Seasonal and interannual variation in net ecosystem production of an evergreen needleleaf forest in Japan

Abstract

Carbon dioxide (CO 2 ) flux was measured above the forest at the Fujiyoshida site on the northern slope of Mount Fuji in Japan in 2000-2008 using an eddy covariance technique. The forest mainly consists of Japanese red pine (Pinus densiflora) and Japanese holly (Ilex pedunculosa). The 9-year average of monthly mean net ecosystem production (NEP) ranged from -0.1 g C m -2 day -1 in January to 2.5 g C m -2 day -1 in May. The maximum net uptake was observed in May, although gross primary production (GPP) was highest in July. Variation in the leaf amount did not notably affect seasonal variation in GPP. This site was characterized by carbon uptake even in winter, if the meteorological conditions were conducive for photosynthesis and a resulting long period of carbon uptake. The 9-year averages of annual NEP, GPP, and ecosystem respiration (RE) were 388, 1,802, and 1,413 g C m -2 year -1 , respectively. The annual NEP was lowest in 2003 and highest in 2004 over the 9 years. Year-to-year variability of NEP mainly depended on air temperature and photosynthetically active radiation in summer, and the dependence of the deviation of annual NEP on that of GPP was greater than that of RE. Long-term observational data indicated that the carbon uptake ability at the study site was at a moderate level in comparison with other temperate humid evergreen forests around the world. These data also indicated that the site had a high carbon uptake ability compared with other deciduous forests in Japan because of the duration of carbon uptake.

Comparison of Carbon Dynamics among Three Cool-Temperate Forests (<i>Quercus serrata, Larix kaempferi</i> and <i>Pinus densiflora</i>) under the Same Climate Conditions in Japan

“…Hirata et al [7] demonstrated that the photosynthetic capacity of L. kaempferi was higher than that of other species, and the P max rapidly increased with leaf expansion. However, the photosynthetic activity of Q. serrata was larger than that of P. densiflora in those studies: V c values for Q. serrata and P. densiflora were about 25 and 60 μmol•m −2 •s −1 in summer, respectively [18]. These previous studies suggest to us that photosynthetic activity is highest in L, followed by Q and P forests (Table 5), although this trend was different for NPP in our study.…”

Seasonal variability of forest sensitivity to heat and drought stresses: A synthesis based on carbon fluxes from North American forest ecosystems

“…NEP, being the difference between GEP and RE, showed a complicated seasonal pattern in its sensitivity to climate anomalies (Figure ). In this study, we used the seasonal dynamics of photosynthesis (GEP) and respiration (RE) and their limiting factors to interpret the sensitivities of NEP in different types of forests (Mizoguchi et al, ).…”

“…FLUXNET2015) dataset, we developed a series of daily indices of their limiting factors to interpret the sensitivities of NEP in different types of forests (Mizoguchi et al, 2012).…”

Canopy fluxes of monoterpene, isoprene and isoprene oxidation products in a pine-oak forest

“…A meteorological tower of 32 m height was built at the forest site and temperature, photosynthetic photon flux density PPFD , wind direction, and wind speed have been measured on the tower. Further details regarding the site information are provided in Mizoguchi et al 2012 andOhtsuka et al 2013 . We did not measure the PPFD µmol m -2 s -1 around the major trees in the lower layer of the forest. To estimate the PPFD at a height of 15 m above the broadleaf trees , we used the following equation:…”

“…NEE µmol m -2 s -1 was calculated by the CO 2 flux plus the rate of change in CO 2 storage in the canopy. Details regarding that calculation is described in Mizoguchi et al 2012 . O 3 concentrations ppb were measured 17 m above the ground on the meteorological tower. O 3 concentration was monitored using an ultraviolet light absorption analyzer 49C, Thermo Scientific, USA .…”