Maximum crown width equations play an important role the the last 3 decades of American forest management. They play a role in determining the level of competition Krajicek et al. (1961) and in the Gingrich (1967) stocking guide.
We would like to enlist the help of foresters from around the state of Missouri to collect a few open grown tree to assist us in the evaluation of the previous published maximum crown width to diameter equations.
Maximum crown width measurements are taken on open grown trees of all size classes. The trees should be open grown and not experienced suppression in the trees life time. The variables to collect include:
The following table lists the number of current observations in each of the various size classes for the species on interest.
| Species | 0-4 | 4-8 | 8-12 | 12-16 | 16-20 | 20-24 | 24+ | Total |
| Shortleaf Pine | 12 | 36 | 20 | 20 | 31 | 15 | 7 | 141 |
| Black Oak | 0 | 1 | 0 | 0 | 2 | 0 | 1 | 4 |
| Scarlet oak | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Northern Red Oak | 2 | 1 | 3 | 1 | 0 | 1 | 1 | 9 |
| White Oak | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 2 |
| Post Oak | 1 | 0 | 3 | 5 | 4 | 0 | 5 | 18 |
| Hickories | 0 | 0 | 2 | 3 | 0 | 0 | 0 | 5 |
Gingrich, S. F. 1967. Measuring and evaluating stocking and stand density in upland hardwood forest in the central states. Forest Science 13(1):38-53.
Krajicek, J. E., K. A. Brinkman, and S. F. Gingrich 1961. Crown Competition--A measure of density. Forest Science 7(1):35-42.