URBANA, ILConsider the cumulative stresses that transplanted trees must endure from the time they are harvested until they become established in a landscape. Multiple stress factors can mean the difference between survival and death for trees. For starters, when "balled-and-burlapped" trees are dug prior to transport, the majority of the root system is often separated from the tree. After this initial stress, trees are typically taken to a loading site and placed on trucks or trailers for shipment. At each stage of the transplanting process, trees are exposed to mechanical shock and vibration that can further disrupt the root system and cause considerable injury.
As if these issues are not harmful enough, trees are not usually watered during transport. If they are not covered to limit evaporation, the trees are apt to suffer additional damage. Transplanted trees can also be subjected to rapidly changing temperatures and humidity levels as they are moved from sunny to shady sites, from low to high elevations, in and out of box trailers, and across plant hardiness zonesall of which may occur in the course of a few hours. All these stress factors can add up to significant trauma, shock, and even death for these vulnerable trees.
Although any one of these stress factors may be the sole cause of a tree's death or decline, it is more likely a combination of stress factors that leads to trees' reduced growth or death after planting. Water stress, mechanical damage, or extreme temperatures alone may be sufficient to severely damage or kill a transplanted tree; when these stressors are combined, the prospect of trees' survival in the landscape is greatly reduced.
Andrew K. Koeser, J. Ryan Stewart, Germn A. Bollero, and Donald G. Bullock from the University of Illinois at Urbana-Champaign, and Daniel K. Struve from The Ohio State University recently published a study in HortScience that examines the impact of stress on balled-and-burlap
|Contact: Michael W. Neff|
American Society for Horticultural Science