Neotropical Forest Dynamics

Abstract

Neotropical forest dynamics are reviewed by focusing on four questions: (1) What is a mature neotropical forest? (2) How long does it take to attain maturity? (3) How important are gaps to species regeneration? and (4) What are the important equilibrium processes in neotropical forest dynamics? The absence of regeneration of dominants has often been used as a distinguishing feature of late secondary forest; however, the abundance of shade-intolerant species in mature forest suggests that local absence of regeneration is an inadequate criterion for distinguishing between late secondary and mature forest. Recent studies estimate forest turnover rates of 75-150 years, indicating tropical forests are much more dynamic than thought previously. The dependence on gaps by almost half of the 320 tree species in a Costa Rican wet forest for successful regeneration illustrates the importance of gaps in tropical forest dynamics. Factors important in determining which species successfully colonize a gap are: time of gap occurrence; proximity and dispersal of seeds; size of gap; substrate conditions; and plant-herbivore interactions.