The goal of this session is to generate a science-policy dialogue and provide credible scientific information for sound decision making related to the role of tropical wetlands in climate change adaptation and mitigation strategies. This session will encompass biophysical, socio-economic and governance facets of wetlands for effective conservation and restoration.
Chair: Kristell Hergoualch, Natalia Málaga
The recent IPCC report confirmed that an average global temperature increase of 2oC above pre-industrial levels poses greater risks than previously believed. Limiting warming to 1.5oC can substantially lower these risks – but requires dramatic emission reductions by 2030 and carbon neutrality by around 2050. The Paris Agreement requires Parties to the United Nations Framework Convention on Climate Change to contribute their emission reduction target through Nationally Determined Contributions (NDCs).
Southeast Asia and the Amazon are among the regions with great opportunities to transform their NDC ambitions through peatlands. Indonesia’s first NDC with emission reduction target of 29% would bring the emission level to 2,034 Mt CO2-e in 2030 from 1,334 Mt CO2-e in the base year of 2010. Meanwhile, Peru’s first NDC with emission reduction target of 20% would bring down its emission level to 298 Mt CO2-e in 2030 from 171 Mt CO2-e in the base year of 2010.
Provided the current strong policy on peatland conservation and restoration is sustained, Indonesia could further lower its emissions by 11 to 110 Mt CO2-e annually depending on how peatland fires prevention can be imposed. Since Peru has no peatland-related policy in place, the opportunity from emission avoidance of around 30% due to drainage might be missed. The only factor that sustain Peruvian peatlands is their remoteness and lack of road network.
Palm swamp peatlands of the Amazonia have barely been the subject of biogeochemical investigation despite their large extent and potential to mitigate climate change. In Peru, these ecosystems are suffering recurrent degradation due to slashing of palms for harvesting their fruits. We conducted long-term research to evaluate how this practice affects carbon and nitrogen dynamics across a gradient of degradation that comprised an intact site, a moderately and a heavily degraded site. Site properties and fluxes of above and below-ground litter, soil heterotrophic respiration, and CH4 and N2O were monitored monthly for 1−4 years. Degradation altered the hummock-hollow micro-topography of the forest floor, the structure and composition of the vegetation and properties of the soil. Inputs of organic matter to the peat decreased by twofold while outputs increased by 40% as a result of heavy degradation. The net CO2 balance indicated that the peat at the intact and moderately degraded sites was neutral (0.5 ± 5.3 and 2.8 ± 3.6 Mg CO2 ha-1 y-1) but it was a source at the heavily degraded site (25.9 ± 3.4 Mg CO2 ha-1 y-1). Soil CH4 emissions were high (200 kg C ha-1 yr-1) and not affected by degradation. Small site-differences in N2O emissions seemed driven by spatial heterogeneity of soil water-filled pore space. Palm swamp peatlands in their natural state constitute a net source of greenhouse gas (27 ± 8 Mg CO2-equivalent ha-1 y-1). Their degradation leads to increased emission rate by 70% highlighting the urgency to develop sustainable management practices.