中龄和老龄杉木人工林凋落物量及养分归还

为揭示中龄和老龄杉木人工林在凋落物量及养分归还方面的差异,对福建省南平市王台镇溪后村安曹下16年生和88年生杉木人工林进行了2 a的研究。结果表明,16年生和88年生杉木人工林年均凋落物量分别2 879.2、3 070.3kg.hm-2,凋落物各组分中落叶和落枝所占比重较大,16年生杉木人工林在杉木部分凋落量大于88年生,其它组分凋落量均小于88年生。2个林分凋落物养分含量各组分大小顺序基本表现为:N>K>P,16年生和88年生杉木人工林N、P、K年归还量分别为27.693、1.160、3.703 kg.hm-2和33.280、1.907、6.369 kg.hm-2。16年生和88年生杉木人工林凋落物量分别在2007年2月、11月,2006年11月以及2007年5月表现出2个明显峰值,2个林分N、P、K归还量动态变化趋势大致与各自凋落物量变化规律一致。

Litter production and nutrient return in 2 plantations of young and old Cunninghamia lanceolata

The primary purpose of this study was to determine litter production,seasonal dynamics and nutrient return in 2 forests of young(16 year-old) and old(88 year-old) plantation of Cunninghamia lanceolata located at Wangtai in Nanping,Fujian,during a period of 2006-2008.The results showed as follows: Mean annual total litterfall in 2 years of observations varied from 2 879.2 kg·hm-2 in the 16 year-old C.lanceolata to 3 070.3 kg·hm-2 in the 88 year-old C.lanceolata,The fraction of litterfall in 16 year-old C.lanceolata was larger than that in 88 year-old C.lanceolata,while the other components were opposite.The ranking of nutrient concentration in each fraction were all showed as N>K>P in the 2 plantations.Nutrient return of N,P,K content in the 2 plantations were 27.693,1.160,3.703 kg·hm-2 and 33.280,1.907,6.369 kg·hm-2 respectively.Litterfall of the two C.lanceolata plantations showed two-peak distribution pattern with two peaks in February(or May) and November of each year,meanwhile the dynamics of N,P,K in nutrient return was consistent with litterfall.