Is the Natura 2000 network effective to prevent the biological invasions?

Abstract

Protected areas are considered effective tools to protect biodiversity from global change; however, their success against invasive alien species (IAS) is still quite unknown. The European Natura 2000 network (N2000) appears vulnerable to invasions as human activities are not prohibited, despite being the main drivers of biological invasions. This study was carried out in the region of Castilla-La Mancha (Spain), which represents a 2.3% of the European N2000, being higher than the network surface in 52% of the European countries. We specifically (1) compared the total IAS between protected (N2000) and unprotected sites (2) analyzed the effect of an additional protection as national park or nature reserve on the total IAS; and (3) assessed the contribution of human pressure to explain the occurrence of IAS within the network. This is the first time that the approach of gap analysis was used to assess the efficacy of N2000 against IAS. We compiled 3664 georeferenced records for 95 fauna and flora species. Mean total IAS of fauna and flora were similar between protected and unprotected UTM 10 × 10 km grid cells; therefore, as expected, N2000 sites are vulnerable to IAS despite protection. Furthermore, a stricter management of human pressure under additional regulations did not seem to prevent IAS occurrence in N2000 sites. The accessibility to protected sites seems to be a relevant factor explaining the IAS occurrence. It is imperative to improve the monitoring, quality, and updating of IAS data within the network and the surrounding areas to prevent new invasions and the worsening of current negative IAS impacts. Keywords: Conservation planning, Gap analysis, Invasive alien species, Natura 2000, Protected areas