Management of three endangered plant species in dynamic Baltic seashore meadows

Question: Arctophila fulva var. pendulina, Primula nutans var. jokelae and Puccinellia phryganodes are threatened early successional species growing in the seashore meadows of the northern Baltic Sea. Patches formed by these species are destined to be replaced by other species during primary succession and in order to persist in the area they have to continuously colonize new areas. We studied whether the displacement of the species could be slowed down and their sexual and/or vegetative reproduction enhanced by management targeted to surrounding vegetation. Location: Bothnian Bay, Baltic Sea, W Finland. Methods: Vegetation surrounding patches of all study species was mown in four successional growing seasons. Moreover, the impact of additional soil turning on creating new favourable growing sites was tested for A. fulva. Results: Deterioration of suitable habitats of A. fulva and P. nutans was markedly slowed down by management and the vegetative and/or sexual reproduction of these species was enhanced. In the case of P. phryganodes, however, no positive response to management was obtained. Conclusions: In order to improve the long‐term persistence of these three species successional vegetation changes should be slowed down and their dispersal and colonization success improved by continuous management of the populations. We further suggest that the colonization of new areas should be aided by transplantations to the non‐vegetated islets, which have recently risen from the sea and cannot be reached by means of dispersal.