The response of soil-atmosphere greenhouse gas exchange to changing plant litter inputs in terrestrial forest ecosystems

Jinglan Cui; Shu Kee Lam; Shan Xu; Derrick Yuk Fo Lai

doi:10.1016/j.scitotenv.2022.155995

The response of soil-atmosphere greenhouse gas exchange to changing plant litter inputs in terrestrial forest ecosystems

Sci Total Environ. 2022 Sep 10;838(Pt 2):155995. doi: 10.1016/j.scitotenv.2022.155995. Epub 2022 May 16.

Authors

Jinglan Cui¹, Shu Kee Lam², Shan Xu¹, Derrick Yuk Fo Lai³

Affiliations

¹ Department of Geography and Resource Management, The Chinese University of Hong Kong, Shatin, Hong Kong.
² School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia.
³ Department of Geography and Resource Management, The Chinese University of Hong Kong, Shatin, Hong Kong; Centre for Environmental Policy and Resource Management, The Chinese University of Hong Kong, Shatin, Hong Kong, China. Electronic address: dyflai@cuhk.edu.hk.

PMID: 35588851
DOI: 10.1016/j.scitotenv.2022.155995

Abstract

Various global change factors (e.g. elevated CO₂ concentrations, nitrogen deposition, etc.) can alter the amount of litterfall in terrestrial forests, which could subsequently lead to changes in the physical, chemical, and biological properties of forest soils. Yet, there is hitherto a lack of consensus on the role of litter in governing the soil-atmosphere exchange of greenhouse gases (GHGs) in forest ecosystems, which can significantly affect the overall climatic cooling impacts of forests as a net carbon sink. In this study, we carried out a meta-analysis of over 250 field observations to determine the response of soil GHG fluxes to in situ litter manipulation in global forests. Our results showed that overall, litter addition enhanced soil CO₂ emissions from terrestrial forests by 26%, while litter removal reduced soil CO₂ emissions from these forests by 26%. The negative response of soil CO₂ emissions to litter removal was stronger in the tropical forests (-33%) than in the subtropical (-27%) and temperate (-21%) forests, and was significantly correlated with mean annual temperature and precipitation. Moreover, litter removal was observed to enhance soil CH₄ uptake in tropical (+24%) and temperate (+9%) forests, but not in subtropical forests. Litter removal reduced N₂O emissions from forest soils by 20% on average, with this negative effect increasing with mean annual precipitation. The duration of litter removal experiment was negatively correlated with the response of soil CO₂ emissions but had no influence on the response of soil CH₄ and N₂O fluxes. We found that plant litter supply could alter soil GHG fluxes in forests by modulating the microclimate as well as the labile and recalcitrant soil carbon pools. Our findings highlighted the importance of considering the effects of changing plant litter inputs on soil-atmosphere GHG fluxes in terrestrial forests and their spatio-temporal variability in biogeochemical models.

Keywords: Carbon dioxide; Climate change; Forest soil; Greenhouse gas; Litter manipulation; Methane; Nitrous oxide.

Publication types

Meta-Analysis

MeSH terms

Atmosphere / analysis
Carbon Dioxide / analysis
Ecosystem
Forests
Greenhouse Gases* / analysis
Methane / analysis
Nitrous Oxide / analysis
Soil / chemistry

Substances

Greenhouse Gases
Soil
Carbon Dioxide
Nitrous Oxide
Methane