Dandelion Survey: Western Japan 2020, Kochi Prefecture. Distribution Survey of Native, Alien and Hybridized Dandelions (Taraxacum spp.) through Citizen Participation in Kochi Prefecture

A citizen-participatory survey using dandelions, a familiar plant, as an environmental indicator, was initiated in Osaka in the 1970s. Since then, the survey has expanded to the Kinki region and Western Japan, and in Kochi Prefecture, we have been participating in the Dandelion Survey: Western Japan 2010 and have started a distribution survey of Dandelion species in the prefecture in collaboration with citizens. The survey has been continued until the 2020 survey as a two-year survey, with one year of preliminary survey and one year of main survey. From the results of the survey in Kochi Prefecture in the Dandelion Survey: Western Japan 2020, the native species found in Kochi Prefecture were Kansai Tanpopo (Tanpopo means Japanese name of dandelion), Kushiba Tanpopo, Tsukushi Tanpopo, Yamazato Tanpopo, Kibishiro Tanpopo, Shirobana Tanpopo, and Kibanashiro Tanpopo (yellow flower variety of Shirobana Tanpopo), and the native species presumed to be naturalized in Japan were Tokai Tanpopo, Shinano Tanpopo, and Ezo Tanpopo, and the alien species were Seiyo (Seiyo means Western in Japanese) Tanpopo, Akami Tanpopo and a total of 13 taxonomic groups including native species presumed to be hybrids. The collected samples consisted of 38.2% native species, 60.6% alien species, and 1.1% domestic naturalized species, with alien species accounting for 60% of the samples. The proportion of meshes confirmed to be native involucral bract type alien species in all meshes where alien dandelions were confirmed has doubled in 10 years, and it is thought that the native involucral bract type alien species has doubled in 15 years from the number of collected meshes and samples. In addition, the flowering of Shirobana Tanpopo in the prefecture has been advancing at a rate of 0.9 days over 10 years, and it is presumed that the trend of earlier flowering is due to the long-term rise in temperature during the period when this phenomenon occurs. We have made efforts to promote awareness by holding exhibitions, training sessions, and issuing newsletters so that citizens can pay attention to and become familiar with the nature around them. After the survey, we published the “Dandelion Survey 2020: Western Japan Kochi Prefecture Report” as a summary of the survey results. This paper is based on this report (Hori Kiyotaka, Tanabe Yuki, Sakamoto Akira, Kokami Yasushi (eds) 2021. Dandelion Survey: Western Japan 2020 Kochi Prefecture Report. pp.63. Public Interest Incorporated Foundation Kochi Prefecture Makino Memorial Foundation. https://www.makino.or.jp/img_data/PAGE_science-new_2_23.pdf?4 ). We believe that this survey has provided many citizens with an opportunity to think about changes in the natural environment around them. The correspondence table between the Japanese names of dandelion and scientific names is shown in Table 8.1.