Historical changes of the upper tree line in the Carpathian Mountains (Ukraine)

Most of the world's mountain areas have a long history of human influence and development and in the Carpathian Mountains (Europe) there has been several thousand years of human impact. Human adaptation to environmental gradients and limitations (elevation zones, seasonal weather changes etc.) has created a vertical system of land use in mountain areas. Expansion of forests into previous agricultural areas after a long period of deforestation has been recorded in the many places around the world. Several studies of the human impact on the structure and character of the tree line in the Carpathian Mountains were undertaken by Polish, Czech, Slovak and Hungarian naturalists in the beginning of the last century. After World War II, when most of the East Carpathians became a part of the USSR, Soviet and Ukrainian scientists carried out studies of natural and anthropogenic dynamics of vegetation. The aim of this paper is to assess changes in forest cover over the past two centuries; to evaluate the transformation of the traditional system of land use and identify threats to the Carpathian mountain ecosystem.