Predicting Crown Size and Shape from Simple Stand Variables

Abstract

In an early paper, Berlyn (1962) argued that stem and crown form and size are linked, as both reflect time integrals of production within the crown. Berlyn's results suggest that dimensional relationships among tree components should remain fundamentally stable. Here, I develop predictive relationships relating crown size and shape to stem size for Pinus strobus (L.) in New Hampshire. Live crown ratio (crown length as a fraction of tree height), relative crown width (crown width as a fraction of tree height), and tree height as a fraction of Lorey's height are all dimensionless ratios, and can be predicted from two other dimensionless ratios: a modified version of Wilson's relative spacing (mean tree spacing as a fraction of Lorey's height) and tree diameter as a fraction of stand quadratic mean diameter. These simple models outperform other predictive models employing common measures of tree size and stand density, such as Reineke's stand density index.