刈割对山地草甸草原群落特征及多样性的影响

Effects of Cutting on the Community Characteristics and Diversity of the Mountain Meadow

【目的】结合独立样本t检验和Spearman秩相关分析,研究刈割对草原群落特征及多样性的影响。【方法】设置刈割和不刈割2个处理,用目测法估测盖度,用测量法量取高度,密度为样方中的物种数目,分种齐地面剪割测定植被地上生物量。【结果】刈割对草地群落特征和物种多样性的影响仅在地上生物量上表现为差异显著(P<0.05);刈割后,植被高度均高于不刈割,禾草和杂类草的地上生物量减少,相反,豆科和莎草科增加;刈割处理中,Margalef指数和Shannon-Wiener指数与地上生物量呈显著负相关,而不刈割处理中,前者没有相关性,后者表现出极弱的负相关性;刈割后的Simpson指数和Pielou指数与地上生物量表现为无相关性,但在不刈割处理中,二者均呈极弱的负相关性。【结论】刈割对植被地上生物量的影响效果显著;不同生活型的植物刈割后在高度、地上生物量和组成比例上均发生了变化;刈割对地上生物量和多样性的相关性影响有三种结果。

【Objective】The purpose of this project aims to explore the effect of cutting on community characteristic and diversity with Independent- Samples T Test and Spearman Correlation Analysis.【Method】Two treatments were designed in this study： cutting and non- cutting,and visual method was used to determine the vegetation coverage and measurement to determine the height,and density is the number of species in a quadrat,determination of aboveground biomass of different vegetation.【Result】The effects of cutting on the community characteristics and species diversity only showed that the significant difference existed in aboveground biomass（ P〈0. 05）; After cutting,vegetation height was higher than non- cutting,and the aboveground biomass of grasses and forbs decreased. On the contrary,legumes and sedge increased. In cutting treatment,Margalef index and Shannon- Wiener index with aboveground biomass was significantly negatively correlated,but in no cutting treatment,the former shosed no correlation,the latter showed a very weak negative correlation; After cutting the Simpson index and Pielou index with the ground biomass showed no correlation,but in no cutting treatment,both showed a very weak negative correlation. 【Conclusion 】Effects of cutting on aboveground biomass were significant; Different plant life forms after cutting in terms of height,aboveground biomass and composition were changed. There were three kinds of results after cutting between aboveground biomass and diversity in correlation.