322 research outputs found
Soil detritivore functioning in heterogeneously contaminated soils
Full text linkVerhoef, H.A. [Promotor]Berg, M.P. [Copromotor]Faber, J.H. [Copromotor
Economics of spatial coexistence of genetically modified and conventional crops: Oilseed rape in Central France
Full text linkEurope is currently struggling to implement coherent coexistence regulations on genetically modified (GM) and non-GM crops in all EU Member States. We conduct simulations with the software ArcView® on a GIS dataset of a hypothetical case of GM herbicide tolerant oilseed rape cultivation in Central France. Our findings show that rigid coexistence rules, such as large distance requirements, may impose a severe burden on GM crop production in Europe. These rules are not proportional to the farmers’ basic incentives for coexistence and hence not consistent with the objectives of the European Commission. More alarming, we show that in densely planted areas a domino-effect may occur. This effect raises coexistence costs and even adds to the non-proportionality of rigid coexistence regulations. Instead, we show that flexible measures would be preferable since they are proportional to the incentives for coexistence and, hence, less counterproductive for European agriculture.regulation, GIS modelling, domino-effect, Crop Production/Industries,
Biodiversity of collembola on green roofs:A case study of three cities in Belgium
Full text linkGreen roofs are often promoted as a mean to counter the negative environmental effects of urbanization on nature and to increase the amount of green space in cities. Green roofs often enhance aboveground biodiversity, especially herbivores and pollinators. However, if and in what way they support belowground biodiversity, and more specifically soil fauna, is rarely studied. Therefore, we evaluated the diversity of a dominant group of soil fauna, Collembola (springtails), on twelve extensive green roofs in three cities in Belgium (Antwerp, Ghent and Hasselt), over a one year period. The roofs differed in height above the ground, surface area, vegetation type, and age, i.e. time since construction. We analysed if these roof characteristics influenced species richness, abundance or diversity of Collembola. In total we found ten species of Collembola. Species richness was not higher on roofs that were larger (habitat area) or closer to the ground (isolation to surrounding soil), indicating that island-biogeographic theory is not applicable to species richness in our study system. However, significant differences in the mean number of individuals (abundance) were found between different months. Collembola taxonomical composition also varied between the roofs, but this variation could not be related to any of the measured roof variables. Roof communities were characterised by hemiedaphic life forms, preferring neutral to semi-moist conditions. Apart from the age of the roof that showed a positive significant impact on the abundance of Collembola present, our results suggested that the collembolan fauna showed no significant differences in abundance, species richness or diversity between roofs with different characteristics. However, we suggest that future studies are needed to investigate whether our findings are applicable to other groups of soil-living arthropods.</p
What's up down there?: Climate change effects on subarctic springtail communities and their role in carbon turnover
Full text linkCornelissen, J.H.C. [Promotor]Berg, M.P. [Copromotor
The use of plant litter and soil fauna traits in a mechanistic assessment of litter decomposition under global change
Full text linkAerts, M.A.P.A. [Promotor]Berg, M.P. [Copromotor
Living on the edge: Resource availablity and macroinvertebrate community dynamics in relation to sand nourishment
Full text linkAerts, M.A.P.A. [Promotor]Berg, M.P. [Copromotor]Bodegom, P.M. van [Copromotor
Self as CYC Educator: An Arts-Based Reflection from Matty Hillman
No full textThis week is the fifth in our uploads from the 20th Canadian National Child and Youth Care conference held in Vancouver, British Columbia this past May. In this episode, Matty Hillman talks about transitions he has gone through as a CYC student, a muralist, community citizen, CYC practitioner, and now as an educator. Matty Hillman is a Child and Youth Care instructor in the Human Services program at Selkirk College in British Columbia (the traditional territory of the Sinixt people). He has a Bachelor’s and Master’s degree in Child and Youth Care from the University of Victoria. His research interests include, sexual violence prevention and response on post-secondary campuses, healthy masculinities and critical youth mentorship. As a muralist, he is especially interested in the intersection of youth work and public art - exploring the opportunity these complimentary practices create for empowerment, community building and social justice advancements.Not peer reviewe
Importance of environmental and spatial components for species and trait composition in terrestrial snail communities
Full text linkAim: Despite the huge diversity of soil animals and their recognized contribution to many ecosystem functions, little is known about the relative importance of factors controlling their abundance and distribution. We examined the relative importance of environmental and spatial factors in explaining the species and functional trait composition of terrestrial snail communities at the level of meta-communities (spatial extent c. 100 × 100 km) in a heterogeneous, intensively used landscape. We hypothesized that both spatial and environmental factors contribute to the variation in community structure across the landscape, but expected environmental variables describing local habitat conditions to be most important. Location: County of Skåne, south Sweden. Methods: We quantified community structure in terms of species composition and as functional trait composition, because functional traits directly link species performance to environmental conditions. To disentangle the unique and shared contribution of environmental and spatial factors to the variation in snail community structure (in terms of species and trait composition) we applied a partial redundancy analysis. Results: Species traits explained more of the variance in community composition than species identity. Snail traits such as tolerance to environmental stress (related to soil moisture content) and niche width were correlated with the main environmental gradient. Environmental variables (i.e. soil moisture content, vegetation characteristics and soil pH) contributed considerably more to variation in community composition (species: 11.4%; traits: 24.9%) than the spatial variables (species: 6.5%; traits: 4.2%). Main conclusions: The results highlight that both environmental and spatial variables are required to understand the relative importance of niche-based and intrinsic population processes as drivers of terrestrial snail community structure. However, at the scale of our study niche-based community structuring explained by the trait–environment relationship is considerably more important than spatial patterning independent of the environment
Living logs: Tree trait effects on decomposition and associated invertebrate diversity
Full text linkCornelissen, J.H.C. [Promotor]Berg, M.P. [Promotor]Hefting, M.M. [Copromotor
The unique epicuticular chemistry of Collembola – A cross-species analysis
Full text linkSpringtails (Collembola), tiny hexapod arthropods, are abundant in the soil of most ecosystems, but our knowledge of their secondary metabolites is limited, in contrast to that of insects. In insects, the outer cuticle is usually covered by mixtures of long-chain hydrocarbons serving different functions, such as water regulation or chemical communication. In contrast, the knowledge of the epicuticular chemistry of springtails is scarce. We analyzed the cuticular lipids of 23 species covering different lineages. The often complicated structures were elucidated using gas chromatography/mass spectrometry, microderivatization, and synthesis. In contrast to insects, the terpene biosynthetic pathway is used for many of these lipids, producing unprecedented higher terpenes. In addition, evidence for de novo cholesterol biosynthesis in springtails was found, which is absent in insects. Finally, diverse non-insect linear compounds originating from the fatty acid biosynthetic pathway were identified. Our comparative analysis showed clear differences compared to insects and shed light on phylogenetic relationships.</p
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