Influences of Climate and Land Use History on Forest and Timberline Dynamics in the Carpathian Mountains During the Twentieth Century

Abstract

The forest-tundra mountain ecotone, associated with the alpine timberline and treeline, is reported to have risen in elevation in many parts of the world as a result of global warming. The main goal of this study was to analyze the changes in timberline position over the Carpathian mountain range with respect to observed climate change and other global change issues, such as land use change. Global climate change has resulted in periods of significant warming in the Carpathian region, with the most significant of these occurring over 1975–2000. Forest cover change was analyzed for elevations above 1,000 m between 1880 and 2000 by comparing military maps of the Austro-Hungarian Empire and Landsat imagery. The whole region had a forest cover ratio of 72.8 % in 1880, decreasing to 71.2 % in 2000. There has been considerable forest increase at timberline (34 % of the total afforestation), indicating that substantial changes are happening at this ecotone, similarly to other European mountains; 12 % of total deforestation was observed also at timberline. Forest cover changes varied among regions, increasing by 8 % in the West Carpathians, by 1.4 % in the Ukrainian Carpathians, and decreasing in the North Romanian and South Carpathians by 6.1 and 0.7 %, respectively. Forest cover in the Ukrainian, North Romanian, and South Carpathians has declined at lower elevations, which can be attributed to widespread illegal logging in post-socialist times. At higher, less accessible elevations forest cover has mostly increased. In the West Carpathians forest cover has evenly risen at all elevations—a result of the declining importance of agriculture and increasingly sustainable forestry practices. We consider these observed changes to be a result of favorable climate change coupled with ongoing land use change.