Demographic differentiation among pioneer tree species during old-field succession of a Neotropical rainforest

Early pioneer species share life histories enabling them to colonize disturbed sites, but how much they differ demographically and how such differentiation determines pioneer species turnover during succession are still open questions. Here, we approached these issues by comparing the demography of dominant pioneer tree species during the old-field succession of tropical rainforest in Southeast Mexico.

We assessed changes in population density, population structure, vital rates, and intrinsic population growth rate (r) of the pioneer species Trema micrantha, Cecropia peltata, and Trichospermum mexicanum during the first 35 years of succession. For this, we combined chronosequence and long-term (from 2000 to 2018) data from 14 old-fields with 0.5-35 years fallow age.

Trema colonized and disappeared first during succession (< 15 years), followed by Cecropia (< 28) and Trichospermum (> 31). All species exhibited hump-shaped successional trajectories of population density and...