An old-growth forest at the Caspian Sea coast is similar in epi-phytic lichens to lowland deciduous forests in Central Europe

We have recorded 138 species (125 of them epiphytic/epixylic) in a single preserved lowland forest in Dagestan (Russia), Samurski forest at the west coast of the Caspian Sea. Within its 2,000 hectares, some remnants of oldgrowth forests persist, dominated by Acer campestre, Carpinus betulus and Quercus robur. This mix of tree species is typical of many lowland deciduous forests in Central Europe, and we found that the lichen flora of Samurski also has much in common with those forests, but less in common with other types of Central European forests. Comparison with geographically closer lowland forests in Azerbaijan, Russia and Iran is impossible due to a lack of data. Using Detrended Correspondence Analysis, we defined a group of species diagnostic for temperate lowland deciduous forests; it includes about 20 species recorded in Samurski, most of which are crustose and usually with Trentepohlia as photobiont. In contrast to Central European lowland deciduous forests, the lichen flora of Samurski includes several species known mainly from the oceanic western Caucasus and Western Europe. To enable comparison with fixedarea lichen inventories, we have obtained a separate list of 82 lichen species from a detailed survey of a 1 ha plot in one of the best-preserved forest spots in Samurski. Fifty-nine species in 17 genera (Arthothelium, Bactrospora, Bryostigma, Catinaria, Coniocarpon, Cresporhaphis, Dendrographa, Enchylium, Enterographa, Inoderma, Lecanographa, Lepraria, Pachnolepia, Peridiothelia, Sclerophora, Xanthoriicola, Zwackhia) are new to Dagestan. Agonimia flabelliformis, Arthonia exilis, Bacidina auerswaldii, Cresporhaphis wienkampii, Caloplaca raesaenenii, C. tominii, Candelariella superdistans and Verrucaria umbrinula are new to the Greater Caucasus. Agonimia borysthenica, Bacidina adastra and Lecanographa lyncea are new to Russia. Candelariella superdistans is new to Asia.