白蜡凋落叶在水体中的分解及对水质的影响

Decomposition of Fraxinus chinensis Leaf Litters and Their Effects on the Water Quality

于实验室内模拟北方秋季白蜡(Fraxinuschinensis)凋落叶在小型水体中的分解过程,研究了水体总氮(TN)、总磷(TP)和高锰酸盐质量浓度(DMn)的变化。结果表明:水体T N在24 h和132 h内均表现为升—降—升—降—升的波浪型变化,落叶中氮呈现出释放—吸收—释放—吸收—再释放的动态变化。水体TP在12 h达峰值后下降,至84 h时达最低值后又上升,磷整体表现为释放—吸收—释放特征;DMn质量浓度呈上升—下降—波状波动变化趋势,落叶中还原性无机物和可被氧化的有机物在12 h内有明显的释放。白蜡凋落叶释放物对水体T P和DMn质量浓度的影响集中于落叶浸泡12 h内,而氮在24 h内有两次明显的释放高峰,于132 h仍有释放高峰。整体上都表现为营养元素的释放,水体TN、TP质量浓度和DMn质量浓度显著升高。

Decomposition dynamics of Fraxinuschinensis leaf litters in the small size water bodywere studied by simulation experimentsin northern area autumn,variations of total nitrogen(TN),total phosphorus(TP),andpermanganate index(DMn)were measured.The results showed that TN of water showed out a wavevariation of increase-decrease-increase-decrease-increase,and leaf nitrogen with a release-accumulation-release-accumulation-release fluctuation.TP was peaked at 12 h,then decreased,with a minimum value at 84 h,ascended again,accordingly,phosphorus elements of leaf litters with a release-accumulation-release dynamics traits on the whole.With an increase-decrease-fluctuation change tendency of DMn,reductive inorganic substances and oxidizable organic substancesof leaf litters showed out anobvious release process in 12 h.During decomposition of leaf litters,TP and DMn with a maximum value within 12 h,while TN with double peak within 24 h,even still another maximum at 132 h.Overall,leaf litters showed out a release process of nutrients,the content of TN,TP and DMn in water were significantly increased.