Effect of Changes in Throughfall on Soil Respiration in Global Forest Ecosystems: A Meta-Analysis

To date, there has been limited knowledge about how soil carbon dioxide (CO<sub>2</sub>) emissions from forest ecosystems at a global scale respond to the altered precipitation, and the key influencing mechanisms involved. Thirty-seven studies conducted under throughfall manipulation con...

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Main Author: Xingkai Xu
Format: Article
Language:English
Published: MDPI AG 2023-05-01
Series:Forests
Subjects:
Online Access:https://www.mdpi.com/1999-4907/14/5/1037
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author Xingkai Xu
author_facet Xingkai Xu
author_sort Xingkai Xu
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description To date, there has been limited knowledge about how soil carbon dioxide (CO<sub>2</sub>) emissions from forest ecosystems at a global scale respond to the altered precipitation, and the key influencing mechanisms involved. Thirty-seven studies conducted under throughfall manipulation conditions in forest ecosystems around the globe were selected in this meta-analysis, with a total of 103 paired observations. Experimental categories such as climate types, forest types, soil texture, and the area size of changes in throughfall manipulation were included to qualify the responses of annual soil CO<sub>2</sub> emissions to the altered throughfall. The responses of the annual soil CO<sub>2</sub> emissions to the altered throughfall would be more sensitive in temperate forests than those in tropical and subtropical forests, probably due to the relatively long residence time of soil carbon (C) and the seasonal freeze–thaw events in temperate forests, as well as the relatively high concentration of non-structural carbohydrates in the belowground part of temperate terrestrial plants. A relatively large positive response of the soil CO<sub>2</sub> emissions to the increased throughfall was observed in Mediterranean forests due to small precipitation during the growing season and mostly coarse-textured soils. Besides climate types, the sizes of the effect of the altered throughfall on the soil CO<sub>2</sub> emissions (lnR<sub>CO2</sub>) varied with forest types and soil texture categories. Based on the regression analysis of the lnR<sub>CO2</sub> values against the changes in throughfall, the annual soil CO<sub>2</sub> emissions in forest ecosystems at a global scale would be increased by 6.9%, provided that the change in annual precipitation was increased by 10%. The results of structural equation modeling analysis indicate that fine root biomass and soil microbial biomass, along with the changes in annual precipitation, would substantially affect the altered throughfall-induced annual soil CO<sub>2</sub> emissions in global forest ecosystems. The findings of this meta-analysis highlight that the measurement of soil respiration components, the priming effects of soil organic C decomposition, and C allocation between the aboveground and belowground parts of different tree species under the altered precipitation conditions, deserve more attention in the future.
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spelling doaj.art-cd8b264f00944c7a8ed31abf0f0296432023-11-18T01:25:19ZengMDPI AGForests1999-49072023-05-01145103710.3390/f14051037Effect of Changes in Throughfall on Soil Respiration in Global Forest Ecosystems: A Meta-AnalysisXingkai Xu0State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, ChinaTo date, there has been limited knowledge about how soil carbon dioxide (CO<sub>2</sub>) emissions from forest ecosystems at a global scale respond to the altered precipitation, and the key influencing mechanisms involved. Thirty-seven studies conducted under throughfall manipulation conditions in forest ecosystems around the globe were selected in this meta-analysis, with a total of 103 paired observations. Experimental categories such as climate types, forest types, soil texture, and the area size of changes in throughfall manipulation were included to qualify the responses of annual soil CO<sub>2</sub> emissions to the altered throughfall. The responses of the annual soil CO<sub>2</sub> emissions to the altered throughfall would be more sensitive in temperate forests than those in tropical and subtropical forests, probably due to the relatively long residence time of soil carbon (C) and the seasonal freeze–thaw events in temperate forests, as well as the relatively high concentration of non-structural carbohydrates in the belowground part of temperate terrestrial plants. A relatively large positive response of the soil CO<sub>2</sub> emissions to the increased throughfall was observed in Mediterranean forests due to small precipitation during the growing season and mostly coarse-textured soils. Besides climate types, the sizes of the effect of the altered throughfall on the soil CO<sub>2</sub> emissions (lnR<sub>CO2</sub>) varied with forest types and soil texture categories. Based on the regression analysis of the lnR<sub>CO2</sub> values against the changes in throughfall, the annual soil CO<sub>2</sub> emissions in forest ecosystems at a global scale would be increased by 6.9%, provided that the change in annual precipitation was increased by 10%. The results of structural equation modeling analysis indicate that fine root biomass and soil microbial biomass, along with the changes in annual precipitation, would substantially affect the altered throughfall-induced annual soil CO<sub>2</sub> emissions in global forest ecosystems. The findings of this meta-analysis highlight that the measurement of soil respiration components, the priming effects of soil organic C decomposition, and C allocation between the aboveground and belowground parts of different tree species under the altered precipitation conditions, deserve more attention in the future.https://www.mdpi.com/1999-4907/14/5/1037forest soilfine root biomassmicrobial biomass carbonsoil carbon dioxide emissionsoil respirationthroughfall manipulation
spellingShingle Xingkai Xu
Effect of Changes in Throughfall on Soil Respiration in Global Forest Ecosystems: A Meta-Analysis
Forests
forest soil
fine root biomass
microbial biomass carbon
soil carbon dioxide emission
soil respiration
throughfall manipulation
title Effect of Changes in Throughfall on Soil Respiration in Global Forest Ecosystems: A Meta-Analysis
title_full Effect of Changes in Throughfall on Soil Respiration in Global Forest Ecosystems: A Meta-Analysis
title_fullStr Effect of Changes in Throughfall on Soil Respiration in Global Forest Ecosystems: A Meta-Analysis
title_full_unstemmed Effect of Changes in Throughfall on Soil Respiration in Global Forest Ecosystems: A Meta-Analysis
title_short Effect of Changes in Throughfall on Soil Respiration in Global Forest Ecosystems: A Meta-Analysis
title_sort effect of changes in throughfall on soil respiration in global forest ecosystems a meta analysis
topic forest soil
fine root biomass
microbial biomass carbon
soil carbon dioxide emission
soil respiration
throughfall manipulation
url https://www.mdpi.com/1999-4907/14/5/1037
work_keys_str_mv AT xingkaixu effectofchangesinthroughfallonsoilrespirationinglobalforestecosystemsametaanalysis