Natural vegetation consists mainly of steppelike grasslands in the Moldavian and Walachian lowlands, with tall, deep-rooted grasses in the more humid sections and short, shallow-rooted grass in the drier parts. The Carpathian system is covered with forests, with deciduous trees at lower elevations and conifers at altitudes above 1,070–1,220 m (3,500–4,000 ft). Alpine meadows occupy the highest parts of the mountains. Wild animals, including the black chamois, Carpathian deer, wolves, hares, marten, brown bear, lynx, boar, and fox, have sought refuge in the sparsely inhabited and forested Carpathians. Water birds flourish in the Danube Delta, and sturgeon abound in the waters of the lower Danube. Carp, bream, and pike populate the lakes; dace, barbel, and trout are found in rivers and streams.