神农架巴山冷杉天然林凋落量及养分特征

 研究了湖北神农架巴山冷杉(Abies fargesii)天然林凋落物量、凋落物N、P、K、Ca、Mg的含量及其归还量。结果表明: 巴山冷杉天然林的年凋落量为5 702.99 kg·hm^–2; 巴山冷杉林的凋落物组成比较丰富, 主要有落叶、落枝、球花、球果和其他5部分, 其中以落叶为多, 占总凋落量的46.00%; 凋落量的月变化模式呈双峰型, 分别在2006年10~11月和2007年4~5月达到峰值; 凋落物养分含量的大小顺序为: N＞K＞Ca＞P＞Mg; N、P、K、Ca、Mg的年归还量分别为: 39.106 3、4.534 6、13.436 7、5.496 5和0.091 1 kg·hm^–2; 就凋落物各组分的养分年归还量而言, 落叶的养分归还量远远大于其余组分的养分归还量, 占总归还量的52.65%。因此, 不论凋落量还是养分归还量, 巴山冷杉林凋落物中的落叶都占绝对优势。

LITTER PRODUCTION AND NUTRIENT CHARACTERISTICS OF ABIES FARGESII NATURAL FOREST IN SHENNONGJIA NATURE RESERVE, HUBEI, CHINA

Aims Forest litter contains many components, including remains of leaves, twigs, flowers and fruits, and is important in the transfer of energy and nutrients to the soil and plants by decomposition. Our objective is to study the functions of forest litter by analyzing litter production, nutrient concentration and nutrient return. Methods We focused on litter production and nutrients by collecting litter from Abies fargesii natural forest and analyzing it in the lab. Important findings Annual litter production was 5 702.99 kg·hm^–2, which approximates litter production in the subtropics. The majority was leaf litter, accounting for 46.00% of total production. The annual pattern exhibited two peaks: October–November 2006 and April–May 2007. The rankings of nutrient concentration and nutrient return were: N＞K＞Ca＞P＞Mg. With its large production, leaf litter also had the largest nutrient return.