Development of an eco-acoustic research protocol and its application for monitoring the acoustic environment in the Integral Nature Reserve of Sasso Fratino (Italy)

The study of target species sounds (Bioacoustics) and as well as of all sounds that constitute the whole acoustic environment of an ecosystem (Ecoacoustics) has proved to be a valid and powerful tool for the monitoring and conservation of biodiversity and the assessment of habitat quality, collecting long-term information on animal distribution and variations in community dynamics, including those driven by anthropogenic activities. Through Passive Acoustic Monitoring (PAM) of a habitat, it is possible to obtain a picture of the Soundscape that consists of three different components: the sounds produced by animals (biophony), the sounds of atmospheric and physical events (geophony) and the noises linked to the presence of man (anthropophony or technophony). But if on the one hand, the PAM allows new research perspectives for the biodiversity monitoring, since it is possible to record continuously and simultaneously different locations, on the other one, it generates a huge quantity of data that needs to be analyzed and interpreted, implying great time and knowledge efforts to get useful information. The new challenge is to draw up an analysis methodology to optimize resources both in the field (saving memory cards and batteries) both in the lab, reducing time and effort of analyses, while maintaining high the accuracy of the information. The aim of this Ph.D. project is to define the methodological and analytical Research Protocol to investigate the Soundscape at multi time and space scales with ecoacoustic analysis procedures. This elaborated protocol is composed of four main sections: 1. selection of surveys sites; 2. data collection (devices programming and sampling methodology); 3. qualitative analysis of acoustic data (generation of compact daily spectrograms); 4. quantitative analysis of acoustics data (bioacoustic analysis and sound identification; ecoacoustic indices and statistical analysis). By the application of this protocol, it is possible to describe the soundscape of a well-protected integral nature reserve internationally known for its conservation and biodiversity. From a five-year SABIOD’s archive of sound recordings, collected in the Integral Natural Reserve of Sasso Fratino and surrounding areas of Casentinesi Forests National Park (Italy), acoustic data are compared with cross-sections (horizontal) and time series (vertical) analyses in order to explore the soundscape’s spatial-temporal dynamics across different scales. All sites are characterized by quiet nights and very acoustically dense daylight hours, with a composite biophony occupying the range 1500 to 9000 Hz. But, although the acoustics indices trends are similar, the statistical Principal Component Analysis shows that the sites inside and outside the reserve are well differentiated and distinctly clustered in distinct sonotopes, and this could be due to biophony's different components and to their ecological and spatial heterogeneity. Besides to be a tool for research and conservation, the soundscape can also be considered as an object of study. Hence, the analysis of the single components of the Soundscape (geophony, biophony and anthropophony) is performed separately. Each of them represents an important and rich source of information in the environmental acoustic recording. Improving the knowledge of geophony allows to better discrimination of recordings according to different weather conditions and this can contribute to reducing analyses time for large size of data (e.g. by discarding rainy days). The monitoring of biophony increases the information about the biodiversity while the analysis of anthropophony aims to estimate the level of disturbance.