放牧对典型草原群落生产力、养分含量及其化学计量学特征的影响

发布时间：2018-05-26 18:14

本文选题：划区轮牧 + 生物量　；参考：《内蒙古大学》2017年硕士论文

【摘要】：内蒙古典型草原是我国主要的畜牧业基地,近年来其主要的放牧方式是以家庭牧场为单位的划区轮牧。本研究以内蒙古锡林郭勒盟毛登牧场大针茅(Stipa grandis)+羊草(Leymus chinensis)典型草原为例,通过设置轻度、中度和重度三个放牧梯度的模拟划区轮牧实验,测定和分析了放牧四年后群落生物量、生物多样性、土壤养分含量、植物群落及主要种群养分含量及其化学计量学特征对放牧的响应,研究结果可为放牧生态学理论的研究及草地可持续利用实践提供参考。主要研究结果如下:1)放牧四年后轻度、中度和重度放牧均显著降低了生长季平均生物量,放牧四年后平均生物量分别比对照降低了 20%、22%和41%。2)放牧对群落生物量的影响具有季节性差异,生长高峰期只有重度放牧群落生物量显著降低,其他放牧梯度没有显著变化,但在其他大部分月份中度和轻度放牧群落生物量也明显降低。3)放牧改变了群落主要种群的生物量,大针茅种群生物量随放牧强度增加而显著增加,羊草和知母(Anemarrhena asphodeloides)种群生物量随放牧强度的增加而减少,糙隐子草(Cleistogenes squarrosa)变化不显著。4)放牧对群落的多样性有显著影响,中度和重度放牧群落Shannon-wiener指数与pielou均匀度指数均显著下降。5)经过四年的划区轮牧,不同放牧强度均没有影响土壤有机碳(SOC)、全氮(STN)、全磷(STP)、速效氮(SAN)和速效磷(SAP);对整个群落C、N、P养分含量也无显著影响。6)植物养分含量及其化学计量学特征对放牧的响应有种间差异,放牧对大针茅和羊草的养分含量及化学计量学特征基本无显著影响,而对糙隐子草和知母则有不同程度的影响。
[Abstract]:The typical grassland in Inner Mongolia is the main animal husbandry base in China. Taking Leymus chinensis, Leymus chinensis, Stipa grandisi, Stipa grandisi, Maodeng Ranch in Xilingle League, Inner Mongolia, as an example, the community biomass after four years of grazing was measured and analyzed through a simulated rotation grazing experiment with three gradients of light, moderate and severe grazing. The responses of biodiversity, soil nutrient content, nutrient content of plant community and main population and their chemometrics to grazing are discussed. The results can be used as reference for the study of grazing ecology theory and the practice of grassland sustainable utilization. The main results were as follows: (1) after four years of grazing, light, moderate and heavy grazing significantly reduced the average biomass of growing season. After four years of grazing, the average biomass decreased by 20% and 41%, respectively. The effects of grazing on community biomass showed seasonal difference. Only the biomass of heavy grazing community decreased significantly in the peak growth period, but the other gradients did not change significantly. However, in most other months, the biomass of moderate and light grazing communities also decreased significantly. 3) grazing changed the biomass of the main population of the community, and the biomass of Stipa grandis increased significantly with the increase of grazing intensity. The biomass of Leymus chinensis and Anemarrhena asphodeloidesdecreased with the increase of grazing intensity, but Cleistogenes squarrosa had no significant effect on community diversity. The Shannon-wiener index and pielou evenness index of moderate and heavy grazing communities decreased significantly. Different grazing intensities had no effect on soil organic carbon (SOC), total nitrogen (STN), total phosphorus (STP), available nitrogen (SAN) and available phosphorus (SAPN), and had no significant effect on the nutrient content of the whole community. 6) the plant nutrient content and its chemometrics response to grazing had interspecific differences. Grazing had no significant effect on nutrient content and chemometrics of Stipa grandis and Leymus chinensis, but had different effects on herbage and Anemarrhena.
【学位授予单位】：内蒙古大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S812

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