【作者】 萨娜斯琴；

【导师】 易津；

【作者基本信息】 内蒙古农业大学 ， 植物学， 2010， 硕士

【摘要】 中国内蒙古和蒙古国共同占据着蒙古高原的主体部分。由于各种因素的干扰,中蒙两国草原生态环境已存在不同程度的退化。对蒙古高原草原放牧生态学的系统对比研究尚未见报道。因此本论文选取中蒙两国毗邻小针茅草原类型2个样地进行对比研究,研究内容包括植被群落多样性、植物功能群特征、主要植物营养特性、表层土壤理化特性等。以期探寻不同放牧方式的生态学差异,为蒙古高原小针茅草原生态环境保护和合理利用提供理论依据。主要研究结果如下：1植被群落特性对比研究表明,建群种和优势种重要值表现为四季游牧(FSNG)>定居放牧(SG);一年生植物重要值表现为SG>FSNG。说明内蒙古地区长期定居放牧后导致原生植被中建群种的作用减弱,一年生植物大量增加,植被退化。2植物营养成分分析结果表明,FSNG的氮、可溶性糖、磷、钾含量显著或极显著高于SG。建群种植物营养成分分析结果表明FSNG显著或极显著高于SG；而一年生植物营养成分变化规律与建群种相反,FSNG显著或极显著低于SG。总体结果表明FSNG植物营养水平高于SG。3植物光合色素在不同样地的植物类群间存在显著差异,建群种植物光合色素平均含量为FSNG>SG;一年生植物光合色素变化规律为SG>FSNG。植物营养(氮、可溶性糖、磷、钾含量)与光合色素含量相关分析均呈正相关关系,其中磷、糖与光合色素间的相关性比氮、钾的相关性高。4土壤物理特性研究表明,FSNG表层土含水量显著大于SG; SG砂土含量显著高于FSNG,而轻壤土和中壤土含量显著低于FSNG。土壤化学特性研究表明FSNG表土有机质、C/N、全氮、碱解氮、全磷、速效磷和速效钾含量均显著高于SG。而SG表层土pH值和全钾含量显著高于FSNG。说明内蒙古地区长期定居放牧后,导致原生植被表层土壤理化特性发生变化,土壤营养水平下降。5土壤与植被群落特征相关分析表明,植被群落高度、盖度和重要值均与砂土、砂壤土含量、pH值及全钾含量间基本呈负相关,与土壤其他特性间基本存在正相关。植物营养与土壤特性相关分析表明,植物各营养指标与土壤pH间均呈负相关,可溶性糖与土壤全钾间呈负相关,各营养指标与其余土壤特性间基本呈正相关。群落多样性指数与土壤特性间相关分析表明,群落多样性指数与砂土、pH和全钾间均呈负相关,与其他指标间基本存在正相关性。相关分析结果说明土壤砂化和盐碱化增加不利于植被群落的正常发育,降低其营养水平、生产性能和生态效益。6比较研究结果表明,内蒙古小针茅草原植被严重退化,主要原因可能是由于长期定居放牧,定居点附近超载过牧,植被没有足够恢复生长期,植被枯草盖度明显低于蒙古四季游牧,表层土壤长期得不到营养补给土壤营养水平长期不平衡造成物理性质砂化和盐碱化增加,植被营养缺乏后导致植被退化。更多还原

【Abstract】 Inner Mongolia and Mongolia jointly occupy the main part of the Mongolian Plateau. Due to various factors, Chinese and Mongolian grassland ecological environment have varying degrees of degradation. The study of grasslands on the Mongolian Plateau of a grazing ecology has not been reported. Therefore, in this study, we chose two semi-desert steppes which were adjacent in China and in Mongolia and both of them were with two different grazing(FSNG and SG).The study includes plant community diversity, plant functional group characteristics, the main features of plant nutrition, soil physical and chemical characteristics and so on to explore the ecological differences with different grazing to provide theory that was to the Mongolian Plateau semi-desert grassland ecological environment protection and rational use of available theory. The major findings are as follows:1 The result of vegetation community characteristics in Mongolian Plateau semi-desert grassland showed that the value of constructive species and the dominant species was FSNG(four seasonal nomadic grazing)>SG(settled grazing), the annuals important value was SG>FSNG It meant that the effect of species declined after the long-term settled grazing in Inner Mongolia, annual plants increased and the vegetation degenerated.2 The analysis of plant nutrition showed that the value of Nitrogen, Soluble sugar, Phosphorus, Potassium were Mongolia’s nomadic seasons plot significantly or very significantly higher than the plot of Inner Mongolia. Not similarly constructive species of plant nutrient analysis showed that the value of plots with FSNG in Mongolian was significantly or very significantly higher than the plots with SG in Inner Mongolia. However, the nutrition of annual plants was in contrast with the constructive species. In short, plant nutrition of plots with FSNG in semi-desert grassland Mongolia more than in semi-desert grassland Inner Mongolia.3 There was significant difference between the Photosynthetic pigments of constructive species and the one of Annual, the Photosynthetic pigments of constructive species was SG>FSNG and the one of Annual was FSNG>SG. The average content of constructive species photosynthetic pigments was FSNG in Mongolian higher than other plots in Inner Mongolia, while the photosynthetic pigments of annual plant species was opponent. The relative analysis between plant nutrition (nitrogen, soluble sugar, phosphorus, and potassium) and photosynthetic pigment showed that both of them were positive correlation relationship, in which the correlation between phosphorus, sugar and photosynthetic pigments better than the correlation between N and K.4 The research of soil physical properties showed that the surface soil water content of the plots with FSNG in Mongolian was more than SG in Inner Mongolia, the sand content of the plots with SG in Inner Mongolia more than FSNG in Mongolian, but the Light loam and medium loam content were both less than FSNG in Mongolian. The research of soil chemical properties showed that the surface soil organic matter, C/N, total nitrogen, available nitrogen, total phosphorus, available phosphorus and potassium with FSNG in Mongolian were significantly higher than with SG in Inner Mongolia, but the pH and the total K were opponent. It meant that the soil physical and chemical properties of original vegetation had changed and the level of soil nutrient had gone down.5 The correlation analysis of soil and community characteristics showed that there were negative correlation between vegetation community characteristics (community height, coverage and importance values) and sand, sandy loam, pH, and total K while were positive correlation between other Soil characteristics. The analysis of plant nutrition and soil characteristics showed that there were negative correlation between nutritional indices of plants and soil pH. Soluble sugar and total K were negative correlation. Nutritional indices of plants and the rest of soil characteristics were positive correlations. The correlation analysis of species diversity index and soil characteristics showed that there were negative correlation between species diversity index and sand, pH and total K while were positive correlation with other indicators.6 All analysis could show the reason for the degradation of semi-desert grassland in Mongolian Plateau was mainly due to the imbalances of soil nutrient which caused the changes of physical properties. The vegetation cover sub-tilis of semi-desert steppe region of Inner Mongolia-grazing that was Over-grazing long time was significantly lower than that with FSNG in Mongolia, which led surface soil to could not get nutrient long-term and appeared Serious soil desertification. Soil sand severe degree. Lack of nutrition resulted in vegetation degradation.更多还原