沙地植被碳氮磷化学计量特征与物种多样性的关系

植被化学计量特征表征植物营养限制.它是否会影响物种多样性需要进一步探究.本研究以宁夏哈巴湖国家级自然保护区沙地油蒿群落和沙柳群落为对象,计算了植被碳(C)、氮(N)、磷(P)含量,分析了植被C、N、P生态化学计量特征对沙地植物群落物种多样性的影响.结果表明: 在流动沙丘和半固定沙丘生境中的沙柳群落,物种多样性Simpson指数与植被C/N值存在显著的负相关关系,而与植被N/P值的相关性不显著;在半固定沙丘和固定沙丘生境中的油蒿群落,物种多样性Shannon指数与N/P值存在显著正相关关系,而与C/N值存在显著负相关关系.结合C、N、P生态化学计量特征与冗余分析可知,油蒿群落和沙柳群落的植被P含量对物种多样性的影响不同,导致两个群落的植被N/P值对物种多样性产生不同的影响.

Relationship between vegetation C,N, P stoichiometry and species diversity in sand land.

Vegetation stoichiometry represents plant nutrition limitation status. Whether it can affect the species diversity of plant community remains to be explored. In this study, we examined plant carbon (C), nitrogen (N), phosphorus (P) concentrations and stoichiometry, and further analyzed the relationship between stoichiometry and species diversity in Artemisia ordosica community and Salix psammophila community in sand land of the Ningxia Habahu National Nature Reserve. The results showed that, for the S. psammophila community growing in mobile and semi-fixed sand dunes, there was a significant negative correlation between Simpson index and vegetation C/N ratio, but no significant correlation between Simpson index and vegetation N/P ratio. For A. ordosica community distributed in semi-fixed and fixed dunes, the Shannon index had a significant positive correlation with vegetation N/P ratio and a significant negative correlation with vegetation C/N ratio. Combined the vegetation stoichiometry with the results of regression analysis (RDA), P concentration and thus N/P ratio had different influences on the species diversity for A. ordosica community and S. psammophila community. Our results showed that vegetation stoichiometry has an important influence on species diversity of plant community in sand land.