Is vascular plant species diversity a predictor of bryophyte species diversity in Mediterranean forests? ALESSANDRO CHIARUCCI * , FRANCESCA D’AURIA and ILARIA BONINI Dipartimento di Scienze Ambientali ‘‘G. Sarfatti’’, Universita Di Siena, Via P.A. Mattioli 4, Siena 53100, Italy; *Author for correspondence (e-mail: chiarucci@unisi.it; fax: +39-0577-232896) Received 2 May 2005; accepted in revised form 5 January 2006 Key words: Bryophytes, Conservation, Reservation sets, Reserve site selection, Taxon congruence, Taxon surrogacy, Vascular plants, Woody plants Abstract. This study aimed to (i) investigate the congruence among the species composition and diversity of bryophytes and vascular plants in forests; (ii) test if site prioritization for conservation aims by the maximization of the pooled number of vascular plant species is effective to maximize the pooled number of bryophyte species. The study was performed in six forests in Tuscany, Italy. Four-hundred and twenty vascular plant species (61 of which were woody) and 128 bryophyte species were recorded in 109 plots. Despite the good predictive value of the compositional patterns of both woody plants and total vascular with respect to the compositional pattern of bryophytes, the species richness of the latter was only marginally related to the species richness of the former two. Bryophyte rare species were not spatially related to rare plant species and neither coincided with the sites of highest plant species richness. The species accumulation curves of bryophytes behaved differently with respect to those of woody plants or total vascular plants. Reserve selection analysis based on the maximization of the pooled species richness of either woody plants or total vascular plants were not effective in maximizing the pooled species richness of bryophytes. This study indicates that species diversity of vascular plants is not likely to be a good indicator of the bryophyte species diversity in Mediterranean forests. Introduction Forest ecosystems in the Mediterranean area are floristically extremely diver- sified. Tuscany, central Italy, hosts a wide variety of forest ecosystems, from the coastal Mediterranean ‘‘macchia’’, dominated by sclerophyllous evergreen species, to the high-mountain forests (up to 1600–1800 m) dominated by beech (Bernetti 1987). Forests cover more than half of the region’s surface, an area greater than one million hectares. About 120,000 ha of forest belongs to the Regional Administration of Tuscany and other 100,000 ha to other public administrations. In Tuscany, forests have always been considered a funda- mental resource, especially for timber production and soil protection. How- ever, consideration of forest ecosystems as environmental and landscape resources has developed in recent years. Tuscany was one of the first regions of Italy to establish a monitoring program of forests, within the ‘‘Scheme for the Biodiversity and Conservation (2007) 16:525–545 Ó Springer 2006 DOI 10.1007/s10531-006-6733-1