A taxonomic snapshot of belowground organs in plants of Anatolian steppes

The lack of information on plant traits limits our understanding of how plant species and communities will respond to ongoing global changes. The biodiversity-rich Anatolian steppes have remained unexplored in terms of belowground plant traits. We documented the distribution and representation of belowground organs (excluding roots that do not form a bud bank) in Anatolian steppe plants, categorizing them by taxonomic family and growth form. Comparisons and analyses were made using data from the published Flora of Türkiye. Our results show that one-fifth (736 taxa) of all Anatolian steppe plants and one-third (514 taxa) of polycarpic hemicryptophytes bear a belowground organ with clonality or perennation functions. The proportion of belowground organ types varied between growth forms, as polycarpic hemicryptophytes had mainly rhizomes or rootstocks whereas geophytes had bulbs. Some families, such as the Amaryllidaceae, Asparagaceae and Liliaceae, possessed a specific type of belowground organ, while some others, including the Rosaceae, Caryophyllaceae and Asteraceae, had a higher diversity of belowground organ types. We conclude that the seasonal climate with cold winters and dry summers can be a driver of this belowground organ diversity in Anatolian steppes. The presence of bulbs, rhizomes and tubers appears to be phylogenetically clustered, with the representation of these organs differing between the monocot clade and the eudicot clade; indeed, bulbs and corms are, in this case, exclusive to monocot families. Further measurements of belowground plant traits in the field and laboratory are needed to fully understand the patterns and processes in Anatolian steppe ecosystems.