Long-­term monitoring across elevational gradients to assess ecological hypothesis: a description of standardized sampling methods in oceanic islands and first results

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http://www.horta.uac.pt/intradop/index.php/pt/2013-2014-no-31

Abstract

We are launching a long-term study to characterize the biodiversity at different elevations in several Azorean Islands. Our aim is to use the Azores as a model archipelago to answer the fundamental question of what generates and maintains the global spatial heterogeneity of diversity in islands and to be able to understand the dynamics of change across time. An extensive, standardized sampling protocol was applied in most of the remnant forest fragments of five Azorean Islands. Continuer la lecture →

Population structure in the tropical peat moss, Sphagnum tumidulum Besch. (Sphagnaceae)

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http://dx.doi.org/10.1639/0007-2745-117.4.329

Abstract

Route de BebourSphagnum and Sphagnum-dominated peatlands have long provided a model for analyses of community structure, and recent work has elucidated the genetic structure of various Sphagnum species in the boreal zone. We report here analyses of genetic variation and population differentiation in a tropical species, S. tumidulum, from Réunion Island. Continuer la lecture →

A Functional Characterisation of a Wide Range of Cover Crop Species: Growth and Nitrogen Acquisition Rates, Leaf Traits and Ecological Strategies

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http://dx.doi.org/10.1371/journal.pone.0122156

Abstract

Cover crops can produce ecosystem services during the fallow period, as reducing nitrate leaching and producing green manure. Crop growth rate (CGR) and crop nitrogen acquisition rate (CNR) can be used as two indicators of the ability of cover crops to produce these services in agrosystems. We used leaf functional traits to characterise the growth strategies of 36 cover crops as an approach to assess their ability to grow and acquire N rapidly. We measured specific leaf area (SLA), leaf dry matter content (LDMC), leaf nitrogen content (LNC) and leaf area (LA) and we evaluated their relevance to characterise CGR and CNR. Continuer la lecture →

Stage Master 2 (2014-2015)

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Dynamique de populations en forêt tropicale insulaire

Marelongue_forest_JAN_2007_DS_smallLe suivi de parcelles permanentes en forêt permet d'appréhender la dynamique des populations d'arbres tropicaux à moyen et long terme. A La Réunion, trois hectares en forêt de Mare Longue, dont un nécessitant une nouvelle campagne d'inventaire, sont suivis depuis environ vingt ans.[:] Continuer la lecture →

Stages Master 1 (2014-2015)

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1. Restauration écologique en forêt tropicale semi-sèche

foret_semiseche_colorado_DS_2000_smallSujet : Les forêts tropicales sèches sont parmi les écosystèmes les plus menacés à l'échelle de la planète. Dans les Mascareignes, le programme LIFE+/COREXERUN, achevé en 2014, a initié la reconstitution d'une zone forestière sur une surface de 9 ha dans la ravine de la Grande Chaloupe. Continuer la lecture →

Functional Diversity of Subalpine Bryophyte Communities in an Oceanic Island (La Réunion)

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http://dx.doi.org/10.1657/1938-4246-46.4.841

Abstract

AAAR2014Increasing temperature imperils worldwide tropical subalpine and alpine ecosystems with the threat of mountaintop extinctions and a subsequent loss of biodiversity and ecosystem functions. This paper provides a first assessment of functional diversity along a high climatic gradient for bryophytes, which represent a major plant compartment in these ecosystems. Continuer la lecture →

Isolation and characterization of microsatellite markers of an endangered tropical tree

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http://dx.doi.org/10.1007/s12686-011-9437-0

Abstract

Sideroxylon majus (Sapotaceae) is an endangered endemic tree of La R,union Island that has suffered from human actions. It is present in small and isolated populations that encounter severe difficulties to regenerate. To have powerful tools for population genetic studies, we have isolated and characterized 14 polymorphic microsatellite markers from S. majus. The 14 loci were tested on 57 individuals from 6 populations. The number of alleles per locus varied from 2 to 20, with an average of 11.8. The observed and expected heterozygosity levels ranged from 0.053 to 1.000, and 0.116 to 0.917, respectively. Six of the 14 loci deviated from Hardy-Weinberg equilibrium. These polymorphic microsatellite markers constitute new tools to study the genetic diversity and spatial genetic structure of S. majus. The cross-species amplifications indicate that most of these loci can be used to investigate population genetic structure in S. grandiflorum, S. boutonianum and S. sessiliflorum. These studies will provide useful results for the elaboration of effective conservation strategies.

Citation

cons_genet_2011

Dafreville, S., Payet, G., Simiand, C., Risterucci, A. M., Riviere, E., Lebreton, G., Humeau, L., Strasberg, D.,Chevallier, M. H. 2011. Isolation and characterization of microsatellite markers of an endangered tropical tree, Sideroxylon majus, and cross-species amplification in other Sapotaceae species. Conservation Genetics Resources 3(4): 701-704.