Atelier ORIXAS: Projeto Tripartite África/Brasil/França: luta contra a desertificação: promoção da segurança alimentar e redução da pobreza.

No âmbito do Programa de Cooperação Científica Tripartite entre a Agence Inter-établissements de Recherche pourle Développement (AIRD), Agence Panafricaine de la Grande Muraille Verte (APGMV) e o Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), o projeto ORIXAS "Observatórios Regionais Integrados de Regiões Árida, Semiáridas e Sub-úmidas secas" concebido em uma visão transversal, foca principalmente em metodologias e ferramentas para apoiar dispositivos de monitoramento ambiental para ser aplicado nos países inseridos na iniciativa africana Grande Muralha Verde - GMV (Burkina-Faso, Djibouti, Érythrée, Éthiopie, Mali, Mauritanie, Niger, Nigeria, Sénégal, Soudan, Tchad) e tem como objetivo desenvolver abordagens metodológicas e produtos compartilhados para melhorar a avaliação e monitoramento da desertificação e os impactos diretos ou indiretos de iniciativas para lutar contra o desmatamento e desertificação no âmbito da GMV. Esta publicação contempla aspectos metodológicos utilizados pelo projeto "ORIXAS" durante a primeira oficina de trabalho coletivo África-Brasil-França - Atelier (MAISON DE LA TÉLÉDÉTECTION), realizada de 10 a 19 de junho de 2014, em Montpellier França, objetivando informar a forma de execução dos estudos que vêm sendo realizados no escopo do projeto, visando principalmente a luta contra a desertificação, promoção da segurança alimentar e redução da pobreza nos países inseridos na iniciativa africana Grande Muralha Verde - GMV.bitstream/item/123193/1/DOC-174-Atelier-Orixas.pd

Remote sensing' 96 : integrated applications for risk assessment and disaster prevention for the Mediterranean

This study of desertification is based on ground measurement of reflectance properties of the different land degradation levels recognised by field ecologists in Southern Tunisia. Landsat MSS images from 1972 onwards recorded have been superimposed after geometrical correction. Using the field reflectance data ground features of low temporal variability were taken as radiometric references. This allowed to adjust for the differences in radiometry of the images and to detect temporal variations of image-derived indices. These indices, i.e. brightness, vegetation and colour were found to be correlated with land surface parameters such as roughness, green vegetation density and soil surface composition. As a result fluctuations of areas with degraded soil and mobilised sand could be monitored as well as areas treated by wind barriers or exclosure which appear darker. The overall trend is currently a significant recovery of the ecosystems after the severe drought and eolisation of the 80's. This experiment demonstrates the feasibility of long term monitoring of arid ecosystem changes, and its potential for the implementation of desertification control programmes. (Résumé d'auteur

Coviability of social and ecological systems : reconnecting mankind to the biosphere in an era of global change. Vol. 2 : Coviability questioned by a diversity of situations

The babassu palm tree (Attalea speciosa Mart. ex Spreng.) is a species native to the Amazonian rainforest. The invasive nature of this palm tree results in a high density of babassu palm trees with a subsequent decrease in forage crop production. This is a serious problem for local farmers who have tried to resolve it by removing mature palms, seedlings and young individuals. Within these conditions, is coviability between the babassu palm tree and society possible? Our work consisted in developing tools and methods with the aim of producing knowledge and providing answers to this issue within a given territory. To understand the eco-socio-system, we have explored the available knowledge in the literature, produced specific field data, tools and methods such as mathematical modeling (dynamics of the palm tree population) and remote sensing (land use analysis thanks to Landsat high-resolution images and automatic detection of mature palm trees using Pleiades and GeoEye very high-resolution images). This multidisciplinary research in progress has already given us a good overview of the current situation of this eco-socio-system, enabling us to consider the best way to ensure its sustainability

Dialogue entre les parties prenantes : un levier dans la mutation de la science chahutée par l'anthropocène

Science & You 2021 : Create the Future, Metz, FRA, 16-/11/2021 - 19/11/202

Satellite images combined with field data reveal negative changes in the distribution of babassu palms after clearing off amazonian forests

International audienceWhen the Amazonian rain forest is cut to create pasture, some of the original vegetal species survive clearing, even expressing their ability to invade agro-systems. It is true of the babassu palm, which can be considered, paradoxically, a natural resource by the "Interstate Movement of Babassu Fruit Breaker Women" or as native weed by land owners-farmers. To manage potential conflict of land uses, we study here the current density of this palm tree in different habitats, based on a combination of field data and remote sensing data. Firstly, we checked that the field survey methodology (i.e., counting free-trunk palm trees over 20 cm in circumference) provides density values compatible with those stemming from satellite images interpretation. We can see then that, a PA-Benfica Brazilian territory revealed an average density of the babassu lower in pastures (2.86 ind/ha) than in the dense forest (4.72 ind/ha) from which they originate and than in fallow land (4.31 ind/ ha). We analyze in detail density data repartition in three habitats and we discuss results from the literature on the density of this palm tree versus its resilience at different developmental stages after forest clearing, depending on anthropogenic -or not- factors, including solar radiation, fire, weeding, clear cutting, burying fruit, and competition with forage grass. All these results can be exploited for the design of future management plans for the babassu palm and we think that the linked methodology and interdisciplinary approach can be extended to others palms and trees species in similar problematic issues