Plants sequester atmospheric CO₂a major agent of climate change, during the growing periods and mitigate its rising accumulation in the atmosphere. Pin/IS densiflora and Quercus mongolica are the native tree species dominant in the temperate forests...
Plants sequester atmospheric CO₂a major agent of climate change, during the growing periods and mitigate its rising accumulation in the atmosphere. Pin/IS densiflora and Quercus mongolica are the native tree species dominant in the temperate forests of Korea. This study quantified the annual CO₂uptake by the two species at forest sites in Chuncheon in the middle of the country. The quantification was based on seasonal measurements of C02 exchange rates under natural conditions by an infrared gas analyzer over the growing season (1999). The monthly CO₂uptake per unit leaf area ranged from 1.6-6.7 mg/dm²/h for P. densiflora and from 3.7-8.9 mg/dm²/h for Q. mongolica, with a maximum in mid-summer. An equation for each species was generated to estimate easily the annual CO₂uptake by total leaf area per tree, which subtracted the CO₂release (i.e. respiration) by leaves and woody organs from the gross CO₂uptake (diurnal uptake and release by leaves). Annual CO₂release by leaves and woody organs accounted for 58-73% of the gross CO₂uptake across tree specimens. Annual CO₂uptake per tree increased with increasing dbh (stem diameter at breast height) for the study diameter range, and was greater for Q. mongolica than for P. dellsiflora in the same dbh sizes. This was mainly associated with a greater total leaf area in the former. For example, the annual CO₂uptake by one tree with dbh of 25 cm was 35.6 kg/yr for P. densiflora and 47.9 kg/yr for Q. mongolica. The results from this study can be applied to evaluate an atmospheric CO₂reduction of woody plants by forest type and age class.