@article {Ghent:1969-12-01T00:00:00:0015-749X:417,
author = "Ghent, A. W.",
title = "Studies of Regeneration in Forest Stands Devastated by the Spruce Budworm--IV. Problems of Stocked-Quadrat Sampling",
journal = "Forest Science",
volume = "15",
number = "4",
year = "1969-12-01T00:00:00",
abstract = "Data from two nested-quadrat studies of boreal forest species confirm that binomial-or Poisson-based formulations greatly exaggerate apparent percent stocking when data from one quadrat size are converted to a larger or smaller quadrat area. Various workers have independently obtained an expression equivalent to F' = 1 - (1 - F)^{r}, where F and F' are the observed and estimated stocking respectively, and where r is the ratio of the two quadrat areas. Empirical assessment of the exponent r indicates that the simple ratio of quadrat sizes yields too large a value, and regression analysis of the required vs. the theoretical exponents yields (1/2 + 1/2r) as a close approximation for the species examined. The slope of the actual vs. theoretical exponents is proposed as an appropriate functional coefficient of contagion. Stocking is shown to be related to population density of balsam fir seedlings along a rectangular hyperbola. A model of a 3-dimensional relation of stocking, quadrat size, and population density is presented and recommended for interpretation of stocked-quadrat data in forest management.",
pages = "417-429",
url = "http://www.ingentaconnect.com/content/saf/fs/1969/00000015/00000004/art00014",
keyword = "Betula papyrifera, Populus tremuloides, Picea spp, contagious distribution, Abies balsamea"
}