Consistent shifts in Alpine plant traits along a mesotopographical gradient

• Main Author: Choler, P.
• Other Authors: Laboratoire d'Ecologie Alpine (LECA), Université Joseph Fourier - Grenoble 1 (UJF)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS), Station alpine Joseph Fourier - UMS 3370 (SAJF), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2005
• Subjects: Low-temperature photoinhibition; community composition; climatic; gradient; species traits; leaf traits; seed fates; ecosystem; tundra; strategies; diversity; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDV.BID]Life Sciences [q-bio]/Biodiversity; [SDV.EE]Life Sciences [q-bio]/Ecology; environment; Antarctic and Alpine Research; Arctic; Tundra
• Online Access: https://hal.science/halsde-00293865; https://doi.org/10.1657/1523-0430(2005)037[0444:CSIAPT]2.0.CO;2

International audience Despite an increasing interest in the study of functional diversity, there have been few attempts to link plant traits, habitat variation, and community structure in Alpine landscapes. These interrelationships were examined along a snowmelt and growing-season-length gradient determined by mesotopographical variations. The study site was chosen so as to encompass much of the floristic beta diversity encountered at the Alpine belt of the southwestern Alps. A three-table ordination technique, named RLQ, was used to unravel on a quantitative basis the co-structure of a plot-by-environmental-variable table, a plot-by-species table, and a species-by-traits table. The main covariations between traits and habitat were (1) an increased specific leaf area (SLA) and leaf nitrogen content on a mass basis (N-mass) in late-meting sites, (2) a trend toward upright and thick leaves in the most exposed, physically disturbed, early-melting sites, and (3) an increasing leaf area in the middle of the gradient, which also exhibits small-scale disturbance due to the Alpine marmot. The interplay of intermediate snow-melting dates and intense zoogenic disturbance appears to promote plant diversity and the persistence of species whose mean-elevation distribution is located much below the study site. The adaptive value of trait attributes along the mesotopographical gradient is discussed within the broader context of plant strategies in temperate Alpine grasslands.