生态学报2017，Vol.37Issue(8)：2673-2683,11.DOI:10.5846/stxb201512182529
温带森林不同演替阶段下的土壤CO2排放通量昼间变化
Diurnal variation in soil CO2 emission flux at different stages of temperate forest succession
摘要
Abstract
Climate warming is mainly caused by increasing atmospheric CO2 and CH4.Soil respiration plays an important role in the carbon balance of terrestrial ecosystems.Currently,the increase in atmospheric CO2 is due to human activities,natural distubances and processes.Soil respiration is one of the natural processes that release CO2 to atmoshphere from soil.Quantitative analysis of soil respiration is critial to assess forest ecosystem carbon budget under climate change scenairos.The temperate forest is one of the important components of terrestrial ecosystems.The forest in the Changbai Mountains is the typical temperate forest in China.Therefore,researching of soil respiration in the forests of Changbai Mountains is of great concern in estimating soil carbon budeget in China.In the growing season of 2013 (August),we emploed the temporal-spatial substitution method to determine sample plots on the north slope of the Changbai Mountains,which cover five vegetation succession stages:grassland,shrub forest (young forest),secondary birch (Betula platyphylla) forest,broad-leaved-mixed forest,and broad-leaved Korean pine (Pinus koraiensis) forest.The objectives of this study were to reveal the similarities and differences in soil CO2 emission processes at different succession stages of temperate forests,and to investigate the relationship between soil CO2 emission flux and soil temperature,moisture,physicochemical properties and other environmental factors.The field synchronous observations were conducted to determine the daily variation of soil CO2 emission flux based on the temporal-spatial substitution method.The results showed that:1) Soil CO2 emission flux of the temperate forest was unity at all the five vegetation succession stages.The unity of CO2 emission flux ensured that we could observe brief periods (such as during daylight) to estimate the CO2 emissions;2) The CO2 emission flux during daytime produced an obvious single-peak that appeared at approximately 13:00-15:00.The peak in grassland and shrub forest appeared at approximately 13:00,which was earlier than that of the secondary birch (Betula platyphylla) forest,broad-leaved mixedforest,and broad-leaved Korean pine forest (at approximately 14:00-15:00).Soil respiration in Korean pine broad-leaved forest had an obvious time-lag effect,and its peak appeared at approximately 15:00,which was later than that of the others sample plots;3) Average soil CO2 emission fluxes from low to high ranked as:grassland (2.760 μmol m-2 s-1),shrub forest (2.854 μmol m-2 s-1),secondary birch(Betula platyphylla) forest (3.048 2mol m-2 s-1),broad-leaved mixed forest (3.696 μmol m-2 s-1),broad-leaved Korean pine (Pinus koraiensis) mixed forest (4.61 μmol m-2 s-1).Within temperate forest succession stages,soil CO2 emission tlux increased gradually and ranked as:grassland ＜ shrub forest ＜ secondary birch (Betula platyphylla) forest ＜ broad-leaved mixed forest ＜ broad-leaved and Korean pine (Pinus koraiensis) mixed forest;4) The soil temperature in the 0-5 cm depth soil had the highest correlation coefficient with soil CO2 flux compared with other environmental variables.Therefore,Soil temperature monitoring will be useful for estimating soil CO2 emissions.关键词
土壤CO2排放通量/环境因子/温带森林/演替/长白山Key words
soil CO2emission flux/environmental factors/temperate forests/succession/Changbai Mountains引用本文复制引用
牛莉平,许嘉巍,靳英华,尹海霞,王嫒林,刘羽霞,张英洁..温带森林不同演替阶段下的土壤CO2排放通量昼间变化[J].生态学报,2017,37(8):2673-2683,11.基金项目
国家自然基金资助项目(41571078,41171072) （41571078,41171072）
长白山科学研究院开放基金课题(201501) （201501）
中国地震局资助项目(201208005) （201208005）
