Intermediate Bog

Peat bogs are very specialized habitats, where water and nutrient requirements are met solely by precipitation (ombrotrophy). The flora of the peat bog is disconnected from the water and nutrient stores of the substrate and surrounding areas. Because of this, peat bogs are mostly found in oceanic or montane climates, where there is regular precipitation year round and evaporation is not too high. Before settlers drained the peat bogs in order to turn them into arable land, the Atlantic-influenced North German lowlands were rich in these habitats. Because the climate becomes increasingly continental to the east, eastern Mecklenburg-West Pomerania is essentially the eastern border of the natural peat bog range.

For these reasons, here one progressively encounters intermediate stages between fens and peat bogs. They develop naturally whenever fens do develop only incompletely into peat bogs (raised bogs) due to not continued growth of ombrotraphent peat mosses of raised and blanket bogs, but persist in an intermediate stage. It is characterized by some plant species that interfere from both bog types, as well as some species specific of intermediate bogs such as the greater tussock-sedge (Carex paniculata).

The extreme conditions of the intermediate bog, in terms of water regime, limitations in nutrients and oxygen of the root substrate, and the microclimate of the bog, require great specialization by plant and animal species that only few have evolved to survive and thrive in such a habitat. Accordingly difficult is the creation of such a functionally self-sustaining habitat. Despite countless efforts at habitat restoration of drained and destroyed peat bogs, a successful attempt at recreating a self-sustaining bog complex with its typical species inventory has not yet been achieved. As a consequence, a spatially limited bog section in a botanical garden can only be a collection of bog species that is kept alive with the constant attention of gardeners and not due to ecosystem functioning alone.

The intermediate bog section of the botanical garden in particular presents dwarf-shrubs typical for bogs in Mecklenburg. On hummocks of peat mosses (Sphagnum spp.)grow evergreen dwarf-shrubs, members the Ericaceae family, including species such as bog rosemary (Andromeda polifolia), wild cranberries (Vaccinium oxycoccos), and in drier areas, the bog bilberry (Vaccinium uliginosum), and black crowberry (Empetrum nigrum). The peat bogs also provide evidence of Mecklenburg’s transitional position in terms of phytogeography where species from the western Atlantic and the northeastern boreal floral regions intermingle. Here, Atlantic species, such as the bog myrtle (Myrica gale) and the cross-leaved heath (Erica tetralix) coexist with boreal species, such as the marsh Labrador tea (Ledum plaustre) and the marsh cinquefoil (Comarum palustre).