Location
The Special Protecion Area, covering 33017.8 ha, lies within Torun-Eberswald Praglacial Stream Valley, near the Warta esturay to the Odra river. It encompasses flooded areas of the Warta river together with a part of the Odra Valley and a vast reservoir near Kostrzyn nad Odra.

Geological History and Land Formation
During the last glaciation, on a foreground of the glacier waters flowing from area freed of ice mixed with waters from the melting glacier creating a massive river. Its width reached even 25 km in some places. Valley of that river is nowadays known as Torun-Eberswald Praglacial Stream Valley, where the refuge is located. After ultimate withdrawal of the glacier the Odra and the Warta filled this part of the valley with sediments on which vast wetlands were formed. Today both rivers still form landscape of the area. Riverine forests, which overgrew a bottom of the valley over thousands of years, have been gradually cleared in the last millennium and replaced with open wetlands, meadows and fields, formed by agriculture.

Ecosystem
Protected element of Ujscie Warty are remains of a natural ecosystem formed by a big river - old river beds, riverine willow scrubs and alluvial forests, as well as swampy meadows and pastures which have developed over centuries in result of extensive agriculture. Despite strong interference by human the Warta and the Odra still largely influence the ecosystem, its seasonal changeability and natural variety. There occur types of habitats important for Europe: semi-natural dry grasslands near Owczary and Pamiecin, on which rare species of orchids grow, hydrophilous tall herb fringe communities, flooded oozy terrains, alluvial forests, Luzulo-fagetum beech forests and Central European oak-hornbeam forests.

Flora
Plants which grow in the refuge are adjusted to long flooding that last a few months a year. Places under water are good for development of meadows, scrubs and alluvial forests. Along the Warta banks the water is covered with duckweed. The same habitat is occupied by other water plants, mostly rooted: yellow water-lily, white water-lily, rigid hornwort and a group of horned pondweed, recognized as a species in danger of extinction. There are numerous rush species: common reed, smooth black sedge, common club-rush, water horsetail, common water-plantain and sweet flag. Scrubs and forests are represented by: riverine osier beds built mainly of almond leaved willow and common osier, as well as lobes of willow alluvial forest. Remains of old alluvial forests are old specimens of white willow. On sandy soils sand grasslands have developed. On poorer soils vegetations is dominated by gray clubawn grass. More fertile habitats allow development of more demanding plants, such as sea thrift and maiden pink. Ujscie Warty is a refuge of many rare species of plants, 8 of which is protected. A plant rare and valuable for Europe which occur in the area is bastard toad-flax.

Fauna
Ujscie Warty is one of the most valuable areas in the country in terms of ornithology. 250 species of birds have been recorded here, over 170 of which are hatching ones. At least 27 mentioned in Appendix I of the Bird Directive occur here as well as 11 species listed in Polish Red Data Book Of Animals. Water birds: ducks (mallard, common teal, northern shoveler, shelduck), grebes (red-necked and horned), greylag goose, common coot and mute swan, and since recently also hatching whooper swan are very numerous. Also bittern, white stork, white-tailed eagle, corn crake, red-backed shrike and barred warbler hatch there in large concentrations. Shorebirds - lapwing, common redshank, common snipe, black-tailed godwit, little ringed plover and Eurasian oystercatcher - less and less numerous in Poland, find good living conditions in Ujscie Warty. Huge numbers of birds stop here during migrations. In late autumn flocks of Arctic geese (Taiga bean geese and greater white-fronted geese) fly over here, forming concentrations which reach about 80 thousand specimens. The area is also an important wintering site for whooper swans and mute swans, ducks and white-tailed eagles. In addition in the area of the refuge occurrence of 4 species of mammals from  Appendix II of the Habitats Directive has been recorded, i.e. otter, Eurasian beaver, bats: mouse-eared bat and barbastelle bat, amphibians: great crested newt and fire-bellied toad, as well as one species of fish from the appendix - weather fish.

Threats

• water pollution;
• burning off vegetation;
• building over the river banks;
• abolishment of pasturage;
• decrease of amount of water in a reception basin;
• bothering animals, penetrating their habitats, pouching, activity of predators imported to Europe from South America: American mink and (arrived recently to Ujscie Warty) northern raccoon.

Protection Of Nature
There are nature reserves: "Lemierzyce" (3.3 ha) and "Pamiecin" (2.7 ha), in the area of Ujscie Warty, the refuge of Ramsar: "Slonsk" (4235 ha), Ujscie Warty National Park (8037.6 ha), Ujscie Warty Landscape Park ("Ujscie Warty" Landscape Park) and three areas of protected landscape.