title: CO2-induced growth enhancements of co-occurring tree species decline at different rates.
abstract: To elucidate how enriched CO2atmospheres, soil fertility, and light availability interact to influence the long-term growth of tree seedlings, six co-occurring members of temperate forest communities including ash (Fraxinus americana L.), gray birch (Betula populifolia), red maple (Acer rubrum), yellow birch (Betula alleghaniensis), striped maple (Acer pensylvanicum), and red oak (Quercus rubra L.) were raised in a glasshouse for three years in a complete factorial design. After three years of growth, plants growing in elevated CO2atmospheres were generally larger than those in ambient CO2atmospheres, however, magnitudes of CO2-induced growth enhancements were contingent on the availability of nitrogen and light, as well as species identity. For all species, magnitudes of CO2-induced growth enhancements after one year of growth were greater than after three years of growth, though species' growth enhancements over the three years declined at different rates. These results suggest that CO2-induced enhancements in forest productivity may not be sustained for long periods of time. Additionally, species' differential growth responses to elevated CO2may indirectly influence forest productivity via long-term species compositional changes in forests.
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, 02138, Cambridge, MA, USA.
authors.forename: F A
authors.initials: FA
authors.lastname: Bazzaz
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, 02138, Cambridge, MA, USA.
authors.forename: S L
authors.initials: SL
authors.lastname: Miao
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, 02138, Cambridge, MA, USA.
authors.forename: P M
authors.initials: PM
authors.lastname: Wayne
keywords: Acer; Betula; Elevated CO2 atmospheres; Forest productivity; Quercus