Testing models of unthinned red pine plantation dynamics using a modified Bakuzis matrix of stand properties

The comprehensive graphical matrix of even-aged stand property inter-dependence, first developed by E.V. Bakuzis, facilitates identification and understanding of the relationship among stand properties. Bakuzisʹ original matrix of eight stand properties, contained 64 cells, was symmetric, but only about 11 of the 64 relationships had shown enough regularity among species to have been named. In this paper I simplify the Bakuzis matrix by reordering the rows and columns to make a more compact, lower triangular arrangement of eight rules or law-like relationships. I then demonstrate matrix use by looking for structural flaws in two models of unthinned red pine (Pinus resinosa) plantation dynamics in the Lake States (Minnesota, Wisconsin, and Michigan) (stems and redpine), and one from Ontario (yield tables from Petawawa). Flaws were found in each source of projections. redpine violates the Sukachev effect, predicts trees will have larger diameters on poor sites than on good sites, and that site has a significant effect on the mean height-stem frequency relation All bi-variate relations for the Petawawa data are identical, which violates several rules. The stems program does the poorest job of the three methods of predicting unthinned red pine plantation stand development, primarily because site index has very little effect on any of the stand variables.