In deze bijdrage wordt Pycnomerus sulcicollis voor het eerst uit Nederland gemeld. Een enkel exemplaar van deze soort werd al enige tijd geleden aangetroffen in een bodemval tijdens een meerjarige ...loop- en snuitkeverinventarisatie van Zuid-Limburgse kalkgrashellingen. Het is een soort die in dood hout leeft en waarvan het hoofdverspreidingsgebied gelegen is in de Kaukasus en Zuidoost-Europa.
Here we present the first records of Cyanapion afer for the Netherlands. In the collection of Naturalis Biodiversity Center, we found two specimens that had been collected in 1907, near Wijlre in the ...province of Limburg. In 1999-2001 we collected specimens ourselves, also in Wijlre and additionaly on the Sint-Pietersberg near Maastricht (Limburg). The species occurs throughout Europa and her hostplant, Lathyrus praten$et is not rare at all We therefore suspect that she is being overlooked in the Netherlands.
Van het genus Ischnopterapion komen in Nederland drie soorten voor, waarvan er één pas recent gemeld is. In deze bijdrage wordt een overzicht gegeven van deze soorten. We laten zien hoe ze kunnen ...worden onderscheiden, hun ecologie wordt kort beschreven op basis van literatuurgegevens, en het voorkomen in Nederland wordt besproken en weergegeven in de vorm van verspreidingskaartjes.
Conservation management is expected to increase local biodiversity, but uniform management may lead to biotic homogenization and diversity losses at the regional scale. We evaluated the effects of ...renewed grazing and cutting management carried out across a whole region, on the diversity of plants and seven arthropod groups. Changes in occurrence over 17 years of intensive calcareous grassland management were analysed at the species level, which gave insight into the exact species contributing to regional homogenization or differentiation. Reponses were compared between species differing in habitat affinity, dispersal ability, food specialisation and trophic level. Local species richness increased over the sampling period for true bugs and millipedes, while carabid beetles and weevils declined in local species richness. Species richness remained unchanged for plants, woodlice, ants and spiders. Regional diversity and compositional variation generally followed local patterns. Diversity shifts were only to a limited extent explained by species’ habitat affinity, dispersal ability, trophic level and food specialisation. We conclude that implementation of relatively uniform conservation management across a region did not lead to uniform changes in local species composition. This is an encouraging result for conservation managers, as it shows that there is not necessarily a conflict of interest between local and regional conservation goals. Our study also demonstrates that shifts in diversity patterns differ markedly between taxonomic groups. Single traits provide only limited understanding of these differences. This highlights the need for a wide taxonomic scope when evaluating conservation management and demonstrates the need to understand the mechanisms underlying occurrence shifts.
In the face of ongoing habitat fragmentation, species-area relationships (SARs) have gained renewed interest and are increasingly used to set conservation priorities. An important question is how ...large habitat areas need to be to optimize biodiversity conservation. The relationship between area and species richness is explained by colonization-extinction dynamics, whereby smaller sites harbor smaller populations, which are more prone to extinction than the larger populations sustained by larger sites. These colonization-extinction dynamics are predicted to vary with trophic rank, habitat affinity, and dispersal ability of the species. However, empirical evidence for the effect of these species characteristics on SARs remains inconclusive.
In this study we used carabid beetle data from 58 calcareous grassland sites to investigate how calcareous grassland area affects species richness and activity density for species differing in trophic rank, habitat affinity, and dispersal ability. In addition, we investigated how SARs are affected by the availability of additional calcareous grassland in the surrounding landscape.
Beetle species richness and activity density increased with calcareous grassland area for zoophagous species that are specialists for dry grasslands and, to a lesser extent, for zoophagous habitat generalists. Phytophagous species and zoophagous forest and wet-grassland specialists were not affected by calcareous grassland area. The dependence of species on large single sites increased with decreasing dispersal ability for species already vulnerable to calcareous grassland area. Additional calcareous grassland in the landscape had a positive effect on local species richness of both dry-grassland specialists and generalists, but this effect was restricted to a few hundred meters.
Our results demonstrate that SARs are affected by trophic rank, habitat affinity, and dispersal ability. These species characteristics do not operate independently, but should be viewed in concert. In addition, species' responses depend on the landscape context. Our study suggests that the impact of habitat area on trophic interactions may be larger than previously anticipated. In small habitat fragments surrounded by a hostile matrix, food chains may be strongly disrupted. This highlights the need to conserve continuous calcareous grassland patches of at least several hectares in size.
Based on the assumption that the three functions of operations, improvement and innovation within companies need to be aligned to improve company performance, this article addresses two internal ...alignment mechanisms structural and social-dynamic alignment. A survey of 267 companies confirms that successful companies use non-functional organisational structures to align the three functions. Case studies of three firms suggest that alignment can be characterised as exchange relationships between people representing the three functions. They show in more detail how alignment can be achieved. It appears that both structural and social-dynamic aspects, such as power and trust, play a significant role.
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