Mountain Birch Growth in Relation to Climate and Herbivores

Abstract

In Fennoscandia and Iceland, large parts of particularly elevated areas are treeless. Below these areas there is often a belt of Nordic mountain birch trees, now often called Betula pubescens ssp. czerepanovii. In Fennoscandia, this plant is also common in a zone north of the coniferous trees and is found in small forests in the southwestern-most parts of Greenland and more locally in other parts of Europe. Before the begin of the International Biological Programme (IBP) in the late 1960s and early 1970s,only minor fractions of these ecosystems had been studied. Therefore, alpine and subalpine systems were chosen as the main areas of study in this first,larger interdisciplinary and integrated project in natural science across national borders and,in this way,they made an imp- tant contribution to such research in the Nordic countries. In addition to an interdisciplinary steering committee in each country,a Nordic administration was also established for the so-called IBP “Tundra Biome” studies in the region (although permafrost is not common in most of the region). At the end of the IBP,many results from this research in alpine,subalpine and northern Fennoscandian mountain birch forests were published in two early volumes of the Ecological Studies Series (Wielgolaski 1975a,b). As is common at the end of scientific projects, many questions were not really answered, and this was also the case after IBP. However, the project showed the good collaboration within the Nordic countries.