| Co-Investigator(Kenkyū-buntansha) |
KAWASHIMA Hiroyuki Univ. Tokyo, Facul. Of Agri. Associate Prof., 大学院・農学生命科学研究科, 助教授 (30161318)
KOMIYAMA Akira Gifu Univ., Facul. Of Agri. Professor, 農学部, 教授 (60135184)
AKIYAMA Tsuyoshi Gifu Univ., RBRC, Professor, 流域圏科学研究センター, 教授 (10283318)
MARIKO Shigeru Univ. Tsukuba, Insti. Of Biology, Associate Prof., 生物科学系, 助教授 (10251018)
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| Research Abstract |
Carbon dynamics and budgets were investigated in different successional stage ecosystems in cool temperate deciduous forest. The experiments were carried out in 0 year-old, 50 year-old and 110 year-old deciduous forest and Miscanthus sinensis grassland in central Japan, between April 2000 and March 2003. Carbon budgets were different among the different successional stage ecosystems. The annual carbon balance (NEP) was estimated to be -172 gCm^<-2> for the 0 year-old forest (just after deforestation), +117 gCm^<-2> for the 50 year-old forest and +16 gCm^<-2> for Miscanthus sinensis grassland, respectively. Moreover, the balance was estimated to be -270〜-320 gCm^<-2> for the upland single-cropping field, -160〜-270 gCm^<-2> for the upland double-cropping field, and only -20 gCm^<-2> for the paddy rice single-cropping field. These results suggest that 0 year-old forest ecosystem and the upland agricultural ecosystems may contribute to the increase in the carbon dioxide concentration of the atmosphere as the carbon accumulated in the soil is constantly being released in the atmosphere. On the other hand, the carbon balance for the grassland ecosystem and the paddy ecosystem were in good agreement, sometime resulting in a positive increase in carbon. Moreover, that for the 50 year-old forest resulted in a positive increase in carbon, and there is a mitigation potential of ca. 100 gCm^<-2> yr^<-1> from the use of the forest ecosystem. A rigorous assessment of soil carbon changes and the potential impacts of various mitigation strategies requires the integration of information on land-use and management practices, soils, and climate at regional scales. Therefore, global-scale evaluations and analyses of carbon in terrestrial ecosystems have not yet been done. Further investigations should be needed to understand global carbon cycles in terrestrial ecosystems and improve mitigation potentials in the ecosystems.
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