Changing temperature response of respiration turns boreal forest from carbon sink into carbon source

Sammanfattning

Seventeen years (1997-2013) of carbon dioxide (CO2) fluxes were measured in a boreal forest stand in northern Sweden using the eddy covariance technique. During the measurement period the forest turned from a net carbon sink into a net carbon source. The net ecosystem exchange (NEE) was separated using values from periods of darkness into the gross components of total ecosystem respiration (TER) and gross primary productivity (GPP), which was calculated as GPP=-NEE + TER. From the gross components we could determine that an increase in TER during the autumn (September to end of November) and spring (March to end of May) periods resulted in the forest becoming a net source of CO2, We observed no increase in the GPP from the eddy covariance measurements. This was further supported by measurements of tree growth rings. The increased TER was attributed to a change in the forest's temperature response at lower temperatures (-5 to 10 degrees C) rather than to a temperature increase. This study shows that changes in ecosystem functioning can have a larger impact on the carbon balance than climate warming per se. (C) 2016 Elsevier B.V. All rights reserved.

Nyckelord

Eddy covariance; Carbon dioxide exchange; Temperature response; Boreal forest; Carbon balance; Respiration

Publicerad i

Agricultural and Forest Meteorology
2016, volym: 223, sidor: 30-38
Utgivare: ELSEVIER SCIENCE BV

SLU författare

• Hadden, David

  • Institutionen för ekologi, Sveriges lantbruksuniversitet
    

• Grelle, Achim

  • Institutionen för ekologi, Sveriges lantbruksuniversitet
    

Globala målen (SDG)

SDG15 Ekosystem och biologisk mångfald

UKÄ forskningsämne

Skogsvetenskap
Meteorologi och atmosfärforskning
Klimatforskning

Publikationens identifierare

• DOI: https://doi.org/10.1016/j.agrformet.2016.03.020

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/79684