Biogeographical patterns of zodariid spiders (Araneae: Zodariidae) in the wheatbelt region, Western Australia

Abstract

-117 zodariid species were recorded from the Wheatbelt region of Western Australia after 12 months ot continuous pit trapping ,lt 306 quadrats (12 landform types at each of 24 survey areas), with an average richness of 3,98 per quad rat. Analysis of the data at the landscape scale showed no significant relationships between species composition and substrate at each quadrat, other than a weak north-south changeover in composition. Strongly localised patterns of composition at the species level were overt, with a high proportion of short-range endemic species. However a regional-scale analysis (of species compositional patterns by survey area) showed a distinct relationship with precipitation in the driest period. Also, species richness for each survey area and each landform type revealed a correlation between low richness and both high rainfall and low drainage. Greater knowledge of zodariid ecology is required to determine the possible influence of microhabitats on species composition, INTRODUCTIONThe Zodariidae are medium-sized spiders, currentlv divided into five subfamilies and

Patterns in the composition of ground-dwelling spider communities in the Pilbara bioregion, Western Australia

“…At a broader scale, summer temperatures had some infl uence, again correlated with latitude . The zodariids showed little response to quadrat-level variables but, at a broader scale, summer rainfall appeared to infl uence assemblages (Durrant 2004). It seems that, at regional scales, both temperature (correlated with latitude) and rainfall have the potential to infl uence spider assemblages in all three regions.…”

“…Regional-scale approaches to surveying spiders have been adopted in Western Australia only over the last 20 years, with the Kimberley rainforest survey in the far north (Main 1991), and the Carnarvon Basin (Harvey et al 2000) and agricultural zone surveys (Durrant 2004;Guthrie and Waldock 2004;Harvey et al 2004). All three surveys aimed to document the fauna's composition and distribution across the relevant landscapes, but only the last two could be considered spatially representative and seasonally comprehensive, with 63 and 304 quadrats, respectively, and a sampling time frame that covered a 12 month period.…”

“…All three surveys aimed to document the fauna's composition and distribution across the relevant landscapes, but only the last two could be considered spatially representative and seasonally comprehensive, with 63 and 304 quadrats, respectively, and a sampling time frame that covered a 12 month period. Both surveys revealed patterns of endemism as well as correlations between composition and environmental attributes, both climate and soil (Harvey et al 2000(Harvey et al , 2004Durrant 2004;Guthrie and Waldock 2004). In contrast, other collections of ground-dwelling spiders in north-western Australia have been opportunistic or highly localised.…”