TY - JOUR
T1 - Changing precipitation exerts greater influence on soil heterotrophic than autotrophic respiration in a semiarid steppe
AU - Zhang, Bingwei
AU - Li, Weijing
AU - Chen, Shiping
AU - Tan, Xingru
AU - Wang, Shanshan
AU - Chen, Minling
AU - Ren, Tingting
AU - Xia, Jianyang
AU - Huang, Jianhui
AU - Han, Xingguo
N1 - Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/6/15
Y1 - 2019/6/15
N2 - Future precipitation change is anticipated to have a profound influence on ecosystem carbon (C) cycling, especially soil respiration, the largest C flux from the terrestrial ecosystem to the atmosphere. Due to different substrate sources and biological processes, the heterotrophic (SR h ) and autotrophic (SR a ) components of soil respiration (SR tot ) may respond to changing precipitation in different ways. Determining the differential responses of SR h and SR a to precipitation will facilitate our evaluation of soil C storage and stability under future precipitation change. Here, a 3-year precipitation manipulation experiment with 5 levels of precipitation (±60%, ±30% and ambient growing season precipitation) was conducted in a semiarid steppe to determine the influence of precipitation on soil respiration. Results showed that SR tot increased nonlinearly with increasing water supply, in which, SR h increased much more than SR a . Consequently, the ratio of SR h to SR tot was enhanced significantly with increasing precipitation, i.e., from 41% to 62% as precipitation increased from 122 mm to 408 mm. Structural equation modeling analysis indicated that changes in SR h and SR a were predominated by the soil water content (SWC) and plant growth, respectively. The stronger effects exerted by changes in precipitation on SWC compared with plant growth contributed to the greater change in SR h than in SR a . Additionally, SR a exhibited a higher temperature sensitivity than SR h . Thus, the increased soil temperature in the drought treatments had greater influence on SR a than SR h , and greatly offset the influence of drought stress on SR a , leading to the smaller change in SR a compared with SR h . Our study highlights the different responses of the two soil respiration components to changing precipitation. These results indicate that future increases in precipitation in semiarid regions will increase soil heterotrophic respiration which may accelerate the turnover of soil C, and further affect the stability of soil C stock.
AB - Future precipitation change is anticipated to have a profound influence on ecosystem carbon (C) cycling, especially soil respiration, the largest C flux from the terrestrial ecosystem to the atmosphere. Due to different substrate sources and biological processes, the heterotrophic (SR h ) and autotrophic (SR a ) components of soil respiration (SR tot ) may respond to changing precipitation in different ways. Determining the differential responses of SR h and SR a to precipitation will facilitate our evaluation of soil C storage and stability under future precipitation change. Here, a 3-year precipitation manipulation experiment with 5 levels of precipitation (±60%, ±30% and ambient growing season precipitation) was conducted in a semiarid steppe to determine the influence of precipitation on soil respiration. Results showed that SR tot increased nonlinearly with increasing water supply, in which, SR h increased much more than SR a . Consequently, the ratio of SR h to SR tot was enhanced significantly with increasing precipitation, i.e., from 41% to 62% as precipitation increased from 122 mm to 408 mm. Structural equation modeling analysis indicated that changes in SR h and SR a were predominated by the soil water content (SWC) and plant growth, respectively. The stronger effects exerted by changes in precipitation on SWC compared with plant growth contributed to the greater change in SR h than in SR a . Additionally, SR a exhibited a higher temperature sensitivity than SR h . Thus, the increased soil temperature in the drought treatments had greater influence on SR a than SR h , and greatly offset the influence of drought stress on SR a , leading to the smaller change in SR a compared with SR h . Our study highlights the different responses of the two soil respiration components to changing precipitation. These results indicate that future increases in precipitation in semiarid regions will increase soil heterotrophic respiration which may accelerate the turnover of soil C, and further affect the stability of soil C stock.
KW - Change in precipitation
KW - Responses sensitivity
KW - Semiarid steppe
KW - Soil respiration components
UR - https://www.scopus.com/pages/publications/85063474191
U2 - 10.1016/j.agrformet.2019.03.019
DO - 10.1016/j.agrformet.2019.03.019
M3 - 文章
AN - SCOPUS:85063474191
SN - 0168-1923
VL - 271
SP - 413
EP - 421
JO - Agricultural and Forest Meteorology
JF - Agricultural and Forest Meteorology
ER -
