CO2 elevation and soil warming reduce cold hardiness of jack pine under photoperiods of seed origin and latitudes of potential migration

• Published in: New forests 2021-09, Vol.52 (5), p.777-790
• Main Authors: Newaz, Shah Md, Dang, Qing-Lai, Man, Rongzhou
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Carbon dioxide; Carboxylation; Climate change; Climate prediction; Cold; Cold hardiness; Environmental conditions; Evergreen trees; Forestry; Gas exchange; Growing season; Injury prevention; Latitude; Life Sciences; Photoperiods; Photosynthesis; Pine; Pine trees; Pinus banksiana; Plant species; Seedlings; Soil temperature; Soils; Water use; Water use efficiency
• ISSN: 0169-4286; 1573-5095
• DOI: 10.1007/s11056-020-09831-0

Climate change is predicted to cause northward migration of boreal tree species. However, the success of such a migration will be determined by trees’ ability to acclimate to the environmental conditions at the potential new site. This study was aimed to assess the interactive effects of changes in photoperiod associated with northward migration and soil warming on the ecophysiological traits of jack pine ( Pinus banksiana Lamb.) under different carbon dioxide concentrations [CO 2 ]. We examined the responses of foliar gas exchange and seedling cold hardiness after exposing 1-year old seedlings to two [CO 2 ] (400 and 950 µmol mol −1 ), two soil temperatures (growing season average at seed origin and 5 °C warmer) and three photoperiod regimes (seed origin, and 5° and 10° further north) for one growing season. We found that the CO 2 elevation significantly increased photosynthetic rate measured at treatment CO 2 , photosynthetic water use efficiency, maximum rate of carboxylation and triose phosphate utilization. Some of the effects were modified by photoperiod. Furthermore, the CO 2 elevation and soil warming both reduced seedling cold hardiness, as indicated by increases in injury index. The lack of interactions between photoperiod and other treatments (elevated [CO 2 ] and soil temperature) suggests that young jack pine seedlings may have the ability to acclimate to the new photoperiod regimes at higher latitudes north of the seed origin.