Increased fire activity under high atmospheric oxygen concentrations is compatible with the presence of forests

TY - JOUR

T1 - Increased fire activity under high atmospheric oxygen concentrations is compatible with the presence of forests

AU - Vitali, Rayanne

AU - Belcher, Claire M

AU - Kaplan, Jed O

AU - Watson, Andrew J

N1 - © 2022. The Author(s).

PY - 2022/12

Y1 - 2022/12

N2 - Throughout Earth's history, the abundance of oxygen in our atmosphere has varied, but by how much remains debated. Previously, an upper limit for atmospheric oxygen has been bounded by assumptions made regarding the fire window: atmospheric oxygen concentrations higher than 30-40% would threaten the regeneration of forests in the present world. Here we have tested these assumptions by adapting a Dynamic Global Vegetation Model to run over high atmospheric oxygen concentrations. Our results show that whilst global tree cover is significantly reduced under high O2 concentrations, forests persist in the wettest parts of the low and high latitudes and fire is more dependent on fuel moisture than O2 levels. This implies that the effect of fire on suppressing global vegetation under high O2 may be lower than previously assumed and questions our understanding of the mechanisms involved in regulating the abundance of oxygen in our atmosphere, with moisture as a potentially important factor.

AB - Throughout Earth's history, the abundance of oxygen in our atmosphere has varied, but by how much remains debated. Previously, an upper limit for atmospheric oxygen has been bounded by assumptions made regarding the fire window: atmospheric oxygen concentrations higher than 30-40% would threaten the regeneration of forests in the present world. Here we have tested these assumptions by adapting a Dynamic Global Vegetation Model to run over high atmospheric oxygen concentrations. Our results show that whilst global tree cover is significantly reduced under high O2 concentrations, forests persist in the wettest parts of the low and high latitudes and fire is more dependent on fuel moisture than O2 levels. This implies that the effect of fire on suppressing global vegetation under high O2 may be lower than previously assumed and questions our understanding of the mechanisms involved in regulating the abundance of oxygen in our atmosphere, with moisture as a potentially important factor.

KW - Forests

KW - Fires

KW - Trees

KW - Atmosphere

KW - Oxygen

UR - http://www.scopus.com/inward/record.url?scp=85142618104&partnerID=8YFLogxK

U2 - 10.1038/s41467-022-35081-z

DO - 10.1038/s41467-022-35081-z

M3 - Journal article

C2 - 36435885

SN - 2041-1723

VL - 13

SP - 7285

JO - Nature Communications

JF - Nature Communications

IS - 1

M1 - 7285

ER -