Remote sensing of upper timberline elevation in the Alps on different scales

Natural timberlines are remarkable indicators of climate conditions. Although potential shifts of climate-driven natural borderlines are discussed in the recent climate change debate, maps of natural timberline elevation in the European Alps are rare and not concordant. Problems are caused primarily by the strong human impact on timberline positions in the Alps. In this paper, approaches for detecting actual timberlines and approximating natural timberlines with remote sensing methods are presented. Using Landsat ETM and MODIS imagery, the difference in spatial resolution of the data led to different strategies. Results are encouraging, although numerous sources of error and uncertainty have to be considered. While the aim of this study is not to reach highest possible precision, investigation of large-scale spatial variability of natural timberline elevation in the Alps with remote sensing methods appears promising.