Experimental warming and drying increase older carbon contributions to soil respiration in lowland tropical forests

Abstract

Tropical forests account for over 50% of the global terrestrial carbon sink, but climate change threatens to alter the carbon balance of these ecosystems. We show that warming and drying of tropical forest soils may increase soil carbon vulnerability, by increasing degradation of older carbon. In situ whole-profile heating by 4 °C and 50% throughfall exclusion each increased the average radiocarbon age of soil CO₂ efflux by ~2-3 years, but the mechanisms underlying this shift differed. Warming accelerated decomposition of older carbon as increased CO₂ emissions depleted newer carbon. Drying suppressed decomposition of newer carbon inputs and decreased soil CO₂ emissions, thereby increasing contributions of older carbon to CO₂ efflux. These findings imply that both warming and drying, by accelerating the loss of older soil carbon or reducing the incorporation of fresh carbon inputs, will exacerbate soil carbon losses and negatively impact carbon storage in tropical forests under climate change.

Metadata

Item Type:	Article
Authors/Creators:	McFarlane, K.J. Cusack, D.F. Dietterich, L.H. Hedgpeth, A.L. Finstad, K.M. Nottingham, A.T. https://orcid.org/0000-0001-9421-8972
Copyright, Publisher and Additional Information:	© The Author(s) 2024. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/ licenses/by/4.0/.
Keywords:	Agricultural, Veterinary and Food Sciences; Biological Sciences; Ecology; Forestry Sciences; Climate Action; Life on Land; Soil; Tropical Climate; Carbon Dioxide; Forests; Carbon; Climate Change; Carbon Cycle; Carbon Sequestration; Ecosystem
Dates:	Published: 17 August 2024 Published (online): 17 August 2024 Accepted: 7 August 2024
Institution:	The University of Leeds
Academic Units:	The University of Leeds > Faculty of Environment (Leeds) > School of Geography (Leeds) > Ecology & Global Change (Leeds)
Funding Information:	Funder Grant number NERC (Natural Environment Research Council) NE/T012226/1
Depositing User:	Symplectic Publications
Date Deposited:	28 Aug 2024 10:56
Last Modified:	28 Aug 2024 10:56
Published Version:	https://www.nature.com/articles/s41467-024-51422-6
Status:	Published
Publisher:	Nature Research
Identification Number:	10.1038/s41467-024-51422-6
Related URLs:	PubMed URL Dataset Dataset
Sustainable Development Goals:
Open Archives Initiative ID (OAI ID):	oai:eprints.whiterose.ac.uk:216414