论文部分内容阅读
选取亚热带典型的常绿阔叶甜槠林为研究对象,从2011年4月至2013年6月进行模拟氮(N)沉降试验,以探讨甜槠林凋落物养分归还量对N沉降的响应。氮沉降水平分别为:对照(CK,0 kg N hm-2a-1),低氮(LN,50 kg N hm-2a-1),高氮(HN,100 kg N hm-2a-1),高氮+磷(HN+P,100 kg N hm-2a-1+50 kg P hm-2a-1),每个处理重复3次。在模拟氮沉降2 a后,于2012年7月开始收集各样地的凋落物样品,分析凋落物及其养分归还量。结果表明:不同处理凋落物量没有显著差异,表明氮沉降增加没有显著提高林分凋落物产量;不同处理落叶、落枝中N、P、K、Ca、Mg含量均无显著差异,表明氮沉降亦没有显著增加凋落物各养分含量;模拟氮沉降处理均增加了各养分元素年归还量,但不同元素对N沉降的响应不同。N、K和Mg年归还量与CK存在显著差异,而P和Ca年归还量与CK处理无显著差异。
A typical subtropical evergreen broad-leaved Castanopsis: Castanopsis kawakamii was chosen as the research object. From April 2011 to June 2013, simulated nitrogen (N) sedimentation experiments were conducted to investigate the response of litter nutrient return to N deposition. Nitrogen deposition levels were as follows: CK (0 kg N hm-2a-1), low N (50 kg N hm-2a-1), high N High nitrogen + phosphorus (HN + P, 100 kg N hm-2a-1 + 50 kg P hm-2a-1), each treatment was repeated 3 times. After simulated nitrogen deposition for 2 years, litter samples of various plots were collected from July 2012 to analyze litterfall and its nutrient return. The results showed that there was no significant difference in the amount of litterfall between different treatments, indicating that the increase of nitrogen deposition did not significantly increase the yield of stand litter. There was no significant difference in the contents of N, P, K, Ca and Mg in different treatments, indicating no nitrogen deposition Significantly increased the litter nutrient content; Simulated nitrogen deposition increased annual return of each nutrient element, but different elements of N deposition response. There was a significant difference between annual return of N, K and Mg and CK, but there was no significant difference between return of P and Ca and CK.