Inter-Species and Inter-Organ Differences in Stable C and N Isotope Signatures of Macrophytes from the Largest Freshwater Lake in China

Macrophytes play important roles in shallow aquatic ecosystems. Stable isotope signatures of macrophytes indicate the environmental conditions and macrophyte contributions to food webs. However, have been studied less than other organisms. We determined stable C N 10 plant species from Poyang Lake wetland (Wucheng, Yongxiu County) Nanji (Nanjishan, Xinjian Jiangxi Province, which are Chinese national nature reserves, among different seasons. The for seasons were significantly different. dominant Potamogeton malaianus Nymphoides peltatum. organs these two determined. Both δ13C δ15N values higher P. N. peltatum stems, roots leaves, varied organs. increased order roots<stems<leaves. decreased roots>stems>leaves, may be controlled by various factors including life history, external sources C/N, amount water wetland. These results provided a theoretical reference experimental data support detecting flow trend & elements environment changes lake euhydrophytes.