Torfowiska obszaru Natura 2000 Uroczyska Puszczy Drawskiej Zasoby – stan – ochrona

Kujawa-Pawlaczyk, Jolanta; Pawlaczyk, Paweł

Torfowiska obszaru Natura 2000 Uroczyska Puszczy Drawskiej Zasoby – stan – ochrona

Abstract

Drawa Forest is a big forest complex, ca 2000 km2, in north-western Poland, located on the big post-glacial outwash plain. For preserving outstanding natural values, in the centre of the forest complex, Drawa National Park was established in 1990 y. The whole central part of the complex, ca 740 km2, was designated as Natura 2000 site Uroczyska Puszczy Drawskiej PLH320046. Although the peatbogs occupy no more than 2% of the Natura 2000 site, and are generally small (0,5-100 ha), they are crucial for natural values. Natural habitats 7110, 7140, 7230, 91D0, 3160 and 3140 are protected here (pp. 26-35). Chamaedaphne calyculata, Eriophorum gracile, Liparis loeselii, Hammarbia paludosa are the rarest plats related to peatbogs and fens of the region. Carex limosa, Scheuchzeria palsutris, Epipactis palustris, Dactylorhiza incarnata, D. majalis, D. maculata, Drosera rotundifolia, D. anglica, D. intermedia, Utricularia vulgaris, U. australis, U. minor, U. intermedia, Cladium mariscus have viable populations.Vaccinium uliginosum and Empetrum nigrum are locally rare. There are 26 Sphagnum species in the local bryoflora, most of the number of 36 species growing in Poland. There are numerous localities of Paludella squarrosa, Helodium blandowii, Tomentypnum nitens, and some localities of Drepanocladus verniculosus and Scorpidium scorpioides. Description of 53 representative bogs and fens are presented in this publication. The peatbogs in Drawa Forests are located in various topographic situations: from kettle bogs, through bogs filling post-glacial channels, bogs is small depressions, bogs in bigger depressions, bogs and fens in lakes ends or bays, “pocket bogs” (adjacent to lakes but normally isolated by mineral barriers), to the fens developed from former lakes in post-glacial valleys, commonly adjacent to contemporary rivers. The history of the peatbogs is recorded in their stratygraphy. The general pattern typical for the region is: succession from the lake (documented by gyttja deposits), through sedge fens, and brown moss-sedge fens, towards the Sphagnum peatbogs.Nevertheless, the individual history of the particular sites may be much more various, and stratygraphic profiles are rich in remarks of unexpected stories. The contemporary history may be reconstructed from old topographic maps (from ca 1880 y.) and old aerial photos (from ca 1950 y., see example on p. 10). Generally, some sites are much more stable than can be expected on the base of the single observation. Most of the dystrophic lakes are unexpectly stable in shape and area, at least through last 100 years. On the other hand, in some sites rapid succession, trees expansions and transpiration desiccation occurred, even without easily visible anthropogenic reasons. The water conditions, according to the 20-years experience of authors, are various. Water level in some bogs is extremely stable, whereas in other sites, even some hundreds meters away, is highly fluctuating. After the period of decreasing of the ground water level and desiccation of some peatbogs, last years are mostly “wet phase”. In some bogs, the water level increased rapidly, changing vegetation by trees dieback. There are no clear climatic nor anthropogenic reasons for that. Maybe natural dynamics of the small peatbogs include consecutive dry and wet phases, reflected by the invasion and dieback of trees. For better documentation of the water level dynamics, in 50 points the water levels were recorded daily in the period 2011-2014 y. The results are presented in the sites descriptions. Several conservation projects was implemented by Naturalists Club Poland to conserve Drawa Forest peatbogs. According to the experience Conservation of peatbogs requires modification of forest management in neighbourhood. Protective zones, ca 30-50 m wide, with no cutting trees, should be saved around the peatbogs. This good practice is used in some, but unfortunately not in all forest districts. The beavers can affect the fens by damming water outflow, even overflooding the fen surface. Nevertheless, in more detaily reviewed case, the fen vegetation survive such episode of overflooding (p. 42). Generally, the increasing beavers activity should be accepted, even if some damages appear, for important benefits for general water conditions. Ditches blocking (pp. 101-102) are generally successful for improving water conditions, but for most of the bogs there are no draining ditches to block. Results of trees removing (pp. 104-105) were various. It was generally successful if combined with improving water conditions by ditches blocking, nevertheless hard sprouts regrowth (especially birch) appears in other cases. Maybe the fluctuation of water conditions and trees cover is, at least in some cases, natural, and do not need be fighted against. Spiraea tomentosa is one of the most important threats for the bogs (pp. 108-109). It can be eradicated by consecutive plucking by hand, repeated 4-5 times in consecutive years.

Keywords

mires rich fen poor fen raised bog bog forest mires conservation dystrophic lakes outwash plain landscape

torfowiska wysokie torfowiska niskie torfowska przejsciowe torfowiska alkaliczne ochrona torfowisk jeziorka dystroficzne krajobraz sandrowy

Citation

Kujawa-Pawlaczyk J., Pawlaczyk P. 2014. Torfowiska obszaru Natura 2000 „Uroczyska Puszczy Drawskiej”. Zasoby – stan – ochrona. Wydawnictwo Klubu Przyrodników, Świebodzin, 114 pp.