Drivers and mechanisms of tropical secondary forest succession

Summary

Global land-use and climate changes drive the loss of old-growth tropical forests and lead to the expansion of young tropical secondary forests. This thesis assessed drivers and mechanisms of tropical secondary forest succession in two key successional phases (stand-initiation phase and stand-thinning phase) across three hierarchical scales (species, community and ecosystem) in two climates (dry and wet) and two countries (Ghana and Mexico). I found that 1) in the stand-initiation phase, exogeneous factors such as macroclimate and land-use intensity determine fine-scale differences in starting conditions, and thus the direction of successional trajectories, and 2) in the stand-thinning phase, endogenous factors such as light competition shift tree growth patterns and drive species replacement, and thus determine the pace of forest succession. These results not only increase our fundamental understanding of tropical forest succession, but also provide recommendations on when, where and how to use natural regeneration for forest and ecosystem restoration.