Nutrient Control of Microbial Carbon Cycling Along an Ombrotrophicminerotrophic Peatland Gradient

Authors

Jason K. Keller, Chapman UniversityFollow
Angela K. Bauers, University of Notre Dame
Scott D. Bridgham, University of Oregon
Laurie E. Kellogg, University of Oklahoma Norman Campus
Colleen M. Iversen, University of Tennessee - Knoxville

Document Type

Article

Publication Date

2006

Abstract

Future climate change and other anthropogenic activities are likely to increase nutrient availability in many peatlands, and it is important to understand how these additional nutrients will influence peatland carbon cycling. We investigated the effects of nitrogen and phosphorus on aerobic CH4 oxidation, anaerobic carbon mineralization (as CO2 and CH4 production), and anaerobic nutrient mineralization in a bog, an intermediate fen, and a rich fen in the Upper Peninsula of Michigan. We utilized a 5-week laboratory nutrient amendment experiment in conjunction with a 6-year field nutrient fertilization experiment to consider how the relative response to nitrogen and phosphorus differed among these wetlands over the short and long term. Field fertilizations generally increased nutrient availability in the upper 15 cm of peat and resulted in shifts in the vegetation community in each peatland. High nitrogen concentrations inhibited CH4 oxidation in bog peat during short-term incubations; however, long-term fertilization with lower concentrations of nitrogen stimulated rates of CH4 oxidation in bog peat. In contrast, no nitrogen effects on CH4 oxidation were observed in the intermediate or rich fen peat. Anaerobic carbon mineralization in bog peat was consistently inhibited by increased phosphorus availability, but similar phosphorus additions had few effects in the intermediate fen and stimulated CH4 production and nutrient mineralization in the rich fen. Our results demonstrate that nitrogen and phosphorus are important controls of peatland microbial carbon cycling; however, the role of these nutrients can differ over the short and long term and is strongly mediated by peatland type.

Comments

This article was originally published in Journal of Geophysical Research, volume 111, in 2006. DOI: 10.1029/2005JG000152

Recommended Citation

Keller, J. K., A. K. Bauers, S. D. Bridgham, L. E. Kellogg, and C. M. Iversen (2006), Nutrient control of microbial carbon cycling along an ombrotrophic-minerotrophic peatland gradient, J. Geophys. Res., 111, G03006, doi:10.1029/2005JG000152.

Copyright

American Geophysical Union