The Harvard Forest Carbon Budget: Patterns, Processes and Responses to Global Change

How, where and why carbon (C) moves into and out of an ecosystem through time is a long-standing question in biogeochemistry. In forests, C balance both affects and is influenced by disturbance, successional and trophic dynamics, climate change and atmospheric chemistry. The biogeochemistry of C in forests is also key to understanding whether, how, and for how long this important sector of the terrestrial biosphere will mitigate global environmental changes driven by human activity. Here we bring together hundreds of thousands of observations on the C cycle for the Harvard Forest in central Massachusetts, USA, a mid-latitude landscape dominated by closed-canopy forests 80 to> 250 years old that has experienced a land-use history of harvesting, agricultural land clearance and reforestation that is shared by much of eastern North America. We synthesize these data to answer four questions:(i) how much C …