Flowering Rate Can Vary Considerably Between Geographically Close Populations of Fritillaria Meleagris

Protected and rare species are often managed without basic knowledge on their demographic characteristics, such as population size and population dynamics. This is the case of Fritillaria meleagris, a threatened species declining throughout its range, and a flagship species in conservation. Estimates of its population sizes are usually based on the number of flowering individuals. We aimed to study the inaccuracy of population size estimates based on the number of flowering individuals. We established permanent plots in two populations in Hungary and recorded the individuals present and their morphometric characteristics annually between 2017 and 2023. We classified the individuals recorded into age-state categories. Significant differences were observed between the two populations, consistently across years. A much higher proportion of individuals flowered at Tüskeszent- péter (60.6%) than in Gyékényes (28.9%). The proportion of juveniles at Gyékényes was more than three times higher than in Tüskeszentpéter. A high proportion of individuals entered dormancy after one growing season at both sites. Although one- and two-year dormancy were the most common, the maximum possible dormancy length is not yet known. Because the proportion of reproductive adults was higher at Tüskeszentpéter compared to the Gyékényes site, an equal number of flowering individuals in the two populations would actually correspond to a smaller population size at Tüskeszentpéter compared to Gyékényes. These results reinforce that the inaccuracy of population size estimates based on flowering individuals vary across different populations, and highlight the need to study the demographic structure of the populations for more reliable population size estimates.