@article{oai:kanazawa-u.repo.nii.ac.jp:00047102,
 author = {Tanaka, Ryoko and Koike, Fumito and 田中, 涼子 and 小池, 文人},
 issue = {1},
 journal = {植物地理・分類研究, The journal of phytogeography and taxonomy},
 month = {Dec},
 note = {Seasons are important factors for the activities of organisms, and biological seasons are one of the key factors for in situ studies of wild organisms. In this research, we determined biological seasons based on phenological pattern of local flora. We defined the study areas of 1km × 1km in rural Tokyo, Japan （under warm-temperate climate）, and the random number was used to extract study plant species from the local flora including herbs and woody species. Both reproductive and vegetative activities were studied （presence of leaves, flowers, and fruits）, and we used multivariate analyses to divide biological seasons. Five biological seasons were detected by a cluster analysis （TWINSPAN）; those were biological winter （season I, December to February）, biological early spring （season II, March）, biological spring （season III, April to early June）, biological summer （season IV, late June to early August） and biological autumn （season V, late August to November）. There were more number of biological seasons in the duration from the coldest to the warmest periods （biological spring and biological early summer）, than the duration from the warmest to the coldest periods （biological autumn）. Temperature was the key environment factor determining biological seasons around the cold period, but day length was the key between biological summer and biological autumn.},
 pages = {21--37},
 title = {里山に生育する植物種のフェノロジーを基にした生物学的季節区分},
 volume = {58},
 year = {2010}
}