Japan Geoscience Union Meeting 2014

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Oral

Symbol A (Atmospheric, Ocean, and Environmental Sciences) » A-HW Hydrology & Water Environment

[A-HW29_2PM1] JapanFlux: Role of terrestrial ecosystems in water/material cycles

Fri. May 2, 2014 2:15 PM - 4:00 PM 314 (3F)

Convener:*Takashi Hirano(Research Faculty of Agriculture, Hokkaido University), Katsumi Yamanoi(Forestry and Forest Products Research Institute), Kazuhito Ichii(Faculty of Symbiotic Systems Science, Fukushima University), Nobuko Saigusa(National Institute for Environmental Studies), Chair:Kazuhito Ichii(Japan Agency for Marine-Earth Science and Technology)

3:45 PM - 4:00 PM

[AHW29-07] Continuous measurement of forest floor CO2 fluxes in a larch forest on the base of Mount Fuji

*Munemasa TERAMOTO1, Naishen LIANG1, Jiye ZENG1, Reiko IDE1, Nobuko SAIGUSA1, Yoshiyuki TAKAHASHI1 (1.Center for Global Environmental Research, National Institute for Environmental Studies)

Keywords:soil respiration, chamber, forest floor plants, photosynthesis

Carbon fluxes of forest floor are thought to be important part of forest carbon dynamics. Multi-channel automated chamber system was installed to a larch forest site on the base of Mount Fuji in 2006 for continuous measurement of forest floor CO2 fluxes. We prepared soil chambers for measuring soil respiration (Rs) and heterotrophic respiration (Rh). Root trenching was applied to separate Rs and Rh. Net ecosystem exchange (NEE) on the forest floor was measured with plant chambers. In 2013, the average efflux of CO2 was 2.24, 1.81 and 2.11 μmol CO2 m-2 s-1 in Rs, Rh and NEE, respectively. Root respiration was estimated to occupy 80.7% of Rs. Plants of forest floor was suggested to absorb about 5.9% of CO2 in Rs, and it meant that the amount of carbon fixed by those plants was relatively low. There was little rain in summer time (July-August), and forest floor CO2 fluxes were decreased due to decreased soil moisture. Q10 was 2.49 and 2.87 in Rs and Rh, respectively. Soil respiration was estimated to be 8.48 tC ha-1 yr-1, and the forest floor was seen as 7.98 tC ha-1 yr-1 carbon source.