Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 1999: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1998: ¥2,300,000 (Direct Cost: ¥2,300,000)
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Research Abstract |
Cirsium purpuratum is a perennial herb, native to the central Japan. It grows in disturbed habitats. The eruption in 1707, the vegetation has been growing gradually. C. purpuratum has been the dominant species in this area. Around there, some soil disturbance of large scale that is caused by snow slide and mud stream occurs. In addition to this, some soil movements of small scale occurs, too. Under the circumstances it is necessary for species to survive that the seeds germinate, seedlings grow and bear at regular intervals. Therefore I have focused on the process of the seed production to the seedling growth, and have studied what characteristics of C. purpuratum affect to the maintenance of population in disturbed areas. Though the results of this study suggest that in disturbed area, smaller seed size may be advantageous under conditions of limited water availability such as a soil surface. Small seeds may gain a competitive advantage over large seeds due to earlier germination. Thus seed size variation may potentially, affect not only immediate seedling success but also the subsequent maintenance of the population.
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