Occurrence of the invasive Japanese rose (Rosa rugosa) in the Åland Islands

Authors

• Panu Kunttu Luontotietopalvelu Taiga
• Sanna-Mari Kunttu

Abstract

The Japanese rose (Rosa rugosa Thunb.) is an invasive alien species in Europe that exerts adverse ecological effects on biodiversity. In Finland, it occurs mainly along the coastline and in the archipelagos of the Baltic Sea, where it replaces native plant species and threatens rare and red-listed habitats, like sand beaches and coastal meadows. This study sums for the first time occurrences of Japanese rose stands on the seashores of the Åland Islands in SW Finland. Altogether, 57 stands of Japanese rose were found, mainly from inventories made by the authors in 2014–2020. The median size of the stands was 7 m². Although the most common habitat was stone shores, coastal meadows were also typical. The largest stand, measuring 238 m², was found on a sand beach. Knowledge of the distribution, stand sizes, and habitat types of the naturalized Japanese rose is essential for planning, eradication, and control measures. Since large areas of the archipelago are still without occurrence data, further inventories should be conducted to understand better the occurrence of the Japanese rose in the Åland Islands.