根室半島台地上の歯舞湿原の維管束植物相とその希少性評価

抄録

The Nemuro Peninsula, a part of Konsen area, has a unique natural environment characterized by its coolest climate in the lowlands of Japan due to sea fog, and the development of wetlands on top of a marine terrace.　In Habomai Mire, the largest wetland in the Nemuro Peninsula, we conducted flora surveys for three years from early spring to autumn and created a list of vascular plants.　To evaluate the rarity of the wetland flora of Habomai Mire, we compared it with that of 89 other Hokkaido wetlands in which plant data existed in the “Hokkaido Wetland Plant Database’’ （Suzuki et al. 2016）.　As a result of the surveys, 163 taxa （161 species, one subspecies, one form） of 48 families of vascular plants were recorded.　We found 20 species listed on the Ministry of the Environment Red List 2020, and 16 of them were hygrophyte （excluding aquatic plants）.　This number is the third largest after Kushiro Mire and Bekanbeushi Mire, and is the same number as Lake Utonai, Yururitou Mire, and Kiritappu Mire, and it is the largest among the wetlands without protected designation status.　These results suggest that the richness of red-listed hygrophyte species in Habomai Mire is comparable to wetlands registered under the Ramsar Convention and wetlands designated as natural parks.　In addition, the fact that red-listed species found in only a few other wetlands or only in the Nemuro Peninsula were recorded in our surveys also supports the claim that this mire is highly valuable in terms of diversity of rare species.　These results provide useful scientific information for the discussion to designate the Konsen area as a quasi-national park by 2030.