短期氮磷添加对晋北赖草草地植物群落特征的影响

Effects of short-term N and P addition on plant community characteristics of Leymus secalinus grassland in northern Shanxi Province

以晋北赖草(Leymus secalinus)草地为对象,通过添加氮、磷分析草地群落植物多样性与生产力,研究养分添加对草地群落植物组分、结构和多样性格局的影响。结果表明:短期氮、磷添加对草地群落Shannon-Wiener多样性指数、Pielou均匀度指数和Margalef丰富度指数均无显著影响。单独添加氮、磷对草地群落生产力的影响较小,同时添加氮、磷通过增加杂类草在草地群落中的比例,可增加草地地上生物量,显著降低植物群落根冠比。赖草草地群落多样性与生产力之间呈显著正相关关系。

In order to study the effects of nutrient addition on plant composition,structure and diversity pattern of Leymus Secalinus grassland in northern Shanxi Province,the plant diversity and productivity of grassland community were analyzed by adding nitrogen and phosphorus.The results showed that the Shannon-Wiener diversity index,Pielou evenness index and Margalef richness index were not significantly affected by short-term N and P addition.The results also implied that the effects of addition of N and P alone on grassland productivity were insignificant,whereas,addition of N and P at the same time increased the aboveground biomass,and significantly reduced the root shoot ratio of plant community by increasing the proportion of forb in grassland community.There was a significant positive correlation between community diversity and productivity of Leymus Secalinus grassland.