Ecological impact and cost-effectiveness of wildlife crossings in a highly fragmented landscape:A multi-method approach

Context: Road infrastructure construction is integral to economic development, but negatively affects biodiversity. To mitigate the negative impacts of infrastructure, various types of wildlife crossings are realized worldwide, but little is known about their effectiveness, and cost-effectiveness. Objective: The paper contributes to the methodological and empirical discussion on the effectiveness of wildlife crossings for enhancing the quality of surrounding nature and its cost-effectiveness by analyzing a large-scale wildlife-crossings program in the Netherlands. Method: A multi-criteria cost–benefit analysis is applied, comprised of monetary and non-monetary measures, and a mixed-method approach is used to determine ecological effects. Ecological effects are expressed in the standardized weighted hectare measurement of threat-weighted ecological quality area (1 T-EQA = 1 ha of 100% ecological quality, averagely threatened). Cost-effectiveness is calculated comparing the monetary costs of intervention with ecological benefits (Euro costs/T-EQA), for different types of wildlife crossings and for two other nature policies. Results: The Dutch habitat defragmentation program has induced an increase in nature value of 1734 T-EQA at a cost of Euro 283 million. Ecological gains per hierarchically ordered groups of measures differ strongly: The most effective are ecoducts (wildlife crossing bridges) followed by shared-use viaducts and large fauna tunnels. Ecoducts generated the largest gain in nature value, but were also the most costly measures. In terms of cost-effectiveness, both large fauna tunnels and shared-use viaducts for traffic and animals outperformed ecoducts. Conclusions: Ecoducts deliver ecologically, but their cost-effectiveness appears modest. Purchasing agricultural land for restoration of nature appears more cost-effective than building wildlife crossings. Yet, reducing environmental pressures or their effects on existing nature areas is likely to be most cost-effective.</p

Reconsidering the Effectiveness of Scientific Tools for Negotiating Local Solutions to Conflicts between Recreation and Conservation with Stakeholders

The conflict between the conservation of biodiversity and recreation activities in the European landscape is intensifying. Managers of large nature areas are confronted with increasing numbers of visitors and decreasing biodiversity values. To accommodate the visitors while simultaneously protecting the biodiversity values they need to make changes in the landscape. Current legislation, a lack of knowledge on the recreation-biodiversity relationship, and the diverging point of view of stakeholders make it difficult to find consensual solutions. New approaches such as adaptive management and boundary management can help managers and stakeholders in the process of decision making. In these approaches the role of scientists has changed, as has the use of their tools. Using two research projects in Europe we explore how scientific tools are used in this new context. We argue that such tools (1) should be built on the interactions between recreation and biodiversity functions, (2) can be used interactively to encourage stakeholders to engage in a learning process, (3) allow local knowledge and data to be incorporated into them, and (4) generate output in the form of a map showing where the conflict areas and opportunities are located. These four key features will help managers to improve communication between themselves, stakeholders, and scientists, increase consensus between stakeholders on how the conflict should be perceived, explore solutions, and generate new knowledge. For future research we suggest investigating how adaptive management and boundary management can be used in a stepwise learning strategy and how uncertainties in the tools affect the learning process

Assessing the impact of roads on animal population viability

Different tools have been developed to study the potential effects of spatial developments, such as the construction of roads, on the viability of animal populations. For instance, with dynamic (meta)population models the impacts of spatial developments can be accurately quantified. However, these models are often species specific and require detailed field research to validate the parameters used. If a multi-species analyses is needed, the use of such models is often impractical and expensive. In that case, an expert system, in which analyses of different species can be aggregated, may be a better tool to assess these kinds of impacts. Pros and cons of both types of tools are illustrated with (1) the ex-ante analyses of badger (Meles meles) population viability in central Limburg (The Netherlands) after the (proposed) construction of highway A73, and (2) the multi-species analyses of high priority locations to restore habitat connectivity across main roads in The Netherlands

Using GPS tracking to understand the impact of management interventions on visitor densities and bird populations

To manage the potential conflict between outdoor recreation and nature conservation, managers of nature areas need information to select effective interventions. For large nature areas information on visitor use is often lacking and managers often make decisions based on expert judgement. In this paper we use monitoring data gathered with GPS devices to develop a tool and derive rules of thumb managers can use to estimate the impact of management actions on visitor densities. Using a dataset of 1563 tracks from the New Forest, UK, we developed a random forest model and identified which landscape and environmental features account for the spatial variation in visitor densities. The random forest model shows that distance to car park, distance to roads and openness are the most important factors for predicting visitor densities. The model was used as a tool to assess the impact of potential management interventions on the population of Nightjar. As developing this type of tool requires a lot of data we also derived rules of thumb and a simple algorithm that managers of other nature areas can use to estimate the impact of their interventions on visitor densities. The derived rules of thumb show that changing the location of car parks in relation to tarmac roads can help managers to reduce local visitor densities by 80%. Further research in other nature areas should verify the feasibility of these rules of thumb and the simple algorithm.</p

Data for: Using GPS tracking to understand the impact of management interventions on visitor densities and bird populations

Monitoring data of visitors of the New Forest, UK. Each track has been collected with an eTrex or eTrex Venture GPS device. Explanation of the headers can be found in Table A.3. The dataset contains 1563 tracks of which 1553 could be used for further analyses in our research

Verkenning naar de samenhang van de Vogel- en Habitatrichtlijn en de Kaderrichtlijn Water : een analyse voor het vergroten van de synergie tussen de richtlijnen

This report explores the degree of coherence between the Birds and Habitats Directives and the Water Framework Directive. Based on the objectives, instruments, measures and evaluation methodologies of the European directives, this report describes where there is synergy, complementarity or incompatibility between the directives in Dutch policy practice. This analysis is based on a literature review, interviews and a workshop with stakeholders. Based on the results, the report identifies research questions relevant to the Netherlands Environmental Assessment Agency for further research to support their policy evaluations