【作者】 宋爱云；

【导师】 刘世荣； 史作民；

【作者基本信息】 中国林业科学研究院 ， 生态学， 2005， 博士

【摘要】 本文对卧龙自然保护区亚高山草甸进行了群落学调查和分析,采用DCA(Detrended Correspondence Analysis)排序和TWINSPAN(Two-Way Indicator Speicies Analysis)分类方法研究了群落之间和群落与环境之间的生态关系,在此基础上,从亚高山草甸水源涵养机理的研究着手,系统地研究了草甸主要群落类型的植冠层和土壤层的水文过程及其草甸植被对涵养水源功能的影响,建立了草甸不同群落类型的水源涵养功能的评价指标体系。主要结论如下: (1) 通过野外植被调查,研究卧龙自然保护区亚高山草甸植物种、植物群落与环境的生态关系。该地区亚高山草甸共有植物139 种,隶属于31 科88 属,其中菊科、百合科、兰科、报春花科、玄参科、蓼科、毛茛科、禾本科植物占有重要地位。应用数量分类方法将114 个样方分为12 个群落类型, 分别为糙野青茅+粘毛香青+珠芽蓼群落(Deyeuxia scabrescens+Anaphalis bulleyana+ Polygonum viviparum),糙野青茅+珠芽蓼+扭盔马先蒿(Deyeuxia scabrescens + Polygonum viviparum+ Pedicularis davidii)群落,狼毒+珠芽蓼(Stellera chamaejasme + Polygonum Viviparum)群落,突隔梅花草+珠芽蓼+糙野青茅(Parnassia delavayi+Polygonum Viviparum+ Deyeuxia scabrescens)群落,糙野青茅+珠芽蓼(Deyeuxia scabrescens+Polygonum viviparum)群落,川甘蒲公英+狼毒(Taraxacum lugubre+Stellera chamaejasme)群落,狼毒+川甘蒲公英(Stellera chamaejasme+ Taraxacum lugubre)群落,驴蹄草+圆穗蓼(Caltha palustris + Polygonum sphaerostachyum)群落,蒿草+狼毒+驴蹄草(Kobresia sp+ Stellera chamaejasme+ Caltha palustris)群落,驴蹄草+毛茛状金莲花+蒲公英(Caltha palustris+Trollius ranunculoides+Taraxacum mongolicum)群落,长葶鸢尾+糙野青茅(Iris delavayi+Deyeuxiascabrescens)群落,驴蹄草+薄叶高山耳蕨(Caltha palustris+Pteris bakerianum)群落。(2) DCA 排序图反映出排序轴的生态意义,第一轴反映了各群落类型所在的环境的海拔梯度,从上到下,随着的海拔的升高,植物群落或植物种的耐寒性越来越强;第二轴基本上反映了各群落类型所在的环境的土壤含水量。DCA 排序和TWINSPAN 分类结果基本一致,都较好地反映了群落之间和群落与环境之间的关系,通过定量分析不仅给出了植物群落与环境梯度的解释,而且客观地阐明了植被与环境因子的关系,显示出决定该区植物群落类型和空间分布的主要生态因子是海拔梯度和土壤含水量。(3) 运用物种丰富度、α多样性、β多样性等指标,分析研究了保护区亚高山草甸植被的物种多样性及其变化格局。结果表明,随海拔升高,亚高山草甸植被物种丰富度呈现单峰分布格局;α多样性(Shannon-Wiener指数和Simpson指数)随海拔上升先增加后有下降趋势,均匀度指数则随海拔升高而增加;β多样性(Wilson-Schmida指数、群落相异系数βCS及Cody指数)随着海拔均呈上升趋势。更多还原

【Abstract】 The subalpine meadow and eco-environmental conditions at the source area of Wolong Nature Reserve were investigated. By the means of Detrended Correspondence Analysis (DCA) ordination and Two Way Indicator Species Analysis (TWINSPAN ) classification the ecological relationship among the communities and between the community and the environmental factors were studied. On the basis of the subalpine meadow mechanism of water-conserving,the hydrological process of canny layer and soil layer for vegetations and characteristics for water conservation function have been analyzed. The evaluation index system of water-conserving function has been put forward to. Conclusions are as follows: (1) There are 139 species of plants in this subalpine zone. They belong to 30 families and 108 genera, which are dominated by Compositoe, Liliaceae, Orchidaceae, Pleurosperum, Scrophulariaceae, Polygonaceae, Ranunculaceae and Gramineae. Based on the field investigation of 114 sampling plots in Wolong Nature Reserve, the species composition and community structure of subalpine meadow communities were analyzed. The two-way indicator species analysis and the detrended correspondence analysis were employed to classify and ordinate subalpine meadow communities from 114 sampling plots in order to understand key influencing factors determining the structure and distribution pattern of subalpine meadow communities. The subalpine meadows were classified into 12 types through TWINSPAN analysis. There are Deyeuxia scabrescens+Anaphalis bulleyana+ Polygonum viviparum,Deyeuxia scabrescens+Polygonum viviparum+Pedicularis davidii, Stellera chamaejasme+Polygonum viviparum, Parnassia delavayi+Polygonum viviparum+ Deyeuxia scabrescens, Deyeuxia scabrescens+Polygonum viviparum, Taraxacum lugubre+ Stellera chamaejasme, Stellera chamaejasme+Taraxacum lugubre, Caltha palustris+ Polygonum sphaerostachyum, Kobresia sp.+Stellera chamaejasme+ Caltha palustris, Caltha palustris+Trollius ranunculoides+Taraxacum mongolicum, Iris delavayi+Deyeuxia scabres-ens, Caltha palustris+Pteris bakerianum. (2) DCA ordination of those communities demonstrated that Axis2 indicated a significant relationship between meadow distribution and soil humidity; while Axis1 indicated an important relationship of meadow distribution with altitude, along the gradient of which the communities were distinct from each other. The result of DCA ordination was similar to that of TWINSPAN classification, which reflected the relationship among the communities and between the community and the environmental factors. The quantitative analysis method not only provided the interpretation to the communities and the environmental gradients but also objectively elucidated the relation between the communities and the environmental factors. The analysis results showed that the importance of environmental factors affecting the structure and distribution pattern of subalpine meadow communities were soil moisture and altitude. The communities at this zone play very important roles in improving the conditions of soil and climate, conserving water and maintaining ecological balance. (3) Based on the data from field survey species richness ,αdiversity and βdiversity of the subalpine meadow in Wolong nature reserve ,Sichuan Province, we are analyzed in this paper .The results were as follows: Species richness index was the highest at mid-altitude. Αdiversity indices (Shannon-Wiener index and Simpson index) increased firstly ,then decreased with altitude increasing . Pielou evenness index increased with altitude increasing obviously. βdiversity indices (Cody index and Wilson-Schmida index),increased with increasing altitude. (4) The saturated water-holding capacity of leaves in different communities ranged from 1.00mm to1.40mm,Stellera chamaejasme community was the largest. The available water-holding capability of leaves rate which was the same as saturated water content rate were Stellera chamaejasme community(1.26mm), Deyeuxia scabrescens community(1.06mm), Caltha palustris community(1.10 mm)and Iris delavayi community(0.86mm) (5) There are better physical attributes and high water-holding capability in subalpine meadow soil. The maximum water storage of Caltha palustris community, Stellera chamaejasme community, Deyeuxia scabrescens community and Iris delavayi community were 3242 t/hm2,3193t/hm2, 3213t/hm2,2704t/hm2 in 45cm depth respectively. (6) The initial infiltration rate of Caltha palustris community, Stellera chamaejasme community, Deyeuxia scabrescens community and Iris delavayi community were 16.89 mm/min, 12.57mm/min, 7.33 mm/min and 2.36 mm/min;stable infiltration rate were 9.03 mm/min, 10.37 mm/min, 4.72 mm/min and 1.26 mm/min;cumulate infiltration content in 30mins of Caltha palustris community was higher than other subalpine meadow,time of reaching stable seepage of Iris delavayi community was the shortest. So, the soil infiltration property of Caltha palustris community and Stellera chamaejasme community were superior and the function of regulating the water during the process were marked. We concluded that rainfall intensity was not reach or overrun the stable infiltration rate in all subalpine meadow communities, so surface runoff over infiltration state seldom occured. (7) The soil water varied with time, flatuating during the growing season. The vetical variation of soil moisture indicated to different patterns among the three spatial layers.(8) The method of Analytic Hierarchy Process was applied to establish the hierarchy structure model and evaluation index system of vegetation community .The method of expert assessment and integrative grades were applied to assess the water-holding function of vegetation community. The index value ranges from 2.8 to 8.0. The water-conserving function of community shows as follows: Stellera chamaejasme community> Caltha palustris community> Deyeuxia scabrescens community>Iris delavayi community更多还原