Reflectance and image characteristics of selected noxious rangeland species
Everitt, J.H.; Escobar, D.E.; Davis, M.R.
Journal of Range Management 54(2): A106-A120
This paper demonstrates the use of field reflectance measurements and aerial photography (colour-infrared and conventional colour) for distinguishing noxious plant species on rangelands. The visible/near-infrared (0.45-0.90 micro m) reflectance characteristics of several brush and weed species found on rangelands in the USA and Mexico are presented. The phenological stage of plants has an important influence on their spectral characteristics and subsequent detection on aerial photographs. Canopy architecture, vegetative density, and leaf pubescence are also important for distinguishing some species. Reflectance measurements are related to the plant species colour tonal responses on CIR and CC photographs. Plant species addressed include silverleaf sunflower (Helianthus argophyllus), broom snakeweed (Gutierrezia sarothrae), huisache (Acacia smallii [Acacia farnesiana]), Big Bend locoweed (Astragalus mollissimus var. earlei), Wooton locoweed (Astragalus wootonii), and Chinese tamarisk (Tamarix chinensis).