Assessing the natural capital value of Posidonia oceanica meadows in the Italian seas by integrating Habitat Suitability and Environmental Accounting Models

Ecological systems can be regarded as natural capital that yields ecosystem services vital for human well-being. The provision of these services strictly depends on the protection of natural capital stocks generating them, highlighting the need for conservation and monitoring actions led by proper assessment methodologies. Among the available methods, the Environmental Accounting Model based on the emergy approach is rapidly gaining popularity in ecological applications. We used such method to assess the natural capital value of Posidonia oceanica meadows, widely recognized the most important ecosystems in the Mediterranean basin, at Italian national spatial scale. The natural capital value of P. oceanica was further weighed by the estimates provided by a Habitat Suitability Model. We observed that the estimated level of habitat suitability played an important role as modifier of the average biophysical value of P. oceanica. Our approach allowed to identify the meadows having the highest stability and over space and time, which we defined as the most valuable in biophysical terms, thus with highest natural capital value. The spatially explicit estimates we provided could support managers and policy-makers to ensure the long-term provision of ecosystem services generated by P. oceanica, enhancing ecosystem management and maritime spatial planning.