Stand density management diagram

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A Stand Density Management Diagram is best described as a “simple biological model relating yield and density at any stage of stand development” [1]. Stand density management diagrams are used in forest management and designed to use current stand density to project what the future of the stand will look like.[2] One major reason for the effectiveness of density management diagrams is the relatively low effect of site variance on the diagram’s shape. Density management diagrams are a transformation of the traditional ideas held in stocking diagrams. Gingrich came up with the idea of comparing basal area per acre, trees per acre, and quadratic mean diameter in one graph. He called this the stocking diagram.[1] These same principles are used to make the stand density management diagram work [3]. Basal area and density are plotted against one another and quadratic mean diameter lines are plotted through the plot.

The diagram itself is comprised of a plot of the Natural log (ln) of the volume or yield against the natural log]] of stems per acre. Just like a stocking diagram, the A-line, B-line, and C-line are plotted. In addition, the -3/2 rule maximum density line is plotted just above the A-line.[1] The diagram works well for even aged, single cohort stands. However, it is not as effective with uneven aged stands.[2]

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  1. ^ a b c Kershaw, J. A., and B.C. Fischer. 1991. A stand density management diagram for sawtimber sized mixed upland central hardwoods. pp. 414-428 in McComick, L.H. and Gottschalk, K.W., eds. Proceedings, 8th Central hardwood forest conference.
  2. ^ a b British Columbia Ministry of Forestry. How to use a stand density management diagram. Published 1997. Accessed 17 March 2008.
  3. ^ Fischer