Pinus sylvestris L. var. cretacea Kalen. in the "Kreidova Flora" branch of Ukrainian Steppe Nature Reserve: current state and conservation measures.
The "Kreidova Flora" (Cretaceous Flora) branch of Ukrainian Steppe Nature Reserve was created in 1988 to protect unique cretaceous vegetation, including pine forests on chalk. The Standing Committee of the Berne Convention in 2018 added these forests to the list of endangered habitats as "G3.4G Pinus sylvestris forest on chalk in the steppe zone". For the last 40 years, the area covered with pine trees has doubled, but there are threats of invasive plants, periodical fires and other losses as a result of military actions since 2014. Satellite remote sensing data (Landsat archive) were used to analyze the distribution patterns and disturbances over 40-year period. The assessment of the stability and risks in this habitat shows its rareness, narrow prevalence, poor reproduction, very high (R > 83%) danger of destruction, and strong sensitivity to the environmental changes. Special set of monitoring and conservation measures are considered to provide successful protection of the habitat as a part of Emerald network.