Conservation Letters最新文献

Climate change is threatening marine systems, and its widespread and dynamic effects are creating challenges for designing and managing marine protected areas (MPAs). The majority of recommendations for climate-resilient MPAs focus on enhancing ecological resilience to disturbance and updating management strategies to respond as changes occur. Here, we assess how existing recommendations for climate resilience are applied in real-world MPA management, using criteria from five key management components: objectives, assessments, design, monitoring, and management. Our review evaluates 172 management plans for 555 MPAs across 52 countries and written in nine languages. We find that MPA management plans contain many underlying scientific and management principles for promoting resilience to climate change, even when “climate change” or related terms are not specifically included: plans include long-term objectives (93.6%), threat-reduction strategies (99.4%), monitoring programs (97.7%), and adaptive management (93%). However, there is substantial variation in the degree to which plans explicitly incorporate climate change into their strategies, from not mentioning it at all (21.5%) to developing detailed climate change-specific action plans (20.9%), with most somewhere in between. In addition to identifying common gaps across management plans, we also provide practical examples of activities MPA managers are undertaking to address climate change.

Illegal fishing, unregulated bycatch, and market demand for certain products (e.g., fins) are largely responsible for the rapid global decline of shark and ray populations. Controlling trade of endangered species remains difficult due to product variety, taxonomic ambiguity, and trade complexity. The genetic tools traditionally used to identify traded species typically target individual tissue samples, and are time-consuming and/or species-specific. Here, we performed high-throughput sequencing of trace DNA fragments retrieved from dust and scraps left behind by trade activities. We metabarcoded “shark-dust” samples from seven processing plants in the world's biggest shark landing site (Java, Indonesia), and identified 61 shark and ray taxa (representing half of all chondrichthyan orders), more than half of which could not be recovered from tissue samples collected in parallel from the same sites. Importantly, over 80% of shark-dust sequences were found to belong to CITES-listed species. We argue that this approach is likely to become a powerful and cost-effective monitoring tool wherever wildlife is traded.

Our planet is facing increasing challenges: climate change, biodiversity loss, pandemics, poverty, and many other problems closely linked to a deteriorating environment. Meanwhile, one of our most important assets, rangers working in protected and conserved areas responsible for managing large tracts of the planet's lands and waters, are often underutilized, underrecognized and underequipped. They are generally left out of the debate about conservation and sustainable development policy, despite being central to the success of those policies. This paper outlines the need for global leaders across multiple sectors to recognize the profession of rangers as essential planetary health workers and to position rangers more effectively within global conservation and environmental policy mechanisms. It introduces the challenges facing rangers, the emerging diversity of roles within the ranger profession and the important contribution of rangers to conservation and sustainable development. It presents policy and implementation avenues to improve recognition and professionalization of rangers as key executors of conservation and development policy, particularly considering the recent Global Biodiversity Framework ambitions.

Interventions of the host–pathogen dynamics provide strong tests of relationships, yet they are still rarely applied across multiple populations. After American bullfrogs (Rana catesbeiana) invaded a wildlife refuge where federally threatened Chiricahua leopard frogs (R. chiricahuensis) were reintroduced 12 years prior, managers launched a landscape-scale eradication effort to help ensure continued recovery of the native species. We used a before-after-control-impact design and environmental DNA sampling of 19 eradication sites and 18 control sites between fall 2016 and winter 2020–2021 to measure community-level responses to bullfrog eradication, including for two pathogens. Dynamic occupancy models revealed successful eradication from 94% of treatment sites. Native amphibians did not respond to bullfrog eradication, but the pathogens amphibian chytrid fungus (Batrachochytrium dendrobatidis) and ranaviruses were coextirpated with bullfrogs. Our spatially replicated experimental approach provides strong evidence that management of invasive species can simultaneously reduce predation and disease risk for imperiled species.

Finance is a precondition for many of the activities that harm ecosystems, but how to address this underlying driver of biodiversity loss remains a topic of debate. This paper reviews the Task Force on Nature-Related Financial Disclosures (TNFD), a corporate-led effort that aims to identify how changes to biodiversity may create financial risks for companies and investors. This approach is also promoted as a strategy for managing the impact of business on biodiversity, with the assumption that risk disclosure will more effectively price biodiversity-harming activities. We assess the potential of the TNFD toward this end, and invite conservation scientists, practitioners, and policymakers to engage critically with its theory of change. We find that the relationship between disclosing biodiversity risk and redirecting finance away from environmental degradation is tenuous and unproven, making this mechanism insufficient for addressing the impact of the financial sector on nature. We question the embrace of another industry-led mechanism that implies that a lack of information is the greatest barrier to stopping biodiversity loss. Further, there are risks that this financial sector approach to biodiversity will reinforce the highly unequal concentration of power and wealth, which is itself inimical to transformative change, as called for by the Intergovernmental Science–Policy Platform on Biodiversity and Ecosystem Services.

This editorial reflects on the history of the conservation movement, the strong continuing influence of its colonial past, and the counter-emergence of a more pluralistic and respectful worldview. Conservation Letters seeks to support and foster an ethical and inclusive discipline of conservation that discards elements of its colonial and racist history. This will involve broadening the disciplinary scope of “conservation” and paying greater attention to traditional ecological knowledge and nonwestern conservation approaches. We also see a particular need for theoretical advances that guide conservation practice by informing and connecting different kinds of expertise to understand social-ecological interactions and their implications for both people and ecosystems. Conservation can and should play a vital role in securing the joint future of ecosystems and people, but it will only achieve its full potential if it retains its social license and stays relevant to emerging concerns and values.

Bird conservation depends on robust data on the densities of and threats to each species, and an understanding of the choices and incentives of bird hunters. This first comprehensive study of bird hunting and its effects in Madagascar uses 8 years of data on 87 bird species to determine bird densities and hunting pressure, incentives, choices, methods, spatial variation, and sustainability on the Masoala Peninsula of Madagascar. We find that bird hunting is common, affecting human wellbeing and, for some species, long-term population viability. Hunters caught more abundant species of lower trophic levels and consumers preferred the flavor of abundant granivores and nectarivores, while they disliked carnivores, scavengers, and species with common cultural proscriptions. Wealth increased species selectivity among consumers, whereas food insecurity increased hunting pressure overall. Projected and documented declines in at least three species are concerning, qualifying at least two for increased IUCN threatened species categories. We provide novel, data-driven assessments of hunting's threat to Madagascar's birds, identify key species of concern, and suggest both species- and consumer-specific conservation actions.

Existing quantitative syntheses on how biodiversity responds to anthropogenic habitat change appear to sometimes mix different biodiversity metrics in drawing inferences. This “mixing metrics” practice, if prevalent, would considerably bias our understanding of biodiversity responses and render uninterpretable conclusions. However, the prevalence of this practice remains unknown, and the bias it potentially renders has not been empirically assessed. We fill this gap by conducting a systematic literature assessment of existing syntheses on biodiversity responses to habitat change, along with an analysis of a global database specifically on forest restoration. We found that the “mixing metrics” practice was used in almost a quarter of existing syntheses across a wide range of ecosystem and habitat change types. This practice predictably altered the quantitative, and frequently even the qualitative, inferences on biodiversity responses to forest restoration, in ways contingent on the composition of metrics mixed. We call on future syntheses to be cognizant of the difference in metric meaning and behaviors, and to avoid mixing different metrics in studying biodiversity responses to habitat change.

Trophic rewilding is increasingly being used to promote megafauna reintroductions to island ecosystems, yet ecosystem response to population restoration once megafauna reintroduction occurs remains understudied. In this study of a population of Galapagos giant tortoises reintroduced to an arid island, tortoise exclosures monitored over an 8-year-long period revealed that, in response to the presence of tortoises, herbaceous plant cover and numbers of regenerating woody plants decreased, whereas extent of grass cover increased. Vegetation mapping over a 15-year-long period across the island indicated a threshold density of 1–2 tortoises per hectare halted incursion of woody plants and triggered a shift in this savannah-type ecosystem toward more grasses. Restoration of this giant tortoise population has shaped plant communities at both local and landscape scales with cascading effects on many components of biodiversity on the island.

Complex challenges posed by climate change, biodiversity loss, and global inequality may require intertwined solutions forged through the frame of “Nature and equity.” This timely frame responds to growing calls for conservation to deliver fair outcomes to people and offers strategic value for meeting environmental goals. To clarify how and why approaches that support nature and equity may emerge, this commentary draws on conservation efforts in five different social and political settings. Building on practitioner experiences in Australia, Chile, Kenya, Peru, and Solomon Islands, it identifies a set of equity instruments that recognize local environmental knowledge, rights, and practices, strengthen marginalized voices, and promote fair outcomes, and the enabling conditions that facilitate their use. The article concludes by discussing critical considerations for enhancing nature and equity.