Active raised bogs are the last stage in the development of mires, where the peat formed from the dead parts of the plants is already so thick that the roots of the plants no longer reach the nutrient-rich water: nutrients mainly reach the bog through precipitation. The average thickness of the peat layer in Estonian bogs is 3.2 metres. The Vällamäe bog with its 17 metres has the thickest peat deposit known so far. The vegetation of the active raised bog is dominated by peat mosses and prostrate shrubs; wooded bogs also have some stunted pines, rarely some birches here and there. If the canopy cover of the trees exceeds 0.3 and the average height exceeds four metres, the habitat is a bog woodland (91DO).
As the upper part of the peat moss clods dries up easily, the plants growing on them tolerate not only nutrient scarcity, but also water scarcity well (therefore, the species composition of the prostrate shrubs here is similar to that of heaths). The clods in the active raised bogs alternate with wet, temporarily submerged bog hollows, and small bodies of water – bog ponds, the larger of which are already considered a separate habitat type (3160).
Bogs can be found all across Estonia. The largest bog areas are located in South-Western Estonia (Soomaa), at the foot of the Pandivere Uplands (Endla bog system), and in North-Eastern Estonia (Puhatu and Muraka bogs).
In Estonia, this habitat also includes the habitat type 7150 (depressions on peat substrates of the Rhynchosporion), which in Europe, where there are few unspoiled bogs, are valued as a separate habitat.
Includes the habitat type class 32 (bogs) according to Paal.