Birch sapling characteristics growing beyond the tree line in Norway and Sweden ...

• Main Authors: Hofgaard, Annika, Dalen, Linda, Hytteborn, Håkan
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2009
• Subjects: International Polar Year 2007-2008 IPY; Norway; International Polar Year; IPY
• Online Access: https://dx.doi.org/10.1594/pangaea.811218; https://doi.pangaea.de/10.1594/PANGAEA.811218

Questions: How do population structure and recruitment characteristics of Betula saplings beyond the treeline vary among climatic regions, and what is the potential for development into tree-sized individuals with interacting grazing pressure?Location: Scandes Mountains. Methods: Sapling characteristics of Betula pubescens subsp. tortuosa, their topographic position above the treeline, growth habitat and evidence of recent grazing was investigated in three areas with a long continuous grazing history, along a latitudinal gradient (62-69°N).Results: Saplings were common up to 100 m above the treeline in all areas. The northern areas were characterised by small (<30 cm) and young (mean 14 years old) saplings in exposed micro-topographic locations unfavourable to long-term survival. In the southern area, broad height (2-183 cm) and age (4-95 years; mean 32 years) distributions were found in sheltered locations. Age declined with altitude in all areas. Sapling growth rate varied within and between areas, and ... : Data extracted in the frame of a joint ICSTI/PANGAEA IPY effort, see http://doi.pangaea.de/10.1594/PANGAEA.150150 ...