AimTo compare field-based evidence of plant and animal responses to fire with remotely sensed signals of fire heterogeneity and post-fire biomass recovery.LocationSouth-eastern Australia; New South Wales.Time Period2019-2022.Major Taxa StudiedA total of 982 species of plants and animals, in eight taxonomic groups: amphibians, birds, fish, insects, mammals, molluscs, plants and reptiles.MethodsWe collated 545,223 plant and animal response records from 47 field surveys of 4613 sites that focussed on areas burnt in 2019-2020. For each site, we calculated remotely sensed signals of fire heterogeneity and post-fire biomass recovery, including the delayed recovery index. Meta-regression analyses were conducted separately for species that declined after fire (negative effect sizes) and species that increased after fire (positive effect sizes) for each buffer size (250 m, 500 m, 1 km, 1.5 km, 2 km and 2.5 km radius).ResultsWe found that species exposed to homogenous high-severity fire (i.e., low fire heterogeneity) were more likely to exhibit decreased abundance/occurrence or inhibited recovery. Areas with delayed recovery of biomass also had significant negative on-ground responses, with lower abundance or occurrence in areas where biomass recovery was slower.Main ConclusionsThe fire heterogeneity index and the delayed recovery index are suitable for inclusion in monitoring and reporting systems for tracking relative measures over time, particularly when field survey data is not available at the landscape scales required to support reporting and management decisions. Locations with remotely sensed signals of delayed recovery should be prioritised for protection against further disturbances that may interfere with the recovery process. Research attention must next focus on how cumulative fire heterogeneity patterns of successive fires affect the post-fire recovery dynamics to further inform the application of remote sensing indicators as management tools for biodiversity conservation.
Urban planning which enhances native biodiversity in and around cities is needed to address the impacts of urbanisation and conserve urban biodiversity. The “Biodiversity Sensitive Urban Design” (BSUD) framework incorporates ecological knowledge into urban planning to achieve positive biodiversity outcomes through improved urban design and infrastructure development. BSUD includes principles to direct strategic design and placement of connected wildlife habitat. However, effective BSUD implementation requires defining and quantifying the landscape-scale habitat connectivity needs of a range of taxon groups within urban contexts. The aim of our study was to use expert elicitation to address these gaps in landscape-scale habitat connectivity currently limiting the capacity of urban planning. We estimated habitat connectivity needs for seven representative taxon groups in urban environments, including ideal habitat, habitat constraints, barriers to movement, and movement thresholds that determine habitat connectivity. In using expert elicitation to quantify habitat connectivity requirements for urban biodiversity, our study provides insights on both the usefulness of expert elicitation to inform urban habitat connectivity planning generally, and the functional habitat connectivity requirements of our focal taxon groups specifically. Overall, we consider our expert-derived estimates of connected habitat to be a highly useful set of baseline data for habitat and connectivity modelling and urban planning for a range of taxon groups.
With large wildfires becoming more frequent1,2, we must rapidly learn how megafires impact biodiversity to prioritize mitigation and improve policy. A key challenge is to discover how interactions among fire-regime components, drought and land tenure shape wildfire impacts. The globally unprecedented3,4 2019-2020 Australian megafires burnt more than 10 million hectares5, prompting major investment in biodiversity monitoring. Collated data include responses of more than 2,000 taxa, providing an unparalleled opportunity to quantify how megafires affect biodiversity. We reveal that the largest effects on plants and animals were in areas with frequent or recent past fires and within extensively burnt areas. Areas burnt at high severity, outside protected areas or under extreme drought also had larger effects. The effects included declines and increases after fire, with the largest responses in rainforests and by mammals. Our results implicate species interactions, dispersal and extent of in situ survival as mechanisms underlying fire responses. Building wildfire resilience into these ecosystems depends on reducing fire recurrence, including with rapid wildfire suppression in areas frequently burnt. Defending wet ecosystems, expanding protected areas and considering localized drought could also contribute. While these countermeasures can help mitigate the impacts of more frequent megafires, reversing anthropogenic climate change remains the urgent broad-scale solution.
Threatened ecosystem conservation requires an understanding of the effectiveness of management and the challenges hindering successful protection and recovery. Bringing together researchers, land managers and policymakers to identify key threats, management needs, and knowledge gaps provides a unified account of the evidence and tools needed to improve threatened ecosystem management. We undertook a research prioritization process for Australian alpine and subalpine peatlands with experts across policy, research, and management. Through individual interviews, structured group discussions, and voting, we generated 25 priority research questions that, if addressed, would enhance our capacity to conserve peatlands. Knowledge gaps spanned four topics: understanding peatland dynamics, impacts of threats, methods to manage these, and the effectiveness of management. Consistent monitoring standards, an open-access knowledge platform and commitment to long-term joint research and management were identified as vital. This collaboration enabled development of a shared agenda of research priorities to target knowledge gaps for informing policy and management of threatened alpine peatlands. Our findings substantiate the importance of stronger ongoing collaboration among researchers, land managers and policymakers across jurisdictions to support conservation.
Monitoring aquatic biodiversity through DNA extracted from environmental samples (eDNA) combined with high-throughput sequencing, commonly referred to as eDNA metabarcoding, is increasing in popularity within the scientific community. However, sampling strategies, laboratory protocols and analytical pipelines can influence the results of eDNA metabarcoding surveys. While the impact of laboratory protocols and analytical pipelines have been extensively studied, the importance of sampling strategies on eDNA metabarcoding surveys has not received the same attention. To avoid underestimating local biodiversity, adequate sampling strategies (i.e. sampling intensity and spatial sampling replication) need to be implemented. This study evaluated the impact of sampling strategies along an altitudinal and biodiversity gradient in the upper section of the Murrumbidgee River (Murray-Darling Basin, Australia). An eDNA metabarcoding survey was used to determine the local fish biodiversity and evaluate the influence of sampling intensity and spatial sampling replication on the biodiversity estimates. The results show that optimal eDNA sampling strategies varied between sites and indicate that river morphology, species richness and species abundance affect the optimal sampling intensity and spatial sampling replication needed to accurately assess the fish biodiversity. While the generality of the patterns will need to be confirmed through future studies, these findings provide a basis to guide future eDNA metabarcoding surveys in river systems.