Butterflies in trouble: The effectiveness of Natura 2000 network in preventing habitat loss and population declines of endangered species in urban area

Joanna Kajzer-Bonk,Piotr Nowicki

doi:10.1016/j.ecolind.2021.108518

Abstract

• Valuable habitats in urban areas are under anthropogenic pressure. • Across the 20 years of study the number of habitat patches decreased twofold. • Status of protected species does not guarantee proper protection. • Establishment of Natura 2000 sites ensures stability of populations of focal species. • Existing populations of protected species decline outside Natura 2000 sites. Habitat deterioration and biodiversity decline is progressing worldwide. However, these effects may be somewhat mitigated in urban areas, which are strongly exposed to anthropogenic pressure. The protected sites may here impede habitat loss and serve as effective tool of biodiversity conservation. The aim of this study was to test if location (inside/outside Natura 2000 sites) and size of habitat fragments affect the habitat loss and population trends in metapopulations of three Phengaris butterflies exposed to urbanization pressure. Across 20 years of study the number of habitat patches decreased by half, mainly outside N2000 sites. Total area of available habitat decreased by 13% for P. teleius and P. nausithous butterflies, and by 21% for P. alcon . Negative population trends were observed for all three species at small and medium-size habitat patches located outside N2000 sites as well as at small patches inside N2000 sites. The existing populations appear to be vulnerable outside N2000 sites. Our findings indicate that N2000 sites fulfill their protective function in halting population loss of species of high conservation interest and effective protection of intact habitats may support urban biodiversity. Nevertheless, there is an urgent need to expand the existing protected areas in order to save remnant local populations from their imminent extinctions in near future, as the species legal protection is not effective beyond N2000 sites. As meadow habitats serve a whole range of ecosystem services, their remnants deserve to be effectively protected in urbanized areas.

Highlights

In the face of the sixth global extinction and climate crisis (Ceballos et al, 2015), protection of natural and semi natural ecosystems is one of the most urgent needs in the world
Despite the increasing in terest in ecological studies conducted in Natura 2000 sites, little is known about the actual effectiveness of Natura 2000 sites on the status and population trends of focal species in habitats vulnerable to increasing urbanisation pressure
The grassland habitats include among others humid and mesophilic meadows of the Molinio-Arrhenatheretea class with Sanquisorba offcinallis and Gentiana pneumonathe, which represent the only foodplants of the focal butter flies: the Scarce large blue Phengaris teleius, the Dusky large blue P. nausithous as well as the Alcon large blue P. alcon, respectively (Thomas et al, 1998)

Summary

Introduction

In the face of the sixth global extinction and climate crisis (Ceballos et al, 2015), protection of natural and semi natural ecosystems is one of the most urgent needs in the world. Protected areas are being established worldwide for biodiversity conservation. One of the most important systems of protected areas is Natura 2000 network created in the European Union for the effective protection of its habitats and species, and currently covering 18.5% of the EU land area (EEA, 2020). As negative trends in protected areas intensify recently all over the world, with the cases of their down grading, downsizing, or degazettement (Kroner et al, 2019) as well as land use and climate changes (Vogel, 2017; Forister et al, 2021), it is unclear if existing forms of protected areas still fulfill their protective function. Despite the increasing in terest in ecological studies conducted in Natura 2000 sites, little is known about the actual effectiveness of Natura 2000 sites on the status and population trends of focal species in habitats vulnerable to increasing urbanisation pressure

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