Pulsatilla vulgaris (Ranunculaceae) conservation in Russia: habitat management to enhance the only population

Pulsatilla vulgaris is one of the rarest vascular plant species in Russia. In the Red Data Book of the Russian Federation, it is classified as critically endangered (category 1). The only population of P. vulgaris in Russia is known from the Leningrad Region and it is rapidly declining. The analysis of the population ontogenetic structure demonstrates low level of the population self-sustainment due to lack of seed reproduction. One of the factors that prevent P. vulgaris generative reproduction is the biotope transformation caused by succession. Typical habitats of P. vulgaris are heaths, sparse and low pine forests, dry low-grass meadows and pastures. Successful seed reproduction of the species requires the factors that inhibit woody vegetation development and lead to the damage of dense ground cover and soil (i.e. moderate grazing, weak ground fires etc.). To avoid a complete loss of the species in Russia, artificially damaged sites suitable for successful seed regeneration of P. vulgaris were formed in 2020–2021 in “Nizhnevolkhovskiy” Protected Area (Leningrad Region, Volkhovskiy District). Trees uprooting, grass vegetation removal or damage, soil damage were performed to form exposed and well-warmed sites with sparse vegetation ground cover. These measures have significantly increased germination capacity of the seeds on the managed plots compared to the left untreated (control) areas. Over a two-year period, the population of P. vulgaris has increased by more than 10%. The success of the measures applied allows to recommend them for the restoration of rare and highly specialized species populations growing in similar habitats.