| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1991: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1990: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Research Abstract |
The plant community in the vicinity of the timberline of Mt. Fuji is not in a stable climax stage. On the southeast side, bare land and communities of perennial herbaceous plants are widely distributed over an area extending downward from the vicinity of the Hoei Crater. In such situations, herbaceous perennial communities play an important role in the process of succession to a woody plant community. That is, in almost all cases on Mt. Fuji, the transfer from alpine grassland to forest starts with the invasion of woody plants into patches of P. cuspidatum and P. weyrichii. Therefore, it is assumed that these Polygonum patches offer an "place "in a process where by woody plants can established.
The respiration rate of the rhizomes at the central part of a P. cuspidatum patch was measured to find the relationship between rhizome activity and the low biomass of its central part. Respiration rates of about 1.3mg CO_2 at the peripheral part, and of about 0.5mg CO_2/g/h at the central part were obtained in August on large patch. There was similar tendency observed in September for the respiration of the rhizome in the peripheral part to be higher than in the central part.
Patch growth of harbaceous perennials has been studied with regard to Phragmites communis, Phragmites australis and Pteridium aquilinum. However, there have been no ecophysiological studies on patch structure according to patch size, especially on the activity of rhizome and soil development in the patch. In the present study it was found that the activity of the central part is lower than that of periphery. Although the cause remains to be clearly established, this is thought to result from the crowding and aging of the underground organ of the central part, which may cause the central biomass above ground to wither, and as a result, a doughnut phenomenon is brought about.
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