Search publications of the members of the Royal Belgian institute of natural Sciences
-
Phylogenetic position of Olbitherium (Mammalia, Perissodactyla) based on new material from the early Eocene Wutu Formation
- The genus Olbitherium was originally described in 2004 from the early Eocene of the Wutu Formation in China as a ‘perissodactyl-like’ archaic ungulate. Described material of Olbitherium consists of partial dentaries with lower cheek teeth, isolated upper molars, and an isolated upper premolar. Subsequent collaborative fieldwork by Belgian and Chinese researchers discovered new material including a partial skull, the anterior portion of the dentary, and associated postcrania. In their general form, the skull and postcrania are similar to those of early perissodactyls. The new material provides a more complete picture of the upper dentition, and the anterior dentary demonstrates the presence of three lower incisors and a large canine, both ancestral features for perissodactyls. A phylogenetic analysis was conducted to test the affinities of Olbitherium, using a matrix of 321 characters and 72 taxa of placental mammals emphasizing perissodactyls and other ungulates. The results produced four shortest trees of 1981 steps. In all four trees, Olbitherium is the sister-taxon to all perissodactyls except Ghazijhippus. In contrast, when scoring was restricted to the originally described material, the results produced 16 shortest trees of 1970 steps, and Olbitherium nests well within Perissodactyla as sister-taxon to a clade including Lambdotherium and the brontotheriids Eotitanops and Palaeosyops. The new material not only supports the identification of Olbitherium as a perissodactyl, but it also suggests that it is significant for understanding the ancestral perissodactyl morphotype. Funding Sources U.S. National Science Foundation (DEB1456826), Chinese Ministry of Science and Technology (2009DFA32210), and Belgian Science Policy Office (BL/36/C54).
-
A new genus and species of Cicada from Vietnam: Cochloeopsaltria duffelsi gen. et. sp. nov. (Hemiptera: Cicadomorpha: Cicadidae)
-
Is the vertical distribution of meiofauna similar in two contrasting microhabitats? A case study of a macrotidal sandy beach
- Tides are an important forcing factor of macrotidal sandy beaches because they are directly responsible for the local morphodynamic conditions. Macrotidal beaches may harbor different microhabitats such as sandbars and runnels. We evaluated the influence of tides on the vertical distribution of meiofaunal organisms, particularly nematodes, in these two microhabitats at De Panne Beach, on the North Sea coast of Belgium. The 11 meiofaunal groups found were Acari, Amphipoda, Copepoda, Gastrotricha, Nematoda, Oligochaeta, Ostracoda, Polychaeta, Rotifera, Tardigrada and Turbellaria. The nematodes were identified to species level; the 147 species found included 112 in the sandbar and 117 in the runnel. Only turbellarians and nematodes migrated upward during low tide in the sandbar. The response of the nematodes was species-specific; during low tide, they migrated upward in the sandbar and downward toward deeper layers of the sediment in the runnel. These migration patterns were attributed to the feeding strategies in the sandbar (i.e. possible increase of diatom biomass in the surface layer due to high solar incidence), while environmental variables best explained the migration patterns in the runnel (i.e. preferred grain size and amount of total organic carbon). These results suggest a dissimilar vertical migration of the meiofauna over the tidal cycle in the two microhabitats. We attribute the vertical distribution of nematode species and some other meiofaunal groups to active migration toward preferred sites with more food or better environmental conditions. This study also indicated that other variables such as predation and competition, rather than the commonly studied physical variables should be included in future sampling designs of sandy-beach meiofauna assessments, since the environmental variables measured here could not fully explain the vertical distributions of the major meiofaunal groups or the community as a whole.
-
Preface. in: Degraer, S. et al. (Eds.) (2017). Environmental impacts of offshore wind farms in the Belgian part of the North Sea: A continued move towards integration and quantification.
-
Executive summary. in: Degraer, S. et al. (Eds.) (2017). Environmental impacts of offshore wind farms in the Belgian part of the North Sea: A continued move towards integration and quantification.
-
Effects of pile driving on harbour porpoises in the Belgian part of the North Sea
- The harbour porpoise (Phocoena phocoena) is the most common marine mammal in the Belgian part of the North Sea and is protected by both national and EU law. In the North Sea, the harbour porpoise is considered under threat because of high bycatch levels and increasing noise pollution. Impulsive pile driving noise originating from the construction of offshore wind farms has been shown to affect porpoises up to distances of more than 20 km from the noise source. Driven by high porpoise densities in Belgian waters, a pile driving ban is in force from the start of January up to the end of April. However, The Netherlands do not enforce such an embargo for the Borssele offshore wind farm, which is only one kilometer away from Belgian waters. Considering the high mobility of harbour porpoises, there is a need for improved insights into the impact of pile driving noise on porpoises which can serve as a basis for an objective evaluation of the respective legal regimes. From May to September 2016 pile driving was taking place at the Nobelwind wind farm located on the Bligh Bank in Belgium. In this period, porpoise activity was recorded using passive acoustic monitoring (C-PODs), at various distances from the construction site (1 to 45 km). In this study we compare porpoise detections before, during and after pile driving with the focus on the influence of repeated pile driving events. In addition to porpoise monitoring data, noise measurements and noise levels are extrapolated for the different locations. The data for this study were obtained from the RBINS wind farm monitoring programme and the VLIZ Lifewatch observatory.
-
The influence of pile driving noise on harbour porpoises
-
Effects of Offshore Wind Farms on the Early Life Stages of Dicentrarchus labrax
- Anthropogenically generated underwater noise in the marine environment is ubiquitous, comprising both intense impulse and continuous noise. The installation of offshore wind farms across the North Sea has triggered a range of ecological questions regarding the impact of anthropogenically produced underwater noise on marine wildlife. Our interest is on the impact on the "passive drifters," i.e., the early life stages of fish that form the basis of fish populations and are an important prey for pelagic predators. This study deals with the impact of pile driving and operational noise generated at offshore wind farms on Dicentrarchus labrax (sea bass) larvae.
-
Identifying Elusive Prehistoric Land Use by Integrating Electromagnetic and Invasive Survey Approaches
-
2500 years of charcoal production in the Low Countries: the chronology and typology of charcoal kilns and their relation with early iron production.
-
Early and High Medieval (c. 650 AD - 1250 AD) charcoal production and its impact on woodland composition in the Northwest-European lowland: a study of charcoal pit kilns from Sterrebeek (Central Belgium).
-
Review of two Tonnoir moth fly species, overlooked for a century (Diptera: Psychodidae: Psychodinae)
- A lectotype (male) and paralectotypes (male, female) of Pneumia vittata (Tonnoir, 1919) comb. nov. (= Pericoma crispi Freeman, 1953 syn. nov.) from Belgium are designated. The species is redescribed and illustrated, and a diff erential diagnosis is given. The former designation of a holotype, paratypes and paratypoids by Jung is invalid because it was not published. In addition, a problem with Tonnoiriella obtusa (Tonnoir, 1919) comb. nov. (= Tonnoiriella anchoriformis Salamanna, 1975 syn. nov.) from Belgium is resolved. A female specimen is designated as a lectotype, but only the dissected wings from this specimen are in condition suitable for redescription. There is additional non-type material collected later by Tonnoir; this material, including 3 females and 1 male, was the basis for redescription, illustrations and diff erential diagnosis. The unpublished male lectotype designated by Jung is invalid. Two species are added to the last checklist of Psychodidae from Belgium, raising the total number to 94.
-
Distribution and habitat preferences of Galápagos ants (Hymenoptera: Formicidae)
- We present the first comprehensive review of the ant taxa of the Galápagos archipelago. The review is based on data gathered during literature searches, field surveys, and the revision of museum specimens, and includes information on the distribution, habitat, and ecology of 47 species. At least nine of these species are assumed to be native or endemic to the islands and at least 32 species have been introduced through human-associated pathways. The status of the remaining six species is unknown. The information compiled in this study will allow us to better understand the ecological role of indigenous species and their potential as indicators of ecosystem health. Baseline information on the distribution of introduced ants will be indispensable for assessing impact and spread within the archipelago.
-
Overstorey composition shapes across-trophic level community relationships in deciduous forest regardless of fragmentation context
- 1. Communities across trophic levels, and the functional roles they play, are vital for the sustained provision of ecosystem services. In forest systems, diversification of overstorey composition has been shown to be a key driver of biodiversity, but its influence on across-trophic level relationships remains scarcely known. Species across trophic levels in varied overstorey compositions are also differentially susceptible to fragmentation context. We hypothesise that fragmentation will disrupt community relationships associated with particular overstorey compositions. 2. We test this hypothesis using a tree diversity research platform across 53 deciduous woodland plots in central Belgium. We estimate species abundances within nine, generally taxonomic, community groups across trophic levels: understorey vegetation; leaf miners and gall formers; woodlice, millipedes; carabid beetles, harvestmen, spiders, birds, bats. We use multiple co-inertia analyses to examine how taxonomic and trophic role community matrices covary across gradients of overstorey composition, via three different tree species diversification pathways, and fragmentation. 3. For all trophic role groups, across all plots, there was at least one significant pairwise comparison. Apart from comparisons involving bats, there was at least one significant pairwise correlation between taxonomic groups too. These results indicate correlated community matrices across trophic levels. Overstorey composition related to community tightness, that is, the level of co-ordinated change among taxonomic and/or trophic role groups as revealed by multiple co-inertia analyses. Notably, diversifying woodlands of beech Fagus sylvatica or red oak Quercus rubra with pedunculate oak Quercus robur correlated with increased taxonomic community tightness. Diversifying pedunculate oak forest stands with other overstorey species related to unchanged community tightness. Evidence was lacking for fragmentation affecting community tightness, singly or by interacting with overstorey composition. 4. Synthesis. Overall, changing tree species composition and fragmentation level affected across-trophic level community relationships differently. Yet, we demonstrated a clear signal that diversifying monoculture stands with particular species correlated with greater community tightness, and co-ordinated change among sets of community groups, across trophic levels and regardless of fragmentation context. We postulate that having tighter community relationships suggests that measures to improve biodiversity at one trophic level (i.e. trees) could affect other groups, and their associated roles, in a co-ordinated manner
-
Diversity and abundance of soil-litter arthropods and their relationships with soil physicochemical properties under different land uses in Rwanda
- Soil-litter arthropods are critical for ecosystem functioning and sensitive to land use change, and hence to the variations in soil physicochemical properties. The relationships between soil-litter arthropod communities and soil physicochemical properties, however, remain poorly studied in Rwanda. We explored the relationships between the families of soil-litter arthropods and soil properties in exotic and native tree species, and in varieties of coffee and banana plantations. Soil-litter arthropods were sampled by using Berlese funnels, hand sorting, and pitfall traps, and were identified to the family level. Soil cores were collected and analysed for soil pH, available phosphorus, total nitrogen, soil organic carbon, silt, clay and sand. A total of 3176 individuals of soil-litter arthropods were collected, identified and classified into 13 orders and 23 families. Higher abundance was found in soil and litter sampled in plots of native tree species and banana plantations compared to exotic tree species and coffee plantations. Higher diversity was found in plots of native and exotic tree species. The analysis of soil physicochemical properties indicated that native tree species offer suitable conditions of studied soil properties. The study of the relationships between the land use, soil properties and families of soil-litter arthropods indicated positive correlations and relationships mainly in native tree species. We conclude that forest with native tree species play an important role in the conservation of soil-litter arthropods and for maintenance of better soil conditions.
-
Evaluating Efficiency of Different Sampling Methods for Arboreal Ants (Hymenoptera: Formicidae) in A West African Forest-Savanna Mosaic
- Ants constitute an important part of arboreal arthropod biomass in rainforests. Nevertheless, there are only a few methods which permit a rapid assessment of these insects in the canopy layer. This study aims at evaluating the efficiency of a new variant type of pitfall trap i.e. “the funnel trap”, to sample arboreal ants in a secondary and gallery forest in Lamto reserve (Côte d’Ivoire). This method was compared to standard arboreal pitfall trap and beating. In total, the 3 methods yielded 7072 ant workers belonging to 43 species, 14 genera and 5 subfamilies. Tree beating recorded the highest ant’s numerical abundance (3670 workers), with 27 species, 12 genera and 3 subfamilies followed by the “funnel trap” that yielded 2800 ant workers, with 23 species belonging to 12 genera and 5 subfamilies. Finally, arboreal pitfall traps caught the lowest individual with 602 ant workers from 20 species belonging to 9 genera and 3 subfamilies. The composition of species which are caught by arboreal pitfall trap and “funnel trap” was similar at 53 percent. Tree beating showed a distinct species composition compared to arboreal pitfall trap and “funnel trap”. The “funnel trap” could be a fast and efficient way to quickly assess ant-biodiversity in forest canopies and agroecosystems as it looks like a nondestructive sampling method.
-
Reconstructing the execution and burial of 41 brigands in Mechelen during the Flemish Peasants’ War in 1798
-
Interpreting lime burials. A discussion in light of lime burials at St. Rombout’s cemetery in Mechelen, Belgium (10th- 18th centuries)
-
Comparing maternal genetic variation across two millennia reveals the demographic history of an ancient human population in southwest Turkey
-
St. Rombout’s cemetery in Mechelen, Belgium (10th–18th century AD): A typical urban churchyard?
