Spatial distribution and ecology of orchids (Orchidaceae) of western Serbia

Orhideje su poznate po bogatstvu taksona, kompleksnoj ekologiji i velikom broju ugroženih vrsta. Osnovni ciljevi ove disertacije su utvrđivanje prostorne distribucije i diverziteta orhideja zapadne Srbije, kao i utvrđivanje ekoloških preferencija i konzervacionog statusa orhideja. Za svaki takson izrađene su karte rasprostranjenja u zapadnoj Srbiji. Za ispitivanje uticaja nadmorske visine, 19 bioklimatskih faktora i heterogenosti staništa na bogatstvo taksona u pojedinim UTM kvadratima 10 × 10 km, kao i analizu bogatstva taksona orhideja duž gradijenta nadmorske visine korišćena je regresiona analiza. OMI (eng. outlying mean index) analiza je korišćena za analizu ekoloških niša i faktora koji utiču na brojnost i distribuciju orhideja. Utvrđeno je prisustvo 57 vrsta i podvrsta orhideja, među kojima je 7 novih taksona za floru Srbije. Utvrđeno je da planina Tara predstavlja najvažniji centar diverziteta orhideja u zapadnoj Srbiji, sa 34 registrovana taksona u UTM kvadratu CP76. Rezultati ovog istraživanja su pokazali da nadmorska visina i heterogenost staništa značajno utiču na bogatstvo taksona u UTM kvadratima 10 × 10 km, dok maksimalne vrednosti nadmorskih visina i minimalne vrednosti temperaturnih varijabli najsnažnije utiču na bogatstvo prstastotuberoidnih orhideja. Utvrđeno je da se najviše taksona orhideja javlja u područjima srednjih nadmorskih visina (1000-1100 m). Najveći broj taksona orhideja je registrovan na krečnjacima, u zajednicama klasa Festuco-Brometea, Quercetea pubescentis i Molinio-Arrhenatheretea. Definisano je 6 ekoloških grupa šumskih i 8 ekoloških grupa orhideja zeljastih tipova vegetacije. Određeni su IUCN statusi ugroženosti, kao i faktori ugrožavanja orhideja zapadne Srbije, sa predlogom mera zaštite i konzervacionim prioritetima.Orchids are known for their taxa richness, complex ecology and a large number of endangered species. The main objectives of this dissertation are the determination of spatial distribution and diversity of orchids in western Serbia, and the determination of ecological preferences and conservation status of orchids. Distribution maps were made for each taxon in western Serbia. Regression analysis was used to explore the influence of elevation, 19 bioclimatic factors and the habitat heterogeneity on the taxa richness within individual UTM 10 × 10 km grid cells, as well as to analyse the taxa richness along the elevational gradient. The OMI (outlying mean index) analysis was used to analyse ecological niches and factors affecting the abundance and distribution of orchids. The presence of 57 orchid species and subspecies was recorded, among which 7 new taxa to the flora of Serbia. Mt. Tara represents the most important center of diversity of orchids in western Serbia, with 34 taxa recorded in CP76 UTM grid cell. Results of this study showed that elevation and habitat heterogeneity significantly affect the taxa richness in UTM 10 × 10 km grid cells, whereas the maximum values of elevations and minimum values of temperature variables most significantly affect the richness of orchids with palmate and fusiform tubers. It has been found that most of orchid taxa occur in the middle elevations (1000-1100 m). The largest number of orchid taxa was recorded on limestone, in the communities of the classes Festuco-Brometea, Quercetea pubescentis and Molinio-Arrhenatheretea. Six ecological groups of forest orchids and eight ecological groups of orchids of herbaceous vegetation types were defined. IUCN threatened status, as well as the threats to orchids of western Serbia were determined, with a proposal for protection measures and conservation priorities