New research published in Nature Climate Change has highlighted the role of mature forests in the climate change fight.
In their study, researchers from the University of Birmingham’s Institute of Forest Research (BIFoR) have found that older trees respond to increased atmospheric CO2 levels by increasing the production of woody biomass. This, they said, counters existing theories that mature woodland has no capacity to respond to elevated CO2 levels.
However, BIFoR Director and Professor Rob MacKenzie said that even if the increase in tree growth translates to a medium-term increase in carbon storage in forests, this “in no way offers a reason to delay reductions in fossil fuel consumption.”
The experts found exposure to elevated levels of the greenhouse gas increased wood production by an average of 9.8 per cent over a seven-year period.
No corresponding increase in production of material such as leaves or fine roots, which release CO2 into the atmosphere relatively quickly, could be detected, it was shared.
These findings come from data from the long-running free-air CO2 enrichment (FACE) experiment at the University of Birmingham’s Institute of Forest Research (BIFoR).
Researchers at BIFoR are conducting the FACE experiment in a 180-year-old 52-acre woodland in central England populated by 26-metre-tall English oak trees.
The researchers began changing the atmosphere around the forest in 2017, measuring the effect of elevated CO2 on wood production by using laser scanning to convert measured tree diameters into wood mass.
“Our findings refute the notion that older, mature forests cannot respond to rising levels of atmospheric CO2, but how they respond will likely depend on the supply of nutrients from the soil,” said lead author Professor Richard Norby from the University of Birmingham.
“Evidence from BIFoR FACE of a significant increase in woody biomass production supports the role of mature, long-established forests as natural climate solutions in the coming decades while society strives to reduce its dependency on carbon,” Norby outlined.
Professor Iain Hartley, from the University of Exeter, added that the protection of mature forests remains an “important priority for climate change mitigation.”
MacKenzie noted that the results, at about the halfway point of its 15-year experiment at BIFoR FACE, will prove “invaluable” for policymakers around the globe as they grapple with the complexities of climate change.
The BIFoR FACE experiment will continue into the 2030s to analyse long-term responses and the interactions between forest carbon, other plant nutrients and the forest food web.