Temperature and substrate availability regulate soil respiration in the tropical mountain rainforests,Hainan Island,China  

作　　者：Zhang Zhou Lai Jiang Enzai Du Huifeng Hu Yide Li Dexiang Chen Jingyun Fang 

机构地区：[1]Department of Ecology,College of Urban and Environmental Sciences,Peking University,Beijing 100871,China [2]School of Urban Planning and Design,Shenzhen Graduate School,Peking University,Shenzhen 518055,China [3]State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China [4]Research Institute of Tropical Forestry,Chinese Academy of Forestry,Guangzhou 510520,China

出　　处：《Journal of Plant Ecology》2013年第5期325-334,共10页植物生态学报（英文版）

基　　金：National Basic Research Program of China on Global Change(2010CB950600);National Natural Science Foundation of China(#31021001);Ministry of Science and Technology(2010DFA31290).

摘　　要：Aims Tropical forest plays a key role in global C cycle;however,there are few studies on the C budget in the tropical rainforests in Asia.This study aims to(i)reveal the seasonal patterns of total soil respiration(R_(T)),litter respiration(R_(L))and soil respiration without surface organic litter(R_(NL))in the primary and secondary Asian tropical mountain rainforests and(ii)quantify the effects of soil temperature,soil moisture and substrate availability on soil respiration.Methods The seasonal dynamics of soil CO_(2) efflux was measured by an automatic chamber system(Li-8100),within the primary and secondary tropical mountain rainforests located at the Jianfengling National Reserve in Hainan Island,China.The litter removal treatment was used to assess the contribution of litter to belowground CO_(2) production.Important Findings The annual R_(T) was higher in the primary forest(16.73±0.87 Mg C ha−1)than in the secondary forest(15.10±0.26 Mg C ha−1).The rates of R_(T),R_(NL) and R_(L) were all significantly higher in the hot and wet season(May–October)than those in the cool and dry season(November–April).Soil temperature at 5cm depth could explain 55–61%of the seasonal variation in R_(T),and the temperature sensitivity index(Q_(10))ranked by R_(L)(Q_(10)=3.39)>R_(T)(2.17)>R_(NL)(1.76)in the primary forest and by R_(L)(4.31)>R_(T)(1.86)>R_(NL)(1.58)in the secondary forest.The contribution of R_(L) to R_(T) was 22–23%,while litter input and R_(T) had 1 month time lag.In addition,the seasonal variation of R_(T) was mainly determined by soil temperature and substrate availability.Our findings suggested that global warming and increased substrate availability are likely to cause considerable losses of soil C in the tropical forests.

关 键 词：soil respiration soil temperature LITTER tropical mountain rainforest 

分 类 号：S71[农业科学—林学]