ABSTRACT

Line intersect sampling (LIS) is a form of pps sampling in which the sampling unit consists of a line or transect. Also widely known as line intercept sampling, LIS was popularized in forestry and ecology literature by Canfield (1941) in a Journal of Forestry article concerned with estimating the density of range vegetation. It is clear, however, that the use of a line as the sampling unit was not novel with this exposition; see, for example, Rosiwal (1898), Clements (1905), Schumacher & Bull (1932), and Bauer (1936). Canfield (1941, p. 388) provided the statistical basis for estimating density “through randomization in the locations of the sampling units.” Within the natural resources literature, alone, the range of application of LIS has been very broad, having been used, for example, for the estimation of boundary length, diversity indices, fuelwood loading, plant canopy and area coverage, forest gap size, root length, logging residue, and standing basal area. Presently, LIS is used widely to estimate the abundance of coarse woody debris (CWD) and woody detritus on the forest floor.