References of "Coos, William"
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See detailImproving Ecotope Segmentation by Combining Topographic and Spectral Data
Radoux, Julien; Bourdouxhe, Axel ULiege; Coos, William ULiege et al

in Remote Sensing (2019), 11

Ecotopes are the smallest ecologically distinct landscape features in a landscape mapping and classification system. Mapping ecotopes therefore enables the measurement of ecological patterns, process and ... [more ▼]

Ecotopes are the smallest ecologically distinct landscape features in a landscape mapping and classification system. Mapping ecotopes therefore enables the measurement of ecological patterns, process and change. In this study, a multi-source GEOBIA workflow is used to improve the automated delineation and descriptions of ecotopes. Aerial photographs and LIDAR data provide input for landscape segmentation based on spectral signature, height structure and topography. Each segment is then characterized based on the proportion of land cover features identified at 2 m pixel-based classification. The results show that the use of hillshade bands simultaneously with spectral bands increases the consistency of the ecotope delineation. These results are promising to further describe biotopes of high ecological conservation value, as suggested by a successful test on ravine forest biotope. [less ▲]

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See detailCombining ecotope segmentation and remote sensing data for biotope and species distribution modelling
Coos, William ULiege; Delangre, Jessica ULiege; Radoux, Julien et al

Poster (2016, April 29)

The design of appropriate biodiversity conservation actions requires an extensive knowledge of biotope and species distributions. Biodiversity monitoring is often a time-consuming task; however, it can be ... [more ▼]

The design of appropriate biodiversity conservation actions requires an extensive knowledge of biotope and species distributions. Biodiversity monitoring is often a time-consuming task; however, it can be optimised by biotope and species distribution models. In the Lifewatch project, a database combining segmentation in homogeneous landscape units (“ecotopes”) and environmental attributes derived from regularly updated remote sensing data (land cover, topography, potential solar energy,…) and other data sources (climate and edaphic factors) has been designed. Our aim was to assess the usefulness of this database for biotope and species distribution modelling. As a case study, the distributions of a peatbogs (actual and potential) and of a peatbog specialist butterfly (the cranberry fritillary Boloria aquilonaris (Stichel, 1908)) were independently modelled, using the Random Forest algorithm. The agreement between the biotope and species distribution models was assessed. Our map of predictions was compared to a model derived from a more classical grid-based approach. We observed that ecotope segmentation fitted more closely objective limits on the field, thereby improving the efficiency of biodiversity monitoring. The comparison between actual and potential biotopes allowed us to identify potential restoration areas. [less ▲]

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See detailModelling seed dispersal and tropical forest regeneration :application to Staudtia kamerunensis in the WWF Lake Tele-Tumba Landscape in DR Congo
Coos, William ULiege; Dury, Marie ULiege; Trolliet, Franck ULiege et al

Poster (2014, June)

Unsustainable hunting and slash-and-burn farming in tropical forests can lead to the empty forest syndrome. It is characterized by the loss of key species essential in the maintenance and regeneration of ... [more ▼]

Unsustainable hunting and slash-and-burn farming in tropical forests can lead to the empty forest syndrome. It is characterized by the loss of key species essential in the maintenance and regeneration of the forest. Indeed the main mechanism of this regeneration is seed dispersal, which for tropical trees is usually driven by animals, and the alteration of this process through a reduction of the disperser population may have serious consequences on forest composition. Computer models are powerful tools to study these processes, not only towards a better understanding of the key mechanisms controlling tropical forest regeneration, but also with the aim of optimising forest management and exploitation to reach a better equilibrium between tropical tree species and their seed dispersers. This study describes a seed dispersal module ultimately developed to analyze the regeneration of the rainforest in the WWF Lake Tele – Lake Tumba Landscape in RD Congo (BIOSERF project funded by Belgian Science Policy). The module has been developed to upgrade the CARAIB dynamic vegetation model, which is used in the BIOSERF project. Data are derived from a field study in which we analyzed seed dispersal of a common tree species (Staudtia kamerunensis) and we determined the community of its main dispersers (largely dominated by the hornbill Bycanistes albotibialis). Additional data (density of S. kamerunensis, habitat use and retention time in the digestive tract of hornbills to simulate dispersal kernel) were obtained from literature and satellite images. Different simulations were performed to represent seed rain over time and a survival rate was applied to show the regeneration. The module was able to provide a percentage of recolonization of degraded places. In the end, this result was compared to field studies, which provide close percentage of recolonization [less ▲]

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