Faunas of unflooded saline wetland floors of the Western Australian wheatbelt

Abstract

-Five saline wetlands in the Western Australian wheatbelt were surveyed for their terrestrial invertebrate fauna (Araneae, Scorpionida, Coleoptera, Dermaptera, Formicidae and lsopoda). Surveys were restricted to dry lake floor and fringing samphire and woodlands with the aim of assessing whether there are species of native fauna restricted to one or more of these habitats. A total of 356 species were recorded (123 spiders, 6 scorpions, 173 beetles, 45 ants, 4 earwigs and 4 isopods). Of these, 198 were from the inundation zone (lake floor and samphire zones) and 229 from woodland; only 72 species were common to both areas. Thus, the inundation zone fauna is not a subset of that found in woodland. Assemblage richness and structure differed between wetlands, reflecting recorded levels of regional diversitv. Classification and ordination of the data reflected differences in faunal~omposition both between habitats and between geographic areas, although all woodland habitats were more closely related to each other than to either lake floor or samphire habitats from the same wetland.Permanent inundation of the wetlands surveyed would adversely affect the fauna associated with inundation zones. Further surveys are required to determine the extent of these effects and whether the species occur at neighbouring wetlands.