Abstract

Temperatures over the Arctic region are increasing at three times the rate of the global average. Consequently, Arctic vegetation is changing and trees are encroaching into the tundra. In this study, we examine the establishment and growth of mountain birch (Betula pubescens ssp. tortuosa), which forms the treeline in subarctic Europe, and its impact on community composition across the treeline ecotone nearby Abisko, Sweden. Birch advancement along elevational gradients was studied by comparing data collected in 2016 with data collected 10 and 15 years previously. Species identity, cover, and phylogenetic relatedness were used to assess the impact of birch encroachment on community composition. Our results show that birch occurrence above the treeline did not affect plant community composition, probably owing to the observed lack of significant growth due to herbivore browsing, nitrogen limitation, or a reduction in snow cover. Independent of birch performance, the tundra community structure shifted toward a novel community dissimilar from the forest plant community found below the treeline. Taken together, our findings are explained by species-specific responses to climate change, rather than by a linear forest advance. Future treeline advancements are likely more restricted than previously expected.

Keywords

Betula pubescens; climate change; Oroarctic; phylogenetic diversity; plant community structure; treeline advance

Published in

Ecology and Evolution
2022, Volume: 12, number: 6, article number: e9028
Publisher: WILEY

SLU Authors

• Sundqvist, Maja

  • Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
    
  • University of Gothenburg

UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1002/ece3.9028

Permanent link to this page (URI)

https://res.slu.se/id/publ/118229