POST-DISTURBANCE ABOVEGROUND BIOMASS ACCUMULATION IN GLOBAL SECONDARY FORESTS

Abstract

To examine rates of aboveground biomass accumulation (ABA) in global secondary forests following stand-clearing disturbances, we compiled aboveground biomass data from 283 known-age plots drawn from chronosequence and long-term studies. We focused on three likely influences on ABA for which data are readily available: climate, soil texture, and forest type. Growing-season degree-years (GSDY, stand age × growing-season length × growing-season temperature) generally predicted ABA better than stand age alone. Using regression analyses and slope homogeneity tests, we determined that broadleaf forest plots on sandy textured soils exhibited slower GSDY-adjusted ABA than those on nonsandy soils. On nonsandy soils, the GSDY-adjusted ABAs of tropical and nontropical plots were indistinguishable; tropical forest post-disturbance ABA was not particularly slow. Compared to broadleaf forests, needle-leaf forest, GSDY-adjusted ABA was less sensitive to soil texture and was intermediate in rate between sandy and nonsandy broadleaf forest ABA. Foliar nutrient concentration did not significantly influence the GSDY-adjusted ABA of a subset of the nonsandy broadleaf forests for which foliar nutrient data were available. At the global scale, differences in climate (represented by growing-season length and temperature) and moisture-holding capacity (represented by soil texture) are the principal independent factors influencing ABA in most post-disturbance secondary forests.