Manipulating hedgerow quality: Embankment size influences animal biodiversity in a peri-urban context

Hedgerows are important features within urban, peri-urban, and agricultural habitats because they shelter most of the biodiversity in a landscape dominated by infrastructures or a monoculture. Hedges are characterized by their vegetative cover but also by their base, notably the breadth of the embankment and the various microhabitats made by stones, coarse woody debris, and leaf litter. These features determine the availabilities of arboreal and ground refuges. Their respective roles on biodiversity remain poorly explored. We experimentally manipulated the size of the embankment in newly-constructed hedges in a peri-urban context. We used nonlethal rapid biodiversity assessments and functional indices (accounting for body mass, trophic level, and metabolic mode) to monitor the presence of a wide range of animal taxa. We observed a positive effect of embankment size on animal biodiversity. Various elements of the fauna (e.g. arthropods, reptiles) rapidly colonized newly-constructed hedges provided with an embankment. Guidelines to restore hedgerows should consider embankment size and quality. Both of these features can be improved by simply retaining the materials that are extracted when establishing agricultural plots such that a diversity of microhabitats and ground refuges become available

Importance of ground refuges for the biodiversity in agricultural hedgerows

tIn most agro-ecosystems, hedgerows provide important habitat for many species. Unfortunately, largescale destruction of hedges has stripped this structure from many landscapes. Replanting programs have attempted to restore hedgerow habitats, but the methods employed often fail to replace the unique micro-habitats (complex matrix of stones, logs and roots found along the base of the hedge) that provided key refuges to an array of animal species. We examined the influence of ground refuges on animal diversity in an agricultural landscape. We used non-lethal rapid biodiversity assessments to sample invertebrate and vertebrate taxa in 69 hedges having different levels of herbaceous cover, tree cover, and refuge availability. Co-inertia analyses compared hedge characteristics with the animal biodiversity sampled. We also used a functional index (accounting for body mass, trophic level, and metabolic mode of the species sampled) to compare hedges. In addition, large sedentary predators (e.g. snakes) were used as indicators of shelter presence/quality and as bio-indicators of food web structures. Finally we used unbiased Chao-estimates to evaluate species richness. All results were convergent and show that complexity of the base of the hedge (e.g., bank size and stone abundance) positively influenced biodiversity and predator abundance. Guidelines to restore hedgerows should integrate refuges that can be constructed by retaining the materials that are extracted during the planting of the hedges

Verplichtgestelde bedrijfstakpensioenregelingen en het algemeen pensioenfonds

Aanleiding voor het onderzoek is de wens van verplichtgestelde bedrijfstakpensioenfondsen om te komen tot schaalvergroting in een algemeen pensioenfonds. Een algemeen pensioenfonds mag meerdere pensioenregelingen uitvoeren en is dus niet gebonden aan een bepaalde sector. Het moet wel gescheiden vermogens aanhouden. Dit onderzoek richt zich op de mogelijke aanpassing van verplichte deelneming in een bedrijfstakpensioenfonds, waardoor ook een algemeen pensioenfonds een verplichtgestelde bedrijfstakpensioenregeling kan uitvoeren. De aanpassing houdt in dat de verplichtstelling alleen geldt voor de bedrijfstakpensioenregeling en niet ook voor het bedrijfstakpensioenfonds als de uitvoerder van de regeling. Uit het onderzoek blijkt dat het verplichtstellen van alleen de bedrijfstakpensioenregeling niet in strijd is met het mededingingsrecht. De trend naar consolidatie zal door aanpassing van de verplichtstelling worden versterkt. Er blijven naar verwachting voldoende spelers op de markt voor effectieve concurrentie