Using remote sensing for detecting and mapping noxious plants.
Remote sensing techniques offer a timely, cost-effective means to distinguish and measure infestations of noxious plants on rangelands. An overview is presented on the application of aerial photography, airborne videography and satellite sensor imagery for detecting brush and weed species on rangelands in southwestern USA. Ground reflectance measurements are used to determine the spectral characteristics of plant species; phenological stage of plants is important in this process. Computer-based image analysis is used to measure the proportion of landscapes infested by noxious plant species in aerial and satellite images. Plant species distinguished, and in some cases measured, by these techniques include silverleaf sunflower (Helianthus argophyllus), Texas lantana (Lantana horrida), broom snakeweed (Gutierrezia sarothrae), false broomweed (Ericameria austrotexana), spiny aster (Aster spinosus), blackbrush (Acacia rigidula), huisache (Acacia farnesiana), Mexican palo-verde (Parkinsonia aculeata), common goldenweed (Isocoma coronopifolia), Drummond goldenweed (Isocoma drummondii), Chinese tamarisk (Tamarix chinensis), pricklypear (Opuntia lindheimeri), Big Bend locoweed (Astragalus mollissimus var. earlei) and shin oak (Quercus havardii).