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The Biebrza River Valley is a vast, flat and wet terrain covered by peatlands (photo by Sebastian R. Bielak)
The Biebrza River Valley is a vast, flat and wet terrain covered by peatlands (photo by S. R. Bielak)

The Biebrza River Valley – a land of wild wetlands

The Biebrza River Valley is located in north-eastern Poland and undoubtedly it is one of the most beautiful places in this region. Here occur vast and quite natural lowland peatlands with fragments of raised bogs which are considered to be the greatest in Poland and one of the biggest in Europe (acreage of almost 250 000 acres, that equals 1000 km2). During last century these wetlands luckily have resisted numerous attempts of draining peat soil for agricultural purposes. In a scale of the whole continent the Biebrza River Valley, and especially its Lower Basin, is a unique refuge for migratory water birds and birds of prey. Most of 280 bird species seen in the valley nest here and some of them are very rare or even endangered. In 1993, because of high natural values of the valley, the Biebrza River National Park was established. With the acreage of 140 000 acres (600 km2) it is now the biggest national park of Poland. As an area of global importance in wildlife conservation the Biebrza River Valley has been registered in the Ramsar Convention. It also belongs to two European systems of wildlife protected areas: Nature 2000 and Econet. Significance of the Biebrza River Valley is so great because nowadays there remains only half of natural wetlands which existed around the world in the past.

The biggest dense complex of alder swamp forests in Poland occurs in the Biebrza River Valley (photo by Sebastian R. Bielak)
The biggest complex of alder swamp forests in Poland occurs in the Biebrza Valley (photo S. Bielak)

The Biebrza River and its spring inundations

The Biebrza River is the main force responsible for unique, natural values of the valley. During past millennia this river was shaping local landscapes together with changing species composition of plants growing alongside its channel. The Biebrza River is quite natural and unregulated so as a typical lowland watercourse it flows lazily across peatlands, along the way creating numerous meanders and ox-bow lakes. Total length of the river counts approximately 100 miles (165 km) and over 90% of it is situated inside the borders of the national park. During summer a narrow channel of the Biebrza River is usually hidden among inaccessible reed scrub and willow thicket but in spring, when water table in the river-bed rises even a dozen feet (a few meters) or so, everything looks quite different. At this time of the year, when it gets warmer, vast amounts of snow standing over the river’s catchment slowly begin to melt. Finally, usually at the turn of March and April, huge volume of water flows into the valley. Narrow channel of the Biebrza River cannot hold such amount of water so it spreads widely across the whole area, changing the valley into a gigantic lake of acreage varying from 25 000 to 50 000 acres (100-200 km2). In the widest spots such inundations can be several miles (few kilometers) wide and last until the second half of May.

Majestic European moose is called by local people the Lord of the Biebrza Marshes (photo by Sebastian R. Bielak)
European moose is called by local people the Lord of the Biebrza Marshes (photo by Sebastian Bielak)

European Moose in alder swamp forests

Not all wetlands located in the Biebrza River Valley are typical open space marshes. Some of them are alder swamp forests in which woods are flooded by water during at least six months per year. This type of forest is dominated by one species of tree, i.e. the black alder. The biggest dense complex of natural alder swamp forests growing in Poland occurs exactly in the Biebrza River National Park and close to Laskowiec village, with acreage of about 4000 acres (16 km2). To many people a bog seems to be an inaccessible and dangerous place but for numerous species of animals it is a perfect refuge. Good example is the European moose whose accommodation to swampy habitat is so good that local people call him the Lord of the Biebrza Marshes. The Biebrza River Valley was the only place in Poland where moose survived the second World War. Now there live about 600-700 of these animals which is the most numerous population of moose in Poland. This number is only an assessment because nobody really knows how many moose live in the Biebrza River Valley, as during most seasons these animals usually live hidden deep inside wetlands.