热带森林群落土壤种子库对海拔梯度的响应  

Responses of soil seed banks in tropical forests to an elevational gradient

作　　者：张敏[1,2] 宋晓阳[1,2] 

机构地区：[1]中国科学院西双版纳热带植物园热带森林生态学重点实验室,云南勐腊666303 [2]中国科学院大学,北京100049

出　　处：《生态学杂志》2015年第9期2390-2400,共11页Chinese Journal of Ecology

基　　金：国家重大科学研究计划项目(2014CB954104);中国科学院对外合作重点项目(GJH201317)资助

摘　　要：在西双版纳海拔800~1400 m的热带森林中,设置海拔梯度垂直样带和样地,研究热带森林群落土壤种子库对海拔梯度的响应。结果发现：（1）土壤种子库的密度和物种丰富度在海拔800 m最大,分别为10540±1578粒·m-2和71个种,最小的土壤种子库密度和物种丰富度则分别出现在海拔1400 m和1200 m。基于Bray-Curtis相似性系数,对4个海拔的土壤种子库物种进行了NMDS排序,发现不同海拔土壤种子库物种组成存在显著的空间分异。（2）土壤种子库中的异质性成分丰富度也因海拔不同存在差异,海拔800 m有9个异质性成分种,海拔1400 m只有5个;而异质性成分种的多度却在海拔1200 m最大。（3）土壤种子库与地上植被的相似性在4个海拔带都低于15%。研究表明,海拔变化对土壤种子库的密度、物种组成格局都能产生显著影响。Knowledge about how soil seed banks in tropical forests respond to elevational gradients is crucial for predicting how tropical forests adapt to climate change. Soil seed banks of tropical forests in Xishuangbanna were investigated by setting transects and plots at four elevations（ 800,1000,1200,and 1400 m）,in which soils were sampled and transported to a greenhouse for seed germination. The results showed that：（ 1） Seed density and species richness were the highest at 800 m; while the lowest seed density and species richness occurred at 1400 and 1200 m,respectively. NMDS analyses based on Bray-Curtis similarity indices showed great distinctions in species composition of soil seed banks among the 4 elevations.（ 2） The abundance of nonconstituent species in soil seed banks varied along the elevation gradient; nine species were found at800 m,while only five at 1400 m. The number of individuals for nonconstituent species peaked at1200 m.（ 3） The similarity in species composition between standing vegetation and soil seed banks was low at all elevations（ 15%）. All of these results suggested that forest soil seed banks respond significantly to the changes in elevation in Xishuangbanna.

关 键 词：热带森林 土壤种子库 海拔梯度 响应 

分 类 号：S714[农业科学—林学]