raised bog

views updated Jun 08 2018

raised bog An ombrogenous bog community, typically dome-shaped in section, which develops on former lake sediments, uniform clay substrates, and sometimes on valley bog surfaces. In the British Isles, living (i.e. still growing upward) raised bogs are confined to western oceanic areas, most notably central Ireland. The living bog surface shows a complex of hummocks and pools (the regeneration complex) with different Sphagnum species occupying different positions in relation to the degree of waterlogging. Hummocks are typically colonized by wet heath species, e.g. heathers (Calluna vulgaris and Erica tetralix) and sedges (e.g. Eriophorium species). See also bog and ombrogenous peat. Compare blanket bog and valley bog.

raised bog

views updated May 23 2018

raised bog An ombrogenous bog community, typically dome-shaped in section, that develops on former lake sediments, uniform clay substrates, and sometimes on valley bog surfaces. In the British Isles, living (i.e. still growing upward) raised bogs are confined to western oceanic areas, most notably central Ireland. The living bog surface shows a complex of hummocks and pools (the regeneration complex) with different Sphagnum species occupying different positions in relation to the degree of waterlogging. Hummocks typically are colonized by wet heath species, e.g. heathers (Calluna vulgaris and Erica tetralix) and sedges (e.g. Eriophorium species). See also BOG and OMBROGENOUS PEAT; compare BLANKET BOG and VALLEY BOG.