Belgium, one of the smallest and most crowded countries in Europe, has been a representative democracy since independence in 1830, led by a hereditary constitutional monarch. From a cultural point of view, Belgium is a heterogeneous country, situated on the border between the Romance and Germanic language families of Western Europe. With the exception of the Ardennes, the whole of Belgium lies in a deciduous forest zone. Oak is the dominant tree, the others being beech, birch and elm. Much of the Belgian plain is now occupied by agricultural or human settlements. The remaining open areas are dominated by small groups of deciduous trees and grasses. However, in Kempenland, significant areas are dedicated to planted forests of silver birch and Corsican pine. It lies within the Ardennes zone of mixed deciduous and coniferous forests. Today, the Ardennes is dominated by coniferous forests in the higher altitudes and mixed coniferous and deciduous forests, especially beech and oak, in the foothills. South of the Sambre-Meuse valley, the landscape is dominated by forests and grasslands. Human activities have significantly reduced wildlife numbers. Most of the remaining wildlife is found in the Ardennes, where wild boar, wild cat, deer and pheasant are among the most common animals. The Belgian lowlands are home to many species of birds, including sandpipers, woodcocks, snipes and lapwings.