Searching for the Super Tree

It is now recognized that trees and shrubs planted within towns and cities face a multitude of environmental stresses detrimental to their health. Drought and heat waves have become more predominant over the past few years with record heat temperatures recorded world-wide annually. Consequently, inappropriate species selection can be short-lived planting schemes as 100'000's of plants degenerate and die as they fall victim to one stress, or another. This talk will discuss the processes by which trees are selected for urban plantings and if the right choices being made? If not, what alternative options are available to enable more appropriate species/site selection. These questions will become of greater importance as future resource allocations to urban tree management are likely to decline, increasing pressure to deliver superior services at less costs. Results from ongoing research trials by the author will show how many tree species exist that possess superior drought and heat tolerance which are under utilized in urban planting schemes. In addition, this talk will address important physiological characteristics within a tree that confer robustness to heat and drought stress and so offer a means to identify tree species with inherent heat and drought tolerance. Finally, the importance of provenance selection will be highlighted as a means of offering an abundance of largely untapped genetic resource to select for stress tolerance.