Collaborative Research: Forest Productivity and Hydrological Patterns Regulate Methane Fluxes From Peatlands in the Amazon BasinDuration:05/01/2014 – April/30/2017
Award Amount:$103,000 out of $729,999
Principal Investigator: Qianlai Zhuang, in collaboration with Hinsby Cadillo-Quiroz at Arizona State University and Joost van Haren at University of Arizona
The Amazon basin contains nearly one million square kilometers of wetlands, predominantly peatlands, which are known to be highly productive and to store significant quantities of carbon in plant biomass and soil. Peatlands are characterized by soils rich in organic matter that are often saturated with water, and are therefore often low in oxygen. These conditions often lead to the release of methane, a greenhouse gas with ~25 times the heat-trapping capacity of carbon dioxide, and peatlands are known to be important global sources of methane. Until very recently, peatlands were not expected to be a significant component of the Amazon basin since these wetlands are more common in cold, northern latitudes and there were few records of their existence in the Amazon. In recent years, however, multiple studies aided by satellite imagery and guided field explorations have documented hundreds of peatlands across basins in the West and Central Amazon. An estimated 3-6 millions of tons of organic carbon are contained in these newly discovered Amazon peatlands, which may also represent a significant, previously unrecorded, source of methane annually. The magnitude of organic carbon stored in plants and soils every year vs. that released as methane from these peatlands is not known. This project proposes to evaluate for the first time a set of diverse Amazonian peatlands their organic carbon content, and rates of forest productivity and methane formation and release. This work will also include experimental manipulations of water levels to evaluate responses of productivity and methane release to environmental changes likely to occur as the climate warms. This project will also develop mathematical models of these ecosystems to evaluate the impact of peatlands at larger scales and to propose quantitative predictions for future productivity and methane emissions. Two hypotheses will be tested in this study including (i) whether vegetation change and water regime determine methane production and release, and (ii) whether the response of methane production to altered water regimes is modulated by the diversity of Amazon peatlands.