Changes in the summit flora of a Mediterranean mountain (Sierra Nevada, Spain) as a possible effect of climate change

Abstract

Fernández Calzado, M.R. & Molero Mesa, J. Changes in the summit flora of a Mediterranean mountain (Sierra Nevada, Spain) as a possible effect of climate change. Lazaroa 34: 65-75 (2013). The evidences on climate change-induced impacts on alpine plant communities is growing and some of them warn us about the expected changes in vegetation of the generally fragmented Mediterranean high mountain areas in a warmer and drier future. Short-term (2001-2008) changes in vascular plant species richness, cover and abundance were studied on four summits in the Sierra Nevada (Spain). The resurvey revealed a decrease in species richness on each summit, which is confirmed by small-scale changes in species abundance within the same summits. These changes involve local losses of high-elevation endemic species as well as the new appearance of predominantly more widespread species. Some of the latter species were also observed to expand elsewhere in the Sierra Nevada. On a small scale, cover of several endemic species decreased and cover of some species that occur on a wider altitudinal range increased. Although the observed changes are statistically only marginally or not significant, they are largely consistent with pan-European studies suggesting stagnant or declining species richness on summits of the Mediterranean biome and a 'thermophilisation' of the species composition in high mountain plant communities over the past years. Even though we cannot rule out other non-climatic factors, our results give rise to concern about the situation of the mainly endemic high-altitude flora of the Sierra Nevada and give an incentive to intensify monitoring efforts. © 2013. Universidad Complutense de Madrid.