SREL Reprint #2732

Photosynthetic potential of laurel oak seedlings following canopy manipulation

K. W. McLeod1 and M. K. Burke2

1Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802
2Center for Forested Wetlands, Southern Research Station, USDA Forest Service, Charleston, SC 29414

Abstract: The theory of forest gap dynamics predicts that replacement individuals are those that can most fully use the light environment gap. Along the Coosawhatchie River in South Carolina, 12 canopy gaps were identified in a bottomland hardwood forest dominated by laurel oak (Quercus laurifolia Michaux). Each gap was enlarged to a uniform size by girdling large trees and removing smaller ones. In each gap, some plots were trenched, while some plots were left intact. Other plots, located in adjacent closed canopy forest, were treated identically. Photosynthetic light response curves of laurel oak seedlings were determined after gap enlargement. Seedling photosynthetic rates were significantly greater in gaps than under closed canopy for all light levels ≥ 150 µmol/m2 per second. Maximum photosynthetic rates were approximately 50 percent of that for seedlings growing in full sunlight. Trenching, which eliminates root competition and increases availability to soil resources, did not affect photosynthesis. Based on these observations, laurel oak seedlings growing in gaps should have greater photosynthesis than those existing under full canopy.

SREL Reprint #2732

McLeod, K. W. and M. K. Burke. 2004. Photosynthetic potential of laurel oak seedlings following canopy manipulation. pp. 513-519 In: K. F. Connor (Ed.). Proceedings of the 12th Biennial Southern Silvicultural Research Conference. Gen. Tech. Rep. SRS-71. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).