© 1994 Heron Publishing—Victoria, Canada
Shade, leaf growth and crown development of Quercus rubra, Quercus velutina, Prunus serotina and Acer rubrum seedlings
Kurt W. Gottschalk
US Department of Agriculture, Forest Service, Northeastern Forest Experiment Station, 180 Canfield Street, Morgantown, WV
26505-3101, USA / Received July 19, 1993
Summary
The study was conducted in an open field to determine the optimum irradiance for establishment and growth of two oak species
and two major associated woody species. Half-sib seedlings of black cherry (Prunus serotina Ehrh.), red maple (Acer rubrum L.), northern red oak (Quercus rubra L.) and black oak (Q. velutina Lam.) were grown for two years under shade-cloth tents. Eight shade treatments (94, 70, 57, 45, 37, 27, 20 and 8% of full
sunlight) with three replications each were used. Measurements were made on seedlings harvested at the end of the first and
second growing seasons. In the second year, shading significantly decreased the number of leaves for all species except black
cherry, but only significantly decreased leaf area in northern red oak. Shading significantly decreased average leaf size
of red maple. Average leaf size of black cherry was largest in the intermediate shade treatments and decreased significantly
with increased and decreased shade. Leaf weight/leaf area (mg cm–2) increased significantly in a quadratic pattern with decreasing shade for all four species. Leaf area ratio (cm2 g–1) decreased significantly with decreasing shade for all species except red maple in the first year and black oak in the second
year. Total branch development increased significantly with decreasing shade in red maple and northern red oak, whereas indeterminate
branches increased significantly with decreasing shade only in black cherry, and short branches increased significantly with
decreasing shade only in red maple.
Keywords:
black cherry, black oak, branch development, growth analysis, leaf area, leaf area ratio, leaf weight/leaf area, northern
red oak, red maple.
