Effects of Water Quality on Decomposition of Elodea nuttallii and Potamogetor crispus under Eutrophic Nutrient Condition

[Objective] The research aimed to study the effects of different water qualities on the decomposition of Elodea nuttallii and Potamogetor crispus.[Method] An indoor experiment was conducted.[Result] Both two kinds of aquatic plants had a roughly decomposition in water with high nitrogen and high phosphorus.The nitrogen content of both plants didn't change regularly along with time.At the end of this experiment,the nitrogen contents of both plants were close to the initial values.The phosphorus content of both plants decreased along with time,especially in the initial time,and the degree of the phosphorus release of Elodea nuttallii was higher than that of Potamogetor crispus.[Conclusion] Time had significant effect on the decomposition rate,the release of N and P of Elodea nuttallii,as well as the decomposition rate of Potamogetor crispus.N-availability in water had significant effect on the decomposition rate and the release of N of Potamogetor crispu.The effect of P availability in water on the release of N of Elodea nuttallii was significant.