Low impact of climate change on subalpine grasslands in the Swiss Northern Alps?

Détails

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Etat: Serval
Version: de l'auteur
ID Serval
serval:BIB_4598E7CF05AD
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Low impact of climate change on subalpine grasslands in the Swiss Northern Alps?
Périodique
Global Change Biology
Auteur(s)
Vittoz P., Randin C., Dutoit A., Bonnet F., Hegg O.
ISSN
1354-1013
Statut éditorial
Publié
Date de publication
2009
Peer-reviewed
Oui
Volume
15
Numéro
1
Pages
209-220
Langue
anglais
Résumé
While phenological shifts and migration of isolated species under climate change have already been observed on alpine summits, very few studies have focused on community composition changes in subalpine grasslands. Here we use permanent plots monitored since 1954 and precisely located phytosociological censuses from 1970 to study compositional changes of subalpine grasslands in two distinct regions of the Swiss Northern Alps. In both areas, warming trends during the monitoring period were associated with changes in land management (abandonment of goat and sheep pasturing or grazing replaced by mowing). Old and recent inventories were compared with correspondence analyses (CA). Ecological indicator values, community-affinities and biological traits of the species were used to infer the factors responsible for triggering the observed changes. In both regions, subalpine grasslands were stable with smaller changes than have previously been observed in alpine environments. Only a few species appeared or disappeared and changes were generally limited to increasing or decreasing frequency and cover of certain taxa. At one site, grazing abandonment favoured fallow species. Some of these species were located at their upper altitudinal distribution limits and may have spread because of rising temperatures. In both areas, declining species were predominantly alpine and low growing species; their decline was probably due to increased competition (e.g., shade) with more vigorous subalpine taxa no longer limited by grazing. We conclude that vegetation communities can respond rapidly to warming as long as colonisation is facilitated by available space or structural change. In the subalpine grasslands studied, changes were mainly driven by land management. These communities have a dense vegetation cover and newly arriving herbaceous species preferring warmer conditions may take some time to establish themselves. However, climate disturbances, such as exceptional drought, may accelerate community changes by opening gaps for new species.
Mots-clé
biological traits, community change, competition, correspondence analysis, ecological indicator value, facilitation, global warming, pasture abandonment, Switzerland
Web of science
Open Access
Oui
Création de la notice
23/06/2008 8:27
Dernière modification de la notice
08/05/2019 17:54
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