The wetland habitats, biogeography and population dynamics of Petalura gigantea (Odonata: Petaluridae) in the Blue Mountains of New South Wales

Abstract

Petalura gigantea is a poorly understood dragonfly with a long-lived fossorial larval habit that is unique to the Petaluridae. The species has been recorded from bogs, swamps and seepages of the coast and ranges of New South Wales, including a small number of records in the Blue Mountains. This topographically and hydrogeologically complex landscape includes a widely distributed network of wetlands characterised by considerable heterogeneity in patch size, quality and geographic separation. It provided the opportunity to elucidate the biogeography, and investigate population dynamics of this species at a landscape scale, within the context of metapopulation theory. This study was undertaken between late 2003 and early 2010. The objectives of the biogeographic component were to identify where P. gigantea occurs within the Blue Mountains and why it occurs there. Typologies of existing wetlands were reviewed, and a set of 22 types was identified for use in this thesis. A total of 284 swamps were surveyed, with P. gigantea recorded in 111 of these. The species was recorded from six swamp types, with potential habitat identified in an additional four swamp types. Hydrogeomorphically, these upland mires range from hanging swamps and localised seepage springs to valley-fill impeded-drainage swamps. Petalura gigantea has been observed utilising each of these hydrogeomorphic expressions across a wide range of slopes and patch sizes. All of these swamp types may be considered groundwater dependent ecosystems.

Date of Award	2012
Original language	English