Population scale multi-year monitoring of Iris pumila in Deliblato Sand: flowering phenology

Abstract

Population scale multi-year monitoring of flowering and fruiting of Iris pumila L. can shed light on various evolutionary issues such as mechanisms of flower color polymorphism maintenance as well as provide information on population structure and dynamics that is important for this species in situ conservation. In the monitoring process flowering is recorded each year in 35 experimental plots (more than 4000 m2 in total) on two-day basis during flowering period (early spring) in population occupying undisturbed natural habitat in the Natural Protected Reserve of Deliblato Sands. That enables determination of spatial position, flowering date, flowering span, flower color, and pollination success for more than thirteen thousand individual flowering ramets per year. Preliminary findings indicate that in the second year of monitoring flowering started almost a month earlier and had almost two times greater flowering span compared to the first year. Number of flowering individual ramets was lower, but fruit to flower ratio was by the order of magnitude higher in the second year of the study.