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Elevational gradients of species diversity, breeding system and floral traits of orchid species on Reunion Island

Jacquemyn, Hans, Micheneau, Claire, Roberts, David L., Pailler, Thierry (2005) Elevational gradients of species diversity, breeding system and floral traits of orchid species on Reunion Island. Journal of Biogeography, 32 (10). pp. 1751-1761. ISSN 03050270 (ISSN). (doi:10.1111/j.1365-2699.2005.01307.x) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

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Abstract

Aim: This research investigates changes in orchid species composition and diversity, plant breeding system and floral traits along an elevational gradient spanning 2300 m (200-2500 m). Location: The study was conducted on Réunion Island (Mascarene Islands, Indian Ocean). Methods: Data on the distribution of 135 orchid species from 35 genera were gathered from 121 localities situated between 200 and 2500 m a.s.l. For each locality, 500-m transects were walked and each orchid species was recorded. Measures of species diversity (species richness, a modified Shannon diversity index and the modified Shannon equitability index) were related to altitude using ordinary least-squares regression. Species turnover and elevational gradients in species composition were determined by: (1) relating scores of detrended correspondence analysis to altitude using ordinary least-squares regression, and (2) relating Sørensen similarity indices to differences in altitude using Mantel tests. Finally, the average proportion of species displaying similar floral traits or showing the same breeding system were compared among altitudinal zones. Results: Species richness per transect ranged from 1 to 36 species (mean 14.3) and decreased significantly with increasing altitude. Similarly, species evenness decreased significantly with increasing altitude. Around 50% of all orchid species were rare (occurred in fewer than 5% of all localities), and only a few occurred in more than 50% of all localities. Orchid species composition changed continuously with altitude, indicating turnover of species with increasing altitude. Analogously, orchid breeding systems and floral traits also changed with altitude. Relatively more auto-pollinating species were found at high altitudes compared with mid- and low-altitude sites where animal-pollinated species were most abundant. Species characterized by a cleistogamous pollination system were found almost exclusively in high-altitude sites, whereas the proportion of species displaying floral traits related to pollination by long-tongued moths (sphinx) and flies sharply decreased with increasing altitude. Main conclusions: Environmental conditions associated with altitude exert a large influence on orchid species composition and the distribution of orchid breeding systems. Our results revealed a high proportion of auto-pollinating species, and confirm earlier findings that auto-pollinating species are more frequent in high-altitude sites. © Blackwell Publishing Ltd.

Item Type: Article
DOI/Identification number: 10.1111/j.1365-2699.2005.01307.x
Additional information: Unmapped bibliographic data: PY - 2005/// [EPrints field already has value set] AD - Laboratory for Forest, Nature and Landscape Research, Catholic University of Leuven, Leuven, Belgium [Field not mapped to EPrints] AD - Université de la Réunion, UMR C53 Cirad-Université, Peuplements Végétaux et Bioaggresseurs en Milieu Tropical, Saint-Denis Messag, Cedex 9, France [Field not mapped to EPrints] AD - Royal Botanic Gardens, Kew, Richmond, Surrey, United Kingdom [Field not mapped to EPrints] AD - Laboratory for Forest, Nature and Landscape Research, University of Leuven, Vital Decosterstraat 102, B-3000 Leuven, Belgium [Field not mapped to EPrints] AD - University of Leuven, Belgium [Field not mapped to EPrints] AD - Royal Botanical Gardens [Field not mapped to EPrints] AD - University of La Réunion, Reunion [Field not mapped to EPrints] JA - J. Biogeogr. [Field not mapped to EPrints]
Uncontrolled keywords: Breeding system evolution, Elevational gradient, Floral traits, Indian Ocean, Island colonization, Mascarene Islands, Orchidaceae, Species composition, Species turnover, autogamy, environmental conditions, floral trait, least squares method, regression analysis, reproductive strategy, species diversity, species evenness, species richness, Indian Ocean, Indian Ocean islands, Mascarene Islands, Reunion, Animalia, Lepidoptera, Orchidaceae
Subjects: Q Science
Q Science > QH Natural history
Q Science > QH Natural history > QH75 Conservation (Biology)
Divisions: Faculties > Social Sciences > School of Anthropology and Conservation
Faculties > Social Sciences > School of Anthropology and Conservation > DICE (Durrell Institute of Conservation and Ecology)
Depositing User: David Roberts
Date Deposited: 20 Feb 2014 14:43 UTC
Last Modified: 29 May 2019 10:10 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/33841 (The current URI for this page, for reference purposes)
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