Abstract

Authors

WATANABE Tsutomu, YASUDA Yukio, YAMANOI Katsumi, OHTANI Yoshikazu, OKANO Michiaki, MIZOGUCHI Yasuko

Year

2001

Title

Seasonal variations in energy and CO₂ fluxes over a temperate deciduous forest at Kawagoe, Japan

Journal

CGER Report: International workshop for advanced flux network and flux evaluation proceedings

Volume

M-011-2001

Page

11-17

DOI

Keywords

URL

http://www.cger.nies.go.jp/publications/report/m011/m011_2001.html

Abstract

Long-term flux measurements have been conducted since 1995 at a deciduous broadleaf forest in Kawagoe, Japan. The forest is intensively influenced by human activity through the influence of the anthropogenic emission of CO₂ and the management by farmers who utilize litters of the forest to fertilize their cultivated field. In technical aspects, we present methods for the determination of the frequency response of the eddy covariance systems and for the calibration of sensors for the energy balance to Bowen ratio method in order to reduce possible system-originated errors. Seasonal variations in energy, water vapor and CO₂ fluxes are clearly correlated with the seasonal change in the leaf area index. The annual amount of carbon absorption by the forest is about 300gCm^-2 y^-1 but this would be decreased by 175 gCm^-2 y^-1 if litters were not taken out from the forest. The carbon absorption by the Kawagoe forest is smaller than the average of other natural deciduous forests. Through comparing eddy covariance fluxes and energy balance fluxes, it became clear that the underestimation in the latent heat flux by the eddy covariance is responsible for the non-closed energy budget that is often reported.

Site

KWG

Remarks