Search publications of the members of the Royal Belgian institute of natural Sciences
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Canopy laser scanning to study the complex architecture of large old trees
- Canopy laser scanning to study the complex architecture of large old trees Barbara D'hont1 , Professor Kim Calders1 , Professor Alexandre Antonelli6 , Dr. Thomas Berg7 , Dr. Karun Dayal1 , Dr. Leonard Hambrecht5 , Dr. Maurice Leponce2,3, Prof. Arko Lucieer5 , Olivier Pascal4 , Professor Pasi Raumonen8, Professor Hans Verbeeck1 1Q-ForestLab, Department of Environment, Ghent University, Ghent, Belgium, 2Royal Belgian Institute of Natural Sciences, Brussels, Belgium, 3Université Libre de Bruxelles, Brussels, Belgium, 4Fonds de Dotation Biotope Pour La Nature, France, 5School of Geography, Planning, and Spatial Sciences, University of Tasmania, , Australia, 6Royal Botanic Gardens, Kew, Richmond, Surrey, United Kingdom, 7ARAÇÁ Project, Nova Friburgo, Rio de Janeiro, Brazil, 8Faculty of Information Technology and Communication Sciences, Tampere University, Tampere, Finland Large trees are keystone structures providing multiple ecosystem functions in forests all around the world: they disproportionately contribute to forest biomass and biodiversity. Large trees can have an extremely complex structure, housing many epiphytes on their stem and branches. High point-density 3D point clouds, in which leaves and epiphytes in the tree can be distinguished, are useful to make the link between the distribution of organisms on the tree, the tree architecture and its microclimate. In addition, a comprehensive branching model can improve above ground biomass (AGB) estimates. Highly detailed, complete point clouds of large trees are, however, exceptionally difficult to derive. With terrestrial laser scanning, the state-of-the-art method to capture 3D tree structure, the plant material blocks the view of (or, occludes) the top part of the dense crown. Drone or airborne laser scanning data on the other hand, lacks detail in the subcanopy. Combining these two methods minimises occlusion; however, increased distance from the tree to the scanner still leads to a relatively low resolution of the canopy point clouds. To improve the level of precision of the tree point clouds, we introduce a new concept, called canopy laser scanning (CLS). With CLS, a laser scanner is operated statically inside the tree canopy, reducing the distance between the area of interest and the instrument. We lifted a high-end laser scanner (RIEGL vz-400(i)) inside the canopy of six large emergent trees. Four of these trees are located in different types of tropical rainforests in Colombia, Brazil and Peru. They are part of biodiversity programs in which organisms and their spatial distributions are studied (Life On Trees, Araçá). The two other trees are famous giants located in the wet temperate eucalypt forests of southern Tasmania. We will present the practical aspects of CLS, evaluate the extra value of using canopy scans, looking at occlusion and point cloud precision, estimate epiphyte cover and AGB. We demonstrate that canopy laser scanning opens up new opportunities in sciences in which multi-disciplinary teams perform in depth research on large individual trees.
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Biodiversity research and monitoring related capacities in Kisangani (DRC)
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Towards less invasive methods to inventory and monitor wildlife in the Congo Basin
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Phenotypic plasticity of feeding performance as a response to diet in cichlids: suction verus biting.
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Phenotypic plasticity of feeding performance as a responce to diet in cichlids: suction versus biting
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Miscellanea Herpetologica Gabonica VII
- We present new Gabonese locality records, ecological data or unpublished museum material for Crocodylus niloticus (Crocodylidae), Trionyx triunguis (Trionychidae), Agama lebretoni (Agamidae), Hemidactylus fasciatus and H. mabouia (Gekkonidae), Gastropholis echinata (Lacertidae), Trachylepis albilabris (Scincidae), Afrotyphlops angolensis (Typhlopidae), Dipsadoboa viridis, Hapsidophrys smaragdinus, Toxicodryas pulverulenta (Colubridae), Naja melanoleuca (Elapidae), Lamprophis olivaceus, Psammophis cf. phillipsii (Lamprophiidae), Natriciteres fuliginoides (Natricidae), Causus lichtensteinii and C. maculatus (Viperidae). We document predation cases by Hapsidophrys smaragdinus on Hemidactylus mabouia and Trachylepis albilabris, by Naja melanoleuca on Sclerophrys regularis (Anura: Bufonidae) and by Psammophis cf. phillipsii on Phrynobatrachus auritus (Anura: Phrynobatrachidae), and consumption of Arius latiscutatus (Siluriformes: Ariidae) and Tragelaphus spekii (Cetartiodactyla: Bovidae) by Crocodylus niloticus. We add one, two and one snake species, respectively, to Estuaire, Moyen-Ogooué and Nyanga provinces’ reptile lists. We add four reptile species to the list for Wonga-Wongué Presidential Reserve. We refer all records of Agama agama in Gabon to A. picticauda.
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Ammonoids and anoxia from the Belgian Frasnian: the Carrière de Lompret section
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A double whammy for dinosaurs and ammonites: fake news or the real deal
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Bedforms as Benthic Habitats: Living
on the Edge, Chaos, Order and Complexity
- Bedforms as benthic habitats are studied increasingly as acquisition and analysis of acoustic data improve in capturing, visualizing and quantifying terrain variables on various scales. However, feedback mechanisms between geomorphology and benthos are not always clear and complexity increases where humans also affect the benthos-landscape relationship. Based on research-oriented seabed mapping along the Belgian part of the North Sea (BPNS), a synthesis is provided on where increased biodiversity has been observed in relation to active bedforms.
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Building a 4D Voxel-Based Decision Support System for a Sustainable Management of Marine Geological Resources
- For sustainable management of marine geological resources, a geological knowledge base is being built for the Belgian and southern Netherlands part of the North Sea. Voxel models of the subsurface are used for predictions on sand and gravel quantities and qualities, to ensure long-term resource use. The voxels are filled with geological data from boreholes and seismic lines, but other information can be added also. The geology provides boundary conditions needed to run environmental impact models that calculate resource depletion and regeneration under various scenarios of aggregate extraction. Such analyses are important in monitoring progress towards good environmental status, as outlined in the Marine Strategy Framework Directive. By including uncertainty, data products can be generated with confidence limits, which is critical for assessing the significance of changes in the habitat or in any other resource-relevant parameter. All of the information is integrated into a cross-domain, multi-criteria decision support system optimised for user-friendliness and online visualisation.
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Cryptic diversity and ecosystem functioning: a complex tale of differential effects on decomposition
- Marine ecosystems are experiencing accelerating population and species loss. Some ecosystem functions are decreasing and there is growing interest in the link between biodiversity and ecosystem functioning. The role of cryptic (morphologically identical but genetically distinct) species in this biodiversity-ecosystem functioning link is unclear and has not yet been formally tested. We tested if there is a differential effect of four cryptic species of the bacterivorous nematode Litoditis marina on the decomposition process of macroalgae. Bacterivorous nematodes can stimulate or slow down bacterial activity and modify the bacterial assemblage composition. Moreover, we tested if interspecific interactions among the four cryptic species influence the decomposition process. A laboratory experiment with both mono- and multispecific nematode cultures was conducted, and loss of organic matter and the activity of two key extracellular enzymes for the degradation of phytodetritus were assessed. L. marina mainly influenced qualitative aspects of the decomposition process rather than its overall rate: an effect of the nematodes on the enzymatic activities became manifest, although no clear nematode effect on bulk organic matter weight loss was found. We also demonstrated that species-specific effects on the decomposition process existed. Combining the four cryptic species resulted in high competition, with one dominant species, but without complete exclusion of other species. These interspecific interactions translated into different effects on the decomposition process. The species-specific differences indicated that each cryptic species may play an important and distinct role in ecosystem functioning. Functional differences may result in coexistence among very similar species.
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Active dispersal is differentially affected by inter- and intraspecific competition in closely related nematode species (vol 124, pg 561, 2016)
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Speciation genomics of cichlids (Ophthalmotilapia) from Lake Tanganyika
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Pinpointing behavioral responses during mating using differential gene expression in the female brain of cichlid fish
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Bostryx hennahi (Gray, 1828) the largest Chilean bulimulid (Mollusca: Pulmonata) rediscovered among Tillandsia communities in northern Chile
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The land Mollusca of Saint Kitts and Nevis (Lesser Antilles), with description of a new species
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Synopsis of Central Andean Orthalicoid land snails (Gastropoda, Stylommatophora), excluding Bulimulidae
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A new species of Bothriembryon (Mollusca, Gastropoda, Bothriembryontidae) from southeasternmost Western Australia
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Combining mitochondrial DNA and morphological data to delineate four new millipede species and provisional assignment to the genus Apeuthes Hoffman & Keeton (Diplopoda : Spirobolida : Pachybolidae : Trigoniulinae)
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Les tombes tardo-romaines dans le bassin moyen de la Meuse au travers des découvertes du Tienne del Baticulle à Nismes
