University of Antananarivo

About: University of Antananarivo is a education organization based out in Antananarivo, Madagascar. It is known for research contribution in the topics: Population & Lemur. The organization has 1561 authors who have published 1703 publications receiving 30922 citations. The organization is also known as: Tananarive University & Antananarivo University.

Signification des fluides carboniques dans les granulites et les skarns du Sud-Est de Madagascar

Abstract: In the granulites of southeast Madagascar, extensive skams are the signature of intense fluid circulation coeval with regional metamorphism. Fluid inclusions in different minerals from gneisses and skarns are CO 2 -rich ( X CO 2 ≥ 0.8). Corresponding isochores are in good agreement with mineral thermobarometry. Such fluids, with high P CO 2 and P O 2 and low P H 2 O , are in equilibrium with the observed mineral assemblages. Contrary to some assumptions that granulite fades were produced through fluid-absent metamorphism, these results demonstrate equilibrium between granulite mineral paragenesis and a CO 2 -rich fluid phase.

Population densities and conservation assessments for three species of chameleons in the Toliara region of south-western Madagascar

Abstract: Madagascar is a high conservation priority. Rainforests receive most of the focus, but the dry deciduous and spiny forests of south-western Madagascar house many endemics, are under high deforestation pressure, and remain largely unprotected. Charismatic vertebrates, like chameleons, face a secondary threat: harvesting for the commercial pet trade. Six chameleons inhabit the arid southwest near Toliara: Furcifer antimena, F. belalandaensis, F. labordi, F. lateralis, F. oustaleti, and F. verrucosus. We measured population densities of three of those species. Furcifer verrucosus has a large distribution, was dense (97.7 ha −1 ; 95% CI = 60.2-158.6), and inhabited forests and anthropogenic habitats. Furcifer labordi was much less dense (30.8 ha −1 ; 13.4-70.9), has a restricted range, and has a unique life history that makes it susceptible to perturbations from deforestation or illegal harvesting. Furcifer antimena was the least dense (17.0 ha −1 ; 9.3-30.9) and has an even smaller distribution range. We lack density data for F. lateralis, but this species was abundant in anthropogenic habitats. Within their respective ranges, there are currently no protected areas for F. antimena and only few for F. labordi; these two species are far less abundant than the more widely spread F. verrucosus. We recommend that high conservation priority be focused on F. antimena and the southern populations of F. labordi due to their restricted distributions, susceptibility to extirpation, lower population densities, and lack of formal protection. Establishing protected areas in the Ranobe region and north of the Fiherenana River, in the Belalanda region, would help protect important populations of these vulnerable species.

Provenance and progeny performances and genotype × environment interactions of Eucalyptus robusta grown in Madagascar

Abstract: In Madagascar, plantations of Eucalyptus robusta are grown on more than 150,000 ha. Coppice-managed plantations of this species supply most of the charcoal to the capital, Antananarivo. A study of genetic variability and genotype × environment interactions for growth and wood volume production was undertaken. It involved five E. robusta trials (two provenance trials and three progeny trials) in two contrasting bioclimatic regions. The five trials were thinned to become seed orchards, and growth was monitored for more than 12 years in oldest trials. Growth results showed that the species is well adapted to the island. The results revealed the importance of the choice of provenances/progenies, especially with less suitable growing conditions. The best provenances mostly came from summer rainfall regions of Australia and the worst from marginal regions to the north and south of the natural range. Estimated provenance repeatability and family repeatability of the growth traits was high, and the estimated individual-tree heritability values were generally moderate. In the provenance trials, approximate gains from selecting provenances or progenies were higher than gains from selecting individual trees within provenances/progenies, and in the progeny trials, it was the opposite. Despite the thinning, individual selection would make it possible to achieve further significant genetic gains. Multisite analyses revealed high significant site effect; these sites differed by rainfall, temperature, and soil type. There were few provenance × site interactions, the best provenances at the two sites being largely the same. However, the progeny × site interactions were greater. Interest in this fast-growing species with high plasticity is increasing, especially in view of climate change, and our findings should help forestry decision-makers.

Food insecurity related to agricultural practices and household characteristics in rural communities of northeast Madagascar.

Abstract: Ending hunger and alleviating poverty are key goals for a sustainable future. Food security is a constant challenge for agrarian communities in low-income countries, especially in Madagascar. We investigated agricultural practices, household characteristics, and food security in northeast Madagascar. We tested whether agricultural practices, demographics, and socioeconomics in rural populations were related to food security. Over 70% of respondents reported times during the last three years during which food for the household was insufficient, and the most frequently reported cause was small land size (57%). The probability of food insecurity decreased with increasing vanilla yield, rice yield, and land size. There was an interaction effect between land size and household size; larger families with smaller land holdings had higher food insecurity, while larger families with larger land had lower food insecurity. Other socioeconomic and agricultural variables were not significantly related to food insecurity, including material wealth, education, crop diversity, and livestock ownership. Our results highlight the high levels of food insecurity in these communities and point to interventions that would alleviate food stress. In particular, because current crop and livestock diversity were low, agricultural diversification could improve outputs and mitigate food insecurity. Development of sustainable agricultural intensification, including improving rice and vanilla cultivation to raise yields on small land areas, would likely have positive impacts on food security and alleviating poverty. Increasing market access and off-farm income, as well as improving policies related to land tenure could also play valuable roles in mitigating challenges in food security.