Effects of biochar addition on dynamics of soil respiration and temperature sensitivity in a Phyllostachys edulis forest
GE Xiao-Gai;ZHOU Ben-Zhi;XIAO Wen-Fa;WANG Xiao-Ming;CAO Yong-Hui;YE Ming;Research Institute of Subtropical Forestry,Chinese Academy of Forestry;Qianjiangyuan Forest Ecosystem Research Station,State Forestry Administration;State Forestry Administration Key Laboratory of Forest Ecology and Environment;Research Institute of Forest Ecology,Environment and Protection,Chinese Academy of Forestry;Shouchang Forest Center of Jiande;
Aims Recent studies have shown that artificial addition of biochar is an effective way to mitigate atmospheric carbon dioxide concentrations.However,it is still unclear how biochar addition influences soil respiration in Phyllostachys edulis forests of subtropical China.Our objectives were to examine the effects of biochar addition on the dynamics of soil respiration,soil temperature,soil moisture,and the cumulative soil carbon emission,and to determine the relationships of soil respiration with soil temperature and moisture.Methods We conducted a two-year biochar addition experiment in a subtropical P.edulis forest from 2014.05 to 2016.04.The study site is located in the Miaoshanwu Nature Reserve in Fuyang district of Hangzhou,Zhejiang Province,in southern China.The biochar addition treatments included: control(CK,no biochar addition),low rate of biochar addition(LB,5 t·hm~(–2)),medium rate of biochar addition(MB,10 t·hm~(–2)),and high rate of biochar addition(HB,20 t·hm~(–2)).Soil respiration was measured by using a LI-8100 soil CO_2 efflux system.Important findings Soil respiration was significantly reduced by biochar addition,and exhibited an apparent seasonal pattern,with the maximum occurring in June or July(except LB in one of the replicated stand) and the minimum in January or February.There were significant differences in soil respiration between the CK and the treatments.Annual mean soil respiration rate in the CK,LB,MB and HB were 3.32,2.66,3.04 and 3.24 μmol·m~(–2)·s~(–1),respectively.Compared with CK,soil respiration rate was 2.33%–54.72% lower in the LB,1.28%–44.21% lower in the MB,and 0.09%–39.22% lower in the HB.The soil moisture content was increased by 0.97%–75.58% in LB,0.87%–48.18% in MB,and 0.68%–74.73% in HB,respectively,compared with CK.Soil respiration exhibited a significant exponential relationship with soil temperature and a significant linear relationship with combination of soil temperature and moisture at the depth of 5 cm; no significant relationship was found between soil respiration and soil moisture alone.The temperature sensitivity(Q10) value was reduced in LB and HB.Annual accumulative soil carbon emission in the LB,MB and HB was reduced by 7.98%–35.09%,1.48%–20.63%,and –4.71%–7.68%,respectively.Biochar addition significantly reduced soil carbon emission and soil temperature sensitivity,highlighting its role in mitigating climate change.
【Fund】： 国家自然科学基金(31600492和31670607);; 中央级公益性科研院所基本科研业务费专项资金(CAFYBB2016SY006;CAFBB2014Q-A008和CAFRISF2013002)
【CateGory Index】： S714
【CateGory Index】： S714