Fine Root and Rhizosphere Respiration of Young Scots Pine Seedlings under Elevated and Ambient CO2

Abstract

Effects of elevated atmospheric CO2 on fine root respiration and rhizosphere respiration were assessed in three-year old Scots pine (Pinus sylvestris L.) seedlings. Besides significant effects of high CO2 on root production, fine root respiration per unit dry mass was significantly enhanced. This increase under elevated CO2 was related to a higher nitrogen concentration of the roots in the elevated treatment. Rhizospheric respiration was also strongly enhanced. This effect lasted throughout the whole growing season, but could have been solely due to increases in fine root biomass and respiration.