Improving the contribution of citizen-science to monitoring programs requires integrated planning

Abstract

Monitoring biodiversity is a fundamental tool for its conservation, as it provides information that can guide and eventually improve the effectiveness of management outcomes. Citizen-science is increasingly advocated as a complement to governmental monitoring programs to overcome scarcity of resources and deliver important information for policy-making. In this study, we used the spatial optimization tool Marxan to explore the advantages and limitations of combining government and citizen-science monitoring networks to achieve monitoring targets for bird species of conservation concern for the EU in Catalonia (NE Spain), a region where both schemes are well established. We designed and compared optimal monitoring networks under four different scenarios: (1) the No-constraints scenario simulates a monitoring network built ex novo, assuming no prior monitoring efforts and no spatial constraints to the selection of monitoring sites; (2) the Protected Areas–only, in which the monitoring would occur exclusively within protected areas where resources from the Regional Administration exist – e.g. personnel - that could be mobilized for monitoring surveys; (3) the Protected Areas–Extended recognizes existing monitoring efforts within the network of protected areas, and allows also monitoring efforts outside protected areas to achieve the monitoring targets for the bird species; (4) Protected Areas-Citizen Science recognizes both the existing resources within protected areas as well as the existing citizen-science bird monitoring programs. The four monitoring network schemes sought to cover the distribution of bird species of conservation concern for the EU in Catalonia under different pressure levels (low, medium and high) of the main threats to each species (agricultural intensification, closure of open spaces, forest immaturity, freshwater pollution and urban development) . In our case study, current government efforts, limited to public land and protected areas, were insufficient to cover the whole spectrum of target species and threat levels, reinforcing the assumption that citizen-science data can greatly assist in achieving monitoring targets. However, simply carrying out both government and citizen-science monitoring ad hoc led to inefficiency and duplication of efforts: some species were represented in excess of monitoring targets while several combinations of species-threat levels were under-sampled. Our study highlights the importance of accounting for species threats when designing monitoring networks, since the ability to link detected negative species trends to potential drivers would make the monitoring data more directly useful for policy decisions. Our results also suggest policy-making should concentrate on providing an adequate platform for coordination of government and citizen-science monitoring to minimize duplicated efforts, overcome the biases of each monitoring scheme and obtain the best from both.