TABLE 1.

Functional characteristics of the tree species studied.

Species/Trait	Celtis occidentalis	Fraxinus pennsylvanica	Tilia cordata
Foliar carbon (%)	41.0	46.5	47.0
Foliar nitrogen (%)	1.2	2.0	2.7
Foliar carbon/nitrogen	33.9	23.4	18.0
Specific leaf area (mm2 mg–1)	17.3	15.2	18.6
Photosynthetic capacity (μmol CO2 m–2 s–1)	6.0	13.7	15.3
Wood density (mg mm–3)	0.7	0.6	0.4
Growth rate	Moderate	Intermediate	Rapid
Shade tolerance*	Intermediate	Intermediate	Tolerant
Lifespan	Moderate	Short	Moderate

*Data from Niinemets and Valladares (2006).