中国水土保持科学2017，Vol.15Issue(1)：33-42,10.DOI:10.16843/j.sswc.2017.01.005
黄土丘陵区油松、沙棘人工林土壤呼吸动态及其对土壤温度和水分的响应
Soil respiration dynamics and its response to soil temperature and water content of Pinus tabulaeformis and Hippophae rhamnoides plantations in the Loess Hilly region
摘要
Abstract
[Background] As an essential component of the carbon flux in terrestrial ecosystems,soil respiration plays a critical role in maintaining global carbon cycling and the carbon balance.Exploring the process of soil respiration and its influencing factors is conducive to understanding ecosystem carbon emissions and regulation mechanisms.[Methods] In order to analyze the dynamic characteristics of soil respiration rate (Rs) and its response to the main environmental factors in the dominant plantations in the hilly Loess Plateau region,the Rs of Pinus tabulaeformis and Hippophae rhamnoides plantations were measured using a LI-8100 soil carbon flux measurement system from June 2015 to May 2016.Soil temperature (T) and soil water content (W) were simultaneously monitored.At seasonal and daily scales,there were significant differences in Rs and significant effects of T and W on Rs in the two plantations.In addition,temperature sensitivities of Rs were investigated using the Q1o function at the seasonal scale.[Results] 1) The seasonal dynamic patterns of Rs in P.tabulaeformis and H.rhamnoides plantations were similar,with the respective maxima (2.31 and 2.89 μmol CO2·m-2 ·s-1)in summer (June-August) and minima (0.60 and 0.65 μmol CO2 · m-2 · s-1) in winter (Decembe-February);the annual mean Rs in the plantations was 1.36 μmol CO2· m-2· s-1(p.tabulaeformis) and 1.64 μmol CO2·m-2·s-1(H.rhamnoides),with corresponding annual total Rs emissions of 18.90 and 22.81 tCO2· hm-2· a-1 The Rs emission during winter accounted for 14,.67％ and 12.65 ％ of the annual total emission in P.tabulaeformis and H.rhamnoides,respectively.In addition,the Rs maxima of P.tabulaeformis and H.rhamnoides appeared during 10:00-16:00,and the minima at 06:00 in the diurnal dynamic.2) At the seasonal scale,at 5 cm depth,Rs was significantly exponentially related with T and negatively linearly related with W (both P ＜ 0.01) in the two plantations.Moreover,the temperature sensitivity of Rs in H.rhamnoides (Q10 =1.40) was significantly (P ＜ 0.01) higher than that in the P.tabulaeformis plantation (Q10 =1.34).3).At the daily scale,the contribution of T to Rs increased when W exceeded 13％ and 12％ for P.tabulaeformis and H.rhamnoides,respectively.[Conculsions] The results indicate that the response of Rs to T is mainly affected by W in this region.Therefore,to ensure accuracy of the carbon balance budget and improve the regional carbon cycle model for the loess hilly region under conditions of climate change,we should fully consider the effects of T and W on Rs and strengthen observations of soil respiration in winter in future research.关键词
黄土丘陵区/人工林/土壤呼吸/土壤温度/土壤水分Key words
loess hilly region/plantation/soil respiration/soil temperature/soil water content分类
农业科技引用本文复制引用
谢育利,陈云明,唐亚坤,吴旭,温杰..黄土丘陵区油松、沙棘人工林土壤呼吸动态及其对土壤温度和水分的响应[J].中国水土保持科学,2017,15(1):33-42,10.基金项目
国家自然科学基金“黄土丘陵区油松和沙棘人工林的水分来源变化及其生理响应研究”(41501576) （41501576）
公益性行业(国家气象局)科研专项(重大专项)“干时气象科学研究——我国北方干旱致灾过程及机理”(GYHY2015060013) （国家气象局）
