Gaëlle Viennois

• French Agricultural Research Centre for International Development

Remote sensing classification methods mostly use only the physical properties of pixels or complex texture indexes but do not lead to recommendation for practical applications. Our objective was to design a texture-based method, called the Paysages A PRIori method (PAPRI), which works both at pixel and neighborhood level and which can handle differ...

Revegetation of abandoned aquaculture regions should be a priority for any integrated coastal zone management (ICZM). This paper examines the potential of a matchless time series of 20 very high spatial resolution (VHSR) optical satellite images acquired for mapping trends in the evolution of mangrove forests from 2001 to 2015 in an estuary fragmen...

The poster pressent the map of forest landscapes diversity within Central Africa. The methodology is presented in the paper ’New insights in tropical forest diversity mapping in Central Africa using low resolution remote sensing. It was presented at the World Bank annual congress, March 23rd-27th, Washington DC, USA. DOI: 10.13140/RG.2.1.3242.5128

Mapping zonations of mangrove species (ZMS) is important when assessing the functioning of such specific ecosystems. However, the reproducibility of remote sensing methods for discriminating and mapping mangrove habitats is often overstated due to the lack of temporal observations. Here, we investigated the potential use of temporal series of high-...

Mapping zonations of mangrove species (ZMS) is important when assessing the functioning of such specific ecosystems. However, the reproducibility of remote sensing methods for discriminating and mapping mangrove habitats is often overstated due to the lack of temporal observations. Here, we investigated the potential use of temporal series of high-...

African forests are predicted to experience profound climatic changes in the next decades. In order to ensure that human societies can adapted to these changes, it is needed to have a better understanding of the forest functioning. A forest type’s location map is a fundamental stage. This map was processed from 14 years remotely sensed MODIS time...

Mangrove restoration has been attempted in the 7 km² Perancak Estuary, Bali since the 90's following shrimp farming loss of profitability. We characterized the surface types of estuarine zone and monitored mangrove changes since 2001 using a series of 20 very high resolution satellite images acquired over the estuary. Mangrove development was furth...

Our study aims at developing a generalizable method to exploit high resolution satellite images (VHR) for mapping coconut-based agrosystems, differentiating them from oil palm agrosystems. We compared two methods of land use classification. The first one is similar to that described by Teina (2009), based on spectral analysis and watershed segmenta...

There is a need to document how fast mangrove coasts are changing. Within the framework of the INDESO project, we are implementing methods for monitoring changes in Indonesian mangroves over the past decade. The Perancak river estuary, Jembrana, Bali was selected as a pilot site to analyze the impact of aquaculture and plantation practices in a 7 k...

Sustainable management of mangroves depends on our ability to maintain ecosystem functions. It requires a careful monitoring of several forest characteristics such as the species composition. Very high resolution multispectral satellite images provide pivotal information at the individual tree scale that may support identification and mapping of sp...

Central African forests, when mapped at regional scale using remote sensing, are generally represented as one great homogeneous ‘forest’ land cover class. However, studies based on ecological and detailed forest inventories have identified spatial patterns of species diversity, functional traits and biomass, outlining the existence of several fores...

Very high resolution (VHR) satellite images provide crucial information on fast changing coastal regions of the world. Within the framework of the INDESO project, we designed a specific application dedicated to the monitoring of mangroves in Indonesia. In this work, we focused on the case study of the Perancak river estuary, Jembrana, Bali. The est...

Savannas and tropical forests delineated by sharp boundaries are two alternative stable ecosystems. What is the natural evolution of forests over savannas in coastal savanna in French Guiana? The dynamic balance between forest advance and retreat is a response to disturbances such as fire or extreme drought events. Fire maintains savanna by its act...

Savannas and tropical forests delineated by sharp boundaries are two alternative stable ecosystems. What is the natural evolution of forests over savannas in coastal savanna in French Guiana? The dynamic balance between forest advance and retreat is a response to disturbances such as fire or extreme drought events. Fire maintains savanna by its act...

The characterization of leaf phenology in tropical forests is of major importance for forest typology as well as to improve our understanding of earth–atmosphere–climate interactions or biogeochemical cycles. The availability of satellite optical data with a high temporal resolution has permitted the identification of unexpected phenological cycles...

Local tree density may vary in young Eucalyptus plantations under the effects of environmental condi-tions or inadequate management, and these variations need to be mapped over large areas as they have a significant impact on the final biomass harvested. High spatial resolution optical satellite images have the potential to provide crucial informat...

The characterization of leaf phenology in tropical forests is of major importance and improves our understanding of earth-atmosphere-climate interactions. The availability of satellite optical data with a high temporal resolution has permitted the identification of unexpected phenological cycles, particularly over the Amazon region. A primary issue...

L'objectif de ce projet est de cartographier les forêts tropicales humides selon un axe phénologique dans une zone d'intervention prioritaire située en Afrique Centrale. Nous présentons une méthode originale basée sur une procédure itérative multi-échelles allant de l'échelle locale (GeoEye-1, SPOT-5) à l'échelle régionale (MODIS). Pour la première...

A new methodology based on pulsed lasers has been developed in order to estimate wheat outer layer mechanical properties without sample preparation. Laser experiments were carried out with an Argon Fluoride (λ = 193 nm) excimer laser source delivering pulses of 15 ns duration. Wheat grains from two cultivars were irradiated by single laser pulses w...

Les procédés de première transformation des céréales conduisent à l'obtention majoritaire de produits alimentaires intermédiaires de type farine. Les enveloppes du grain de blé, éliminées dans les sons, présentent toutefois un potentiel nutritionnel important dû à leur richesse en minéraux, micronutriments et fibres. La valorisation de l'ensemble d...

Aquaporins form a family of water and solute channel proteins and are present in most living organisms. In plants, aquaporins play an important role in the regulation of root water transport in response to abiotic stresses. In this work, we investigated the role of phosphorylation of plasma membrane intrinsic protein (PIP) aquaporins in the Arabido...

Grain legumes can contribute to cropping systems through their ability to fix atmospheric N2 in their root-nodules. However, the symbiotic nitrogen fixation process requiadditional phosphorus. Thus, the production of grain legumes, particularly common bean, is limited by P-deficiency in many soils, mostly in tropical and Mediterranean areas. Recomb...

Expression of a mycorrhizal fungal-specific phosphate (P) transporter gene (HcPT1) was studied in mycelium of the ectomycorrhizal fungus Hebeloma cylindrosporum, by in situ reverse transcriptase polymerase chain reaction using amplification of complementary DNA sequences. The expression of HcPT1 was visualised under two different P treatments. Myce...

In Arabidopsis the NRT2.1 gene encodes a main component of the root high-affinity nitrate uptake system (HATS). Its regulation has been thoroughly studied showing a strong correlation between NRT2.1 expression and HATS activity. Despite its central role in plant nutrition, nothing is known concerning localization and regulation of NRT2.1 at the pro...

Presynaptic metabotropic glutamate receptors (mGluRs) of group III constitute possible targets for putative neuroprotective drugs acting against glutamate excitotoxic insults. Indeed, in glutamatergic cerebellar granule neurones in culture, high concentrations of L-2-amino-4-phosphonobutyrate (L-AP4, above 0.3 mM, thus activating mGluR7) inhibit NM...