Picea omorika (Pinaceae): an endangered endemic species from Serbia and Bosnia-Herzegovina, locally naturalised in the Brembana Valley (Orobic Alps, Italy)

Picea omorika is an endangered conifer endemic to Serbia and Bosnia-Herzegovina. This research reports the first case of its naturalisation in Italy, specifically in a restricted area of the upper Brembana Valley (Orobic Alps, Lombardy), where an uneven-aged population, of approximately 50–60 individuals, grows within a wood pasture at 1,760–1,790 m a.s.l., inside the Orobie Bergamasche Regional Park. Dendro- chronological analysis indicates that this population likely originated from a single tree planted for orna- mental purposes near a mountain hut in the 1960s. Over the past 30 years, the species has propagated in the study area under cold, suboceanic climatic conditions and on moderately moist, nutrient-poor, slightly acidic soils, as inferred from climatic data and Ellenberg ecological indicator values. Grime’s com- petitor, stress tolerator, ruderal (CSR) functional strategy analysis classified P. omorika as a strictly stress- tolerant species (C = 0.0%, S = 100.0%, R = 0.0%) with low invasive potential. Phytosociological analysis indicates that the P. omorika community is part of a secondary succession that is progressing from pastures of Nardion strictae towards high-montane coniferous forests of Piceion excelsae. This research contributes to a better definition of the ecological niche of P. omorika.