Here we report the changes in net carbon storage in trees and
soil in a mixed hardwood forest ecosystem in central Massachusetts
in response to a 5 °C increase in soil temperature. The study in-
cludes one large area (30 × 30 m) in which the soil was heated and
an adjacent area (30 × 30 m) as a control. We present results after
8 y, including one pretreatment year followed by 7 y of soil
warming. We quantified changes in plant carbon storage by using
direct measurements of tree growth. To assess changes in soil
carbon storage, we measured soil respiration, fine-root respiration,
and fine-root biomass. We also measured changes in nitrogen
availability in response to soil warming, as this ecosystem is nitrogen
limited (24). This information has provided us with insights into the
importance of carbon–nitrogen interactions in determining net
carbon storage in forests in response to soil warming.