Evaluation of vegetation communities, water table, and peat composition as drivers of greenhouse gas emissions in lowland tropical peatlands

Hoyos-Santillan, Jorge; Lomax, Barry H.; Large, David; Turner, Benjamin L.; Lopez, Omar R.; Boom, Arnoud; Sepulveda-Jauregui, Armando; Sjögersten, Sofie

Abstract

© 2019 Elsevier B.V. Tropical peatlands are globally important source of greenhouse gases to the atmosphere, but data on carbon fluxes from these ecosystems is limited due to the logistical challenges of measuring gas fluxes in these ecosystems. Proposals to overcome the difficulties of measuring gas carbon fluxes in the tropics include remote sensing (top-down) approaches. However, these require information on the effect of vegetation communities on carbon dioxide (CO2) and methane (CH4) fluxes from the peat surface (bottom-up). Such information will help reducing the uncertainty in current carbon budgets and resolve inconsistencies between the top-down and bottom-up estimates of gas fluxes from tropical peatlands. We investigated temporal and spatial variability of CO2 and CH4 fluxes from tropical peatlands inhabited by two contrasting vegetation communities (i.e., mixed forest and palm swamp) in Panama. In addition, we explored the influence of peat chemistry and nutrient status (i.e., factorial nitrogen (N) and phosphorus (P) addition) on greenhouse gas fluxes from the peat surface. We found that: i) CO2 and CH4 fluxes were not significantly different between the two vegetation communities, but did vary temporally across an annual cycle; ii) precipitation rates and peat temperature were poor predictors of CO2 and CH4 fluxes; iii) nitrogen addition increased CH4 fluxes at the mixed forests when the water table was above the peat surface, but neither nitrogen nor phosphorus affected gas fluxes elsewhere; iv) gas fluxes varied significantly with the water table level, with CO2 flux being 80% greater at low water table, and CH4 fluxes being 81% higher with the water table above the surface. Taken together, our data suggested that water table is the most important control of greenhouse gas emissions from the peat surface in forested lowland tropical peatlands, and that neither the presence of distinct vegetation communities nor the addition of nutrients outweigh such control.

Citation

Hoyos-Santillan, J., Lomax, B. H., Large, D., Turner, B. L., Lopez, O. R., Boom, A., …Sjögersten, S. (2019). Evaluation of vegetation communities, water table, and peat composition as drivers of greenhouse gas emissions in lowland tropical peatlands. Science of the Total Environment, 688, 1193-1204. https://doi.org/10.1016/j.scitotenv.2019.06.366

• Journal Article Type: Article
• Acceptance Date: Jun 22, 2019
• Online Publication Date: Jun 24, 2019
• Publication Date: Oct 20, 2019
• Deposit Date: Jul 16, 2019
• Publicly Available Date: Jun 25, 2020
• Journal: Science of The Total Environment
• Print ISSN: 0048-9697
• Electronic ISSN: 1879-1026
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 688
• Pages: 1193-1204
• DOI: https://doi.org/10.1016/j.scitotenv.2019.06.366
• Keywords: Environmental Engineering; Waste Management and Disposal; Pollution; Environmental Chemistry
• Public URL: https://nottingham-repository.worktribe.com/output/2311865
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0048969719329390
• Additional Information: This article is maintained by: Elsevier; Article Title: Evaluation of vegetation communities, water table, and peat composition as drivers of greenhouse gas emissions in lowland tropical peatlands; Journal Title: Science of The Total Environment; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.scitotenv.2019.06.366; Content Type: article; Copyright: © 2019 Elsevier B.V. All rights reserved.
• Contract Date: Jul 16, 2019