Key Laboratory of Agro-ecological Processes in Subtropical Region, The Chinese Academy of Sciences, Changsha, Hunan, 410125, China.
Dongting Lake Station for Wetland Ecosystem Research, Institute of Subtropical Agriculture, Changsha, 410125, China.
Sci Rep. 2017 Jun 6;7(1):2820. doi: 10.1038/s41598-017-03126-9.
We examined foliar nitrogen (N) and phosphorus (P) stoichiometry of 3 wetland plants (Phalaris arundinacea, Miscanthus sacchariflorus, and Carex brevicuspis) distributed along an elevation gradient in the Dongting Lake, China, and how this stoichiometry is related to soil physico-chemical characteristics, elevation, and flooding days. Plant and soil samples were collected from 3 lakeshore sites. Total N and P concentrations of plants and six physico-chemical characteristics of the soil were measured, in addition to the elevation and flooding days. P. arundinacea and M. sacchariflorus had higher total N and P concentrations than C. brevicuspis. The foliar N:P ratio decreased with increasing elevation, and only increased with increasing foliar total N concentration. Canonical correspondence analysis indicated that the foliar stoichiometry was primarily regulated by soil water content, followed by soil nutrient concentration. The foliar N and P stoichiometry of the 3 wetland plants was insignificantly correlated with soil total P concentration. However, foliar stoichiometric characteristics and soil total N concentration significantly differed among the 3 species. These results demonstrate that spatial variation of foliar stoichiometry in wetland plants exists along an elevation gradient, with this information being useful for the conservation and management of wetland plants in this lake.
我们研究了沿中国洞庭湖海拔梯度分布的 3 种湿地植物（菰、荻和短叶茳芏）的叶片氮（N）和磷（P）化学计量特征，以及这种化学计量特征与土壤理化特性、海拔和水淹天数的关系。在 3 个湖滨地点采集了植物和土壤样本。除了海拔和水淹天数外，还测量了植物的总 N 和 P 浓度以及土壤的 6 种理化特性。菰和荻的总 N 和 P 浓度高于短叶茳芏。叶片 N:P 比值随海拔升高而降低，仅随叶片总 N 浓度升高而升高。典范对应分析表明，叶片化学计量主要受土壤水分含量调控，其次是土壤养分浓度。3 种湿地植物的叶片 N 和 P 化学计量与土壤总 P 浓度无显著相关性。然而，叶片化学计量特征和土壤总 N 浓度在 3 个物种之间存在显著差异。这些结果表明，湿地植物叶片化学计量在海拔梯度上存在空间变化，这为该湖泊湿地植物的保护和管理提供了有用信息。
