Sheel Bansal

Our research focuses on the abiotic and biotic factors that regulate greenhouse gas fluxes of PPR wetlands and uplands to reduce the uncertainties associated with temporal and spatial variability that characterizes these wetland systems. Our studies range from plot-level experiments in wetland catchments situated in grasslands and agricultural fields, to regional- and national-scale modeling to predict changes in soil processes associated with climate and land use. We use a combination of commercial and custom-made sampling devices to facilitate the collection of temporally-intensive data. The ability to extrapolate plot-level fluxes and to assess potential effects of climate and land-use change on wetland ecosystems...

Categories: Project

Temperature and hydrology affect methane emissions from Prairie Pothole wetlands

The Prairie Pothole Region (PPR) in central North America consists of millions of depressional wetlands that each have considerable potential to emit methane (CH4). Changes in temperature and hydrology in the PPR from climate change may affect methane fluxes from these wetlands. To assess the potential effects of changes in climate on methane emissions, we examined the relationships between flux rates and temperature or water depth using six years of bi-weekly flux measurements during the snow-free period from six temporarily ponded and six permanently ponded wetlands in North Dakota, USA. Methane flux rates were among the highest reported for freshwater wetlands, and had considerable spatial and temporal variation....

Diurnal patterns of methane flux from a seasonal wetland: Mechanisms and methodology

Methane emissions from wetlands are temporally dynamic. Few chamber-based studies have explored diurnal variation in methane flux with high temporal replication. Using an automated sampling system, we measured methane flux every 2.5 to 4 h for 205 diel cycles during three growing seasons (2013–2015) from a seasonal wetland in the Prairie Pothole Region of North America. During ponded conditions, fluxes were generally positive (i.e., methanogenesis dominant, 10.1 ± 0.8 mg m−2 h−1), had extreme range of variation (from −1 to 70 mg m−2 h−1), and were highest during late day. In contrast, during dry conditions fluxes were very low and primarily negative (i.e., oxidation dominant, −0.05 ± 0.002 mg m−2 h−1), with the...

Abundant carbon substrates drive extremely high sulfate reduction rates and methane fluxes in Prairie Pothole Wetlands

Inland waters are increasingly recognized as critical sites of methane emissions to the atmosphere, but the biogeochemical reactions driving such fluxes are less well understood. The Prairie Pothole Region (PPR) of North America is one of the largest wetland complexes in the world, containing millions of small, shallow wetlands. The sediment pore waters of PPR wetlands contain some of the highest concentrations of dissolved organic carbon (DOC) and sulfur species ever recorded in terrestrial aquatic environments. Using a suite of geochemical and microbiological analyses, we measured the impact of sedimentary carbon and sulfur transformations in these wetlands on methane fluxes to the atmosphere. This research represents...

Diurnal patterns of methane flux from a depressional, seasonal wetland

Data on diurnal variation in wetland methane flux were collected to 1) improve understanding of short-term, mechanistic drivers of methane flux, and 2) inform sampling protocols to achieve research objectives. An automated gas flux sampling system was used to measure methane flux every 2.5–4 hours for over 230 diel cycles over the course of three growing seasons (2013–2015). Data were collected from a seasonal, depressional wetland located in the Prairie Pothole Region of central North America. These data directly support the associated publication “Diurnal patterns of methane flux from a depressional, seasonal wetland: mechanisms and methodology” which is referenced within the Metadata.

Categories: Data; Types: Citation; Tags: North Dakota, Prairie Pothole Region, Stutsman County, USGS Science Data Catalog (SDC), United States of America, All tags... environment, greenhouse gases, hydrology, inlandWaters, mathematical modeling, wetland ecosystems, Fewer tags