Bryophytes of Kenya's coastal forests - A guide to common species

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Bryophytes of Kenya's coastal forests - A guide to common species
Authors : Wilding N., Hedderson T., Ah-Peng C & Malombe I.
Date: dec. 2016

Front page of the guideThis guide was produced in the framework of the Kenyan Coastal forest project funded by the Indian Ocean Commission (FED/20015/358-516-SVC-101). This field guide presents 20 species of bryophytes (12 mosses and 8 liverworts) commonly encountered in Kenya's coastal forest region. Each species is accompanied by high quality images and easy to understand descriptions. A glossary of terms is provided as well as further reading and references on African bryophytes. Continuer la lecture →

Contrasting predation services of predator and omnivore diversity mediated by invasive ants in a tropical agroecosystem

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New article published in Basic & Applied Ecology :
http://dx.doi.org/10.1016/j.baae.2016.09.005

Abstract

cover_bae_s14391791Invasive natural enemies are known to either strengthen or weaken the suppression of herbivorous arthropods. However, the impact of invasive species on the predation service provided by natural enemy diversity remains largely unexplored. Here, we tease apart the roles of invasive ants as providers of a predation service and a potential disservice, i.e. reducing the diversity of natural enemies. In mango orchards on Reunion Island, we evaluated the predation service in 20 open fields by simultaneously monitoring the predation on bait eggs and arthropod communities in two strata: the ground surface and the mango tree canopy. Continuer la lecture →

Ecole thématique sur les invasions biologiques, 17-19/10/2016

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Description synthétique de l'action

Organisateurs / cofinanceurs : Université de La Réunion, Université de Stellenbosch CIB, Parc National de La Réunion, DEAL, CIRAD, UICN international.

Comité d'organisation : D. Strasberg, C. Julliot, C. Ah Peng, C. Cybèle, F. Chiroleu

Logistique: Audrey Valery, Even&Sciences

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Visit of Esther Baumann / project ECOPOTENTIAL

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E. Baumann is a Master'student (M2) from the University Of Bayreuth supervised by Pr. Carl Beierkunhlein and visiting the island to acheive the fieldwork of her project. She describes her experience.

On the 10th of August I arrived on the Island of La Reunion to conduct the fieldwork for my Master Thesis, which is embedded in the ECOPOTENTIAL project (H2020). The study aims at detecting patterns in leaf coloration along an elevational gradient in the subalpine shrublands of La Réunion island.

Beyond that aim, stands the concept that the elevational gradient is considered as a proxy for changing environmental conditions, as e.g. increased UV-radiation and increased wind speeds.

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The tale of Gastrodia similis, a terrestrial endemic orchid in La Réunion

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Once established, second-growth forests dominated by alien plants may provide suitable environmental conditions for the maintenance of populations of some rare native species, and thus should not be neglected in conservation studies.

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Pix: Gastrodia similis in the forest of Mare longue (credit: F. Martos)

We illustrate the case of Gastrodia similis Bosser, a small terrestrial orchid endemic to the lowland rainforest of Reunion island. Despite some very specific ecological requirements (necessary mycorrhizal symbiosis with wood-decay fungi and pollination by specialized drosophilid flies), the populations of this rare species are spreading beneath some secondary forests growing at low altitude, extending northward the species geographical distribution. Other native species might also restore populations in this place. We call for more biodiversity assessments and experimental trials in these hybrid ecosystems.

Augros S. & Martos F. (2016). Nouvelles observations de Gastrodia similis Bosser dans le Nord de La Réunion et intérêt des écosystèmes hybrides pour la conservation de la biodiversité de l'île (Orchidaceae, Gastrodieae), Cahiers scientifiques de l'océan indien occidental 7:3-6

Inventaire de Mare Longue (suite suite)

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During the month of August, 2 Master students Sébastien Albert and Sohan Sauroy-Toucouère finished the measurements of the dbh of the trees.
Trunks were measured for woody plants > 4 cm diameter at breast height (dbh) in the one hectare plot in the forest of Mare Longue around 300 m above sea level.

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Pix: Left, Sohan and Asplenium nidus var. nidus in the understorey. No day without rain during three weeks in the tropical rain forest, but no drop of rain mitigated our enthusiasm.

Dominance-diversity distribution for trees (dbh > 8 cm) was compared between 2005 and 2016 (Fig.1). With 36 species in 2016, 4 species have disappeared from the plot since 2005 : Pittosporum senacia, Cyathea excelsa, Memecylon confusum and the endangered Ochrosia borbonica.
The three most common species represent more than half of total trees. Labourdonnaisia calophylloides is more numerous in 2016 (362) than in 2005 (335). At the same time, Antirhea borbonica lost 40 trees, and this trend is stronger if we considered dbh > 4 cm (Fig.2). This species is the one which lost the most of stems (140) between 2005 and 2016, the second one is Chassalia corallioides which lost 69 stems. The important death-rate of the heliophilous species Antirhea borbonica is likely due to the canopy closure, while the shrub Chassalia corallioides shows a very important turnover with plenty of seedlings in the understorey.

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Scientific visit from the University of Cape Town

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pixDeux chercheurs de l'Université du Cap du département de Sciences biologiques sont actuellement en visite dans l'ile (19 au 30 juin 2016), Pr. Terry Hedderson (bryologue) et Dr. Adam West (écophysiologue) ains que deux étudiants de Honours (Laura Figenschou et Mark Fitzgibbon), ils mènent une étude sur l'écophysiologie des bryophytes de La Réunion.
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