89 research outputs found
On the identity of broad-shelled mussels (Mollusca, Bivalvia, Mytilus) from the Dutch delta region
Late Quaternary (Eemian) deposits of the Netherlands contain
shells that resemble those of living Mytilus galloprovincialis.
Similar broad-shelled mytilids also occur in estuaries of the
southwestern Netherlands together with slender individuals
typical of M. edulis. We sampled living mussels along a depth
gradient in the Oosterschelde to a) investigate whether a relation
exists between shell shape and depth, b) test if the broadshelled
specimens might represent M. galloprovincialis (or a
hybrid with M. edulis) and c) assess by inference if the Quaternary
specimens might be attributed to M. galloprovincialis as
well. In order to do so, we compared genetic (length polymorphism
of Me 15/16, COIII sequences and AFLPs) and shellmorphological
characteristics (juvenile L/W ratios and socalled
Verduin parameters) of the same specimens. The obtained
dataset indicates that all studied mussels from the Oosterschelde
should be attributed to M. edulis, including those with
broad shell outlines. No correlation of shell-morphology and
depth-distribution was found. The worn and generally damaged
state of the Eemian specimens precluded measurement of the
Verduin parameters, while juvenile L/W ratios turned out not to
be diagnostic. Therefore the shell characters examined in this
study are insufficient to demonstrate the possible presence of
M. galloprovincialis shells in Quaternary deposits of the Netherlands.
Simulation of the long-term carbon and nitrogen dynamics in Dutch forest soils under Scots pine
International audienceDynamics of C and N in forest soils in the Nutrient Cycling and Soil Acidification Model (NUCSAM) are described by the transformation and decomposition of three organic matter compartments, litter, fermented material and humic material. These three compartments are allocated to the morphological distinguishable L, F and H horizons of the organic layer. Changes in the pools of these organic compartments are described with first order equations for decomposition and transformation. Rate constants for decomposition and transformation were derived by calibrating the model to measured organic matter pools in organic layers of a chrono-sequence of five first succession Scots pine stands between 15 and 120 years old. Simulated pools of organic matter in the organic layers were in agreement with measured pools in the five pine stands, except for the first thirty years of the H-horizon. During this period, an increase in organic matter in the H horizon was simulated while no H horizons were observed in the field. The simulated total pool of organic matter in the organic layer agreed well with values from a field inventory in 20 other Scots pine stands, but the simulated distribution over the three horizons differed from the field measurements which varied among sites. For the Scots pine stands the model was able to simulate the organic matter accumulation in the top 40-cm of the mineral soil; derived almost completely from fine root turnover. The accumulated pool of nitrogen in the organic layer was in agreement with measured pools for the oldest Scots pine stand but was too high for the younger stands. Especially, the accumulation of N in the F-horizon was too fast, presumably due to an overestimated retention of nitrogen
SMASS - a simulation model of physical and chemical processes in acid sulphate soils; Version 2.1
The Simulation Model for Acid Sulphate Soils (SMASS) has been developed to predict the effects of water management strategies on acidification and de-acidification in areas with acid sulphate soils. It has submodels for solute transport, chemistry, oxygen transport and pyrite oxidation. The model must be used together with the water transport model SWACROP. It combines physical and chemical processes. The output includes the acidity and chemical quality of soil and groundwater, and the occurrence of toxic compounds. This user's manual presents an outline of input and output files, guidelines for installation on a VAX-VMS computer, and the description of an application
Verspreiden van bagger op het land in klei- en veengebieden
De meeste baggerspecie, inclusief licht verontreinigde baggerspecie die vrijkomt bij onderhoud van watergangen, wordt verspreid op landbouwpercelen. Het in dit rapport beschreven onderzoek is opgezet om op praktijkschaal na te gaan of op dit moment de praktijk van het verspreiden van licht verontreinigde bagger meetbare effecten heeft veroorzaakt en aan te geven wat er in de toekomst kan worden verwacht bij voortzetting van de huidige praktijk. De belangrijkste conclusie van het onderzoek is dat in de onderzochte klei- en veengebieden de praktijk van verspreiden van baggerspecie niet heeft geleid tot een sterke achteruitgang van de bodem. Achteruitgang is echter wel mogelijk als de praktijk van verspreiden meer opschuift in de richting van de kwaliteit die maximaal is toegestaan. Op basis van het onderzoek worden diverse aanbevelingen voor het beleid gemaakt
Map maker’s guide: a decision support system for interpolation, aggregation, and disaggregation : technical documentation
This report documents a decision support system (DSS) that has been developed to assist environmental researchers in selecting interpolation, aggregation, and disaggregation methods. The DSS has been implemented as a web-application. This facilitates updating and makes the DSS generally accessible. The DSS asks the user several questions. The answers are compared with those given by experts. The degree of similarity between both sets of answers is used to assign suitability scores to a huge set of interpolation, aggregation, and disaggregation methods stored in a database. These methods are ranked from most to least suitable and presented to the user in a dynamic table. The user can compare recommended methods (backgrounds, available software, literature, performance) and evaluate dynamically which methods would have been recommended if deferent answers had been given (what-if analysis
Case report: Lumpy skin disease in an endangered wild banteng (Bos javanicus) and initiation of a vaccination campaign in domestic livestock in Cambodia
We describe a case of lumpy skin disease in an endangered banteng in Cambodia and the subsequent initiation of a vaccination campaign in domestic cattle to protect wild bovids from disease transmission at the wildlife-livestock interface. Lumpy skin disease virus (LSDV) was first detected in domestic cattle in Cambodia in June of 2021 and rapidly spread throughout the country. In September 2021, a banteng was seen in Phnom Tnout Phnom Pok wildlife sanctuary with signs of lumpy skin disease. Scab samples were collected and tested positive for LSDV. Monitoring using line transect surveys and camera traps in protected areas with critical banteng and gaur populations was initiated from December 2021-October 2022. A collaborative multisector vaccination campaign to vaccinate domestic livestock in and around priority protected areas with banteng and gaur was launched July 2022 and a total of 20,089 domestic cattle and water buffalo were vaccinated with LumpyvaxTM. No signs of LSDV in banteng or gaur in Cambodia have been observed since this initial case. This report documents the first case of lumpy skin disease in wildlife in Cambodia and proposes a potential intervention to mitigate the challenge of pathogen transmission at the domestic-wildlife interface. While vaccination can support local livestock-based economies and promote biodiversity conservation, it is only a component of an integrated solution and One Health approach to protect endangered species from threats at the wildlife-livestock interface
Response and participation of underserved populations after a three-step invitation strategy for a cardiometabolic health check
Validation of Transfer Functions Predicting Cd and Pb Free Metal Ion Activity in Soil Solution as a Function of Soil Characteristics and Reactive Metal Content
Reductions of greenhouse gas emissions in Annex I and non-Annex I countries for meeting concentration stabilisation targets
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