【作者】 赵洋毅；

【导师】 王玉杰；

【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】 缙云山位于长江三峡库区的尾端,处于嘉陵江水系的中上游端,作为重庆市的-个重要水源区,针对三峡库区近年来水土流失和水环境污染日趋严重的状况,区域内水源涵养林对蓄水保土和改善水质等具有重要作用。为探讨水源林结构对生态功能的影响和调控机制,本论文依托“十一五”国家科技支撑课题“重庆北部水源区水源涵养林构建技术试验示范(2006BAD03A1802)”,在重庆缙云山开展水源涵养林结构特征、保育土壤、涵养水源和改善水质功能的研究,以求为三峡库区乃至整个长江流域的水源涵养林建设和管理提供科学依据。研究内容主要包括水源林总体分布格局、林分非空间结构和空间结构特征、保育土壤功能、涵养水源功能、改善水质功能、生态功能综合评价、结构对生态功能影响机制、最优林分类型和水源林群落筛选等,主要研究成果如下：利用缙云山森林资源GIS数据库和遥感图像得到水源林主要分布于低山中陡坡和西北和北坡向地区,呈典型异龄林特征,林分已基本郁闭。以缙云山9种典型水源涵养林——马尾松阔叶树混交林、杉木阔叶树混交林、马尾松杉木阔叶树混交林、四川大头茶混交林、栲树混交林、毛竹马尾松混交林、毛竹杉木混交林、毛竹阔叶树混交林和毛竹纯林作为研究对象,采用大样地调查法对林分树种组成、直径、树高、林层分布、物种多样性等非空间结构特征首次进行系统研究,得到各林分密度、树种组成式、混交比例等。林分呈典型异龄林直径结构,树高分布范围广,林分类型对林木直径和树高分布的影响显著。应用混交度、大小比数、角尺度、方差均值比率和聚集指数5个空间结构参数首次对缙云山林分空间结构进行分析,结果为.：8种混交水源林平均混交度在0.48—0.82之间,马尾松阔叶林混交度最高(0.82),群落状态最稳定,毛竹杉木林最差(0.48),竹林群落普遍单种聚集严重(0.526—0.548),混交度最差；林分平均大小比数在0.35—0.65之间,毛竹马尾松林和毛竹阔叶林的大小分化严重,其它多数林分平均大小比数在0.5左右,处于中庸状态；林分平均角尺度在0.485—0.548之间,各林分中呈随机分布的林木比例最大,林木空间分布格局为随机分布的林分有马尾松阔叶林(0.485)、马尾松杉木阔叶林(0.499)和栲树林(0.517),其它林分均为聚集分布。针阔混交水源林以随机分布为主,常绿阔叶林有从聚集分布向随机分布演变的趋势,而竹林群落普遍为聚集分布。缙云山针阔混交水源林的结构较好,其中以马尾松阔叶树混交林结构最优,常绿阔叶林次之,竹林群落较差。对水源林的保育土壤功能进行研究和评价,结果为：林地土壤酸化严重,平均仅为4.14,物理化学指标除pH为弱度变异水平外,其余均为中等变异；土壤养分分级属稍缺偏中等水平,林地土壤供肥保肥能力较好。各林分保育土壤功能大小为：马尾松阔叶林(0.422)>栲树林(0.404)>杉木阔叶林(0.394)>四川大头茶林(0.388)>马尾松杉木阔叶林(0.383)>毛竹阔叶林(0.346)>毛竹马尾松林(0.344)>毛竹杉木林(0.340)>毛竹纯林(0.316)。对水源林的林冠层、灌草层、枯落物层和土壤层的涵养水源功能分别进行研究和评价,9种林分综合涵养水源功能强弱依次为：马尾松阔叶林(0.838)>马尾松杉木阔叶林(0.815)>杉木阔叶林(0.738)>栲树林(0.685)>四川大头茶林(0.661)>毛竹阔叶林(0.648)>毛竹杉木林(0.570)>毛竹马尾松林(0.452)>毛竹纯林(0.450)。对大气降水和水源林地产流水质分别进行对比研究并采用综合污染指数法、灰色关联法、BP神经网络法对径流水质进行综合评价,结果表明,林分对降雨酸性的缓冲作用显著,各水源林地输出水的水质得到较好的改善,均达到国家《地表水环境质量标准》(GB3838-2002)的Ⅱ类水以上,已达到集中式生活饮用水水平。采用层次分析法构建缙云山水源林生态功能评价指标体系和模型,并引进综合评分法得各林分生态功能大小依次为：马尾松阔叶树混交林(0.668)>马尾松杉木阔叶树混交林(0.612)>杉木阔叶树混交林(0.594)>栲树混交林(0.533)>四川大头茶混交林(0.512)>毛竹阔叶树混交林(0.491)>毛竹杉木混交林(0.480)>毛竹马尾松混交林(0.445)>毛竹纯林(0.387)。水源林生态功能以马尾松阔叶树混交林强,毛竹纯林最差；针阔混交型水源林最优,常绿阔叶型水源林次之,竹林群落最差。通过逐步回归和通径分析得到对生态功能因子具有显著影响的结构因子及其作用机制。林分结构对保育土壤、涵养水源和改善水质功能的影响作用均显著(p<0.05),构建并验证得到缙云山水源涵养林结构与生态功能耦合模型：Z=11.907-0.006X1+0.084X2-0.166X3+0.025X4+0.024X5—0.008X6-0.043X7+0.226X8+0.17X9+1.246X10+0.451X11+0.058X12+0.648X13+0.771X14-0.556X15+0.436X16-2.885X17其中,Z表示水源涵养林生态功能量化值；X1——X17为林分结构因子。采用单因素敏感性分析法检验结构因子对生态功能的影响程度,从大到小依次为：林分密度,土壤厚度,下层林密度,上层林密度,枯落物厚度,中层林密度,林木分布格局,草本多样性,群落总体物种多样性,平均胸径,树种混交度,乔木多样性,树种大小分化度,灌木多样性,郁闭度,平均树高,下木盖度。通过模型模拟预测和实测对比可知,缙云山水源涵养林最优群落为针阔混交型群落,最优林分类型为马尾松阔叶树混交林。以树种混交度大,林木呈随机分布、大小分化程度差异不大、林层密度分布均匀的林分结构对林木生长及提高物种多样性水平有促进作用,进而对发挥林分生态功能具有积极作用。更多还原

【Abstract】 Jinyun Mountain is located in the end of the Three Gorges Reservoir, as an important source of water in Chongqing area. Water conservation forest in this region has an important role to improved water quality. The quantitative and qualitative research on the structural characteristics and ecological functions of water conservation forest in Jinyun Mountain was conducted by using field surveys, location monitoring and laboratory analysis of the means applied to statistical analysis, to survey a large sample, the classical statistical analysis method, the weighted index method, BP neural network, gray correlation method, AHP, etc. more comprehensive and in-depth on research, respectively, and the establishment of relations between structure and ecological function of the coupling model. The mechanism on forest structure on the ecological function was analyzed by path analysis and sensitivity testing. These fill in the blanks of analysis and evaluation of water conservation forest structure and ecological function and mechanism at Jinyun Mountain. The purpose of this paper is to provide scientific evidence for the management of water conservation forest of Three Gorges reservoir area of the Yangtze River and the whole construction. The main results are as follows:The nine typical forests were studied by analyzing the overall distribution pattern of the forest by using the forest resource GIS database and remote sensing images, which contains Pinus massoniana and Broad-leaved tress mixed forest(MKF); Cunninghamia lanceolata and Broad-leaved tress mixed forest(SKF); Pinus massoniana, Cunninghamia lanceolata and Broad-leaved tress mixed forest(MSKF); Gorodnia axillaris and other Broad-leaved tress mixed forest(DKF); Castanopsis fargesiiFranch and other Broad-leaved tress mixed forest(KKF); Phyllostachys pubescens and Pinus massoniana mixed forest(ZMF); Phyllostachys pubescens and Broad-leaved tress mixed forest(ZKF) Phyllostachys pubescens and Cunninghamia lanceolata mixed forest(ZSF); and Phyllostachys pubescens Pure forest(ZPF).The non-spatial structure of stands has been studied quantitatively, and the stand density, species composition style, mixed ratio, diameter distribution, tree height distribution characteristics are indicated using a large sample investigation and classical statistical analysis, from the species composition, diameter, tree height, tree species distribution within the forest floor, and other aspects of species. Overall forest is the diameter structure of a typical uneven-aged forest. There is a wide range of tree height of the stand. The forest type on the distribution of tree height and diameter significantly. The spatial structure of forests is analyzed by the index of five parameters containing mixed degrees the size ratio of the number of angular scale, the variance mean ratio and the aggregate for the first time. The mingling degree and frequency, neighborhood comparison and frequency and spatial pattern of stands as well as the degree of aggregation within the size of tree species of the typical stands have been received. The structure of mixed coniferous water conversation forest structure type is the best, followed by evergreen broad-leaved forest, and the one of bamboo forest community is the worst.The spatial variation of soil physical and nutrient characteristics was moderate heterogeneity to evaluate and study on soil ecological functions of stands. The order of soil conservation function of forest as follows:MKF(0.422)>KKF(0.404)>SKF(0.394)>DKF(0.388)> MSKF(0.383)>ZKF(0.346) >ZMF(0.344)>ZSF(0.340)>ZPF(0.316).Water conservation mechanism of the forest in Jinyun Mountain was studied and evaluated respectively, based on the quantitative analysis on canopy, shrub, litters and soil horizon. Results showed that the hydrological function of MKF is the strongest. However, pure bamboo forest is the worst. The strength order of water conservation functions of 9 stands as follows:MKF(0.838)> MSKF(0.815)>SKF(0.738)>KKF(0.685)>DKF(0.661)>ZKF(0.648)>ZSF(0.570)>ZMF(0.452)> ZPF(0.450).Comparison of water quality of rainfall and runoff water of forest stands and the multi-method evaluation in the Jinyun Mountain, the results showed that the water quality of the output of the forest has gotten better improvidently, the buffering effect of acid rain a significant, are up to state, "Surface Water Quality Standard "(GB3838-2002) of theⅡclass of water or more, has reached the level of centralized drinking water, some plots have been basically reached for the source of water, the water level of the National Nature Reserve.The ecological functions model of water conservation forest in Jinyun Mountain was constructed by AHP, and adopt an integrated score obtained the order of the ecological functions of forests, the results showed that:MKF(0.668)> MSKF(0.612)>SKF(0.594)>KKF(0.533)>DKF(0.512)> ZKF(0.491)>ZSF(0.480)>ZMF(0.445)>ZPF(0.387). Ecological functions of forest the size of water to mixed conifer forest community is better than the evergreen broad-leaved forest community, which is better than the bamboo community.The structure factors on the ecological functions of individual factors with significant influence and the order of the direct and indirect factors influence have been received by stepwise regression and path analysis. The role of stand structure on soil conservation, water conservation, and improve the function of water quality are very significant, especially the density characteristics, tree species diversity and spatial pattern characteristics of the most prominent. The coupling model of forest structure and ecological function is constructed, as follow, Z=11.907-0.006X1+0.084X2-0.166X3+0.025X4+0.024X5-0.008X6-0.043X7+0.226X8+0.17X9+1.246X10+0.451X11 +0.058X12+0.648X13+0.771X14-0.556X15+0.436X16-2.885X17Where, "Z" for water conservation forest ecological function of quantitative indicators; "X1-X17" for the stand structure factor.The degree of influence structural factors on the ecological function of is drawn by single factor sensitivity analysis. It showed that Stand density>Soil thickness>Undergrowth density> upper forest density>litter depth>Middle forest density>Distribution pattern>Herb diversity>overall species diversity>Average dbh> Mingling degree and frequency>Tree diversity＞Neighbourhood comparison and frequency>Shrub diversity>Canopy density>Average height>Undergrowth coverage. The impact of various structural factors than significant interactions between factors together restrict the ecological functions.更多还原