A contribution of root exudation to carbon cycle and its responsibility to environmental conditions in forest ecosystems

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K14609
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Ecology/Environment
• Research Institution: Waseda University
• Principal Investigator: Koizumi Hiroshi 早稲田大学, 教育・総合科学学術院, 教授 (50303516)
• Research Collaborator: TOMOTSUNE Mitsutoshi ; HONDA Asahi ; TANAZAWA Yumina ; MARIKO Shigeru ; MURAOKA Hiroyuki
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 根圏滲出物 / 森林生態系 / 炭素循環 / 生態系純生産 / 純一次生産 / 独立栄養生物呼吸

Outline of Final Research Achievements

To clarify seasonal variation in carbon flux from live root to pedosphere (root exudation) and contribution of it net primary production (NPP), root exudation rate was measured from 2016 to 2017 in two types of forests; dominated by Quercus serrata (deciduous broad-leaved tree; Q forest) and Pinus densiflora (evergreen conifer tree; P forest). Using a new method developed by us, averaged exudation was measured at 0.49 and 1.09 mg C g fine root-1 day-1 in the Q and P forest, respectively. It in Q forest showed significant seasonal variation with high value in summer season, although that in P forest showed no clear seasonal variation. Annual exudation was estimated at 30 and 61 gC m-2 year-1, which contributed to NPP at 2.6 and 9.6%, in Q and P forest, respectively. These results suggest that the root exudation rate vary based on tree functional type, and is important factor to evaluate the carbon balance of forest ecosystem.

Free Research Field

生態系生態学