水生植物分解过程中生态化学计量学特征研究  

Ecological Stoichiometry Characteristics of Aquatic Macrophytes in the Decomposition Process

作　　者：张雷燕[1] 关保华[2] 程寒飞[1] 詹茂华[1] 

机构地区：[1]中冶华天工程技术有限公司,江苏南京210019 [2]中国科学院南京地理与湖泊研究所,湖泊科学与环境国家重点实验室,江苏南京210008

出　　处：《水生态学杂志》2017年第6期34-39,共6页Journal of Hydroecology

基　　金：南京市科技计划项目(201608016);国家自然科学基金(31270409)

摘　　要：为揭示水生植物分解过程中的生态化学计量学特征,选取沉水植物苦草(Vallisneria natans)和马来眼子菜(Potamogeton malaianus)以及漂浮植物浮萍(Lemna minor),分别置于温室(处理组A、B)和池塘中(处理组C),实验时间为5周,每隔1周随机从各重复组中取1份样品,测定干物质重和总氮(TN)、总碳(TC)、总磷(TP)含量,分析其残存干物质的分解过程。结果表明,在整个分解过程中,3种植物的C/N为7.43~10.06,低于全球水平22.5,C/P为43.09~91.77,明显高于全球水平23.2,说明同一种植物在相同的同化C能力前提下,对N的利用效率较高,对P的利用率较低;N/P为4.71~9.24,小于14,说明植物主要受N的限制。沉水植物苦草和马来眼子菜的C/N在温室和自然条件下规律一致,而漂浮植物浮萍则变化较大,说明沉水植物分解C和N的速率一致且不受环境影响,而漂浮植物浮萍分解C和N受环境影响较大;苦草和浮萍残存干物质C/N在开始有一个快速增长期,说明这2种植物N的释放速率超过C;3种植物残存干物质的C/P和N/P都在第1周快速增长且各处理变化较大,说明3种植物P分解速率都在1周内超过C和N,且受环境影响较大。研究结果将对水生态修复过程中是否移除残存水生植物提供理论依据。Plant matter from three macrophytes from different environments was dried and analyzed over time to investigate macrophyte stoichiometry during decomposition and the effect of environment on macrophyte stoichiometry.A floating plant,Lemna minor,and two submerged plants,Vallisneria natans and Potamogeton malaianus,were prepared and placed in three water environments： Treatment A： beaker with 200 m L tap water ＋ 3 cm of sediment in a greenhouse; Treatment B： beaker with 200 m L tap water in a greenhouse; Treatment C： in situ in a pond.Each treatment was run in triplicate with six plants per trial. Each week for five weeks,one plant was randomly selected from each treatment for determination of dry weight,TN,TC and TP. The C/N range in the three macrophytes was 7. 43-10. 06,much lower than the global level of 22. 5,and the C/P range was 43. 09-91. 77,significantly higher than the global level of 23. 2. The results indicate that,with the same assimilation capacity of C,the utilization efficiency of N is higher than that of P. The N/P range（ 4. 71-9. 24） in the three macrophytes was lower than the global level of 14,showing that N was the limiting nutrient for the macrophytes. Furthermore,the submerged plants V. natans,and P. malaianus exhibited similar C/N ratios in the greenhouse and under natural conditions,indicating a consistent release rate of C and N from the submerged macrophytes and implying a small environmental effect. However,the C/N ratio of L. minor varied markedly between treatments,implying a large environmental effect. The C/N ratio in L. minor and V. natans increased rapidly at the beginning,indicating that the release rate of N from both macrophytes was higher than the release rate of C. The C/P and N/P ratio in the three macrophytes increased rapidly in the first week and the ratios varied significantly among the three groups. This indicates that the P release rate from the three macrophytes was higher than the release rates of C and N during the first week and the environmental effec

关 键 词：碳 氮 磷 干物质 化学计量学 水生植物 

分 类 号：Q178.1[生物学—水生生物学]