Harmonizing outdoor recreation and bird conservation targets in protected areas: Applying available monitoring data to facilitate collaborative management at the regional scale.

In protected areas managers have to achieve conservation targets while providing opportunities for outdoor recreation. This dual mandate causes conflicts in choosing between management options. Furthermore, the persistence of a protected species within the management unit often depends on how conservation areas elsewhere in the region are managed. We present an assessment procedure to guide groups of managers in aligning outdoor recreation and bird conservation targets for a regional scale protected area in the Netherlands. We used existing bird monitoring data and simulated visitor densities to statistically model the impact of outdoor recreation on bird densities. The models were used to extrapolate the local impacts for other parts of the area, but also to assess the impact on conservation targets at the regional level that were determined by the national government. The assessment shows impacts of outdoor recreation on Nightjar (Caprimulgus europaeus), Stonechat (Saxicola torquata) and Woodlark (Lullula arborea), reducing the regional population by up to 28 percent. The Woodlark population size was reduced below the level of the politically determined conservation target. The output of the regression models provides information that connects implications of local management to regional scale conservation targets. The spatial maps of bird densities can help in deciding where reducing visitor disturbance is expected to result in increasing bird populations, or where alternative measures, such as improving the habitat conditions, could be effective. We suggest that by using our assessment procedure collaborative decision making is facilitated.

No evidence of the effect of extreme weather events on annual occurrence of four groups of ectothermic species.

Weather extremes may have strong effects on biodiversity, as known from theoretical and modelling studies. Predicted negative effects of increased weather variation are found only for a few species, mostly plants and birds in empirical studies. Therefore, we investigated correlations between weather variability and patterns in occupancy, local colonisations and local extinctions (metapopulation metrics) across four groups of ectotherms: Odonata, Orthoptera, Lepidoptera, and Reptilia. We analysed data of 134 species on a 1×1 km-grid base, collected in the last 20 years from the Netherlands, combining standardised data and opportunistic data. We applied dynamic site-occupancy models and used the results as input for analyses of (i) trends in distribution patterns, (ii) the effect of temperature on colonisation and persistence probability, and (iii) the effect of years with extreme weather on all the three metapopulation metrics. All groups, except butterflies, showed more positive than negative trends in metapopulation metrics. We did not find evidence that the probability of colonisation or persistence increases with temperature nor that extreme weather events are reflected in higher extinction risks. We could not prove that weather extremes have visible and consistent negative effects on ectothermic species in temperate northern hemisphere. These findings do not confirm the general prediction that increased weather variability imperils biodiversity. We conclude that weather extremes might not be ecologically relevant for the majority of species. Populations might be buffered against weather variation (e.g. by habitat heterogeneity), or other factors might be masking the effects (e.g. availability and quality of habitat). Consequently, we postulate that weather extremes have less, or different, impact in real world metapopulations than theory and models suggest.