【作者】 蓝振江；

【导师】 曾宗永；

【作者基本信息】 四川大学 ， 生态学， 2004， 硕士

【摘要】 植物群落的生物量是生态系统的功能指标，有重要的生态学意义，它可以作为群落在生态系统中的相对重要性的量度之一。对植物群落的生物量进行研究还可以为生态系统中研究能量平衡、能量流动和养分循环等功能过程提供基础数据。因此，生物量研究在生态保护中的重要作用已逐渐为人们认识。 本文以九寨沟国家级自然保护区为研究地，研究了九寨沟主要植物群落的生物量，并分析论述了整个九寨沟生物量和生产力的空间分布格局。与本项研究有关的其他研究结果说明，九寨沟陆生植物群落从低到高主要分布有桦木栎类落叶阔叶林、油松林、云冷杉林、落叶松林、方枝柏林、亚高山、高山灌丛、高山草甸和高山流石滩植被。本文所作的生物量调查即包括了以上所有的群落类型，调查海拔从2130m至3790m。在野外实地工作中，对乔木和灌木、草本植物的生物量采取了不同的调查方法：对于乔木群落的林下层以及灌丛、草甸群落，采用的是皆伐法，即将样方中所有活体植株的地上部分采集称量鲜重；乔木的生物量则采取相对生长法测定，即在调查中只测量乔木的胸径、树高，利用已发表的经验公式估算乔木层的生物量。 研究结果表明，所有群落中生物量最大的为亚高山暗针叶林，平均为380t·hm^-2左右，总生物量亦了占整个九寨沟总生物量的90％以上，为九寨沟陆地生态系统中最重要的植物群落；高山草甸和流石滩群落的平均生物量最小，平均为1t·hm^-2以下。整个九寨沟植物群落的总生物量约为8.3×10⁶t，平均生产力大于5.89t·hm^-2·a^-1。垂直分布上，生物量一般随海拔的升高而增加，在3000h_alt／m以上达到最大值，之后则随海拔的升高而急剧下降，这种分布格局与土壤、气候、人类干扰等各种环境因素密切相关。与全国平均水平相比，九寨沟几乎所有类型的群落的平均生物量都要高于全国同类群落的平均水平。九寨沟陆生植物群落的生物量和生产力研究 由于大熊猫是九寨沟保护区的保护对象之一，因此大熊猫主食竹在九寨沟的分布和生长状况也就有着其较为特殊的意义。利用以上生物量调查的结果，我们分析了箭竹在九寨沟的分布和生长状况。对各类群落中箭竹灌丛的生物量调查结果分析表明，九寨沟现有的竹林（灌丛）数量少，分布窄，其生物量远远低于同处一个山系、同一纬度的王朗大熊猫保护区。因此，从当前九寨沟箭竹现存量水平来看，很难满足大熊猫生存的需求。九寨沟当前的条件基本不适合大熊猫生存。 本项研究还利用各群落林下植物的生物量调查资料，计算和比较了不同群落林下植物的物种多样性，并探讨了这一方法的合理性和可行性。结果显示，桦木、辽东栋等落叶阔叶林群落的林下多样性一般要大于暗针叶林。油松林所处环境较为干早贫痔，因而林下灌木、草本盖度和生物量都不高，但因海拔较低，热量条件好，仍然具有比较高的多样性。区内不同位置的青杆林群落所处演替阶段不同，有的己是稳定的成熟群落，其林下多样性一般不是最高:而处于演替过程中的青杆针阔叶混交林则因物种组成比较复杂，林下多样性较高，有时甚至要高于落叶阔叶林。用生物量计算出来的物种多样性指数与物种多度和物种生物量均匀性这两个因素是正相关的，即物种数越多，生物量平均度越高，则多样性指数越高。这与Shannon指数的生态学意义是相一致的。但其优于Shannon指数之处在于，它避免了对构件生物的个体计数问题，同时又在结果中包含了个体大小、能量等更为丰富的信息，这些信息都代表着物种对于群落的重要程度。因此，将生物量引入物种多样性的评价从方法上和意义上说都是可行的。关键词:九寨沟植物群落生物量生产力箭竹林下植物多样性指数更多还原

【Abstract】 Biomass of various plant communities is an important index for the health of ecosystems, which can be one of the measurements of the relative importance of a community in the ecosystem. A study on community biomass may provide basic data for ecology study associated with energy balance, energy flow and nutrient cycles, etc. The importance of biomass study is being recognized more and more.In this paper, biomass of the major plant communities and their spatial distributions was sampled and analyzed to delineate relative importance of different plant communities in the terrestrial ecosystem at the Jiuzhaigou Valley Nature Reserve. In other research, conclusion was drawn that 10 major types of plant communities are consisted in the ecosystem at the Jiuzhaigou valley as follows: Birch forest, Oak forest, pine forest, Spruce-Fir forest, Larch forest, Cypress forest, Alpine and Sub-alpine Shrubs, Alpine Meadow and Alpine alluvial communities, all of which occur in our study. Various survey methods were used to sample plant communities: 1) Harvesting method was used to measure the understory, i.e. shrub and grass, herb communities; 2) Tree biomass was estimated by the empirical functions with tree heights and chest-height diameters.The results suggest that the biomass of the alpine Spruce-Fir forest, as much as 380 t hm-2 in average, is the largest and its total biomass accounts for over 90% of that of the Jiuzhaigou Valley. The alpine Spruce-Fir forest is the most important plant community in the Jiuzhaigou Valley. The average biomass of the alpine meadow and alpine alluvial communities is both less than 1 t-hm’2. The total biomass of the Jiuzhaigou Valley is about 8.3 × 106t and the average net primary productivity is over 5.89 t hm-2 a-1. As for the distribution along the altitude,biomass increases as the altitude increases until it reaches the maximum at 3 000 halt/m, and then it declines while the altitude increases. The distribution is influenced by many factors such as soil, climate and interference of human etc. In comparison to national wide, the mean biomass of almost all kind of communities at the Jiuzhaigou Valley is higher than that of other plant communities national wide except Oak forest.Specially, the arrowbamboo shrub was regarded as a special type of community, for it consist the main diet for the giant panda. In this paper, the distribution and growth status of arrowbamboo at the Jiuzhaigou Valley were analyzed, and the results show that arrowbamboo is less, and the distribution is limited in few places and cannot meet need of giant panda. That is to say, the current condition of Jiuzhaigou Valley is unsuitable for the giant panda.Further more, the biodiversity indexes of understory of different communities were calculated and compared, and the feasibility and rationality of this method was analyzed. The results suggest that the broadleaf forests often are higher in biodiversity than conifers are generally. The pine forest is high in biodiversity in spite of bad conditions, for they got more, sunlight than other communities. A positive correlation between the indices of biodiversity and the number of species occurred, so it is between the indices of biomass diversity and the biomass evenness. That is, more species contained in a community and more evenly the biomass distributes, the higher diversity is. The ecological meaning of this index is similar to Shannon diversity index. However, more important information such as body size, energy is involved in this index. And this method avoids the difficulty in calculating the number of plant individuals, which is ineluctable in estimating the biodiversity using Shannon and other indices. Conclusion can be drawn that it is feasible to estimate biodiversity by biomass.更多还原