Gas Exchange and Growth of Selected Transplanted and Nontransplanted Landscape Tree Species

Abstract

Gas exchange and growth of transplanted and non-transplanted Acer platanoides `Schwedleri' and Tilia cordata `Greenspire' trees were investigated. This study was conducted on trees planted in 1991 in a field nursery near Logan, Utah. In Spring 1995, three trees of each species were moved with a tree spade to a new location within the nursery and three non-transplanted trees were selected as controls. To simulate landscape conditions, all trees were watered at the time of planting and once per week during the growing season. Pre-dawn water potential, dawn-to-dusk stomatal conductance, mid-day photosynthesis, and growth data were collected over a 2-year period. Transplanted trees of each species were under more water stress (indicated by more negative pre-dawn water potential) than non-transplanted trees. However, pre-dawn water potential of transplanted A. platanoides recovered to near non-transplanted levels, while transplanted T. cordata did not. Dawn-to-dusk studies in 1995 and 1996 showed that stomatal conductance was lower throughout the day in transplanted trees. Once again, transplanted A. platanoides recovered to near non-transplanted levels, while transplanted T. cordata did not. A similar trend for mid-day photosynthesis was found for both species in 1995 and 1996. Transplanted trees of each species had less stem area increase, shoot elongation, and total leaf area than non-transplanted trees for each year. These data indicate that transplanted A. platanoides can recover to near non-transplant pre-dawn water potential and gas exchange levels earlier, and therefore establish faster, than transplanted T. cordata. However, after 2 years neither transplanted tree species were able to fully recover to non-transplanted growth rates.