Recent changes in mountain birch forest structure and understory vegetation depend on the seasonal timing of reindeer grazing ...

• Main Authors: Stark, Sari, Ylänne, Henni, Kumpula, Jouko
• Format: Dataset
• Language: English
• Published: Dryad 2021
• Subjects: reindeer herding; mountain birch; sub-Arctic; crowberry; lichen; browsing; Ungulate; Arctic; Crowberry; Rangifer tarandus; Subarctic; Tundra
• Online Access: https://dx.doi.org/10.5061/dryad.4qrfj6q91; https://datadryad.org/stash/dataset/doi:10.5061/dryad.4qrfj6q91

1. Subarctic forest-tundra ecotones dominated by mountain birch (Betula pubescens ssp. czerepanovii) is an important habitat for semi-domestic reindeer (Rangifer tarandus). The seasonal timing of reindeer grazing may direct vegetation trajectories in these systems, because in the summer ranges, mountain birches are subjected to browsing, while in the winter ranges, reindeer feed on understorey vegetation and arboreal lichens but leave the mountain birches intact. 2. Based on earlier research, we predicted that (1) summer browsing dampens ongoing vegetation ‘shrubification’ in semi-dry and dry mountain birch forests and (2) ‘shrubification’ is accompanied by a decline in lichens. We tested these predictions through re-analysing forest structure and understorey vegetation after 12 years in areas where winter and summer ranges had been separated since the 1980’s. We also tested how changes in lichen abundances align with changes in shrub abundances through correlation analyses. 3. The number of tall mountain ...