Large-scale colour infrared aerial photographs were obtained for part of a tropical coastal salt-marsh in south-east Queensland, Australia. Print reflectances were classified using a numerical divisive hierarchical procedure and related to field data. Vegetation characteristics such as species, size, dry weight and density were significantly associated with each spectral class al the general (macro) and at the detailed (micro) scales. At the macro scale there were four vegetation types: pure stands of tallSporobolus virginicus; medium-tallSporobolusdominant but with someSarcocornia quinqueftora; a mixed type; and finally a type dominated bySarcocornia. At the micro scale vegetation types were further differentiated by size and dry weight of the two dominant species.