ombrogenous bog

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ombrogenous bog 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.