洪湖三种水生植物的分解速率及氮、磷动态

用分解袋法,对生长于洪湖的菰(茎、叶)、莲(叶、叶柄)、微齿眼子菜(整株)进行480d原位分解研究.结果表明,莲叶和菰叶分解最快,其干重损失率分别为96.5%和96.6%;微齿眼子菜和莲叶柄分解最慢,其干重损失率分别为66.8%和71.6%.到实验结束时,菰茎和莲叶柄中的N浓度分别增加了1倍和2倍,P浓度均增加了1倍;莲叶和微齿眼子菜中的N、P含量均降低.5种分解材料分别释放其初始N、P总量的22.6%～98.0%和43.5%～97.4%.分解速率和N、P变化取决于分解材料的烧失重与总氮比值.

Decomposition rate and nitrogen and phosphorus dynamics of three kinds of hydrophyte in Lake Honghu

The in situ decomposition studies were conducted on the Zizania latifolia,Nelumbo nucifera and Potamogeton maackianus using decomposition bag method for 480 days in Lake Honghu.The leaves of N.nucifera and Z.latifolia decomposed most quickly with dry weight loses of 96.5% and 96.6% respectively;while the P.maackianus and N.nucifera petioles decomposed most slowly with the lost of 66.8% and 71.6% respectively.At the end of experiment,the N concentration of Z.latifolia stem and N.nucifera petioles increased 1 and 2 times,respectively,and P concentration all increased 1 time.The N,P contents of N.nucifera leaf and P.maackianus all decreased.5 kinds of decomposition material released their initial N,P total amounts of 22.6%~98.0% and 43.5%~97.4% respectively.The decomposition rates and N,P changes were decided by the ratio of AFOW to TN.