Vegetation of alpine screes on Bjelašnica Mt. — syntaxonomy and ecology

We analised vegetation of calcareous screes in the alpine belt of Bjelašnica Mt. (Western Balkan) by the Central European phytosociological method. In total, 69 relevés were submitted to numerical analysis in R ver. 3.5.2. (UPGMA clustering with chord distance). The obtained cluster dendrogram showed differentiation in nine associations, of which Festuco xanthinae—Valerianetum montanae Trakić et al. ass. nov. and Drypido spinosae—Seslerietum wettsteinii Trakić et al. ass. nov. are new ones. In lower section of the alpine belt we described new subassociation Pseudofumarietum leiospermae helictochloetosum Trakić et al. subass. nov. which raises questions about ecological preferences of the alliance Corydalion ochroleucae. We also neotypified the association Drypidi—Heracleetum orsinii Redžić et al. ex Trakić et al. and made correction for Pseudofumarietum leiospermae Lakušić et Redžić 1991 nom. corr. The observed high diversification of the alpine screes on Bjelašnica Mt. is based upon its ecological heterogeneity and tranzitional position in the Dinarides.