DBH and height show significant correlation with incoming solar radiation: a case study of a radiata pine ('Pinus radiata' D. Don) plantation in New South Wales, Australia

The aim of this study was to determine whether diameter at breast height (DBH, at 1.3 m) and total height of radiata pine ('Pinus radiata' D. Don) trees showed any significant relationships with microsite estimates of solar radiation. A total of 77 plots were established in two even-aged stands of radiata in Nundle State Forest, New South Wales, Australia. Within these plots, tree DBH and height measurements were recorded and their relationships with solar radiation evaluated. Airborne light detection and ranging (LiDAR) data were processed to generate a high resolution digital elevation model (DEM), and the DEM was used for calculating the incoming solar radiation. Overall, at both study sites, taller and larger trees were found on areas with lower solar radiation, possibly due to a lower loss in soil moisture. The findings of this study suggest that LiDAR-derived DEM estimates of solar radiation are significantly correlated with DBH and height variation, and therefore suitable for use as a sub-compartment stratification variable as well as for possible inclusion in fine-scale estimates of 'P. radiata' growth and productivity.