HISTORICAL ROOTS OF HYDROLOGICAL CONCEPTS IN PEATLAND SCIENCE WITH A MODERN PERSPECTIVE FROM NORTHERN PEAT BASINS

As early as the late 17th century, W. King noted the close relationship between hydrology and peatland development. He and later workers inferred that 1) waterlogging inhibits decomposition and permits peat to accumulate, and 2) changing water levels affect plant growth creating the characteristic topography of hummocks and hollows. By 1902 C.A. Weber presented a concept of peatlands that integrated peat landforms, water chemistry, vegetation, and hydrology. In this system the primary determinant for peatland development was the source of the surface waters either from precipitation alone (in bogs) or from varying mixtures of precipitation and groundwater (in fens). Weber also inferred interactions between local and regional flow systems on the basis of his chemical measurements and hypothesized responses of the hydrology to past changes in climate and sea level. However, it was not until groundwater investigations began in the large peat basins of North America in the 1980s that these ideas were tested by the rigorous hydrogeologic techniques. These studies confirmed the original insights of Weber, Dau, and also those of some important landscape ecologists, such as Kulcynski. By demonstrating that the peatland surface patterns are closely linked to groundwater flow systems at both local and regional scales these studies also refuted the contemporary concept of peatland hydrology that flow is negligible in the deeper peat.