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The critically endangered golden sun-moth Synemon plana occurs in urban fringe areas of southeastern Australia that are currently experiencing rapid and extensive development. The urban fringe is a complex and uncertain environment in which to manage threatened species with the intersection of fragmented natural habitats, built environments and human populations generating novel, poorly understood interactions. In this context, management frameworks must incorporate ecological processes as well as social considerations. Here, we explore how biodiversity sensitive urban design might improve the fate of the golden sun-moth, and threatened species generally, in urban fringe environments. We: (i) developed an expert-informed Bayesian Belief Network model that synthesizes the current understanding of key determinants of golden sun-moth population viability at sites experiencing urbanizing pressure; (ii) quantified the nature and strength of cause-effect relationships between these factors using expert knowledge; and (iii) used the model to assess expectations of moth population viability in response to different combinations of management actions. We predict that adult survival, bare ground cover and cover of resource plants are the most important variables affecting the viability of golden sun-moth populations. We also demonstrate the potential for biodiversity sensitive urban design as a complementary measure to conventional management for this species. Our findings highlight how expert knowledge may be a valuable component of conservation management, especially in addressing uncertainty around conservation decisions when empirical data are lacking, and how structured expert judgements become critical in supporting decisions that may help ameliorate extinction risks faced by threatened species in urban environments.

Summary 1.Environmental managers have the difficult task of ensuring species persistence despite considerable uncertainty about their response to management. Spatially-explicit population models provide one solution for simulating the dynamics of species and evaluating alternative management regimes. 2.We used a Bayesian model to investigate wetland occupancy dynamics of the endangered growling grass frog Litoria raniformis at a wastewater treatment plant in southern Victoria, Australia. We coupled prior information from earlier research on this species with our survey data to quantify the effects of patch-scale variables and connectivity on the probabilities of occupancy, population extinction and colonisation. Hydroperiods of 13 sites were experimentally enhanced to bolster occupancy rates by L. raniformis. We used simulations to assess the extent to which the enhanced hydroperiod regime improved the viability of the focal metapopulation. 3.Occupancy rate increased by 15% among the enhanced sites in 2013–2014, whereas the rate of occupancy among unenhanced sites fell by 11% in that year. Forward simulation using the dynamic occupancy model suggested that the minimum occupancy rate across the metapopulation would be 18% higher if the enhanced hydroperiod regime was retained over the next 20 years. 4.Mean posterior effects of patch-scale variables and connectivity on the occupancy dynamics of L. raniformis were consistent with the prior effect in all cases, with only small changes to the size of these effects. There was no clear effect of water chemistry on occupancy dynamics. 5.Synthesis and applications. This work suggests that managing the hydroperiod of constructed wetlands can be an effective tool for the conservation of amphibians, and demonstrates the utility of spatially-explicit models for assessing metapopulation viability. We encourage managers to experimentally test the efficacy of manipulating patch-scale variables to improve occupancy rates within amphibian metapopulations. This article is protected by copyright. All rights reserved.

Fire is an integral disturbance shaping forest community dynamics over large scales. However, understanding the relationship between fire induced habitat disturbance and biodiversity remain equivocal. Ecological theories including the intermediate disturbance hypothesis (IDH) and the habitat accommodation model (HAM) offer predictive frameworks that could explain faunal responses to fire disturbances. We used an 80 year post-fire chronosequence to investigate small reptile community responses to fires in temperate forests across 74 sites. First, we evaluated if changes in species richness, abundance and evenness post-fire followed trends of prior predictions, including the IDH. Second, using competing models of fine scale habitat elements we evaluated the specific ways which fire influenced small reptiles. Third, we evaluated support for the HAM by examining compositional changes of reptile community post-fire. Relative abundance was positively correlated to age post-fire while richness and evenness showed no associations. The abundance trend was as expected based on the prior prediction of sustained population increase post-disturbance, but the trend for richness contradicted the prediction of highest diversity at intermediate levels of disturbance (according to IDH). Abundance changes were driven mainly by changes in overstorey, ground layer, and shelter, while richness and evenness did not associate with any vegetation parameter. Community composition was not strongly correlated to age since fire, thus support for the HAM was weak. Overall, in this ecosystem, frequent fire disturbances can be detrimental to small reptiles. Future studies utilizing approaches based on species traits could enhance our understanding of biodiversity patterns post-disturbance.