Aerial tree volume functions for eucalypts in Western Australia

Abstract

Large-scale, fixed-base aerial photography is being used together with ground sampling in a major inventory of eucalypt forest in Western Australia. This paper describes the aerial tree volume functions derived for that inventory, covering species in the jarrah (Eucalyptusmarginata) forest. The equations, derived from ground measurements, predict gross bole volume from estimates of total height and vary with the site quality of the forest. They are used to predict volume from photomeasurements of total height that have been corrected for measurement error. The functions appear suitable for this forest type, although the volumes of veteran trees with severely damaged crowns are underestimated.

Novel 3D geometry and models of the lower regions of large trees for use in carbon accounting of primary forests

“…Incorporating tree height into allometric equations can result in inaccurate outcomes for mature trees, for example after crown loss (e.g. Biggs 1991 ), or crown regeneration. Diameter at breast height-based allometric equations can be inaccurate predictors if, for example, applied to trees of different fire or histories and therefore different hollow sizes ( Adkins 2006 ), or of different senescence, to those from where the allometry was developed.…”

Small format aerial photography: methods and achievements in Australian forestry

“…A strong exponential relationship between bole volume and total tree height (Biggs 1991) was used to estimate stem volumes from photo-measured tree heights in the first phase samples, with adjustments for different species. Tree heights were measured with the parallax method and species were identified on the basis of geographic and topographic location; tree shape, size, and branching pattern; colour of foliage and stems; flowering and associated vegetation.…”