PurposeThe soil is the largest carbon pool in the terrestrial ecosystem. Changes of soil respiration with the climate warming are essential for the carbon cycling between the terrestrial ecosystem and the atmosphere. The aim of this study was to investigate the temperature adaptability of soil respiration and the possible mechanisms.Materials and methodsExperiments with a meadow soil were conducted through pre-incubation for 3days at 22 degrees C, then incubation under temperatures of 221, 301, and 38 +/- 1 degrees C, respectively, for 35days. For the different incubation temperatures, gas samples were collected on days 3, 9, 13, 16, 20, 23, 30, and 35, respectively. The gas samples were used for measurements of CO2 concentrations and calculation of soil respiration rates. The temperature sensibility of soil respiration was characterized with the index Q(10) (i.e., the increasing multiple of respiration rate with temperature increase of 10 degrees C). Soil properties related to respiration rates were measured, including total carbon (TC), dissolved organic carbon (DOC), soil organic matter (SOM), microbial biomass carbon (MBC), enzyme activities, and microbial community structure.Results and discussion p id=Par3 After 35days of incubation, the temperature sensibility of soil respiration decreased with the incubation temperatures, i.e., Q(10) (22 degrees C) >Q(10) (30 degrees C) >Q(10) (38 degrees C). The result showed that soil respiration exhibited temperature adaptability. The TC and SOM contents were not significantly different among the different temperatures, indicating sufficient substrate availability during the short incubation period. The warming scenarios led to lower activities of enzymes relative to C and N cycles and MBC and significantly changed the microbial community, especially decreased abundance of gram-negative bacteria. The elevated temperatures also reduced the comparability of bacteria and fungi and increased the diversity of microbial community structure.ConclusionsMechanisms of the temperature adaptability of soil respiration included reduction of the carbon-use efficiency and temperature adaptation of microorganisms. Among them, the microbial adaptation was the dominant mechanism for the temperature adaptability of soil respiration during the short-term incubation experiments.
1.Sun Yat Sen Univ, Sch Environm Sci & Engn, Guangdong Prov Key Lab Environm Pollut Control &, Guangzhou 510006, Guangdong, Peoples R China 2.Fujian Agr & Forestry Univ, Coll Resources & Environm, Fujian Prov Key Lab Soil Environm Hlth & Regulat, Fuzhou 350002, Fujian, Peoples R China
Recommended Citation:
You, Guiying,Zhang, Zhiyuan,Zhang, Renduo. Temperature adaptability of soil respiration in short-term incubation experiments[J]. JOURNAL OF SOILS AND SEDIMENTS,2019-01-01,19(2):557-565