Major carbon losses from degradation of Mauritia flexuosa peat swamp forests in western Amazonia

Abstract

Tropical peat swamp forests are major global carbon (C) stores highly vulnerable to human intervention. In Peruvian Amazonia, palm swamps, the prevalent peat ecosystem, have been severely degraded through recurrent cutting of Mauritia flexuosa palms for fruit harvesting. While this can transform these C sinks into significant sources, the magnitude of C fluxes in natural and disturbed conditions remains unknown. Here, we estimated emissions from degradation along a gradient comprising undegraded (Intact), moderately degraded (mDeg) and heavily degraded (hDeg) palm swamps. C stock changes above- and below-ground were calculated from biomass inventories and peat C budgets resulting from the balance of C outputs (heterotrophic soil respiration (Rh), dissolved C exports), C inputs (litterfall, root mortality) and soil CH4 emissions. Fluxes spatiotemporal dynamics were monitored (bi)monthly over 1–3 years. The peat budgets (Mg C ha−1 year−1) revealed that medium degradation reduced by 88% the soil sink capacity (from − 1.6 ± 1.3 to − 0.2 ± 0.8 at the Intact and mDeg sites) while high degradation turned the soil into a high source (6.2 ± 0.7 at the hDeg site). Differences stemmed from degradation-induced increased Rh (5.9 ± 0.3, 6.2 ± 0.3, and 9.0 ± 0.3 Mg C ha−1 year−1 at the Intact, mDeg, and hDeg sites) and decreased C inputs (8.3 ± 1.3, 7.1 ± 0.8, and 3.6 ± 0.7 Mg C ha−1 year−1 at the same sites). The large total loss rates (6.4 ± 3.8, 15.7 ± 3.8 Mg C ha−1 year−1 under medium and high degradation), originating predominantly from biomass changes call for sustainable management of these peatlands.

Modeling Land Cover Change Using MOLUSCE in Kahayan Tengah Forest Management Unit, Kalimantan Tengah

“…Kahayan Tengah FMU is located in Kalimantan Tengah Province, Indonesia. This FMU is dominated by swamp forests, the most carbon sink and biodiverse forest ecosystem in the world, and swamp forests have received much attention for their essential contribution to global climate change mitigation strategies (Astiani et al 2017;Hergoualc'h et al 2023;Igu 2016;Ledheng et al 2022;Miettinen et al 2016;Novita et al 2021). However, this land cover has been degraded and deforested due to agricultural expansion and forest fires (Afitah and Isra 2021;Boakye et al 2020;Irwani and Kartodihardjo 2022;Marwanto and Pangestu 2021;Scriven et al 2015), therefore, it is important to identify land cover changes and their projected changes to achieve sustainable forest management in the Kahayan Tengah FMU.…”

Tropical Peatland Water Table Estimations From Space

“…These biomes act as large reservoirs for C and play a critical role in the global C cycle (Page et al, 2011;Ribeiro et al, 2021). Changes in peatland WT are documented to govern GHG flux variability, especially in tropical regions where there is ample precipitation (Adeolu et al, 2015;Hergoualc'h et al, 2023;Hirano et al, 2014Hirano et al, , 2015Holden et al, 2004;Kwon et al, 2013;Rosenberry et al, 2006;Strack et al, 2005;Taufik et al, 2022Taufik et al, , 2023. Carbon dioxide (CO 2 ) fluxes are recorded to be greater when WT is lowered, while methane (CH 4 ) fluxes increase at persistently high WT (Hoyos-Santillan et al, 2019;Wong et al, 2020).…”

Spatial Distribution of Degradation and Deforestation of Palm Swamp Peatlands and Associated Carbon Emissions in the Peruvian Amazon

“…As a result, M. flexuosa abundance and density decrease in increasingly degraded sites (Horn et al, 2012;Hidalgo Pizango et al, 2022) and become more male-dominated which reduces the capacity of the species to reproduce (Virapongse et al, 2017;Falen Horna and Honorio Coronado, 2018). Consequences include a reduction in biomass and necromass C stocks and in litter C inputs which build up the peat over time (Hergoualc'h et al, 2017;Bhomia et al, 2019;Dezzeo et al, 2021;Hergoualc'h et al, 2023). Depending on the intensity of degradation the natural C sink capacity of the soil can be reduced, or the soil can turn into a C source (van Lent et al, 2019;Hergoualc'h et al, 2020).…”