Multi-scale analysis of butterfly diversity in a Mediterranean mountain landscape: mapping and evaluation of community vulnerability

This paper is an attempt to outline a protocol for animal diversity census andevaluation aimed for areas in view of landscape planning of territories of hundred squarekilometres and more, that may work utilising different faunal groups and be anyway usefulat various scales. Many papers are addressed to elaborate tools for landscape planningstarting from biodiversity evaluation and butterflies are often utilised because of theirsensitivity to landscape modifications. In this work, the biodiversity evaluation has beenperformed using three hierarchically linked landscape units at micro-, meso- and macroscale.Being species diversity values often inadequate to define the conservation interest ofa landscape portion, more importance has been given to which species compose the speciesassemblages. A community vulnerability Index was coded and used for evaluatingpotential consequences of human disturbance on butterfly assemblages. Forty-four yearsamples were gained by visual census in the Sila Greca, Southern Italy, on an area ofapproximately 520 square kilometres. During 5 years work, 2,535 specimens and 94species were recorded, equal to 75.8% of the whole Calabrian fauna. Four vulnerabilitylevels have been established and used for mapping butterfly assemblage vulnerability in thearea, starting from a vegetation map. Species richness was found somewhat contradictoryat micro-scale, where the community vulnerability Index gives a sounder approach. Sdiversity gives a more reliable picture of naturalness at meso-scale, a level we identifiedwith the ‘‘ecotope’’. At this more ‘‘geomorphic’’ scale level, biological functions reflectedby butterfly assemblages revealed to be clearly linked to seral processes. Similarityanalysis results show that the ecotope species richness, here called ‘‘eta-diversity’’, couldbe an useful measure of zoological landscape (faunation) potentialities.