Stretching from the Baltic Sea in the north to the Carpathian Mountains in the south, Poland is covered predominantly by farm land and flat plains. Forests make up about one-quarter of the territory and are home to various species, including European bison, lynx, forest Bilgoraj horse, boar and wild goat. Wolves and brown bears are found in the mountains, while moose and deer are fairly numerous in the lake districts.
Poland’s forests are particularly vulnerable to acid rain and other forms of air pollution, especially from the emissions of coal-fired plants. Other environmental problems facing the country are water pollution from industrial and municipal sources. About 60% of the rivers and 10% of the lakes in Poland have unsatisfactory or bad water quality. Two major rivers, the Vistula and the Oder, pour a considerable amount of organic pollutans into the Baltic Sea - one of the most polluted seas in the world.