Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Flora Guardians' report from the Swedish national park Gotska Sandön.

Abstract

During 26-30 June 2019, the Swedish Flora Guardians surveyed threatened plant species on the Baltic island Gotska Sandön (37 kn). We counted 35 000 plants of Cephalanthera rubra, constituting ca 70% of the Swedish population. The island also hosts some of the largest subpopulations of Koeleria glauca (13700 tussocks), Oxytropis pilosa (568 plants) and Viola tricolor subsp. curtisii (ca 330 plants) in Sweden. Two large occurrences of Chimaphila umbellata were found. Ca 70% (6600 fertile plants) of the Swedish population of Eryngium maritimum also occurs here. We additionally recorded new taxa for the island: Epipactis phyllanthes subsp. arenaria, E. helleborine subsp. orbicularis, E. atrorubens x helleborine, a morph of E. atrorubens lacking red pigmentation, Luzula divulgata, and finally giant, late-flowering plants of Pulsatilla pratensis, with wide leaflets. The national park is outstanding but in need of actions. Fires and sand-dune dynamics should be reintroduced to counteract overgrowth, and expanding invasive alien species (notably Rosa rugosa) should be eradicated.