Long-term phenology data on woody plants at The University of Tokyo Hokkaido Forest from 1930 to 2010

地球温暖化自体注目され始めたのが1980 年代に入ってからであるため，気候変動の研究に資する長期データは世界的にも限られている。東京大学北海道演習林では1930 年から樹木のフェノロジーを調査してきた。しかし，元データが公表された最初の8 年間を除くと，解析した結果が公表されたのみで，外部の研究者が貴重な長期データを利用できる状況になかった。一方で，元データが部分的に紛失した期間があり，調査対象個体の継続性についても未整理の状態で，内部の研究者でも解析できる状況になかった。そこで，本報告では，しばしば変更された調査項目や調査個体と個体数，観測者を整理して，時系列データの接続性を検討した。そして，できる限り調査個体すべての元データを数値データとして公表した。The number of long-term datasets available for research into climate change is limited because global warming has only been a major research subject since the 1980s. The University of Tokyo Hokkaido Forest (UTHF) has accumulated phenology data of woody plants since 1930. However, researchers outside the UTHF have not been able to utilize these valuable long-term data because only analyzed data have been published, with the exception of the first 8 years when original data were published. Also, it is even difficult for researchers at the UTHF to use these data because the continuity of the time-series is not clear and because the original data for the 13 years from 1938 to 1950 was lost. In this paper, the continuity of the long-term time-series data was clarified by organizing observed events, observed species and individuals, the number of individual trees for each species, and observers, which have been frequently changed. We have tried to publish the original numerical data (=dates) for all the individual trees that have been observed