SREL Reprint #2774




Quercus michauxii regeneration in and around aging canopy gaps

L. L. Battaglia1, B. S. Collins2, and P. B. Weisenhorn3

1Department of Plant Biology, Mailcode 6509, Southern Illinois University, Carbondale, IL 62901, USA
2Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, USA
3Department of Biological Sciences, 202 Life Sciences Building, Louisiana State University,
Baton Rouge, LA 70803, USA

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 levels that did not differ from levels in forest canopy. Seedling height and maximum root depth were greatest in gap centers, 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.

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