Patterns in the composition of ground-dwelling araneomorph spider communities in the Western Australian wheatbelt

WA Museum Records and Supplements | Updated 7 years ago

ABSTRACT – Ground-dwelling araneomorph spiders were sampled at 304 quadrats chosen to represent the geographical extent and diversity of uncleared terrestrial environments in a 205 000 km2 area known as the Western Australian wheatbelt. A total of 744 species comprising 39 families were recorded, of which the families Salticidae (121 species), Zodariidae (117), Theridiidae (80), Lycosidae (61), Oonopidae (46) and Lamponidae (41) exhibited a marked species-level radiation. For analysis, families with a high proportion of arboreal species, and quadrats that were often flooded or overtly affected by secondary salinity, were excluded. Thus, a total of 622 species from 240 quadrats were analysed, with an average of 21.9 (s.d. = 8.3) species per quadrat. Most of the variation observed in the patterns of species composition could be explained in terms of summer temperature, precipitation seasonality, soil salinity and pH attributes. Assemblage species richness was constrained by soil salinity, except for the Lycosidae which showed a positive relationship.