title: Leaf photosynthetic characteristics of seedlings of actinorhizal Alnus spp. and Elaeagnus spp.
abstract: Single leaf photosynthetic characteristics of Alnus glutinosa, A. incana, A. rubra, Elaeagnus angustifolia, and E. umbellata seedlings conditioned to ambient sunlight in a glasshouse were assessed. Light saturation occurred between 930 and 1400 μmol m(-2)s(-1) PAR for all species. Maximum rates of net photosynthesis (Pn) measured at 25°C ranged from 12.8 to 17.3 μmol CO2m(-2)s(-1) and rates of dark respiration ranged from 0.74 to 0.95 μmol CO2m(-2)s(-1). These values of leaf photosynthetic variables are typical of early to midsuccessional species. The rate of Pn measured at optimal temperature (20°C) and 530μmol m(-2)s(-1) PAR was significantly (p<0.01) correlated with leaf nitrogen concentration (r=0.69) and negatively correlated with the mean area of a leaf (r=-0.64). We suggest that the high leaf nitrogen concentration and rate of Pn observed for Elaeagnus umbellata and to a lesser degree for E. angustifolia are genetic adaptations related to their crown architecture.
authors.affiliation: Department of Forestry, University of Illinois, 110 Mumford Hall, 1301 West Gregory Drive, 61801, Urbana, IL, USA.
authors.forename: B
authors.initials: B
authors.lastname: Côté
authors.forename: R W
authors.initials: RW
authors.lastname: Carlson
authors.forename: J O
authors.initials: JO
authors.lastname: Dawson