Quercus michauxii regeneration in and around aging canopy gaps
L.L. Battaglia, B.S. Collins, and P.B. Weisenhorn
Abstract: Floodplain forests are subject to frequent
windstorms, which create canopy gaps and microtopographic heterogeneity.
Forest regeneration may be enhanced when light and microtopographic conditions
are both favorable, but slower growing canopy species may still require
multiple disturbance events to reach the canopy. In 2001, we revisited
a cohort of Quercus michauxii Nutt. seedlings planted in 1995
on pit-mound microsites that were constructed in and around canopy gaps
to determine patterns of seedling persistence and investigate the effects
of canopy openness and microtopography on seedling survival and growth.
After 7 years, canopy openness in gap centers had decreased to lev- els
that did not differ from levels in forest canopy. Seedling height and
maximum root depth were greatest in gap cen- ters, where light was initially
greater but seedling growth rates declined over time. Soil moisture was
greater in pits, where establishment and survival were very low. Roots
of some seedlings reached from mound surfaces to depths and moisture levels
comparable to those of adjacent pits, which might facilitate survival
in both floods and droughts. Quercus michauxii can persist on
elevated sites in aging gaps, and positive feedback in sites favorable
for recruitment can enhance seedling growth; ascent into the canopy will
likely require additional canopy-opening events.
SREL Reprint #2774
Battaglia, L. L., B. S. Collins and P. B. Weisenhorn. 2004. Quercus michauxii regeneration in and around aging canopy gaps. Canadian Journal of Forest Research 34:1359-1364.
