Evidence of autumn phenology control on annual net ecosystem productivity in two temperate deciduous forests

Phenology exercises a critical control on annual carbon uptake by terrestrial ecosystems. Autumn phenology, while less studied relative to spring phenology, may also constrain annual net ecosystem productivity (NEP). Using 17-year (1992–2008) records of C flux phenology (CFP) derived from continuous eddy covariance (EC) measurements at the Harvard Forest (HF), here we show that the autumn phenology played a more significant role than the spring …