Wahyu Catur Adinugroho1) and Keiji Sakamoto2)
Bamboo forests are important ecosystems from various ecological aspects in the world, especially in Japan, and account for about 3.2% of the total forest area in the world. Bamboos have not only economic values brought by many different uses but also the ecological function for environmental conservation. Among environmental problems, a major problem facing this world is global warming. Bamboos are known to have the comparatively fast growth rates in the world so do their absorption and stock of CO2 has the potential to mitigate global warming. The aim of this study was to determine the potency of carbon stock in the abandoned bamboo forest stand consisting of Phyllostachys nigra Munro var. Henonis Stapt. with the analysis of the stand dynamics. P.nigra has monopodial rhizomes and almost every part of this bamboo is usable. The field survey was conducted in a P.nigra stands, which is located in urban fringes of Okayama city, the western Japan (34°43’ N, 133°56’E) and is adjacent to a secondary deciduous broad-leaved forest in the outer part. We used long-term data that was obtained from 1993 to 2009 in a 10mx40m permanent plot, which was divided into inner and outer plot in the analysis. This study only covers the above ground organs, i.e., culms, branches and leaves. Biomass (B) of P.nigra was estimated from allometry relations, and carbon stock (C) was calculated as follows; C=0.45*B.
This research showed that density of living culms is higher in inner plot than in outer plot. The density of living culms in outer plot has been increasing with positive and higher growth rates of culms that were calculated from the balance between mortality rates and recruitment rates of culms. As the results, the bamboo stand has expanded to an adjacent forest. On the other hand, density of living culms in inner plot tended to be more stable and the changes were smaller with low growth rates of culms. Above ground biomass of P.nigra was mostly allocated in culms. Above ground biomass and C-stock in the stand level have increased in outer plot at the rate of 1.59 ton C ha-1 yr-1. It is likely that the biomass and C-stock have attained to a stable condition in inner plot. The total C-stock in that stable condition of P.nigra stands averaged 68.2±2.9 ton C ha-1, which is likely to be similar with other forests or larger than other forests. Therefore, P.nigra stands probably possess a great capacity for carbon dioxide reduction. It is expected that C-stock in the bamboo forests will increase because the bamboo forests have been expanding. However, at the same time we must consider the management so that suitable relations to other forests can be maintained.
(Globalization of Education System of Bioscience based on Biodiversity Symposium, March 2nd,2011, Okayama University 50th Anniversary Hall)
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