Fire has been a source of global biodiversity for millions of years. However, interactions with anthropogenic drivers such as climate change, land use, and invasive species are changing the nature of fire activity and its impacts. We review how such changes are threatening species with extinction and transforming terrestrial ecosystems. Conservation of Earth’s biological diversity will be achieved only by recognizing and responding to the critical role of fire. In the Anthropocene, this requires that conservation planning explicitly includes the combined effects of human activities and fire regimes. Improved forecasts for biodiversity must also integrate the connections among people, fire, and ecosystems. Such integration provides an opportunity for new actions that could revolutionize how society sustains biodiversity in a time of changing fire activity.

Diversifying selection between populations that inhabit different environments can promote lineage divergence within species and ultimately drive speciation. The mitochondrial genome (mitogenome) encodes essential proteins of the oxidative phosphorylation (OXPHOS) system and can be a strong target for climate-driven selection (i.e., associated with inhabiting different climates). We investigated whether Pleistocene climate changes drove mitochondrial selection and evolution within Australian birds. First, using phylogeographic analyses of the mitochondrial ND2 gene for 17 songbird species, we identified mitochondrial clades (mitolineages). Second, using distance-based redundancy analyses, we tested whether climate predicts variation in intraspecific genetic divergence beyond that explained by geographic distances and geographic position. Third, we analysed 41 complete mitogenome sequences representing each mitolineage of 17 species using codon models in a phylogenetic framework and a biochemical approach to identify signals of selection on OXPHOS protein-coding genes and test for parallel selection in mitolineages of different species existing in similar climates. Of 17 species examined, 13 had multiple mitolineages (range: 2-6). Climate was a significant predictor of mitochondrial variation in eight species. At least two amino acid replacements in OXPHOS complex I could have evolved under positive selection in specific mitolineages of two species. Protein homology modelling showed one of these to be in the loop region of the ND6 protein channel and the other in the functionally critical helix HL region of ND5. These findings call for direct tests of the functional and evolutionary significance of mitochondrial protein candidates for climate-associated selection.

Aim To understand how environmental conditions and landscape structure interact at different spatial scales to shape the community composition of arid zone aquatic invertebrates with different dispersal abilities.Methods For each of five drainage basins and for their encompassing region (Pilbara), we built matrices of dissimilarities in presence-absence patterns of aquatic invertebrate community composition. This was carried out for all taxa collectively and separately for five dispersal trait groups: obligate aquatics, passive aerial dispersers, animals moving by aerial phoresy, weak and strong fliers. We analysed correlations between community dissimilarities and (1) dissimilarities in local environmental conditions, (2) geographic distances and (3) landscape resistance distances among the sites from which invertebrates were sampled. Calculation of landscape resistances accounted for longitudinal connectivity along the river channels (least-cost-path), lateral connectivity between streams and the potential effects of rugged topography on invertebrate dispersal. ResultsLocal environmental factors and landscape resistances explained differences in community composition at the regional scale. In basins with complex topography, local environmental conditions were the main factor explaining community dissimilarities in most dispersal groups. Conversely, in basins where flatter topography meant that moderate to high lateral connectivity between streams is possible, the spatial configuration of the dendritic network determined the community composition of most dispersal trait groups. Geographic and least-cost-path distances were poor predictors of community composition. None of the groups showed a consistent correlation with environmental factors alone, or just landscape resistances, across all basins.Main conclusions Local environmental conditions, hydrological connectivity and landscape resistance to dispersal are all important influences on community composition of arid zone aquatic invertebrates. The impact of each of these factors varies with dispersal trait group and spatial configuration of basins: the importance of lateral connectivity for explaining a substantial proportion of community composition points to a major role of flooding regimes in maintaining biological communities.