Forest-bird relationships within two differently managed Natura 2000 alpine sites: an application of the bioacoustics approach at small scale

The Natura 2000 network was implemented more than 25 years ago, however, some gaps in knowledge about its overall implementation have been identified. Better understanding of forest biodiversity status changes over space and time within Natura 2000 protected areas needs to be achieved through effective monitoring programs, and by reframing current indicators, parameters and drivers. Birds have demonstrated to be reliable and robust indicators of biodiversity. Indeed, forest bird species’ composition and richness seem to be related mainly to forest structure – both vertical and horizontal – which is directly dependent on forest management. This paper describes a research project aimed at comparing the impact on biodiversity in two Natura 2000 sites, sharing similar ecological and structural characteristics, but differing in their recent management histories. The study areas correspond to the alpine watersheds of Val Tovanella (SCI IT3230031, 8.845 ha, and SPA IT3230089, 70,397 ha), and Cajada (SCI IT3230083, 31.383 ha). To evaluate the bird-forest relationships for the sites, information about bird species richness and composition are collected through the use of a network of fixed recording devices (AudioMoth, by Open Acoustic Devices) throughout the breeding season (April-June). Considering the position of the recorders as the centroid of the circular sample plots, data about forest structure, vegetation composition, tree-related microhabitats, and information about the presence of deadwood are collected too. The difference in mean species richness between the two forest management types is tested through permutation tests, while differences in species composition are tested by principal coordinates analysis and the permutational multivariate analysis of variance. Based on the results, it should be possible to draw conclusions about the forest management approach that should be adopted to fulfil the requirements of biodiversity conservation in Natura 2000 sites.