Abstract:
Despite the importance of treefall gaps in tropical forest dynamics, few studies have followed gap-phase processes for more than 2 y. We monitored, for five years, the growth and survival of many seedlings of Tetragastris panamensis (Engler) O. Kuntze, Protium panamense (Rose) I. M. Johnston, and Desmopsis panamensis (Rob.) Saff. (three common tree species of the Panamanian tropical moist forest) in artificially created treefall gaps and under intact-canopy control plots. On these same plots, we also monitored light levels using hemispherical photographs taken over an 8-y period. Seedling height growth was faster in gaps than under intact canopies during the first 42 mo of regrowth, then declined to rates similar to those under intact canopies. Light levels in gaps similarly rose and fell, returning to pre-gap levels by month 48. Only Tetragastris panamensis showed higher survival in gaps, contrary to the general assumption that seedling survival is enhanced by gap creation. Our results document important transition points that mark the conclusion of the gap phase, suggesting an estimate of dry for the duration of the gap phase in this tropical forest.

Author Keywords:
average daily global radiation, Desmopsis, gap phase regeneration, Panama, Protium, Tetragastris, treefall gap, tropical forest

KeyWords Plus:
TROPICAL MOIST FOREST, RAIN-FOREST, TREEFALL GAPS, CANOPY GAPS, NEOTROPICAL FOREST, SEEDLING GROWTH, SURVIVAL, DEFINITION, LIGHT, ENVIRONMENTS

Addresses:
Fraver S, N Carolina State Univ, Dept Forestry, Box 8002, Raleigh, NC 27695 USA
N Carolina State Univ, Dept Forestry, Raleigh, NC 27695 USA
Manomet Ctr Conservat Sci, Manomet, MA 02345 USA
Smithsonian Trop Res Inst, Balboa, Panama
Univ Miami, Dept Biol, Coral Gables, FL 33124 USA

Publisher:
CAMBRIDGE UNIV PRESS, 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA

IDS Number:
139GQ

ISSN:
0266-4674