© 2003 Heron Publishing—Victoria, Canada
Factors influencing red expression in autumn foliage of sugar maple trees
P. G. Schaberg (1, 2), A. K. van den Berg (3), P. F. Murakami (1), J. B. Shane (4) and J. R. Donnelly (4)
1. USDA Forest Service, Northeastern Research Station, South Burlington, VT 05403, USA / 2. Author to whom correspondence should be addressed (pschaberg@fs.fed.us) / 3. The University of Vermont, Proctor Maple Research Center, Underhill Center, VT 05490, USA / 4. School of Natural Resources, The University of Vermont, Burlington, VT 05405, USA / Received May 15, 2002; accepted September 6, 2002; published online March 3, 2003
Summary
We evaluated factors influencing the development of autumn red coloration in leaves of sugar maple (Acer saccharum Marsh.) by measuring mineral nutrient and carbohydrate concentrations, water content, and phenology of color development
of leaves from 16 mature open-grown trees on 12 dates from June through October 1999. Mean foliar nutrient and carbohydrate
concentrations and water content were generally within the range published for healthy sugar maple trees. However, foliar
nitrogen (N) concentrations were near deficiency values for some trees. The timing and extent of red leaf coloration was consistently
correlated with both foliar N concentrations and starch or sugar concentrations, which also varied with N status. Leaves of
trees with low foliar N concentrations turned red earlier and more completely than those of trees with high foliar N concentrations.
Low-N trees also had higher foliar starch concentrations than high-N trees. During the autumn development of red leaf coloration,
foliar starch, glucose and fructose concentrations were positively correlated with red leaf color expression. At peak red
expression, the concentrations of glucose, fructose, sucrose and stachyose were all positively correlated with red color expressed
as a percent of total leaf area.
Keywords:
anthocyanins, carbohydrates, fall color, leaves, nitrogen.
