An integrated approach to conservation of rare fern species using the example of Polystichum craspedosorum (Dryopteridaceae) in Amur Region, Far East оf Russia

Abstract

Currently changes in the earth's vegetative cover have reached a planetary scale. The danger of extinction of species and ecosystems has become increasingly significant. Active measures must be undertaken to restore particular plant species and populations in order to minimise an ongoing loss of species. Polystichum craspedosorum is a cliff-dwelling fern, an East-Asian relict species whose northern range includes the Russian Far East. The northernmost population of this species, located in the Amur Region, is at risk of flooding by the Lower Bureya Dam. A series of measures were developed and implemented to conserve this plant. Plant individuals were translocated from the flood zone to other suitable habitats on the territory of the Amur Region. Monitoring has indicated that, after three years, the translocated plants have their usual seasonal rhythm, sporulation and the formation of gemmae. The survival rate at new places ranged from 60% to 88%. However, the final conclusions about the research efficiency can be made only after long-term monitoring for more than ten years. Cultivation of this species is being done in outdoor conditions at the Amur Branch of the Far Eastern Botanical Garden-Institute of RAS. The seasonal rhythm of cultivated plants was similar to the natural one in both spore production and gemma formation. The species can be assigned to cold hardiness zone 3 and it is promising for cultivation in the Amur Region. The possibility of cryopreservation of P. craspedosorum spores has been studied along with in vitro culture. After ultra-low temperatures, spores did not lose their viability and, thus, they can be stored in cryobanks for a long time. An integrated approach provides the maximum opportunity for the species conservation in nature and in culture. This integrated approach to conservation of a rare fern species is unique for Russia.