Carbon balance in a cool–temperate deciduous forest in northern Japan: seasonal and interannual variations, and environmental controls of its annual balance

Abstract

We monitored variation in seasonal and annual net ecosystem production (NEP), gross primary production (GPP), and ecosystem respiration (R E ) based on 7-year eddy covariance measurements above a cool-temperate deciduous broad-leaved forest (Japanese beech forest). The 7-year means (±SD) of annual NEP, GPP, and R E were 312 ± 64, 1250 ± 62, and 938 ± 36 g C m -2 year -1 , respectively. Variation in NEP was much larger than variation in GPP and R E . During the growing season, the main factor controlling carbon balance was air temperature; variation in seasonal integrated NEP was regulated by accumulated air temperature (degree-day) with a significant negative correlation, whereas the seasonal ratio of R E to GPP was correlated positively with accumulated air temperature. Because the deviation of seasonal NEP was also significantly correlated with seasonal R E /GPP, NEP was controlled by R E /GPP, depending on air temperature during the growing season. Seasonal R E in the defoliation and snow seasons was also important for evaluating the annual carbon balance, because the total number of days in the two seasons was quite large owing to a long snowy winter. In the defoliation and snow seasons, we found defoliation season length was a major factor determining seasonal integrated R E , illustrating the positive correlation between R E and defoliation season length. The major factors controlling interannual variations in forest carbon balance are discussed.

Inversely Estimating the Vertical Profile of the Soil CO2 Production Rate in a Deciduous Broadleaf Forest Using a Particle Filtering Method

“…The responses of NDIR sensors are known to drift with the passage of time [ 20 ]. To detect this drift, a pipe was inserted into a sheath attached to each CO 2 sensor so that CO 2 -free air or a standard gas of known CO 2 concentration could be introduced into the buried sensors for calibration.…”

A comparison of lignin-degrading enzyme activities in forest floor layers across a global climatic gradient

“…These findings can be interpreted as control of enzyme activity and dominant fungal communities by Table 2 Chemical properties of the organic layers in the boreal, temperate, and tropical forests studied. Data sources of C/N ratio are Gower et al (1997) for Sites 1-3, Nakane et al (1997) for Sites 3-5, Megonigal et al (1997) for Site 6, Yasuda et al (2012) and Fujii et al (2019) for Sites 7-8, Fujii et al (2008) for Site 9, Inagaki et al (2012) for Sites 10-11, Fujii et al (2011) for Sites 12-14, Shibata et al (2017) for Sites 15-16, Fioretto et al (2007), Maisto et al (2013), and Criquet et al (2000) for Site 17, and Fujii et al (2013b) for Sites 18-20. L (litter), F (fermented), H (humified), and FH (mixture of F and H layers) corresponds to Oi, Oe, Oa, and Oea horizons in soil taxonomy, respectively (Soil survey staff, 2014).…”

“…sites information areGower et al (1997) for Sites 1-3,Nakane et al (1997) for Sites 3-5,Megonigal et al (1997) for Site 6,Yasuda et al (2012) andFujii et al (2019) for Sites 7-8,Fujii et al (2008) for Site 9,Inagaki et al (2012) for Sites 10-11,Fujii et al (2011) for Sites 12-14,Shibata et al (2017) for Sites 15-16,Criquet et al (2002) for Site 17, andFujii et al (2013b) for Sites 18-20.…”

Increased phytotoxic O3 dose accelerates autumn senescence in an O3-sensitive beech forest even under the present-level O3

“…On the basis of the practical approach, we performed long-term O 3 flux-based risk assessments on photosynthetic CO 2 uptake in a cool temperate deciduous forest, consisting purely of deciduous broadleaf tree species, Japanese beech ( Fagus crenata Blume) 18 , and a warm temperate mixed deciduous and evergreen broadleaf forest, dominated by deciduous broadleaf tree species, Konara oak ( Quercus serrata Thunb. ex.…”