Urban biodiversity hotspots wait to get discovered: The example of the city of Ioannina, NW Greece

Abstract

Given the global urban sprawl that runs in favor of the anthropogenic habitats, cities that naturally encompass wildlife will set a future paradigm. Montane Mediterranean cities have been understudied in terms of biodiversity, although they are often embedded in biodiversity hotspots. It therefore remains an open question, to which extent they may harbor species of special conservation interest and if the latter can be incorporated in urban planning. In this context, we assessed the urban flora of urban habitats in Ioannina (NW Greece), a city located in a highly valued region in terms of biological conservation. In four study areas, 16ha each, we recorded 379 spontaneous taxa of vascular plants and assessed their abundance by a semi-quantitative approach. The representation of alien plants is low, compared to other Mediterranean cities (2.1% archaeophytes, 9.0% neophytes). Furthermore, the low archaeophyte to neophyte ratios in all habitats and the very small absolute numbers of archaeophytes indicate an urban environment submitted to a low rate of alien introduction. Endemics and taxa included in Greek and international conservation lists comprise 7.1% of the total city flora and occur both in indiscriminately inhabit all eleven habitats studied of both seminatural and anthropogenic type, forming medium to large populations in at least one study area. Ioannina displays the highest proportion of endemic taxa (4.8%) among the Mediterranean cities surveyed to date. Our findings illustrate the potential refuge function of urban habitats within Mediterranean cities, which should be strengthened in the further urban development.