Fig. 3. Seasonal compensation explains the different trends of net CO₂ uptake along tree cover and permafrost gradients in the NHL.

a–c show increasing net CO₂ uptake in the early-growing season (a; EGS: May-Aug) and increasing net CO₂ release in the late-growing season (b; LGS: Sep-Oct) and winter (c; Win: Nov-Apr). d shows the variation in net CO₂ uptake seasonal trends along the 5% tree cover interval gradient in the NHL. Pixels with grey color represent environmental conditions that do not exist.