Exclusion of herbivores slows down recovery after experimental warming and nutrient addition in an alpine plant community

• Published in: Journal of Ecology
• Main Authors: Olsen, Siri L., Klanderud, Kari
• Other Authors: Cornwell, Will
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2014
• Subjects: Plant Science; Ecology; Ecology, Evolution, Behavior and Systematics; Arctic; Dryas octopetala
• Online Access: http://dx.doi.org/10.1111/1365-2745.12292; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2F1365-2745.12292; https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/1365-2745.12292

Summary Global change, such as climate warming and nitrogen deposition, has been predicted to induce non‐reversible regime shifts in natural ecosystems. However, we lack knowledge of the potential for recovery from global change perturbations and factors influencing the recovery rate. We examined the recovery of an alpine plant community from a combined warming and nutrient addition experiment, which initially caused profound changes in plant community composition and diversity. We also examined whether the recovery process was affected by herbivory, as the presence of herbivores has been shown to modify the response of plant communities to global change. Many aspects of the alpine plant community had not recovered from experimental warming and nutrient addition 6 years after cessation of the treatments. A persistent shift in vascular plant species composition seemed to inhibit recovery and maintain a community dominated by highly competitive grasses at the expense of the previously dominating dwarf shrub Dryas octopetala , lichens and bryophytes. The exclusion of herbivores decreased the community recovery rate by maintaining unfavourable conditions for lichens and bryophytes. Synthesis . Our findings suggest that a shift in dominance hierarchies in arctic and alpine plant communities due to global change is not readily reversible. Herbivory may, however, facilitate plant community recovery.