Datensatz

Zusammenfassung

This chapter presents a modelling approach to quantify and understand successional patterns in aboveground carbon stock changes, with a focus on the old-growth stage. The model integrates extensive datasets on tree traits and species composition in different United States forest types to explore the carbon-balance imprint of successional changes in traits (maximum height, longevity, wood density, and woody-detritus decay-rates). The model was validated with old-growth biomass data from the literature. Traits differed more between conifers and hardwoods than between successional guilds within these phylogenetic groups. Conifers have, on average, greater maximum height and longevity than hardwoods. Within conifers, maximum height increases and wood density decreases with successional status. The model suggests that successions progressing towards late-successional conifers tend to accumulate carbon during the old-growth stage. In contrast, successions progressing from pioneer conifers to late-successional hardwoods tend to lose carbon. Overall, however, carbon stock declines were rare among the 106 successions analysed, with the majority exhibiting constant or increasing old-growth carbon stocks. This result is consistent with data from forest chronosequences.