ESTIMATING 3-DIMENSIONAL LINE PROCESS DENSITIES FROM TUBE COUNTS

This paper examines the question of inference on three-dimensional lin e process densities from intersection counts with cylinders, when isot ropy of the line process cannot be assumed. It is shown how to modify results derived for planar sections. A motivating application is the s tudy of root development by inserting minirhizotrons into soil. Aspect s of experimental design are suggested, such as placing tubes at an an gle of 54-degrees to the vertical where they will be insensitive to th e degree of anisotropy. The case where axial symmetry may not be assum ed is introduced, and is shown to be considerably more complex. An ana lysis of some experimental data is included.