Source or Sink? Carbon Dynamics in Eastern Old-Growth Forests and Their Role in Climate Change Mitigation

For decades forest scientists have thought that old-growth temperate forests were either carbon neutral or even carbon sources, emitting more greenhouse gases to the atmosphere through respiration and decomposition than they were absorbing through photosynthesis. However, recent research has questioned that assumption, showing that eastern old-growth forests may remain productive and have net positive carbon uptake later into succession and stand development than previously thought. These findings remain contentious and yet have profound implications for our understanding of the role of high-biomass, late successional forests in global carbon budgets. Emerging science strongly supports conservation of old-growth forests and management for old-growth structure as effective strategies in global efforts to reduce carbon dioxide emissions and moderate the intensity of future climate change (Luyssaert et al. 2008; Keith et al. 2009; Burrascano et al. 2013).