二球悬铃木凋落叶分解初期对水体总氮和总磷的影响研究

Effects of early decomposition of Platanus acerifolia leaf litters on water TN,TP

为研究凋落叶在小型水体分解初期对水体N、P含量变化的影响,在实验室内模拟了秋季二球悬铃木(Platanus acerifolia)凋落叶在水体中短期分解的过程,研究了不同质量凋落叶分解对水体总氮(TN)、总磷(TP)的影响。结果表明:二球悬铃木凋落叶中磷(P)在10 h内淋溶作用明显,水体TP含量在10 h内持续上升;而凋落叶质量不同,氮(N)快速淋溶时间不同,1—2 g凋落叶发生在6 h内,3 g凋落叶在24 h内持续释放N。二球悬铃木凋落叶在水体分解4 d过程中,均表现为N、P的整体释放,但N、P变化特征不同,1—2 g凋落叶水体中TN峰值出现在48 h,3 g凋落叶峰值在72 h;而TP峰值分别为10 h(1 g)、72 h(2 g)和96 h(3 g)。随凋落叶质量增加,水体TN、TP含量升高且差异显著,1 g、2 g和3 g凋落叶水体中的TN含量平均值分别为0.217 mg·L–1、0.475 mg·L-1和0.644 mg·L–1,TP含量平均值分别为0.132 mg·L–1、0.192 mg·L–1和0.302 mg·L–1。二球悬铃木凋落叶水体TP显著高于白蜡凋落叶水体TP,TN波动变化但整体上也高于白蜡落叶水体。

In order to study the effects of foliar litter decomposition in early stage on water total nitrogen(TN)and total phosphorus(TP),short-term decomposition process of Platanus acerifolia leaf litters in autumn was simulated in the lab,the decomposition influence of different leaf masses on TN and TP was studied.The results showed that TP content continuously increased in 10 hours as a result of obvious phosphorus eluviation within 10 hours.The eluviation time of nitrogen varied with foliar leaf mass,for 1-2 g of litter,eluviation occurred within 6 hours,and 3 g of litter continuously released nitrogen within 24 hours.On the whole,the nitrogen and phosphorus were released obviously during the decomposition of P.acerifolia deciduous leaf in water for 4 days,but the nitrogen and phosphorus release dynamics varied.TN content peaked at 48 hours and 72 hours in the water of 1-2 g and 3 g leaf litters respectively,while maximal TP appeared at 10 hours,72 hours,and 120 hours in the water of 1 g,2 g,and 3 g leaf litters,respectively.TN and TP in water significantly increased simultaneously with the rise of leaf mass,average value of TN content was 0.217 mg·L-1,0.475 mg·L-1,and 0.644 mg·L-1,and that for TP was 0.132 mg·L-1,0.192 mg·L-1,and 0.302 mg·L-1,respectively in the water of 1 g,2 g,and 3 g foliar litters.TP content in water of P.acerifolia leaf litters was significantly higher than that of Fraxinus chinensis,TN fluctuated and also higher than that of F.chinensis.