Potential of colour-infrared digital camera imagery for inventory and mapping of alien plant invasions in South African shrublands

Australian Acacia plant species invade the fynbos biome of southern Africa and threaten the exceptionally high plant diversity in the Cape Floristic R egion. We examine the utility of very-high spatial resolution (0.5 m) colou r infrared (CIR) digital image data for discriminating Acacia species from native fynbos vegetation, other alien vegetation and bare ground. Image dat a were acquired at a very low cost with a single-chip, digital CIR camera m ounted on a light aircraft. Shrub and tree features were uniquely identifie d using visual or computer-assisted interpretation. However, increases in d ynamic range and accuracy of interpolation schemes for the single chip sens or will be required if semi-automatic and accurate mapping of invasive plan ts is to be achieved.