Spatial assessment of habitat conservation status in a Macaronesian island based on the InVEST model: a case study of Pico Island (Azores, Portugal)

Abstract

A methodological approach for the conservation status assessment of Azorean natural habitats in Pico Island (Portugal) is presented, using the InVEST Habitat Quality model. This spatial analysis-based study was focused on a selected group of 33 endemic plant species occurring in Pico Island and protected under the Habitats Directive’s Listed Habitats for Macaronesia Region. The InVEST model combines information present in a Land Cover map with data on threats to habitats and habitats response, producing habitat quality and degradation maps as outputs, both represented in a score ranging from 0 to 1. Results showed that at higher altitudes habitats present better quality status, mostly due to the absence of the main threats such as Invasive Alien Species and Pasturelands. The study also showed that most areas with higher conservation quality are covered by the Pico Island Natural Park (a set of protected areas). Habitat patches showing higher degradation levels are located outside of the protected areas, supporting the increasing need for an integrated island-based conservation approach. This model valuation scheme might be used as an effective decision-support tool to prioritise areas for conservation actions and management in all nine Azorean Island Natural Parks, as well as in other small Macaronesian islands.