Responses of soil CH_(4) fluxes to nitrogen addition in two tropical montane rainforests in southern China  

作　　者：Fangtao Wu Changhui Peng Chuanyao Wang Huai Chen Weiguo Liu Zhihao Liu Hui Wang Hong Li Dexiang Chen Yide Li Shirong Liu 

机构地区：[1]Center for Ecological Forecasting and Global Change,College of Forestry,Northwest Agriculture and Forestry University,Yangling,712100,China [2]State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,College of Forestry,Northwest Agriculture and Forestry University,Yangling,712100,China [3]Department of Biology Sciences,Institute of Environment Sciences,University of Quebec at Montreal,C.P.8888,Succ.Centre-Ville,Montreal,QC,H3C 3P8,Canada [4]Chengdu Institute of Biology,Chinese Academy of Sciences,Chengdu,610041,China [5]School of Architecture and Urban Planning,Chongqing University,Chongqing,400044,China [6]Jianfengling National Key Field Observation and Research Station for Forest Ecosystem,Research Institute of Tropical Forestry,Chinese Academy of Forestry,Guangzhou,510520,China [7]Research Institute of Forest Ecology,Environment and Protection,Chinese Academy of Forestry,Beijing,100091,China

出　　处：《Forest Ecosystems》2022年第3期335-343,共9页森林生态系统（英文版）

基　　金：funded by the National Key R&D Program of China(No.2016YFC0500203);a Natural Sciences and Engineering Research Council of Canada Discovery Grant.

摘　　要：Background:Atmospheric nitrogen(N)deposition is projected to increase in the next few decades,which may have a marked impact on soil-atmosphere CH_(4) fluxes.However,the impacts of increased atmospheric N depositions on soil CH_(4) flux in tropical rainforests are still poorly understood.From January 2015 to December 2018,a field experiment was conducted in a primary tropical montane rainforest(PTMR)and a secondary tropical montane rainforest(STMR)in southern China to quantify the impact of N additions at four levels(N0:0 kg N⋅ha^(-1)⋅year^(-1);N25:25 kg N⋅ha^(-1)⋅year^(-1);N50:50 kg N⋅ha^(-1)⋅year^(-1);N100:100 kg N⋅ha^(-1)⋅year^(-1)on soil CH_(4) flux.Results:Four years of measurements showed clear seasonal variations in CH_(4) flux in all treatment plots for both forest types(PTMR and STMR),with lower rates of soil CH_(4) uptake during the wet season and higher rates of soil CH_(4) uptake during the dry season.Soil CH_(4) uptake rates were significantly and negatively correlated with both soil temperature and soil moisture for both forest types.Annual CH_(4) uptake for the N0 plots from the PTMR and STMR soils were2.20 and1.98 kg N⋅ha^(-1)⋅year^(-1),respectively.At the PTMR site,mean CH_(4) uptake compared with the N0 treatment was reduced by 19%,29%,and 36%for the N25,N50,and N100 treatments,respectively.At the STMR site,mean CH_(4) uptake compared with the N0 treatment was reduced by 15%,18%,and 38%for the N25,N50,and N100 treatments,respectively.High level N addition had a stronger inhibitory impact on soil CH_(4) uptake than did the low level N addition.Conclusion:Our data suggest that soil CH_(4) uptake in tropical rainforests is sensitive to N deposition.If atmospheric N deposition continues to increase in the future,the soil CH_(4) sink strength of tropical rainforests may weaken further.

关 键 词：Atmospheric nitrogen deposition Greenhouse gases Soil CH_(4)flux Tropical rainforest 

分 类 号：S714[农业科学—林学]