A critical feature of tree growth regulation involves functionally balancing the top of the tree with the bottom. Concepts of shoot / root ratios and how a tree can maintain a resource balance between apparently competing needs have been proposed and tested for accuracy. Of all the working models examined, one form has proven over the last two decades to serve in simply describing regulatory partitioning between shoot and root in trees. This model is called a “Thornley” model, although many derivations and more refined systems exist.
WSFNR-17-04 Coder.pdf (316.4 KB)
Community and Urban Forestry