August 2008


“Deep Roots Research”, by Gary Johnson, Ph.D., University of Minnesota, Extension Professor. Deep or buried root systems have been causing problems for arborists for decades. When root systems stop functioning normally, the entire tree system begins a progressive decline in health and stability.  For almost fifteen years, the University of Minnesota has been studying the effects of three types of dysfunctional root systems:  buried roots, stem girdling roots (SGRs), and pot-bound root systems.  This webcast will focus on the SGR frequency surveys,predisposition to wind storm failures, and the effectiveness of root pruning techniques.

Supporting Material:

Documents and Files:

Web Links:

Environmental Literacy:

  • Natural Inquirer - This first edition monograph series of the Natural Inquirer explores the relationship between carbon, photosynthesis, and roots of trees.

Other Resources:

Archived Video:

You can view this month’s webcast below using the embedded video viewer. Just click on Play and the video will start momentarily. Alternatively, you may download a copy to your own PC. Simply right-click on the provided link and save the presentation to your desktop or other appropriate directory. You can then open the file once it is downloaded and view it by using the default Windows Media Player software.

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Download the file in Windows Media (WMV) format.

Northern Research Station
United States Department of Agriculture
USDA Forest Service


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