L’assetto zoogeografico dell’Appennino centro-settentrionale.

Biogeographia vol. XX VII ~ 2006 (Pubblicato il 30 dicembre 2006) Biogeograﬁa de/l’Appennino centrale e settentrionale: trent’anni dopo L’assetto zoogeograﬁco dell’Appennino centro—settentrionale FABIO STOCH Segreteria Yecniczz per [6 Area Nazumli Protette, Direzione per la Protezione del/4 Nzztum Ministero a'ell’Am/7imte e dellzz Yittelzz del Yerritorio :3 del Mzzre, via Capitan Bzzwzstro 174 00154 Roma (Ital)/)* *Imlz'rz'zzo azmale a’e[[’zzut0re: z/2'4 dello S/aoccatore 3/27, 00069 Yieuzgnaizo Romano, Roma (Italy); e—mzzz'[. -ﬁtoc/7 @f2zumzz'm[z2z.z't Key words: Apennines, historical biogeography, fauna, species richness, endemism SUMMARY During the XVII Congress of the Italian Society ofBiogeography in 1971, dedicated to the Central Apennines, Ruhfo remarked the low degree of Faunistic knowledge of the area. After thirty—five years, biogeographers have at disposition a national database including more than 538,000 distributional records of 10,000 terrestrial and inland water species, mainly invertebrates and lower vertebrates. The records stored in the database were assembled from bibliographical sources, museum collections, as well as unpublished data delivered by taxonomists. The large amount oftaxonomic and faunistic information stored in the inventory is analysed herein to describe the biogeographical features of the Apennines. After discussing the Linnean and the \X/allacean shortfall which influence data reliability, the historic species accumulation curve was used to estimate the total number of species present in the area (approximately 30,000, excluding protozoans). Biogeographic patterns were synthesized Following the chorotypes proposed by Stoch and Vigna Taglianti (2005); most species are widely distributed in the Palearctic (37%), European (26%), and Mediterranean (13%) regions; 23% of the species are endemic. Statistically signiﬁcant (pl0.05) endemism /Jatrpatr in the Apennines are defined using local indicators of spatial association; they are located on the main mountain massifs along the Italian Peninsula. C0/tirporr include the Padanian plain, part of Tuscany as well as most ofsouthern Apennines. A correspondence analysis of the chorotypes x grid cells (UTM grid, datum ED50) matrix allowed to identify a major latitudinal gradient; the first two CA axes explained approximately 50% of total variation. Mapping a combination of the two axes using GIS and geostatistical analysis allowed to divide the Italian peninsula into biogeographical provinces; the Apennines are clearly divided in a Northern part (including Northern and Central Apennines) and in a Southern part were Mediterranean species penetrate up to the inner areas of the massifs. The historical and environmental factors correlated with the biogeographical patterns were analysed using canonical correspondence analysis as well as multiple linear regression analysis applying a spatial error model accounting for autocorrelation. The main gradient displayed by the first CCA axis is strongly correlated to latitude and the inﬂuence of Mediterranean climate, as well as to elevation and the spatial extent of karstified areas, which host a large amount of endemics; the factors explaning this pattern are mainly historical. The second axis is correlated with environmental heterogeneity and anthropization; this is an ' ecological gradient superimposed on the historical pattern. ‘ Maps illustrating the present—day distributional pattern of palaeoendemic species (mainly ofThyrrenian origin), northern species (which colonized the Italian peninsula as far as Sicily during Pliocene and the Quaternary age), as well as Mediterranean species (which expanded their area of distribution northernwards after the retirement of the Quaternary glaciers) are presented to summarize the historical factors which explain the biogeography of the Apennines. Finally, an approach to conservation issues is recommended following the Conservation Biogeography theory, stressing the importance of preserving areas and species assemblages which are the relics of ancient palaeogeographical and palaeoclimatic events which shaped the distribution ofApenninic fauna.