What Factors Control Carbon Mineralization and Flux in Bog Soils and Ho

I. Introduction: What is a Bog? The word "bog," from the old Gaelic "bogach," is commonly used to refer to any stretch of waterlogged, swampy ground. The words, fen, moor, muskeg, peatland, and mire are also used to describe these areas, which can lead to some confusion over terminology. Specifically, a bog is "a peat accumulating wetland that has no significant inflows or outflows and supports acidophilic mosses, particularly sphagnum" (Gosselink and Mitsch 1993). The vast majority of bogs are located in the moist, cool boreal regions of North America and Eurasia. Bogs are also called "peatlands" because of the peat they accumulate, but "peatland" is a more general term that includes "minerotrophic" and "transition" peatlands. These wetlands also accumulate peat, but they differ topographically and hydrologically from bogs. True bogs (ombrotrophic peatlands) are characterized by peat layers higher than their surroundings; they are often called "raised bogs." They also receive nutrients and minerals exclusively by precipitation, i.e. they are hydrologically isolated (Gosselink and Mitsch 1993 p.374). They form in a variety of ways, but once ombrotrophic (rain-nourished) peatlands develop they are stable under "fairly wide environmental fluctuation" (Gosselink and Mitsch 1993 p.372). This discussion will be limited to the true bogs, and they will be referred to as bogs or peatlands. II. Peat Soils and Carbon Mineralization Peat is the name for the soil that forms in bogs and other peatlands. It is an organic soil (Histosol), composed almost entirely of partially decayed plant matter. The high percentage of organic fibers in peat makes it a fibrist, which is a Histosol containing less than one third decayed organic matter... ... the peat." Journal of Ecology 81 (1993), 615-625. Siegel, D. I. et al. "Climate driven flushing of pore water in peatlands" Nature 374 (6 April 1995), 531-533. Singer, Michael J. and Donald N. Munns. Soils: An Introduction. 3rd ed. New Jersey, Prentice-Hall 1991. Soil Taxonomy USDA Soil Conservation Service Agricultural Handbook No. 436. 1975. T.R. Knowles and R. Moore. "The influence of water table levels on methane and carbon dioxide levels from peatland soils." Canadian Journal of Soil Science 69; 1 (1989), 33-38. Woodwell, George M. "Biotic feedbacks from the warming of the earth." Biotic Feedbacks in the Global Climatic System. New York, Oxford University Press 1995, p3-19. Yavitt, Joseph B. et al. "Control of carbon mineralization to CH4 and CO2 in anaerobic, Sphagnum-derived peat from Big Run Bog." Biogeochemistry 4; 2 (1987), 141-157.