Lizard assemblage and reserve size and structure in the Western Australian wheatbelt — some implications for conservation

Abstract

Twenty-three reserves in the Western Australian wheatbelt were examined in detail to evaluate the adequacy of the reserve system in the region for the conservation of lizards. We recorded most of the lizard species known from the region and conclude that the reserve system is at present adequate for their conservation. Lizard species richness in wheatbelt reserves does not appear to be related to isolation from adjacent uncleared land, either in space or time, but is related to the ecology of the reserve. Lizard species richness-area relationships for wheatbelt reserves are very similar to the most comparable late-Pleistocene/Holocene continental island lizard faunas; the slopes of the regression lines are not significantly different and the intercepts are only marginally significant. Multiple regression analysis shows that 75% of the variation observed in lizard species richness between reserves is accounted for by the algorithm of the number of vegetation associations on these reserves; addition of other reserve variables examined (including area) does not significantly increase this explained variation. Reserves as small as 30 ha are valuable as sanctuaries for lizards although it is suggested that 1500 ha is an optimum size. Some vegetation formations are more important for lizards than others; woodlands are most important.