Connectivity in a real fragmented landscape: distance vs movement model based approaches.

Graph theory derived models and measures are increasingly being used to quantify landscape connectivity in order to contribute to conservation biology and management. This is particularly relevant in the case of real landscapes in which local actions may have crucial consequences for maintaining biodiversity on large scale. A number of graphs were compared sharing an identical node weight definition and whose link weights representing functional patch-connectivity, were derived from conceptually different approaches. Habitat suitability was taken into account. Calculated patch-connectivity was compared between all the graphs and these differences, evaluated by a set of indices describing network properties at the element structure level, were investigated

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

Spatially explicit risk analysis: a new solution to contamination problems in the Metropolitan Delta

In the current paper a new conceptual outline for the ecological risk assessment of contamination will be adressed. In the first place risk assessment has to be spatially explicit, taking in account the spatial structure of the landscape (landscape ecotoxicology). Secondly the concept of SSRA (spatially structured risk assessment) being introduced: it is aimed at minimising the contact between organisms and contaninants by spatially structuring the landscape so that organisms will not forage at contaminated site