Scott D. Bridgham

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We examine the carbon balance of North American wetlands by reviewing and synthesizing the published literature and soil databases. North American wetlands contain about 220 Pg C, most of which is in peat. They are a small to moderate carbon sink of about 49 Tg C yr−1, although the uncertainty around this estimate is greater than 100%, with the largest(More)
Understanding the dynamics of methane (CH4 ) emissions is of paramount importance because CH4 has 25 times the global warming potential of carbon dioxide (CO2 ) and is currently the second most important anthropogenic greenhouse gas. Wetlands are the single largest natural CH4 source with median emissions from published studies of 164 Tg yr(-1) , which is(More)
Rising atmospheric CO 2 and temperatures are probably altering ecosystem carbon cycling, causing both positive and negative feedbacks to climate. Below-ground processes play a key role in the global carbon (C) cycle because they regulate storage of large quantities of C, and are potentially very sensitive to direct and indirect effects of elevated CO 2 and(More)
We analyzed how dissolved organic carbon (DOC) concentration in lakes of the North American temperate forest (Upper Great Lakes region) is related to nine catchment characteristics (lake area, lake perimeter, drainage area, ratio of drainage area to lake area, proportion of watershed occupied by wetlands, proportion of lake perimeter in wetlands, shoreline(More)
The validity of nutrient use efficiency as a central concept in ecosystem ecology has recently been subject to challenge based upon arguments over autocorrelation of data, interpretation of graphical approaches, and appropriate statistical analyses. Much of the confusion on the measurement and interpretation of nutrient use efficiency results from the lack(More)
Peatland soils represent globally significant stores of carbon, and understanding carbon cycling pathways in these ecosystems has important implications for global climate change. We measured aceticlastic and autotrophic methanogenesis, sulfate reduction, denitrification, and iron reduction in a bog, an intermediate fen, and a rich fen in the Upper(More)
In prairie ecosystems, abiotic constraints on competition can structure plant communities; however, the extent to which competition between native and exotic plant species is constrained by environmental factors is still debated. The objective of our study was to use paired field and greenhouse experiments to evaluate the competitive dynamics between two(More)
Boreal peatlands, which contain a large fraction of the world's soil organic carbon pool, may be significantly affected by changes in climate and land use, with attendant feedback to climate through changes in albedo, fluxes of energy or trace gases, and soil carbon storage. The response of peatlands to changing environmental conditions will probably be(More)
Peatlands often have readily apparent gradients of plant species distributions, biogeochemistry, and hydrology across several spatial scales. Many inferences have been drawn about the colinearity of these gradients, and these assumptions have become ingrained in the terminology that describes and classifies peatlands. We review the literature and present(More)
The accumulation of litter or thatch can affect plant community composition by affecting the temperature, nutrient availability, and light availability of the soil environment, thereby forming a potentially important linkage between recent productivity and current ecosystem processes. To investigate the importance of litter on a fen peatland plant(More)