Assessing forest canopy density in a highly variable landscape using Landsat data and FCD Mapper software

Summary

Forest canopy density (FCD), estimated with the FCD Mapper, was correlated with basal area and predominant height (PDH) for 48 field plots, measured in highly variable native eucalypt forest at Toolara, south-eastern Queensland, Australia. The Mapper was produced for the International Tropical Timber Organisation and is available on a CD-ROM. It estimates FCD as an undefined index of canopy density using reflectance characteristics of Landsat Enhanced Thematic Mapper images. The Mapper is a ‘semi expert’ computer program which uses interactive screens to allow the operator to make decisions concerning the classification of land into bare soil, grass or forest. The results of a FCD classification are therefore dependent on the operator's decisions and were found to be highly sensitive to small changes in settings. A positive, weak (r ² = 0.36) nonlinear relationship of FCD with basal area was observed, while a strong (r ² = 0.68) similar relationship was observed between FCD and PDH. The strong relationship of FCD with PDH suggests that this remote sensing technique has promise for forest inventory, but that a quick and robust method of measuring FCD in the field is still required for ground truthing.

Keywords:

• land classification
• forests
• forest inventories
• assessment
• remote sensing
• landsat
• multispectral imagery
• canopy
• stand density
• Queensland