気候変動との戦いの最前線には成熟した森林が不可欠(Mature forests vital in frontline fight against climate change)

2024-08-09 バーミンガム大学

＜関連情報＞

• https://www.birmingham.ac.uk/news/2024/mature-forests-vital-in-frontline-fight-against-climate-change
• https://www.nature.com/articles/s41558-024-02090-3

二酸化炭素濃度上昇下で温帯成熟林の木質バイオマス生産が促進される Enhanced woody biomass production in a mature temperate forest under elevated CO2

Richard J. Norby,Neil J. Loader,Carolina Mayoral,Sami Ullah,Giulio Curioni,Andy R. Smith,Michaela K. Reay,Klaske van Wijngaarden,Muhammad Shoaib Amjad,Deanne Brettle,Martha E. Crockatt,Gael Denny,Robert T. Grzesik,R. Liz Hamilton,Kris M. Hart,Iain P. Hartley,Alan G. Jones,Angeliki Kourmouli,Joshua R. Larsen,Zongbo Shi,Rick M. Thomas & A. Robert MacKenzie
Nature Climate Change  Published:12 August 2024
DOI:https://doi.org/10.1038/s41558-024-02090-3

Abstract

Enhanced CO₂ assimilation by forests as atmospheric CO₂ concentration rises could slow the rate of CO₂ increase if the assimilated carbon is allocated to long-lived biomass. Experiments in young tree plantations support a CO₂ fertilization effect as atmospheric CO₂ continues to increase. Uncertainty exists, however, as to whether older, more mature forests retain the capacity to respond to elevated CO_2. Here, aided by tree-ring analysis and canopy laser scanning, we show that a 180-year-old Quercus robur L. woodland in central England increased the production of woody biomass when exposed to free-air CO₂ enrichment (FACE) for 7 years. Further, elevated CO₂ increased exudation of carbon from fine roots into the soil with likely effects on nutrient cycles. The increase in tree growth and allocation to long-lived woody biomass demonstrated here substantiates the major role for mature temperate forests in climate change mitigation.