62 research outputs found
Ecologische netwerkanalyse : een verkenning gericht op toepassingen voor het Natuurplanbureau
User manual for SAFE (Select Application date For Evaluation) to support the use of the GEM scenarios for cultivations in glasshouses
For the assessment of the environmental risks of the use of plant protection products in glasshouse cultivations, exposure scenarios have been developed. These scenarios have been implemented in the Glasshouse Emission Model (GEM). Because the application can cover the entire plant growth cycle, additional guidance was needed to select the application date with the highest Predicted Environmental Concentration for the assessment of leaching to ground water in soil-bound cultivations and that of exposure of aquatic organisms in soilless cultivations. The software tool SAFE (Select Application date For Evaluation) has been developed to assist the user with the selection of the application date. Two variants of this tool have been developed: one for soil-bound cultivations and one for soilless cultivations. The use of both variants is described in this user manual
Ruimtelijke samenhang en genetische variatie van boomkikkerpopulaties in Nederland
Een modelanalyse van de ruimtelijke samenhang heeft plaatsgevonden van een netwerkpopulatie van de boomkikker (Hyla arborea) in Midden-Limburg. De bezettingskans van poelen is bepaald met een regressiemodel en de ruimtelijke samenhang van de leefgebieden is geanalyseerd met het dispersiemodel Smallsteps. Het herstel-scenario 2010 biedt goede potenties voor de uitbreiding van de netwerkpopulatie. Er zijn echter nog enkele zwakke schakels in de ruimtelijke samenhang geconstateerd. Bovendien dient door het nemen van maatregelen nog meer in het huidige verspreidingsgebied van de boomkikker geinvesteerd te worden. Een genetische analyse in de Achterhoek maakt aannemelijk dat herkolonisatie heeft plaatsgevonden vanuit vier bronpopulaties. Hierbij zijn vier populatieclusters ontstaan die genetisch sterk verschillend zijn. De genetische diversiteit in de Doort (Midden-Limburg) is vergelijkbaar met populaties in de Achterhoek maar kleiner dan in twee Zwitserse populatie
Limiting scaring activities reduces economic costs associated with foraging barnacle geese: Results from an individual-based model
With increasing numbers of large grazing birds on agricultural grassland, conflict with farmers is rising. One management approach to alleviate conflict allows foraging on dedicated agricultural land (accommodation areas) and nature reserves, combined with scaring on remaining agricultural land. Here, we examine the cost-effectiveness of these measures by studying the influence on barnacle goose distribution and associated economic damage. We present an individual/agent-based model of barnacle geese (Branta leucopsis) foraging on grasslands in Friesland, the Netherlands. The model is parameterized using field observations and GPS-tracks and allows simulation of management scenarios, differing in scaring probability and accommodation area size, with different potential management costs. Our model shows that, while yield loss decreases with higher scaring probabilities, costs of damage appraisal increase because geese graze on more fields. With small accommodation areas, achieving high scaring probabilities takes more effort and could result in goose population decline. Total management costs are lowest without scaring activity. Synthesis and applications. Considering costs of active scaring and the need to maintain the barnacle goose population in a favourable conservation status, our model suggests that the most cost-effective scenario is to prevent disturbance of geese. A high scaring probability could be beneficial if applied in small areas, for example around sensitive crops or airfields. Scaring in large areas could result in costs outweighing benefits and a declining barnacle goose population
More management, less damage? With increasing population size, economic costs of managing geese to minimize yield losses may outweigh benefits
Conflicts between farmers and geese are intensifying; yet, it remains unclear how interactions between goose population size and management regimes affect yield loss and economic costs. We investigate the cost-effectiveness of accommodation and scaring areas in relation to barnacle goose (Branta leucopsis) population size. We use an existing individual-based model of barnacle geese foraging in nature, accommodation, and scaring areas in Friesland, the Netherlands, to study the most cost-effective management under varying population sizes (i.e., between 20 and 200% of the current size). Our study shows that population size non-linearly affects yield loss costs and total costs per goose. The most cost-effective management scenario for intermediate to large populations is to avoid scaring of geese. For small populations, intensive scaring resulted in minimized yield loss costs and total costs, but also substantially lower goose body mass. Our results strongly suggest that scaring becomes a less effective management measure as goose populations increase
The use of ecological models to assess the effects of a plant protection product on ecosystem services provided by an orchard
This is the final version. Available on open access from Elsevier via the DOI in this record The objective of this case study was to explore the feasibility of using ecological models for applying an ecosystem services-based approach to environmental risk assessment using currently available data and methodologies. For this we used a 5 step approach: 1) selection of environmental scenario, 2) ecosystem service selection, 3) development of logic chains, 4) selection and application of ecological models and 5) detailed ecosystem service assessment. The study system is a European apple orchard managed according to integrated pest management principles. An organophosphate insecticide was used as the case study chemical. Four ecosystem services are included in this case study: soil quality regulation, pest control, pollination and recreation. Logic chains were developed for each ecosystem service and describe the link between toxicant effects on service providing units and ecosystem services delivery. For the soil quality regulation ecosystem service, springtails and earthworms were the service providing units, for the pest control ecosystem service it was ladybirds, for the pollination ecosystem service it was honeybees and for the recreation ecosystem service it was the meadow brown butterfly. All the ecological models addressed the spatio-temporal magnitude of the direct effects of the insecticide on the service providing units and ecological production functions were used to extrapolate these outcomes to the delivery of ecosystem services. For all ecosystem services a decision on the acceptability of the modelled and extrapolated effects on the service providing units could be made using the protection goals as set by the European Food Safety Authority (EFSA). Developing quantitative ecological production functions for extrapolation of ecosystem services delivery from population endpoints remains one of the major challenges. We feel that the use of ecological models can greatly add to this development, although the further development of existing ecological models, and of new models, is needed for this.European Chemical Industry Counci
Computational material flow analysis for thousands of chemicals of emerging concern in European waters
Keeping modelling notebooks with TRACE:Good for you and good for environmental research and management support
Exploring causes, risks, and consequences for ecosystem services of tipping points in Latin American forests - the role of biodiversity.
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