W. Dekoninck - Academia.edu (original) (raw)

Papers by W. Dekoninck

Journal of Tropical Ecology, 2018

To maintain savanna vegetation, mid-seasonal fire has been applied since 1961 in the Lamto Savann... more To maintain savanna vegetation, mid-seasonal fire has been applied since 1961 in the Lamto Savanna (Côte d'Ivoire). However, this prescribed fire has not impeded tree encroachment during recent years, nor have its effects on insect assemblages been documented. Also the impact of tree intrusion on insect assemblages is poorly studied in savanna. To prevent tree density increasing, a change in fire regime might be a solution. In this study, we examined the effect of different fire regimes (early, mid-seasonal and late fires) on leaf-litter ant assemblages in order to suggest appropriate measures for preventing tree invasion without having an effect on insect communities. Sampling was implemented by combining pitfall trapping and leaf-litter sampling before and after three different fire regimes, early, mid-seasonal and late fires. While the ant species richness declined after the passage of early and mid-seasonal fires, significantly more species were found in the burnt savanna after the late fire. However, the losses or gains of species due to different fire regimes did not cause severe changes in the ant species composition. Of the functional groups identified, only the generalists and specialist predators were respectively strongly affected by the early and mid-seasonal fires, certainly due to micro-habitat modification. Based on the trends observed in the present study, we suggest sampling other invertebrate fauna in similar savanna plots to find out if other insect groups have similar reactions to the applied fire regimes.

By means of window-trapping Muscidae and Syrphidae (Diptera) were collected in the fore-dunes, gr... more By means of window-trapping Muscidae and Syrphidae (Diptera) were collected in the fore-dunes, grey dunes and in the old and new salt marshes of the IJzer estuary (Belgian coast). The Syrphidae are mainly represented by migratory species. The Muscidae are ubiquists, except for Helina protuberans, which is a typical species for sand dunes. We discuss the absence of other habitat specialists. Also some notes are included on Hydrotaea aenescens (Muscidae), which is reported for the first time from Belgium.

During the summer of 2001, we conducted a study on the spatial distribution of ants in coastal gr... more During the summer of 2001, we conducted a study on the spatial distribution of ants in coastal grey dunes (Oostduinkerke, Western Flanders, Belgium). Nest locations of the most abundant ant species were analysed with multivariate techniques. Tetramorium caespitum frequented moss-dominated vegetation, whereas Myrmica sabuleti, M. scabrinodis, Lasius flavus and L. meridionalis preferred grassy vegetations. Formica cunicularia and L. psammophilus occurred in all types of grey dune vegetation. According to recent literature, a positive spatial relationship can exist between the positioning of ant nests and the location of the myrmecochorous plants Viola curtisii, Luzula campestris and Polygala vulgaris in coastal dunes. Neither preliminary investigations, nor our study could confirm this significant positive relationship : the occurrence of myrmecochorous plants seems to be independent of the proximity of nests. It is possible that relationships are masked by a high turnover rate of the nest sites or by a restricted seedling establishment. We did not, however, observe ants transporting seeds of Viola, Luzula or Polygala in the field, possibly indicating the inefficiency of searching for those seeds in areas where population densities of these plants are rather low and other food sources are abundantly available.

Nature ecology & evolution, Jan 17, 2017

Climate change, land-use change, pollution and exploitation are among the main drivers of species... more Climate change, land-use change, pollution and exploitation are among the main drivers of species' population trends; however, their relative importance is much debated. We used a unique collection of over 1,000 local population time series in 22 communities across terrestrial, freshwater and marine realms within central Europe to compare the impacts of long-term temperature change and other environmental drivers from 1980 onwards. To disentangle different drivers, we related species' population trends to species- and driver-specific attributes, such as temperature and habitat preference or pollution tolerance. We found a consistent impact of temperature change on the local abundances of terrestrial species. Populations of warm-dwelling species increased more than those of cold-dwelling species. In contrast, impacts of temperature change on aquatic species' abundances were variable. Effects of temperature preference were more consistent in terrestrial communities than ef...

Insectes Sociaux, 2007

We studied the spatio-temporal patterns of ground-dwelling and-foraging ant assemblages in a cont... more We studied the spatio-temporal patterns of ground-dwelling and-foraging ant assemblages in a continuous mixed secondary lowland rainforest on the northern periphery of the Dja Biosphere Reserve in southeast Cameroon. The effect of season and of the interaction of season with vegetation type on ant species density, activity and composition were investigated. We also checked for a possible impact of army ant activity on the ant assemblage. Ants were collected by pitfall trapping in seven vegetation types in each of three seasons during 12 months in 2003 and 2004-2005. Season significantly influenced the ground-dwelling ant assemblage. The late wet season had the lowest ant species density and a different species composition than the early wet and the dry season. Also inter-annual variation in ant species density and composition was detected and could partly be explained by an influence of Dorylus activity. In general, vegetation type and inter-annual variation had a larger influence on the ground-ant assemblage than season. Significant effects of interactions between season, year, vegetation type and army ants on the ant assemblage confirm that also in African rainforests ant assemblages are extremely dynamic and depend on a complex combination of availability of food resources, nest sites and predators.

Belgium Journal of …, 2006

An update of the checklist of the Belgian ant fauna is presented. Until June 2001 (date of the pr... more An update of the checklist of the Belgian ant fauna is presented. Until June 2001 (date of the previous checklist) 73 species were reported for Belgium of which some species were found only once and their persistent occurrence in Belgium was therefore ...

Annales de Limnologie - International Journal of Limnology, 2011

A literature survey and the identification of all available collection material resulted in a che... more A literature survey and the identification of all available collection material resulted in a checklist and distribution maps for the mayflies occurring in Flanders. In addition, the relationship between the occurrence of mayflies and water characteristics was analysed. Of the 32 species that have been recorded, six are now extinct in Flanders (three of which are potamal species), while the majority of the remaining species are rare and their populations are often strongly isolated and therefore extremely vulnerable. Waters with relatively low oxygen levels and high conductivities were characterized by the most tolerant mayfly species Cloeon dipterum and Caenis robusta. However, most other species only occurred at higher oxygen concentrations and lower conductivities and could be separated into two groups. The first group mainly occurred in waters with a high pH and were often restricted to the loamy region or to stagnant waters, while the second group occurred in waters with a lower pH and mainly occurred in the Campine region. For most mayfly species, sustainable populations can only be achieved when their current habitats are adequately protected and, in addition, measures should be taken to connect and enlarge the remaining populations.

VLIZ Home, VLAAMS INSTITUUT VOOR DE ZEE. MARIEN EN KUSTGEBONDEN ONDERZOEK & BELEID IN VLAANDE... more VLIZ Home, VLAAMS INSTITUUT VOOR DE ZEE. MARIEN EN KUSTGEBONDEN ONDERZOEK & BELEID IN VLAANDEREN. ... IMIS: Integrated Marine Information System -, log in. ...

To advance our restricted knowledge on mosquito biodiversity and distribution in Belgium, a natio... more To advance our restricted knowledge on mosquito biodiversity and distribution in Belgium, a national inventory started in 2007 (MODIRISK) based on a random selection of 936 collection points in three main environmental types: urban, rural and natural areas. Additionally, 64 sites were selected because of the risk of importing a vector or pathogen in these sites. Each site was sampled once between May and October 2007 and once in 2008 using Mosquito Magnet Liberty Plus traps. Diversity in pre-defined habitat types was calculated using three indices. The association between species and environmental types was assessed using a correspondence analysis. Twenty-three mosquito species belonging to traditionally recognized genera were found, including 21 indigenous and two exotic species. Highest species diversity (Simpson 0.765) and species richness (20 species) was observed in natural areas, although urban sites scored also well (Simpson 0.476, 16 species). Four clusters could be distingu...

Entomologische Berichten, 2010

Lasius neglectus Van Loon, Boomsma & Andrasfalvy 1990, a new ant species for Belgium was discover... more Lasius neglectus Van Loon, Boomsma & Andrasfalvy 1990, a new ant species for Belgium was discovered in the city of Ghent. Grass lawn edges, stones, footpaths, gravel roads, bare sand and even concrete floors were used as nest places. This most recently known site (Citadelpark in Ghent) of occurrence in Europe (51,02° N; 03,44° E) shows that the species went up north-westwards and may perhaps be found more northwards in the near future. Assumptions on the arrival and expasion-history of the species in Ghent and Europe are made. In the microhabitats where this pest species can settle, L. neglectus impoverished the fauna to an almost single species ant fauna where only huge nests of this species are found. As L. neglectus can assume to be a potential threat for the native ant fauna, its expansion and the environmental factors determining this process should be investigated in Belgium.

The phenology of mosquito communities is important in the assessment of risks of transmission and... more The phenology of mosquito communities is important in the assessment of risks of transmission and control of several arboviruses, especially in situations where migratory and non-migrating bird species congregate, The Etang de Virelles Nature Reserve (Belgium) and its associated wetlands is a prime example of an area attracting large numbers of both resident and migratory birds. Malaise Traps set in four different marshland habitats in this nature reserve, collected nine species of mosquito during the spring and summer of 2006 and proved, both from the operational viewpoint and in the results obtained, to be a good adult Culicidae sampling technique, . When emptied each week they also enable us to construct seasonal activity patterns of the resident mosquitoes. The most abundant species, Ochlerotatus cantans, a potential vector of West Nile virus, and Aedes cinereus/geminus exhibited different seasonal activity patterns, even in adjacent habitats. Densities of the floodwater species...

Medical and Veterinary Entomology