A Simple Distance Estimator for Plant Density in Nonuniform Stands


The following is part of a study of the Texabama Croton (Croton alabamensis var. texensis), a threatened species, done by DLS Associates of Austin, TX.  A density estimate was needed for the croton population on the Fort Hood military base, where a large population was present. The population density varied significantly from place to place, making the standard Point-centered Quarter Method inapplicable. I invented a new method which uses the same data as the PCQ method but combines the data in a way that is not invalidated by systematic variation in density along a transect. 

    My new formula has been tested both by computer simulations and in the field, and is always more accurate than the standard method when density is not uniform. This new formula should replace the standard PCQ formula in all applications, since plant density is virtually never uniform.

    I want to thank my boss at the time, David Steed, and my coworker Dan Thompson for their support in the development of this formula.