J Plant Ecol ›› 2014, Vol. 7 ›› Issue (6): 535-543.

• Research Articles •

### Effects of elevated carbon dioxide concentration and soil temperature on the growth and biomass responses of mountain maple (Acer spicatum) seedlings to light availability

Gabriel Danyagri* and Qing-Lai Dang

1. Faculty of Natural Resources Management, Lakehead University, Thunder Bay, Ontario P7B 6 5E1, Canada
• Received:2013-04-18 Accepted:2013-11-09 Published:2014-11-20
• Contact: Danyagri, Gabriel

Abstract: Aims Some shade-tolerant understory tree species such as mountain maple (Acer spicatum L.) exhibit light-foraging growth habits. Changes in environmental conditions, such as the rise of carbon dioxide concentration ([CO2]) in the atmosphere and soil warming, may affect the performance of these species under different light environments. We investigated how elevated [CO2] and soil warming influence the growth and biomass responses of mountain maple seedlings to light availability.
Methods The treatments were two levels of light (100% and 30% of the ambient light in the greenhouse), two [CO2] (392 μmol mol-1 (ambient) and 784 μmol mol-1 (elevated)) and two soil temperatures (T soil) (17 and 22°C). After one growing season, we measured seedling height, root collar diameter, leaf biomass, stem biomass and root biomass.
Important findings We found that under the ambient [CO2], the high-light level increased seedlings height by 70% and 56% at the low T soil and high T soil, respectively. Under the elevated [CO2], however, the high-light level increased seedling height by 52% and 13% at the low T soil and high T soil, respectively. The responses of biomasses to light generally followed the response patterns of height growth under both [CO2] and T soil and the magnitude of biomass response to light was the lowest under the elevated [CO2] and warmer T soil. The results suggest that the elevated [CO2] and warmer T soil under the projected future climate may have negative impact on the colonization of open sites and forest canopy gaps by mountain maple.

Aims Some shade-tolerant understory tree species such as mountain maple (Acer spicatum L.) exhibit light-foraging growth habits. Changes in environmental conditions, such as the rise of carbon dioxide concentration ([CO2]) in the atmosphere and soil warming, may affect the performance of these species under different light environments. We investigated how elevated [CO2] and soil warming influence the growth and biomass responses of mountain maple seedlings to light availability.
Methods The treatments were two levels of light (100% and 30% of the ambient light in the greenhouse), two [CO2] (392 μmol mol-1 (ambient) and 784 μmol mol-1 (elevated)) and two soil temperatures (T soil) (17 and 22°C). After one growing season, we measured seedling height, root collar diameter, leaf biomass, stem biomass and root biomass.
Important findings We found that under the ambient [CO2], the high-light level increased seedlings height by 70% and 56% at the low T soil and high T soil, respectively. Under the elevated [CO2], however, the high-light level increased seedling height by 52% and 13% at the low T soil and high T soil, respectively. The responses of biomasses to light generally followed the response patterns of height growth under both [CO2] and T soil and the magnitude of biomass response to light was the lowest under the elevated [CO2] and warmer T soil. The results suggest that the elevated [CO2] and warmer T soil under the projected future climate may have negative impact on the colonization of open sites and forest canopy gaps by mountain maple.