The project aims at studying the sensitivity to climate warming of a range of arctic/alpine and boreal species and plant functional types, in different stages of early seedling establishment. Warming is simulated by the exposure of field plots to controlled infrared irradiation, a technique developed at UA. We will also study changes in growth and chemical composition of full-grown vegetation in response to warming, to evaluate whether these changes induce a chemical-ecological barrier for the establishment of new seedlings. The working hypothesis is that climate warming deteriorates the capacity of Arctic plant communities to regenerate.