Seasonal and Individual Variation in Leaf Quality of Two Northern Hardwoods Tree Species

Abstract

Seasonal trends in five traits of sugar maple (Acer saccharum Marsh.) and yellow birch (Betula allegheniensis Britt.) leaves thought to influence feeding by herbivores were measured from 17 May through 19 September, 1979. Total nitrogen and water contents declined and toughness increased through the growth season. These seasonal changes were more pronounced in sugar maple than in yellow birch. Total polyphenol contents and tanning coefficients of leaf extracts from both species reached a season high by the end of May and changed very little after that date; these patterns differ from those reported by several other investigators. Sugar maple leaf extracts exhibited much higher tanning coefficients than did those of yellow birch, a finding which is consistent with current plant defense theory. Significant differences in total polyphenol content and tanning coefficients were found between individual trees in yellow birch, but not sugar maple. The relationship between successional status, leaf quality traits, and variability in these traits in forest trees is discussed.

The reciprocal interaction of angiosperm evolution and tetrapod herbivory

“…Species that are relatively r-selected are more likely to respond to herbivory by regrowth than by protective mechanisms (Schultz et al, 1982;Finegan, 1984;Danell and Huss-Danell, 1985). Such r-selected forms may produce defensive chemicals, but generally they are metabolically inexpensive compounds that are less effective in deterring herbivory than the tannins and other compounds more typical of evergreen, K-selected trees (Coley et al, 1985).…”

Variation in Lupinus arboreus alkaloid profiles and relationships with multiple herbivores

“…The composition and concentration of defensive compounds in individual plants is determined by a variety of environmental factors (Hagele and Rowell-Rahier, 1999;Ralphs and Gardner, 2001;Skaanild et al, 2001), including season (Feeny, 1970;Dement and Mooney, 1974;Schultz et al, 1982;Bowers et al, 1992), site elevation , resource availability (Johnson et al, 1989;Nitao et al, 2002) and previous herbivory (Karban and Baldwin, 1997), as well as genetic variation between populations (Bowers et al, 1992;Wink and Carey, 1994;Berenbaum and Zangerl, 1998) and individuals (Berenbaum and Zangerl, 1992). Thus, individual phenotypic variation can be a result of genetic variation, environmental variation, and their interactions (Falconer, 1989).…”

Leaf fracture toughness and sclerophylly: their correlations and ecological implications

“…Penetrometers have been frequently employed for measuring leaf toughness, particularly in investigations of herbivory (Feeny, 1970;Cherrett, 1972;Schultz, Nothnagle & Baldwin, 1982;Waller, 1982;Coley, 1983;Lowman & Box, 1983;Raupp, 1985;Ayres & MacLean, 1987;Howard, 1988;Larsson & Ohmart, 1988;Cavalier & Goldstein, 1989;Ernst, 1989;Tuomi et al, 1989;Aide & Zimmerman, 1990;Bjorkman & Anderson, 1990;Jing & Coley, 1990;Medina, Garcia & Cuevas, 1990;Nichols-Orians & Schultz, 1990;Reich et al, 1991).…”