于50mm,达到暴雨的标准,且主要分布在雨季。 在此基础上从静态和动态两个角度对巴东县区段不同森林类型的水文生态效应进行了研究。从静态角度分析森林植被持水性,认为乔木层阔叶树种枝叶的持水能力大于针叶树种;灌木草本层及苔藓层具有很强的持水能力,尤其是苔藓层,高达314.61%,说明灌木草本层及苔藓层在对降水的吸收截留方面发挥着很大的作用。 从动态角度用固定标准样地方法对三峡库区巴东县区段5种主要森林类型的林冠对降雨再分配特点进行了研究,结果表明生长季时期降雨林冠再分配特点因林型而异。林内透雨量、树干茎流量与降雨量呈线性正相关,林内透雨率、树干茎流率在降雨初期随降雨量的增加而增大,后期则基本保持不变;林冠截留量与降雨量呈幂函数关系,林冠截留量随降雨量的增加而增加,而林冠截留率随降雨量的增大而减少,在降雨初期下降梯度最大,以后趋于平稳,逐步达到饱和。5种森林类型的林冠截留量平均值为48.64mm;林冠截留率平均值为20.95%。无论是林冠截留量还是林冠截留率,大小排列顺序都是针阔混交林最大、其后依次为马尾松林、阔叶林、针叶混交林和柏木林。 在样地调查及采集各森林凋落物基础上,对森林凋落物进行研究表明:凋落物储量从多到少依次为针阔混交林、柏木林、马尾松林、针叶混交林、阔叶林。各个森林类型的林下凋落物的未分解层的最大持水量由大到小的排列顺序为柏木林(1.98mm)、针叶混交林(1.83mm)、针阔混交林(1.27mm)、阔叶林(1.21mm)和马尾松林(1.10mm);半分解层的最大持水量则是马尾松林(2.30mm)、针阔混交林(2.28mm)、柏木林(2.71mm)、针叶混交林(1.76mm)、阔叶林(1.49mm)。在该区中柏木林的林下凋落物的持水能力最大,其余依次是针叶混交林、针阔混交林、马尾松林和阔叶林。在只有凋落物覆盖的情况下,不同森林类型因其状况不同,不出现水分下渗和地表径流时的最大降水量及最大降水强度不同,分别为柏木林4.19mm,1.96mm/h;针叶混交林3.59mm,2.15mm/h;针阔混交林3.55mm,2.54mm/h;阔叶林2.70mm,1.84mm/h和马尾松林3.40mm,1.45mm/h。更多还原

【Abstract】 With the investigation data on the climate characteristics and forest resources of Badong county in the Three-Gorge Reservoir Area, the hydrological course of the forest, which includes rainfall interception, water absorption for litter-form and soil., were studied carefully by means of dividing the hydrological course.Based on rainfall data of Badong from 1993 to 2003, the characters of rainfall were analysed. It showed that the annual rainfall is abundant (the annual average rainfall is 978.58mm) and various. The annual rainfall is mainly distributed from May to August, in which there are many moderate rains, downfalls, rainstorms.There are five forest types in the research areas, which contains the mixed forest of conifers and broad-leaved trees, the forest of Pinus massoniana Lamb, the forest of broad-leaved trees, the mixed forest of conifers and the forest of Cupressus funebris Endl.. The hydrological effects with five forest types were studied in the point of static and dynamic view. It showed that the water holding capacity of branches and leaves of broad-leaved trees is bigger than that of coniferous trees in arbor layer. Also, the capacity of each layer of shrub, herbage and moss layer is very big, especially moss layer (314.61%), they all play very important part in absorbing rainfall. The rainfall redistribution characteristics of canopy interception for five forest types in Badong county were studied by using fixed standard sample method. The results suggested that in different forest types, the rainfall redistribution characteristics of canopy in growing period were different. Throughfall and stemflow have a positive-linear relationship with rainfall, and the percentage of throughfall and stemflow increase with rainfall during the initial rainfall period, but keep stable in the later stage. There is relationship between the rainfall and Canopy interception as a power regression. The interception increases with rainfall, and the percentage of interception decreases with rainfall contrarily, dropping down quickly during the initial rainfall period, then slowly, and finally reaching the canopy-saturated state. The average canopy interception of five forest types is 48.64mm; the average percentage of canopy interception of five forest types is 20.95%; Not only the canopy interception but also the percentage of canopy interception of five forest types were different, in the order from the largest to the least: the mixed forest of conifers and broad-leaved trees, the forest of Pinus massoniana Lamb, the forest of broad-leaved trees, the mixed forest of conifers and the forest of Cupressus funebris Endl..Through the survey of the amount of forest litter form and experiments of water holding characteristics in five kinds of forest stands in the Lianxia River Watershed in theresearch areas, some characteristics parameter of forest hydrology were gained, such as the different kinds of forest litter form amount, the maximum water capacity and the water absorbing speed. The results showed that the amount of the litter form is in the descending order of the mixed forest of conifers and broad-leaved trees, the forest of Cupressus funebris Endl., the forest of Pinus massoniana Lamb., the mixed forest of conifers and the forest of broad-leaved trees. The maximum water capacity of the undecomposed litter form ranges from the forest of Cupressus funebris Endl. 1.98mm, the forest of conifers 1.83 mm, the mixed forest of conifers and broad-leaved trees 1.27 mm, the forest of broad-leaved trees 1.21 mm and the forest of Pinus massoniana Lamb. 1.1 Omm in the decreasing order. The maximum water capacity of the half-decomposed litter form follows the descending order from the forest of Pinus massoniana Lamb. 2.30 mm, the mixed forest of conifers and broad-leaved trees 2.28 mm, the forest of Cupressus funebris Endl. 2.21 mm, the mixed forest of conifers 1.76 mm and the forest of broad-leaved trees 1.49 mm. In this watershed, the water holding capacity of the litter form of the forest of Cupressus funebris Endl. is the biggest, and conifers, mixed forest of conifers and broad-leaved trees, forest of Pinus massoniana Lamb, and forest of broad-leaved trees follow the previous in order. When only litter form covers soil and there was no water infiltration and no water running off from ground surface, the maximum rainfall amount and the maximum rainfall intensity in different forest stands are 4.19mm and 1.96mm/h for the forest of Cupressus funebris Endl., 3.59mm and 2.15mm/h for the mixed forest of conifers, 3.55mm and 2.54mm/h for the mixed forest of conifers and broad-leaved trees, 2.70mm and 1.84mm/h for the forest of broad-leaved trees and 3.40mm and 1.45mm/h for the forest of Pinus massoniana Lamb respectively.The investigation indicated that different forest soil has different characteristics. The characteristics of forest soil changes regularly with the depth. The total water held in forest soil, which is mainly affected by soil’s total porosity, is cypresse, mixed conifers, mixed conifers and broad-leaved trees, masson pine, broad-leaved trees forest in the decreasing order.On the base of the above analysis and the comparison of the hydrological effect of five forest types, it showed that the integrated capacity of adjusting hydrological effect is the forest of Cupressus funebris Endl., the mixed forest of conifers and broad-leaved trees, the mixed forest of conifers, the forest of broad-leaved trees and the forest of Pinus massoniana Lamb in the decreasing order.更多还原