Author(s):
Ole Rößler - Institute of Biology and Environmental Sciences, University of Oldenburg, Germany
Prof. Dr. Anders Lundberg - Department of Geography, University of Bergen, Norway
Dr. Achim Bräuning - Institute of Geography, University of Stuttgart, Germany
Prof. Dr. Gernot Jung - Institute of Biology and Environmental Sciences, University of Oldenburg, Germany
Roland Pape - Institute of Biology and Environmental Sciences, University of Oldenburg, Germany
Dr. Dirk Wundram - Institute of Biology and Environmental Sciences, University of Oldenburg, Germany
Dr. Jörg Löffler - Department of Geography, University of Bonn, Germany
Abstract:
This study aims at improving the comprehension of the alpine treeline, partly as a means of projecting landscape evolution in an anticipated warmer future. The main problem to be solved is to distinguish effects and responses of climate change and human impact, two driving forces, which have both caused an increase in the altitude of the alpine treeline over the past century. Thus, an interdisciplinary approach was transposed to the Norwegian mountains, combining socio-geographical, landscape ecological and adjusted dendroecological methods. The scope of the project is based on four different study sites covering both the steep oceanic-continental gradient and different intensities of land use found in central Norway. Both aerial photo analysis and dendroecological results concerning the structure of the forest indicate an individual treeline development over the last 50 years, which has to be considered as stagnation and regeneration of formerly used areas, respectively. A climatic, treeline increasing effect as it can be assumed under warmer conditions was not verified. Analysis of meteorological data concerning the last 40 years showed an average warming by 0.3°C/decade. But since strongest warming appears in winter, the alpine treeline is not affected. Thus, in central Norway land use is the main factor of influence. Minor variabilities in climate do not effect the distribution of the treeline.
