Amazonian peatlands: A potentially important but poorly characterised source of atmospheric methane and nitrous oxide

点击翻译按钮获取中文摘要

Tropical peatlands are spatially extensive and biogeochemically dynamic environments that play a critical role in the cycling of greenhouse gases between the biosphere and atmosphere. However, we have relatively few ground-based measurements of greenhouse gas exchange from these ecosystems, as attention has largely focussed on fluxes from terra firme forests, savannas and seasonally flooded environments. The few observations that do exist originate from Indonesia and the Malay Archipelago, with little or no data available from lowland Amazonia. This makes it difficult to accurately assess the relative contribution of Amazonian peatlands for regional or global greenhouse gas budgets, or to predict how emissions from these environments are likely to change due to climate forcing or anthropogenic intervention. We propose conducting some of the first pilot measurements of methane and nitrous oxide fluxes from Amazonian peatlands, in order to begin exploring the significance of these ecosystems for regional and global atmospheric budgets. We will also explore the relationships between trace gas fluxes and key biophysical drivers (e.g. peat depth, water table depth, soil moisture, temperature, etc.), which will help us to better understand how methane and nitrous oxide fluxes are influenced by ecological processes and environmental conditions. These process-based data will allow us to predict the likely outcome of future environmental change or human disturbance, and will be useful for future modelling efforts. This research is important and timely because of ongoing debates over the relative importance of tropical peatlands for current and future climate change. The need for studies like this are particularly acute for regions like the Amazon Basin, because of the rapid pace of development and land use change, which may trigger enhanced carbon losses, greenhouse gas emissions and habitat degradation, all of which may act as a positive feedback to climate change.