Handling the heat: Warming does not reduce alpine plant survival or reproduction under high precipitation conditions

As a result of global climate change, ecosystems are facing increasingly long and intense heat events. While plant species may be able to tolerate, adapt, or shift their ranges in response to climate change, plants in alpine ecosystems are considered especially sensitive to the effects of climate change due to geographic constraints on uphill range expansions. We conducted a novel, in-situ , active warming experiment (under rainy conditions) on alpine plants growing near the summit of Mt Hotham, south-eastern Australia. Contrary to our predictions, we found no relationship between overall change in cover, survival, diversity, or reproductive effort with the intensity or duration of heat events. Additionally, there was no interaction between species’ growth form (i.e., forb, shrub or graminoid) and change in cover in relation to the heat event intensity and duration. Thus, while climate change still poses substantial threats to alpine ecosystems, it is not clear how the intensity or duration of extreme heat events in conjunction with high precipitation might impact alpine communities, or favour particular plant forms. Improving our understanding of which aspects of climate change pose the largest threats to alpine ecosystems remains an important goal that can help us to understand how sensitive plant communities may be affected into the future.