【作者】 葛东媛；

【导师】 张洪江；

【作者基本信息】 北京林业大学 ， 水土保持与荒漠化防治， 2011， 博士

【摘要】 本论文以重庆四面山6种森林植物群落为研究对象,通过野外调查试验和室内实验,采用统计方法、灰色关联法、分形理论、层次分析法、模糊数学方法和逼近理想点决策原理等方法,从林冠层、枯落物层和土壤层3个功能层研究了其水土保持功能,构建了多层次多指标的评价体系,进行了水土保持功能评价和灵敏度分析,得出了6种森林植物群落水土保持功能强弱的排序,以期为在重庆四面山及相邻地区营建结构合理、生态性能稳定的水土保持型植被提供参考和依据。主要研究结果如下：通过测定6种森林植物群落三个功能层的水文功能,结果显示：在林龄和郁闭度基本一致的条件下,不同雨量级的降雨林冠截持率以针叶林的截留能力表现最好,郁闭度低的落叶阔叶林和暖性竹林截留能力最小。乔木冠层枝叶截持的水分占枝叶干质量的15%～25%；在环境因子基本一致的条件下,3种阔叶林群落地表有较好的枯落物储量和分解强度,且最大持水量显著高于以针叶树和竹林,阔叶林林下枯落物持水量为5.13-5.65 mm,能够有效地持存穿透降水；常绿阔叶林土壤具有良好的贮水和水分渗透能力,其土壤总持水量可达312.99 mm。不同群落土壤的饱和导水率与其土壤容重、孔隙度等因素密切相关。通过测定和系统分析6种森林植物群落林地土壤的基本性质、抗蚀和抗冲性能及抗剪强度,揭示出6种森林植物群落林地的土壤保持功能。结果显示,不同森林植物群落对其林下土壤均具有一定的改良作用,不同森林植物群落土壤物理性质存在定差异：3种阔叶林较其它2种针叶林和竹林土壤容重较低,0-20cm土层土壤容重为1.02-1.11g/cm3；非毛管孔隙度较高,可达15.81%～7.66%,3种阔叶林土壤团粒结构数量显著高于针叶林和竹林。土壤结构性和稳定性较优；6种森林植物群落林地土壤抗蚀指数为62.0%～85.0%,抗冲系数为5.56-28.94,土壤抗蚀性与冲刷时间成二次多项式函数关系逐渐降低,土壤抗冲性与冲刷时间成指数关系逐渐增大,其中常绿落叶阔叶混交林的土壤抗蚀性能最好,暖性竹林的土壤抗冲性能最好。在同一土壤剖面,不同层次土壤的抗蚀性和抗冲性随土壤深度的增加呈下降趋势；不同森林植物群落土壤抗剪力在一定垂直压力下,与垂直应力呈线性关系,其抗剪黏聚力、内摩擦角随着土壤深度的增加,其变化存在差异,内摩擦角为21.37°～27.87°、黏聚力值为5.54-38.91KPa,土壤抗剪性能与根密度呈线性正相关关系。不同森林植物群落的抗侵蚀性能与土壤容重、总孔隙度和非毛管孔隙度等土壤物理性质有关。经比较得出阔叶林这3类土壤力学指标相对好于针叶林和竹林。在系统分析重庆四面山不同森林植物群落的水文和土壤保持特性的基础上,采用模糊数学法、层次分析法、MATLAB软件开发的AHP (Analytic Hierarchy Process)评价工具箱模型、逼近理想点决策原理和灵敏度分析法,对6种森林植物群落的水土保持功能进行综合评价和强弱排序,结果为：常绿阔叶林>落叶阔叶林>常绿落叶阔叶混交林>暖性针叶林>暖性竹林>温性针叶林。更多还原

【Abstract】 On the basis of field investigations as well as lab experiments, this paper studied the six types of forest plant communities in Chongqing Simian Mountains about the water and soil conservation function of forests at canopy layer, litters layer and the soil layer respectively. Such research tools as statistic analysis method, grey correlation method, fractal theory, analytic hierarchy process, fuzzy mathematics, technique for order preference by similarity to ideal solution and sensitivity analysis were applied to evaluate the water and soil conservation functions and their corresponding degree of sensitivity. Six types of forest plant communities were consequently ranked in terms of water and soil conservation capacity respectively. This paper aims to shed some lights on the establishment of structurally-reasonable, eco-functionally-stable water and soil conservation vegetation communities in Chongqing Simian Mountains and surrounding regions. The primary findings were summed up as follows:Hydrological study on the three functional layers of the different forest plant communities indicated that, given the almost same stand ages and canopy closures, the maximum canopy interception rate is observed in both coniferous forest communities, whereas the lowest was found in broad-leaved forest and warm bamboo forest with relatively lower canopy interception capability under different rainfall levels. Rainfalls retained by the canopy layers account for 15%-25% of the weight of overall branches and trunks. Given similar environmental factors, the broad-leaved tree dominated stands were sufficiently covered by forest litters and relatively higher decomposition intensity, consequently have noticeably better performance than coniferous forest and bamboo forest dominate stands. With maximum water-holding capacity at 5.13-5.65 mm, the litters of broad-leaved forest are capable of conserving throughfall. The soil layers of evergreen broad-leaved forest demonstrated sound water-storage and penetrating capacities, with their average total water storages reaching at 312.99 mm. The soil saturated hydraulic conductivity and soil bulk density and porosity of different forest plants communities is related closely.Soil conservation function was revealed, through study and analysis on the physical properties, anti-erodibilit, anti-sourability and anti-shear strength of the soil in the six types of forest plant communities, the results showed that, different forest plant community has role of improved its forest soil. There are differences in the soil physical properties of different forest plant communities: Compared with the soil taken from the two types of coniferous forest communities and bamboo forest community, soil taken from the three types of broad-leaved communities has lower density, measured at 1.02-1.11g/cm3 on the 0～20cm layers; the non-capillary porosity is relatively higher, falling at 15.81%-7.66%; soil aggregate structure of the three kinds of broad-leaved forest communities is significantly greater than the two types of coniferous forest communities and bamboo forest community. Soil anti-erodibilit and time are into two polynomial function relation, soil anti-sourability and flush time are into index relation. The best soil anti-erodibilit and anti-sourability are from evergreen and deciduous broad-leaved mixed forest and warm bamboo forest respectively. The soil anti-erodibilit and anti-sourability at different levels of soil in the same soil profile decline with the increase of the soil depth. In a vertical pressure, soil anti-shear strength of different forest plant communities were in a linear relationship to vertical stress. There are differences in the change of the soil internal friction angle and cohesion and pastes. The value of soil internal friction angle and cohesion and pastes of the six types of forest plant communities ranged respectively between 21.37°～27.87°nd 5.54-38.91KPa. Soil anti-shear strength and root density are in a linear correlated. The anti-erodibilit, anti-sourability and anti-shear strength of different forest plant communities are related to soil physical properties such as soil density, whole-capillary and non-capillary porosity. Comparative studies showed that broad-leaved forest communities outdo both coniferous forest communities and bamboo forest community in terms of the mentioned three indicators.The anti-erodibilit indexes, anti-sourability indexes, internal friction angle and cohesion and pastes the value of resistance of the anti-shear strength and sticky indexes of the six types of forest plant communities ranged respectively between 62.0%～85.0%,5.56～28.94,21.37°～27.87°and 5.54～38.91KPa. Comparative studies showed that broad-leaved communities outdo both coniferous forest communities and bamboo forest community in terms of the above-mentioned three indicators.Based on systematical analysis of the characteristic of soil and water conservation of different forest plant communities in Chongqing Simian Mountains and by means of fuzzy mathematics, analytic hierarchy process, MATLAB software-based AHP evaluating tools and models and ideal-point decision-making principles, so that comprehensive assessments could be carried out to rank the six types of plant communities in terms of their corresponding water and soil conserving capacities. It was concluded that the water and soil conserving functions of the six types of plant communities rank as: evergreen broad-leaved forest>deciduous broad-leaved forest>evergreen and deciduous broad-leaved mixed forest>warm coniferous forest>warm bamboo forest>temperate coniferous forest.更多还原