| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1993: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1992: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1991: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Research Abstract |
Wintering forms of perennial herbs (77 species) and shoot phenology of herbaceous and woody plants (30 species) were investigated in Japanese alpine regions. As to the wintering forms, the depth of dormancy, structure of winter buds, and Raunkiaer's life-forms were investigated. To evaluate the depth of dormancy, the number of days required for growth initiation of plants collected in autumn and cultivated at 24ﾟC was recorded. The growth initiation ranged from 5 days to more than 250 days, indicating that the dormancy varied among species. Three types of winter buds were recognized based on the degree of differentiation of scales from young foliage leaves ; buds with no differentiated scale, buds with partly differentiated scales, and buds with perfectly differentiated scales. Two contrasting wintering forms occurred in relation to habitats. The shallow-dormant herbs with no differentiated scale on the ground surface (chamaephytes and hemicryptophytes) were found in exposed and unstable habitats such as gravelly and wind-exposed sites. The deep-dormant herbs with differentiated scales under the ground surface (geophytes) were found in more stable habitats such as Pinus pumila forest floor and meadow. The ecological implications of these wintering forms are discussed. Concerning on the shoot phenology, the times of growth initiation, growth cessation, and leaf death were observed in the field. In both herbs and shrubs, the growth initiation was later in evergreen plants than in summergreen plants, but the growth cessation was not different between the two. In the herbs, rosette plants tended to stop the growth later than others. The leaf death of the plants occurred usually from late September to early October, but the leaves of Fauria crista-galli and Veratrum stamineum decayd in mid September, being earlier than others. Flowering period was also investigated.
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