Models of the geomorphology, hydrology, and development of domed peat bodies

Abstract

Because peat accumulates only beneath the water table, the shape of a peat body should reflect the shape of its water table and thus the hydrology of the peat body. Three different models successfully reproduce the observed peat dome morphology, including a central bog plain. In the first model, the bog plain develops because peat accumulation is limited by anaerobic decay of peat beneath the water table. With certain simplifying assumptions, an analytic solution for this model can be obtained. The other two models are more easily investigated numerically. In the first model, the initial peat accumulation rate is limited only by plant growth and decay and is the maximum rate observed during peat dome development. As a peat dome expands laterally, peat accumulation slows because the water table ceases to rise fast enough to preserve all the available plant material. Eventually, anaerobic decay beneath the water table matches the rate of peat addition to the top of the peat body, and net peat accumulation ceases. 17 refs., 2 tabs.