Abstract
Cylindrical data are bivariate data composed of a linear and an angular component. One can use uniform, first-order (one maximum and one minimum) or second-order (two maxima and two minima) models to relate the linear component to the angular component. Crown radii can be treated as cylindrical data when the azimuths at which the radii are measured are also recorded. The radius is the linear component, while the azimuth is the angular component. Crown radii were measured as part of a hardwood forest research project at Arkansas Post National Memorial near Gillett, AR. The forest is composed of various stands of upland and bottomland hardwoods. Basic descriptive statistics, and uniform, first-order and second-order models were used to examine the circular patterns of crown radii by species.
Parent Publication
Citation
Doruska, Paul F.; Liechty, Hal O.; Marshall, Douglas J. 2003. Modeling hardwood crown radii using circular data analysis. In: Van Sambeek, J. W.; Dawson, Jeffery O.; Ponder Jr., Felix; Loewenstein, Edward F.; Fralish, James S., eds. Proceedings of the 13th Central Hardwood Forest Conference; Gen. Tech. Rep. NC-234. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Research Station: 359