Island biogeography is based on the idea that the larger an island, and the less it is isolated from other areas, the higher the biodiversity it contains. The premise of island size contributing to diversity is based on the fundamental ecological concept—the species area relationship (SAR). Wetlands and, in particular, arid zone spring wetlands can be considered islands as they are wetted habitat surrounded by a harsh and dry landscape—“girt by dirt”—forming an ideal setting to study island biogeography. While studies in spring wetlands have identified SARs that conform to the concept, others identified conflicting information. The aim of our study was to assess the relationship between spring wetland wetted area and its aquatic invertebrate taxonomic richness across three of Australia’s Great Artesian Basin spring complexes. Wetted area and aquatic invertebrates were recorded for 32 individual spring wetlands. The constraint that wetted area has on invertebrate taxonomic richness was analysed using quantile regression. ANOSIM was used to compare differences in the invertebrate community between spring complexes. No significant relationship between wetted area and taxonomic richness was identified across all springs, but the aquatic invertebrate community and taxonomic richness was significantly different across the three spring complexes. Analyses were repeated for one spring complex. Increasing wetland size was found to constrain invertebrate taxonomic richness at Edgbaston Springs. These results contrast with the basic SAR concept but can potentially be the result of a “small island effect” where the relationship is overridden by anthropogenic disturbance.

岛屿生物地理学基于这样一种观点，即岛屿越大，与其他地区的隔离越少，它所包含的生物多样性就越高。岛屿大小有助于多样性的前提是基于基本的生态概念——物种面积关系 (SAR)。湿地，特别是干旱区春季湿地可以被视为岛屿，因为它们是潮湿的栖息地，周围环绕着严酷干燥的景观——“泥泞”——形成了研究岛屿生物地理学的理想环境。虽然对春季湿地的研究确定了符合该概念的 SAR，但其他研究确定了相互矛盾的信息。我们研究的目的是评估澳大利亚三个大自流盆地春季复合体的春季湿地湿润面积与其水生无脊椎动物分类丰富度之间的关系。记录了 32 个春季湿地的湿润面积和水生无脊椎动物。使用分位数回归分析了润湿面积对无脊椎动物分类丰富度的约束。ANOSIM 用于比较弹簧复合体之间无脊椎动物群落的差异。所有泉水的润湿面积和分类丰富度之间均未发现显着关系，但三个泉水复合体的水生无脊椎动物群落和分类丰富度存在显着差异。对一个弹簧复合体重复分析。发现增加的湿地面积限制了 Edgbaston Springs 的无脊椎动物分类丰富度。这些结果与基本 SAR 概念形成对比，但可能是“小岛效应”的结果，其中这种关系被人为干扰所覆盖。