【作者】 范亚宁；

【导师】 李世清；

【作者基本信息】 西北农林科技大学 ， 生态学， 2006， 硕士

【摘要】 黄土高原生态环境脆弱,云雾山草地处黄土高原腹地,是典型的半干旱草地,也是黄土高原草地植被恢复的典型范例。本文以封育的宁夏云雾山草地为研究对象,采用野外调查和室内分析相结合的研究方法,系统研究了小尺度范围内草地养分的分布规律,植物群落的多样性,0～20cm和20～40cm两个土层的养分分布特征,并将传统统计方法和地统计学方法相结合深入分析了土壤养分在小尺度的空间变异特征;并对草地群落的特征与土壤肥力之间的关系进行了相关研究。研究结果对合理利用草原植被和保护黄土高原草地具有一定的生态学意义。通过研究本文得到以下主要结论:1.调查区域共有50种植物,分属20科37属。其中草本植物49种,灌木（小叶锦鸡儿Caragana microphylla Lam.,豆科植物）1种,单子叶植物3科,双子叶植物17科。铁杆蒿（Artemisia gmelinii）的重要值最高,为33.87%,长芒草（Stipa bungeana）其次,为29.12%,云雾山草地就形成了以铁杆蒿（Artemisia gmelinii）和长芒草（Stipa bungeana）为优势种的草地群落。草地中43种主要种群的分布格局为聚集分布,7种少见种为随机分布。2.对群落种类数、个体数和生物量分布类型进行的检验结果表明,物种数和个体数目呈对数正态分布,而生物量呈非正态分布:对植物养分和水分含量的检验发现,含氮量和含水量呈正态分布量,含磷量、含钾量、磷素累积量和钾素累积量呈对数正态分布,而氮素累积量为非正态分布,这一研究结果是对植物养分含量和累积量均按正态分布处理的补充和发展。3.不同类型多样性指数之间的相关性分析表明,丰富度指数和均匀度指数之间缺乏显著的相关性,而丰富度指数与多样性指数之间有一定的相关性,Shannon-Wiener指数与丰富度指数呈极显著的相关性（P<0.01）。均匀度指数与多样性指数之间也有一定的相关性,Simpson指数与均匀度指数呈极显著相关性（P<0.01）。4.对土壤的养分和水分含量进行分布类型检验结果表明,20-40cm土层全氮和0-20cm土层铵态氮既不是正态分布也不是对数正态分布;两个土层的硝态氮含量都呈对数正态分布,0-20cm土层有效磷呈对数正态分布,其它各个层次的养分（TN、A.P、SOM、NH₄⁺ -N和NO₃^- -N）和水分均为正态分布,各个层次土壤养分和水分的变异系数显示其都属于中等强度的变异性。5.应用地统计学对土壤养分和水分进行空间变异性分析表明,各向异性变异的变程均大于取样尺度范围,在取样范围内具有较好的空间相关性。但不论养分还是水分,其强烈的空间自相关性都均由结构性因素引起,受随机性因素干扰较小,所选用的指数模更多还原

【Abstract】 Yunwu Mountain grassland is typical semiarid grassland in Loess plateau and it is a typical example in plant recovered. In this paper applying inner analysis and field research to study small scale plant nutrients distribution, plant diversity, 0-20cm layer and 20-40cm layer soil nutrients distribution, the relationship between soil nutrients and plant community characters in this area; The classical statistics method and geostatistics method combined to analyze the spatial variability of soil nutrients and moisture. The main conclusions are as follows:1. In sample area, there are 20 familia, 37 genus and 50 different species. The important value of Tieganhao is the highest（33.87%）, and next is Changmangcao（ 29.12%） , As dominant species, they forms grassland plant community in this area; 43 species patter distribution are clumped and 7 scale species are random.2. The result shows, species and numbers of unities present normal distribution, but biomass presents logarithm normal distribution; Plant water content and total N content present normal distribution, P content、K content、P accumulation and K accumulation present logarithm normal distribution, but N accumulation is not normal or logarithm normal. The research results are advance and supplementary to plant nutrients content and nutrients accumulation that dealt with normal distribution before.3. The correlation analyses between different diversity indexes shows, Species richness indexes and Species evenness indexes have not correlation, Species richness indexes and species diversity indexes presents correlation, Shannon-Wiener index and Species richness indexes have a great significant correlation, Species evenness indexes and Species diversity indexes presents a significant correlation, Simpson index have a significant correlation with Species evenness indexes.4. The analyses about the distribution patter of soil nutrients and moisture in two soil layers （0-20cm and 20-40cm） shows, 20-40cm soil layer total N and 0-20cm soil layer NH₄⁺ -N are not normal or logarithm normal distribution, the contents of NO₃^- -N presents logarithm normal distribution in two different soil layers, 0-20cm layer A.P presents logarithm normal distribution, the rest nutrients and soil moisture presents normal distribution, the更多还原