The Myth of the Classic Hydrosere Model of Bog Succession

Abstract

The classic hydrosere model of bog succession, which is still often cited and taught by ecologists, proposes that infilling of a shallow lake or pond by organic sediments produces a sequence of vegetation communities beginning with a marsh community of aquatic plants such as sedges, followed by a bog community composed mainly of Sphagnum mosses and various ericaceous shrubs, and culminating in a mature upland or mesic “climax” forest. A careful examination of the supporting literature indicates, however, that this model is based almost solely on observations of spatial zonation of vegetation around infilling water bodies. No studies can be found which contain clear quantitative evidence of successional pathways progressing from bog to upland forest. Indeed, numerous studies conclude that patterns of hydrosere succession are not consistent with the classic hydrosere model. Forest age structure, peat stratigraphy, and radiocarbon data presented from two bogs in Schefferville, Quebec, suggest that many bogs in this region, and elsewhere as indicated in the literature, are climax communities formed via both infilling of a water body (terrestrialization) and expansion of bogs into upland forests (paludification). An alternative model of hydrosere succession based on the bog climax hypothesis is presented.