Land clearing threatens biodiversity, impairs the functioning of terrestrial, freshwater, and marine ecosystems, and is a key contributor to human-induced climate change. The rates of land clearing in the State of Queensland, Australia, are at globally significant levels, and have been the subject of intense and polarised political debate. In 2016, a legislative bill that aimed to restore stronger controls over land clearing failed to pass in the Queensland Parliament, despite the clear scientific basis for policy reform. Here, we provide a short history of the recent policy debate over land clearing in Queensland, in the context of its global and national ecological significance. Land clearing affects regional climates, leading to hotter, drier climates that will impact on the Queensland economy and local communities. Loss of habitat from land clearing is a key threatening process for many endangered animals and plants. Runoff from land clearing results in sediment and nutrient enrichment, which threatens the health of the Great Barrier Reef. Australia has made national and international commitments to conserve biodiversity and reduce our greenhouse gas emissions, but current land clearing policies are not consistent with these commitments. Stronger regulation is needed to reduce vegetation loss, such as target-based regulation, which sets a cap on land clearing and could effectively halt vegetation loss over the long term. Lasting policy reform is required, and we recommend an effective policy mix that restricts clearing, provides economic opportunities for vegetation retention, and informs the Australian community about the value of native vegetation.

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Aim: The persistence of animal populations depends on individuals moving successfully around a landscape, but habitat fragmentation can hinder this by reducing functional connectivity. The proximate cause of population declines in fragmented habitat is dependent on the spatial and temporal scales of movement restrictions. Location: Global.Methods: We present a conceptual framework highlighting the relationship between spatial and temporal scales, and three mechanisms through which detrimental impacts can occur when movement is disrupted in fragmented landscapes: limited resource access, restricted demographic exchange and impeded gene flow. We then review the literature to identify the proportion of studies conducted on each mechanism and whether biases existed in how often each was studied among different geographic zones or taxa. A random selection of 250 articles was classified by the mechanism, geographic region and taxon studied in each article.Results: Our conceptual framework highlighted that each of the three mechanisms tends to be characterized by movement restriction at progressively larger spatial and temporal scales. In our literature review, we found that the overwhelming majority (77%) of articles investigated impeded gene flow, and only 17% and 10% explored restricted demographic exchange and limited resource access, respectively. Work on limited resource access was disproportionately low for particular taxonomic groups, such as reptiles and amphibians.Main conclusions: Distinguishing which mechanisms are disrupted in a particular system is crucial because addressing each is likely to require a distinct conservation management response. We encourage greater focus on the less-studied mechanisms of restricted demographic exchange and limited resource access. K E Y W O R D Sdemographic rescue, food availability, genetic diversity, habitat fragmentation, habitat loss, literature review, matrix, spatial scale, structural connectivity

Habitat loss, fragmentation, and degradation are the leading causes of faunal population declines.Substantial effort has been invested in identifying how these landscape changes are related to population parameters. However, to effectively mitigate declines, we must understand the underlying mechanisms impacted by landscape change. Woodland-dependent avian insectivores seem particularly vulnerable, and decline at rates disproportionately greater than other foraging guilds. This pattern suggests that reduced food availability in less-wooded landscapes may be a contributing factor. However, the evidence supporting this hypothesis is sparse. I adopted a multidisciplinary approach to investigate the mechanisms driving population changes of an avian insectivore in highly-modified landscapes by integrating physiological indices with measures of prey availability and landscape structure. First, I presented a framework for conceptualising how the spatiotemporal scale of fragmentation influences the mechanisms impacting populations. I then used the eastern yellow robin (Eopsaltria australis) in the Brigalow Belt South bioregion of southern Queensland to test the importance of local and landscape factors on robin site occupancy, prey density, and robin condition. I also investigated whether an index of chronic stress could be used to predict changes to robin occurrence and identify potential threats to the population. I concluded this work by conducting a supplementary feeding experiment to determine whether food availability was causing the variation in robin condition. A pilot study conducted in the study region four years earlier found that robins were more physiologically stressed (had higher heterophil:lymphocyte ratios) in sites with less woodland in the surrounding landscape, but site occupancy was unrelated to woodland cover. Re-examining the same study system, I established that woodland cover was now the strongest predictor of iii occupancy. While woodland cover at a local scale (within 500 m) was important for robin persistence, woodland cover at a broader scale relevant to dispersal movements (within 5 km) was not. While my stress index could not accurately predict the precise locations of future extirpations, patterns of stress indices (birds were more stressed where woodland cover was lower) did foreshadow a change to the pattern of occurrence. Extirpations from sites with low levels of woodland cover were balanced by colonisations of more-wooded sites. Surprisingly, I found that arthropod prey density was greater at sites that had less surrounding woodland. This result was primarily driven by a large number of Formicidae (ants). However, Formicidae have low nutritional value and once they were excluded from the results, soil moisture, not woodland cover, became the primary determinant of arthropod density. I predicted that robin condition would be strongly associated with arthropod density, but this was not the case. Instead, robins had elevated stress levels at sites with apparently more-favourable...

Habitat loss and fragmentation are causing widespread population declines, but identifying how and when to intervene remains challenging. Predicting where extirpations are likely to occur and implementing management actions before losses result may be more cost-effective than trying to reestablish lost populations. Early indicators of pressure on populations could be used to make such predictions. Previous work conducted in 2009 and 2010 identified that the presence of Eastern Yellow Robins (Eopsaltria australis) in 42 sites in a fragmented region of eastern Australia was unrelated to woodland extent within 500 m of a site, but the robins' heterophil:lymphocyte (H:L) ratios (an indicator of chronic stress) were elevated at sites with low levels of surrounding woodland. We resurveyed these 42 sites in 2013 and 2014 for robin presence to determine whether the H:L ratios obtained in 2009 and 2010 predicted the locations of extirpations and whether the previous pattern in H:L ratios was an early sign that woodland extent would become an important predictor of occupancy. We also surveyed for robins at 43 additional sites to determine whether current occupancy could be better predicted by landscape context at a larger scale, relevant to dispersal movements. At the original 42 sites, H:L ratios and extirpations were not related, although only 4 extirpations were observed. Woodland extent within 500 m had become a strong predictor of occupancy. Taken together, these results provide mixed evidence as to whether patterns of individual condition can reveal habitat relationships that become evident as local shifts in occupancy occur but that are not revealed by a single snapshot of species distribution. Across all 85 sites, woodland extent at scales relevant to dispersal (5 km) was not related to occurrence. We recommend that conservation actions focus on regenerating areas of habitat large enough to support robin territories rather than increasing connectivity within the landscape.