Spatio-Temporal Development of the Soomaa Mire System in Sw Estonia

Abstract

The spatio-temporal development pattern of a mire system and major factors affecting this process were studied. The Soomaa mire system (25 100 ha) in south-western Estonia is one of the largest and best preserved mire systems in Estonia. Using the bulk densities of peat layers and radiocarbon dates average accumulation rates and increments of different peat types were calculated. On the basis of the obtained and already existing stratigraphical data the probable development of the mire system was reconstructed. Paludification of the Soomaa region started about 10 000 BP and ombrotrophication 7000-6000 BP. The expansion rate of the mire system was rather stable during the whole Holocene and no distinct relationship between the climate and the expansion of mires was detected. The results suggest that the expansion of mires was mostly an autogenous process, while ombrotrophication might have been favoured also by climate changes.The spatial dynamics of paludification was mainly determined by local factorstopographical and hydrological characteristics of the area.