查看更多>>摘要：? 2021 Elsevier LtdKenya's wildlife has been declining substantially for decades, due to rapid human population growth and its associated impacts on natural habitats. Predators and scavengers are particularly sensitive to anthropogenic pressures, and their changing status has corresponding impacts on the ecosystem services they provide. To estimate rates of change in Kenya's raptor populations we compared linear encounter rates (individuals 100 km?1) recorded during road surveys conducted in 1970–1977 and 2003–2020. Encounter rates for 19 out of 22 species examined had fallen, by a median of 70% among those showing a significant or near-significant change. No species had increased significantly. Declines had occurred among all vulture and large eagle species, and were especially pronounced among once-common small and medium-sized raptors. Our findings demonstrate the importance of protected areas (PAs) for Kenya's remaining raptor populations. The median encounter rate for vultures and large eagles had dropped by 23% within PAs and by 76% in unprotected areas. Smaller species showed divergent trends in relation to PA status, their median encounter rate increasing by 104% within PAs while declining by 85% elsewhere. Based on projected declines over three generation lengths, 45% of the species examined would qualify as nationally Endangered or Critically Endangered. Key threats include electrocution/collision with energy infrastructure, deliberate and incidental poisoning, and impacts associated with habitat degradation. Kenya's raptor declines could be reversed through enhanced management of PAs, mitigation of specific threats and the implementation of species recovery plans; all requiring steadfast government commitment and close collaboration with conservation stakeholders.
查看更多>>摘要：? 2021We surveyed epiphytic and epixylic lichens in eleven 1-hectare forest plots located in representative old-forest stands in four distinct regions of Great Britain that are well-known centres of lichen biodiversity. We aimed to analyse the patterns of lichen biodiversity in these important biodiversity hotspots from a British perspective. In total, we recorded 550 lichen species in 11 ha, i.e. 73% of the presently known British epiphytic and epixylic lichen flora. Species richness per site was regionally stratified and varied from 126 to 235 species. Although the presence of frequent species coincided with total species richness in the respective hotspot, rare species (those with <50 records in Great Britain since 2000) were more balanced among hotspots and relatively independent of species richness. Species turnover contributed significantly and evenly to the species composition regardless of species richness so that hotspots did not have nested structure, typical for the hotspots in Central Europe. Although British hotspots generally shared more species within regions than between regions, geographic distances between regions did not correspond with the differences in species composition. The results document the importance and irreplaceability of the surveyed hotspots for lichen diversity in Great Britain, notwithstanding their current species richness and past depletion due to long-term acid deposition and habitat degradation.
查看更多>>摘要：? 2021 Elsevier LtdTurtles are among the most threatened vertebrate groups, and reconstruction of population and distributional trends can be important for evaluating their status and defining conservation targets. Using a two-phase modeling approach along with occurrence records and field surveys, our objectives were to: estimate the potential and current distributions of the wood turtle (Glyptemys insculpta), a semi-terrestrial fluvial specialist of range-wide conservation concern; assess how climate, geomorphology, and land-use relate to its distribution; and estimate habitat loss. Using 1061 occurrences in the northeastern US with stream geomorphology and climate data, we created distribution models at sub-regional scales to estimate that 24% of stream km in the region are potentially suitable for wood turtles. Suitable stream habitat is generally lower gradient, higher sinuosity, and higher flow than random, but varies significantly by subregion, suggesting that distribution or habitat models built at the regional or range-wide level may miss important local variation in habitat and climatic needs at finer scales. We then used landscape composition at multiple spatial scales to predict results from standardized field surveys from 78 sites across 9 states to estimate habitat loss. We estimate that 58% of potential habitat is degraded based on landscape composition. Results support previous observations of decline and habitat loss in the wood turtle, driven by landscape degradation at scales larger than the typical home range, necessitating conservation intervention at multiple spatial scales, and underscoring the importance of models that address locally varying and scale-dependent relationships between species and habitats.
查看更多>>摘要：? 2022High-capacity wells (HCWs) are known to reduce groundwater discharge to fens and impact their floristic quality, but whether HCW impacts have become predictive of fen floristic quality across large areas has not been studied. Here we used Thiem-equation-estimated drawdown as an indicator of regional HCW impacts to predict floristic quality, floral richness, and community composition in fens throughout their Wisconsin (USA) range. This indicator of HCW influence (HCWinfluence) was associated with a strong decline in floristic quality measures and native-species richness, while non-native-species richness increased sharply. Fuzzy Set Ordination of community data suggested estimated drawdown was associated with the loss of high coefficient-of-conservatism graminoids and forbs, specialist species, and state-listed rare species. The abundance of non-native species and weedy natives increased with increasing HCW impact. The fact that our indicator of HCW influence has become predictive of fen quality and community composition statewide suggests that HCWs are a driver of floristic quality across large areas, and that possible declines in fen quality due to cumulative impacts should be addressed before siting wells.
查看更多>>摘要：? 2022 Elsevier LtdThe long-distance, unpredictable movement patterns of nomadic species make them challenging to monitor and conserve. Critically endangered regent honeyeaters Anthochaera phrygia once roamed south-eastern Australia in ‘immense flocks’ but now number fewer than 300 wild birds over a vast 300,000 km2 range. Regent honeyeaters are a rare example where extensive monitoring data are now available for a nomadic species, enabling evaluation of the impact of management actions using population viability analysis (PVA). We combined demographic estimates from wild population monitoring in the 1990s, a zoo-based supplementation program and a contemporary range-wide monitoring program to simulate the wild population trajectory under various management and climatic scenarios. Without intervention, our models predicted extinction within 20 years, and showed that management strategies at their current intensity have limited efficacy to prevent extinction. Conservation actions should aim to increase the size and density of the wild population so that Allee effects no longer suppress population growth. Protection of wild regent honeyeater nests is essential as breeding success has declined over recent decades and droughts increasingly reduce breeding opportunities. Our models emphasise the need for zoo-based breeding to bolster the wild population, but show that release of zoo bred birds into the wild only slows the rate of population decline. To recover the wild regent honeyeater population, the next five years will be critical for implementing the most effective conservation strategy. This requires a combination of nest protection and release of zoo-bred birds with improved fitness, predator suppression, habitat protection and increased rates of habitat restoration.
查看更多>>摘要：? 2022 Elsevier LtdConservation actions need to target ecological mechanisms of species declines to be effective, but these mechanisms are often opaque. Shifting balance of competition is one pathway to species declines. Competitive coexistence is maintained only where competitive pressures balance across space. As resources change and new resources are introduced or disappear across landscapes, so should competition outcomes. We tested how novel anthropogenic disturbances affect this competitive landscape in a region with a diverse large carnivore community. We modelled fine-resolution spatiotemporal co-occurrence of wolverine (Gulo gulo), an at-risk Nearctic facultative scavenger, and other competing carnivores. We posed hypotheses about the different interspecific interactions – competition, predation, and facilitation – that could affect wolverine distribution across a gradient of anthropogenic disturbance. We used an information-theoretic model-selection framework to weigh evidence for hypotheses about the outcomes of interspecific interactions, inferred from habitat selection in relation to co-occurrence or segregation with other carnivores. Wolverine occurrence in space and time was explained by anthropogenic disturbance features and coyote co-occurrence at sites, revealing that coyote occurrence is a synergistic factor with anthropogenic disturbance. Wolverine were generally segregated from coyotes and avoided linear features; however if wolverine and coyotes did co-occur, they were twice as likely to co-occur at sites with linear features. Thus linear features increased opportunity for coyotes—a generalist species thriving in human disturbed landscapes – to compete with wolverines. We suggest this threat of increased competition is a mechanism potentially contributing to broad-scale wolverine range recessions from increasingly disturbed areas. Landscape change manifests as more than just physical disturbances: it alters the ecological processes that structure communities. These processes contribute to declines of species that cannot adapt to the novel disturbance features. We emphasize competition as an overlooked outcome of landscape change that could inform better conservation decisions to stem species declines.
Cunha E.L.T.P.Marcolino C.Soares-Filho B.Sparovek G....
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查看更多>>摘要：? 2021Fake controversies have influenced policy making on health and environmental issues for decades, resulting in major implementation setbacks worldwide. As a case study, in this paper we examine fake controversies produced by a small group of active Brazilian researchers that have seriously impacted environmental conservation, particularly in issues related to deforestation and climate change. Based on the literature, we develop a typology of strategies deployed in fake controversies, which include manufacturing uncertainty, misusing scientific credentials, and disregarding scientific literature. Afterwards, we examine the influence of this group of contrarians at the National Congress. We then analyze the fake controversies promoted by these contrarians and argue that, to properly understand them, we need to consider a strategy so far overlooked in the literature: the manufacture of “pseudo-facts”, namely, affirmations at odds with the established literature but that strives to appear as scientific facts. Unlike other contexts, in which contrarians have mainly sought to cast doubt on consensual issues by arguing that there are still considerable uncertainties surrounding them, in Brazil pseudo-facts on deforestation have been produced and published outside the peer-reviewed literature. We conclude the study with recommendations on how to oppose fake scientific controversies that threaten environmental conservation in general.
NSTL
Elsevier