富营养条件下水质对伊乐藻与菹草生物质腐烂速率的影响

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

[目的]研究了不同水质对伊乐藻与菹草腐烂分解及释放体内营养盐的影响。[方法]在实验室条件下,模拟2种水草的自然腐烂分解过程。[结果]伊乐藻和菹草在高氮、高磷水中腐烂得最为彻底;伊乐藻和菹草植物样含氮量在不同的水质中没有随着时间呈现有规律的变化,在试验结束时2种植物残余物的含氮量接近于原初样;伊乐藻与菹草植物样中磷的释放随时间呈现规律性的变化,且在短时间内大量释放出组织内的磷,菹草释放磷的速率比伊乐藻快。[结论]时间为影响伊乐藻生物量消减、体内氮释放、磷释放与菹草体内磷释放的显著性因素(P<0.05)。氮为影响菹草生物量消减与体内氮释放的显著性因素(P<0.05)。磷为影响伊乐藻体内氮释放的显著性因素(P<0.05)。

[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.