How much carbon a forest ecosystem can sequester is determined by both post-disturbance regrowth and environmentally modified growth. Disturbance causes sharp declines in the short term and is followed by regrowth in the long term. Environmental change may alter carbon accumulation through increasing CO₂, nitrogen deposition, and climate change. Regrowth and modified growth occur simultaneously, yet they are usually studied separately and assessed using an additive approach. Alternatively, an interactive approach using hierarchical models can address their concurrent nature and evaluate their joint effects. Hierarchical models are informed by forest age data, which have recently become available at global scales. The age-based hierarchical framework provides a coherent and feasible way to integrate regrowth and modified growth in understanding forest dynamics.

R Project for Statistical Computing