Cross-sectional area relationships in root systems of loblolly and shortleaf pine

Abstract

The relationship between cross-sectional root area at groundline and composite root area (the sum of the areas of the first-order lateral roots plus the area of the taproot subtending the most distal lateral root) was examined in 3- to 9-year-old loblolly and shortleaf pine (Pinustaeda L. and P. echinata Mill.). For both species, root area at groundline and composite root area were highly correlated, and the slopes in equations relating the two root areas were close to 1.0. These results imply that (i) the pipe model of tree form is appropriate for young root systems, and (ii) the development of basal stem diameter is directly related to root system development.