A peat-forming vegetation community lying above groundwater level: it is separated from the ground flora and the mineral soil, and is thus dependent on rain water for mineral nutrients. The resulting lack of dissolved bases gives strongly acidic conditions and only specialized vegetation, predominantly Sphagnum species (bog mosses), will grow. Two types of ombrogenous bogs are commonly distinguished: raised bogs and blanket bogs. Compare valley bog. The elevated bog forest found in the coastal regions of some of the islands of south-east Asia comprises a third type of ombrogenouos bog. These bog forests form extensive domes, often more than 10 km in diameter and their surfaces are elevated 5–10 m above the groundwater table.
Subjects: Plant Sciences and Forestry — Ecology and Conservation.