中亚热带4种森林凋落物量、组成、动态及其周转期  

Litter production and turnover in four types of subtropical forests in China

作　　者：郭婧[1] 喻林华[1] 方晰[1,2] 项文化[1,2] 邓湘雯[1,2] 路翔[1] 

机构地区：[1]中南林业科技大学生命科学与技术学院,长沙410004 [2]南方林业生态应用技术国家工程实验室,长沙410004

出　　处：《生态学报》2015年第14期4668-4677,共10页Acta Ecologica Sinica

基　　金：国家林业公益性行业科研专项(201304317);国家林业局林业科技推广项目([2012]61)

摘　　要：为研究亚热带次生林保护对森林生态系统养分循环等功能过程的影响。采用凋落物直接收集法,比较湘中丘陵区3种次生林(马尾松+石栎针阔混交林、南酸枣落叶阔叶林、石栎+青冈常绿阔叶林)和杉木人工林的凋落物量、组成特征及其周转期。结果表明:4种林分年凋落物量在414.4—818.2 g m-2a-1之间,3种次生林显著高于杉木人工林,3种次生林两两之间差异不显著,落叶对林分凋落物量的贡献最大,占林分凋落物量的59.9%—66.6%。杉木人工林和南酸枣落叶阔叶林的凋落物量月动态变化呈"双峰型",马尾松+石栎针阔混交林、石栎+青冈常绿阔叶林呈"不规则型"。优势树种的凋落物量对其林分凋落物量的贡献随林分树种多样性的增加而下降,杉木、马尾松凋落物量的月动态与其林分凋落物量的月动态基本呈一致变化趋势,但南酸枣、青冈、石栎没有一致的变化趋势。杉木人工林凋落物分解率最低(0.31),周转期最长(3.2 a),南酸枣落叶阔叶林分解率最高(0.45),周转期最低(2.2 a),凋落物的分解速率和周转随林分树种多样性增加而加快。可见,次生林凋落物量大,且分解快,周转期短,有利于养分归还和具有良好地力维持的能力。Aboveground litter production （leaves, twigs, fruits, flowers） is an important component of the nutrient cycling in forests. In order to quantify annual litter production of subtropical forests and to better understanding of the effects of secondary forests on nutrient cycling in forest ecosystems, litter production, composition and turnover were investigated in four dominant subtropical forest types in Hunan Province, China. The four forest types included three types of secondary forests （i.e. a Pinus massoniana and Lithocarpus glaber mixed forest, a Choerospondias axillaries deciduous broadleaved forest, and a L. glaber and Cyclobalanopsis glauca evergreen broadleaved forest） and a Cunninghamia lanceolata plantation forest. The results showed that mean annual litter productions in the four forests ranged from 414.40 g m^-2 a^-1 to 818.22 g^ -2 a ^-1 with the maximum in P. massonarm and L. glaber mixed forest （818.22 g m ）, followed by C. axillaries deciduous broadleaved forest （794.56 g m^-2 a^-1） and L. glaber and C. glauca evergreen broadleaved forest （723.67 g m^-2 a^-1 ）, and the minimum in C. lanceolata plantation forest （414.40 g m^-2 a^-1）. Leaf litter was the dominant component in the total litter and contributed about 59.92%） to 66.62% in total litter production. Monthly changes in litterfall pattern showed two peaks in both C. lanceolata plantation forest and C. axillaries deciduous broadleaved forest, while no obvious litterfall pattern was found for P. massonana and L. glaber mixed forest and C. glauca and L. glaber evergreen broadleaved forest.The contribution of dominant tree species toward annual litter production became less important with increasing of the tree species richness in the studied forests. In the study site, C. lanceolata and P. massonana contributed significantly great amount of litterfall to monthly litter production in their corresponding forested stands, and therefore, control the seasonal variations in litterfall in the forests. However, the tree spe

关 键 词：湘中丘陵区 次生林 杉木人工林 凋落物量 周转期 

分 类 号：S714[农业科学—林学]