What determines the distribution of Tulipa species in Uzbekistan?

Abstract

/ Аннотация / Annotatsiya English: Although the distribution of Tulipa species in Uzbekistan is well documented, there is no clear understanding of the importance of three classes of environmental variables, namely climate, soil type and topography, as determinants of their distribution. In this study we mapped the richness of Tulipa species across Uzbekistan and conducted species distribution modeling in order to analyze the relative contribution of climate, soil type and topography to their predicted suitable ranges. Occurrence records were compiled from herbarium collections and from field surveys carried out between 2015 and 2021. The relationship between Tulipa species richness and altitude is best described by a hump shaped curve, with the majority of the Tulipa species occurring at the altitude range of 700 to 2200 meters above sea level. Climate was the major determinant of species distribution for the majority of the analyzed species, however topography, expressed as slope angle and aspect, was equally or even more important for several narrowly distributed taxa. Soil type was an important factor only for three species with restricted ranges on gypsum substrates. The conservation implications of these results are discussed in the context of the protected area network of the country, and priority districts for further inventory work are proposed.