Germany is shared between the Atlantic European and Central European provinces of the Circumboreal Region within the Boreal Kingdom. The territory of Germany can be subdivided into two ecoregions: European-Mediterranean montane mixed forests and Northeast-Atlantic shelf marine. The majority of Germany is covered by either arable land (33%) or forestry and woodland (31%). Only 15% is covered by permanent pastures. Plants and animals are those generally common to middle Europe. Beeches, oaks, and other deciduous trees constitute one-third of the forests; conifers are increasing as a result of reforestation. Spruce and fir trees predominate in the upper mountains, while pine and larch are found in sandy soil. There are many species of ferns, flowers, fungi, and mosses. Fish abound in the rivers and the North Sea. Wild animals include deer, wild boar, mouflon, fox, badger, hare, and small numbers of beaver. Various migratory birds cross Germany in the spring and autumn.