Using Ground Penetrating Radar (GPR) to Investigate Greenhouse Gas Releases from Peatland Ecosystems: from boreal to subtropical systems
Using Ground Penetrating Radar (GPR) to Investigate Greenhouse Gas Releases from Peatland Ecosystems: from boreal to subtropical systems
Previously Published Material: Some of the materials that will be introduced as overview on applications of the method have been already published in several scientific journals
Abstract ID#: 35969
English Abstract:
As concerns grow over the effect that greenhouse gas releases to the atmosphere from natural sources have on Earth's climate, studies investigating the contribution from freshwater peatlands have increased largely over the last few decades. Freshwater peat soils are considered important carbon (C) reservoirs and sources of greenhouse gases such as methane (CH4) and carbon dioxide (CO2); it is therefore important to better understand how changes in environmental variables (such as temperature) may affect biogenic gas releases from these soils. Most studies investigating such dynamics have mainly focused on discrete point measures (such as gas chambers) or invasive techniques (such as probe insertion and/or sampling) that may provide little information on spatial and temporal patterns in gas flux variability whilst directly disturbing the gas regime. Although the use of eddy covariance methods has helped to better understand temporal patterns of gas release, the method may not resolve spatially isolated, rapid ebullition events due to the large footprint. Hydrogeophysical methods such as ground penetrating radar (GPR) can be used to non-invasively investigate the spatial and temporal variability in gas releases from freshwater peat at a spatial scale that is intermediate between the footprints provided by chamber and eddy covariance methods. The method has now been used for over a decade to target small contrasts in volumetric gas content (both in time and space) within peat soils (i.e. approximately >1%). In this study we use case studies at multiple scales of measurement (i.e. from field to laboratory scales) to show the potential of GPR to (1) better understand the spatial distribution of biogenic gases in a variety of freshwater peatlands over a wide latitudinal gradient, and (2) monitor in situ gas dynamics driven by environmental forcing. Previously unreported datasets will also be presented to further demonstrate the value of GPR for investigating biogenic gas dynamics in peat soils and highlight the potential of the method to overcome some of the limitations imposed by traditional methods.