Simulation Modeling Unveils the Unalike Effects of Alternative Strategies for Waterbird Conservation in the Coastal Wetlands of Sardinia (Italy)

Simple Summary Natural wetlands supply food and shelter for many bird species and offer stopover sites that allow waterbirds to make long migratory journeys. Human impacts and ongoing climate change are however reducing the ability of wetlands to provide such essential services to avian diversity. Therefore, scientists are now forced to consider new approaches to the proactive management of remaining marginal wetlands so as to preserve the associated biodiversity as well. Because regional planning and wetland management are often debatable issues, we argue here that in silico simulation modeling, combined with field surveys and data collection, provides an appropriate methodology to address this matter effectively. Modeling and dynamically simulating the changes expected to the levels of avian diversity as a function of plausible counterfactual and management scenarios provides an informed and scientifically defensible basis for proactive conservation strategies. Such simulations present an opportunity to test numerous different scenarios, exploring their implications for the conservation of avian diversity, thus providing a well-grounded and realistic approach to dealing with inherent uncertainties in wetland management and waterbird conservation.Abstract The Sardinian wetlands (Italy) act as stopover sites for many migratory birds along the central eastern Mediterranean bird flyway. These wetlands are now severely threatened by human activities and climate change. Accordingly, we built a simulation framework to predict the effects of several counterfactual and management scenarios on the level of avian diversity in the coastal wetlands of Sardinia. We found that the alpha avian diversity (i.e., the mean number of avian species per wetland) is destined to (a) decrease due to the most likely increase in water salinity, water discharges, and tourism pressure; and (b) halve (from 14.9 to 7.4, with 9 wetlands out of 22 predicted to host only between two and five waterbird species) in the worst possible scenario. However, the results also showed that proper management strategies could prevent and reverse such outcomes. Restrictions on tourism activities, water desalination, prevention of future saltwater intrusions, and the prohibition of water discharges could markedly favor the avian diversity in these wetlands, with an expected increase in the alpha avian diversity from 14.9 to 24.8 (and 10 wetlands out of 22 predicted to host from 29 to 32 waterbird species) in the best possible scenario. The importance of our results could be emphasized in the management plans of these important wetlands, most of which belong to the Natura 2000 network.