Distribution of moss-inhabiting diatoms along an altitudinal gradient at sub-Antarctic Îles Kerguelen

• Published in: Antarctic Science
• Main Authors: Gremmen, Niek, Van De Vijver, Bart, Frenot, Yves, Lebouvier, Marc
• Other Authors: Data-Analyse Ecologie, Data Analyse Ecologie, Department of Bryophyta and Thallophyta - National Botanic Garden of Belgium, National Botanic Garden of Belgium, Ecosystèmes, biodiversité, évolution Rennes (ECOBIO), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: climatic gradient; species diversity; transfer function; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDE.MCG]Environmental Sciences/Global Changes; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Antarctic; Kerguelen; Îles Kerguelen; Antarc*; Antarctic Science
• Online Access: https://hal.archives-ouvertes.fr/hal-00154806; https://doi.org/10.1017/S0954102007000041

International audience Altitudinal gradients provide excellent opportunities to study relationships between species distribution and climatic variables. We studied the species composition of 39 samples of moss-inhabiting diatoms, collected at 50 m intervals from 100–650 m above sea level. The samples contained a total of 130 diatom species, of which 51 occurred in 10 or more samples. Altitude appeared to be the most important variable explaining variation in species composition. Of the 51 common species, 33 showed a significant relationship with altitude. Although the majority of the latter declined with increasing altitude, for nine species the probability of occurrence first increased with increasing elevation, but decreased again at higher altitudes, and four species increased systematically with elevation. As a result, expected species richness per sample decreased from an estimated 43 at 100 m to 25 species per sample at 650 m. Diatom distribution patterns proved to be suitable predictors of the altitudinal position of sample sites. Cross-validation yielded a strong relationship between predicted and observed altitudes.