A resampling of 38 small farmland ponds in Belgium after 10 years revealed a high temporal species turnover for both phytoplankton and zooplankton communities, associated with substantial changes in abiotic factors, especially a reduction in total phosphorus concentration.
Across ponds, phytoplankton biomass decreased while evenness and richness increased between the samplings in 2003 and 2013. By contrast, the zooplankton assemblage was characterised by lower biomass, richness and evenness in 2013. Ponds experiencing larger environmental change showed stronger changes in phytoplankton richness and evenness.
Resource use efficiency (RUE) of zooplankton increased with greater environmental change and zooplankton evenness, which points to a switch towards species with higher RUE or greater variety in food sources in higher trophic levels.
As ponds are important habitats for freshwater biodiversity and ecosystems services, the strong but predictable species turnover and the opposing effects of environmental change on different trophic levels need to be embedded in conservation and management plans.
Allocating the operations of multinational enterprises to geographic locations where performance can be optimized has become an important strategic issue. In view of the continuing growth of international trade and foreign direct investment, managers need systematic procedures to determine global allocation strategies. Available frameworks on global business strategy are typically abstract and generalized, making them less suited for the development of tailor‐made allocation strategies. Quantitative allocation models in operations research tend to be biased towards optimizing mathematical algorithms, making them less suited to support managerial decision making. This paper bridges the gap between generic strategy frameworks and highly quantitative operations research models by presenting a scanning tool to support decision making on strategic allocation issues. An important feature of this tool is to systematically filter available data, intended to quality and quantify critical product, process and market characteristics for specific product classes. The scanning tool has been applied in two cases, involving allocation decisions of a European multinational in the fast moving consumer goods industry.
Diapause is a feature of the life cycle of many invertebrates by which unfavourable environmental conditions can be outlived. The seasonal timing of diapause allows organisms to adapt to seasonal changes in habitat suitability and thus is key to their fitness. In the planktonic crustacean Daphnia, various cues can induce the production of diapause stages that are resistant to heat, drought or freezing and contain one to two embryos in developmental arrest. Daphnia is a keystone species of many freshwater ecosystems, where it acts as the main link between phytoplankton and higher trophic levels. The correct seasonal timing of diapause termination is essential to maintain trophic interactions and is achieved via a genetically based interpretation of environmental cues like photoperiod and temperature. Field monitoring and modelling studies raised concerns on whether populations can advance their seasonal release from diapause to advances in spring phenology under global change, or if a failure to adapt will cause trophic mismatches negatively affecting ecosystem functioning. Our capacity to understand and predict the evolution of diapause timing requires information about the genetic architecture underlying this trait. In this study, we identified eight quantitative trait loci (QTLs) and four epistatic interactions that together explained 66.5% of the variation in diapause termination in Daphnia magna using QTL mapping. Our results suggest that the most significant QTL is modulating diapause termination dependent on photoperiod and is involved in three of the four detected epistatic interactions. Candidate genes at this QTL could be identified through the integration with genome data and included the presynaptic active zone protein bruchpilot. Our findings contribute to understanding the genomic control of seasonal diapause timing in an ecological relevant species.
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