亚热带樟树-马尾松混交林凋落物量及养分动态特征

Litter fall production and nutrient dynamic of Cinnamomum camphora and Pinus massoniana mixed forests in subtropics China

选取亚热带典型的针阔混交林作为研究对象,从2009年至2011年每月进行凋落物的测定。结果表明:混交林年凋落物总量为(4634.723±337.1427)kg/hm2,且凋落叶(71.78%)>凋落枝(26.24%)>凋落碎屑(8.46%)>凋落果(3.23%)。凋落总量的月变化趋势明显,在11月份达到了最大值1025.6 kg/hm2,而最小值出现在2月份138.606 kg/hm2。混交林凋落物中大量元素、微量元素含量差异显著。大量元素含量大小顺序:C>N>Ca>K>S>Mg>P,微量元素的含量大小顺序:Mn>Fe>Zn>Pb>Cd>Cu>Ni>Co。C/N的特征是:枝(66.96)>果(63.48)>叶(40.62)。森林凋落物养分的含量直接决定了其养分的归还量。樟树-马尾松混交林凋落物养分归还总量为80.936 kg/hm2。混交林凋落物各元素养分归还量大小顺序特征是:N>Ca>K>S>Mg>P>Mn>Fe>Zn>Pb>Cd>Cu>Ni>Co。各组分养分归还特征是:叶(67.469 kg/hm2)>枝(14.928 kg/hm2)>果(2.361 kg/hm2)。混交林中N的年归还量为40.964 kg/hm2,其中凋落叶的N归还量较大为34.877 kg/hm2。

This study selected typical needle and broadleaved subtropical forests （camphor and pinus massoniana mixed forests） as the research object; from 2009 to 2011 the litter fall was investigated monthly. The results showed that the annual litterfall production was （4634.723±337.1427） kg/hm2,and foliage accounted for 71.78% 〉 branches （26.24%） 〉 litter debris（8.46%） 〉 fruits（3.23%）. The total amount of litterfall had the obvious monthly dynamic. In November, its maximum was 1025.6 kg/hm2; the minimum appears in February which was 138.606 kg/hm2. There were significant differences of macroelemens and microelements in mixed forest. The order of the macroelemens was C 〉 N 〉 Ca 〉 K 〉 S 〉 Mg 〉 P, as the microelement was Mn 〉 Fe 〉 Zn 〉 Pb 〉 Cd 〉 Cu 〉 Ni 〉 Co. The features of C/N was： the branch （66.96%） 〉 fruit （63.48%） 〉 leaf （40.62%）. The content of litter nutrient directly determines the amount of nutrients return in forest. The amount of litter nutrients return was 80.936 kg/hm2 in Camphor and pinus massoniana mixed forest. The features of litter nutrients return of each element size sequence was： N 〉 Ca 〉 K 〉 S 〉 Mg 〉 P 〉 Mn 〉 Fe 〉 Zn 〉 Pb 〉 Cd 〉 Cu 〉 Ni 〉 Co. The characteristics of various components of the nutrients return was： leaf （67.469 kg/hm2） 〉 branch （14.928kg/hm2） 〉 fruit （2.361 kg/hm2）. The amount of N return in mixed forest was 40.964 kg/hm2.Among this, the return amount of N in leaf had a value of 34.877 kg/hm2.