Journal Article

The rich sides of mountain summits – a pan-European view on aspect preferences of alpine plants

Göteborgs Universitet = University of Gothenburg (GU), National Park of Berchtesgaden ; Partenaires INRAE, Benito Alonso, José-Luis, Unterluggauer, Peter, Vienna Institute for Nature Conservation and Analyses (VINCA), Petey, Martina, A. Borza Botanical Garden ; Babes-Bolyai University [Cluj-Napoca] (UBB), Gottfried, Michael, Choler, Philippe, Department of Ecology and Evolution ; Université de Lausanne = University of Lausanne (UNIL), Centre alpien de Phytogéographie (CAP) ; Fondation Jean-Marcel Aubert, Lamprecht, Andrea, Kollár, Jozef, Ilia State University [Tbilisi], Zone Atelier Alpes (LTSER-ZAA) ; LTSER Réseau des Zones Ateliers (RZA) ; Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS) ; Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS) ; Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Moiseev

2016

Overview

Aim In the alpine life zone, plant diversity is strongly determined by local topography and microclimate. We assessed the extent to which aspect and its relatedness to temperature affect plant species diversity, and the colonization and disappearance of species on alpine summits on a pan-European scale. Location Mountain summits in Europe's alpine life zone. Methods Vascular plant species and their percentage cover were recorded in permanent plots in each cardinal direction on 123 summits in 32 regions across Europe. For a subset from 17 regions, resurvey data and 6-year soil temperature series were available. Differences in temperature sum and Shannon index as well as species richness, colonization and disappearance of species among cardinal directions were analysed using linear mixed-effects and generalised mixed-effects models, respectively. Results Temperature sums were higher in east- and south-facing aspects than in the north-facing ones, while the west-facing ones were intermediate; differences were smallest in northern Europe. The patterns of temperature sums among aspects were consistent among years. In temperate regions, thermal differences were reflected by plant diversity, whereas this relationship was weaker or absent on Mediterranean and boreal mountains. Colonization of species was positively related to temperature on Mediterranean and temperate mountains, whereas disappearance of species was not related to temperature. Main conclusions Thermal differences caused by solar radiation determine plant species diversity on temperate mountains. Advantages for plants on eastern slopes may result from the combined effects of a longer diurnal period of radiation due to convection cloud effects in the afternoon and the sheltered position against the prevailing westerly winds. In northern Europe, long summer days and low sun angles can even out differences among aspects. On Mediterranean summits, summer drought may limit species numbers on the warmer slopes. Warmer aspects support a higher number of colonization events. Hence, aspect can be a principal determinant of the pace of climate-induced migration processes.

• Publisher: Wiley,CCSD,Blackwell Publishing Ltd,John Wiley & Sons Ltd,Wiley Subscription Services, Inc
• Subject: alpine life zone / alpine plants / Biodiversity / Biologi / Biological Sciences / climate change / climatic factors / Colonization / Consequences of climate change / convection / diversity / Drought / energy / Europe / extinction debt / Flowers & plants / GLORIA / gradients / heat sums / Herbivores / Life Sciences / long-term monitoring / Microclimate / Mountains / nival ecotone / Northern European region / patterns / Plant diversity / Plant species / slope aspect / soil / Soil temperature / Solar radiation / Species diversity / Species richness / summer / temperate zones / topographic slope / vascular plants
• ISBN: 0003888687000