Conservation Letters最新文献

Land use is both a major cause of the biodiversity crises and a potential solution to it. Decisions about land use are made in complex social–ecological systems, yet conservation research, policy, and practice often neglect the diverse and dynamic nature of land use. A deeper integration of land system science and conservation science provides major opportunities in this context, through a transfer of concepts, data, and methodologies. Specifically, a closer exchange between land-use data developers and users will enable common terminology and better data use, allowing to move beyond coarse land-cover representations of land use. Similarly, archetyping and regionalization approaches can help to embrace, rather than oversimplify, the diversity of land-use actors and practices. Finally, systematically linking land-use actors to portfolios of pressures on biodiversity, beyond their direct impact on habitat, can better represent and map co-occurring and interacting threats. Together, this will enable conservation policymakers and planners to recognize the often-complex and wicked nature of conservation challenges related to land, allowing for more context-specific conservation policymaking and planning, and more targeted conservation interventions.

Invasive species are a major cause of biodiversity loss and are notoriously expensive and challenging to manage. We developed a decision-analytic framework for evaluating invasive species removal strategies, given objectives of maximizing eradication probability and minimizing costs. The framework uses an existing estimation model for spatially referenced removal data—one of the most accessible types of invasive species data—to obtain estimates of population growth rate, movement probability, and detection probability. We use these estimates in simulations to identify Pareto-efficient strategies—strategies where increases in eradication probability cannot be obtained without increases in cost—from a set of proposed strategies. We applied the framework post hoc to a successful eradication of veiled chameleons (Chamaeleo calyptratus) and identified the potential for substantial improvements in efficiency. Our approach provides managers and policymakers with tools to identify cost-effective strategies for a range of invasive species using only prior knowledge or data from initial physical removals.

The preservation of genetic variation is fundamental in biodiversity conservation, yet its importance for population viability remains contentious. Mixed-source reintroductions, where individuals are translocated into a single vacant habitat from multiple genetically divergent and often depauperate populations, provide an opportunity to evaluate how genetic variation and hybridization influence individual and relative population fitness. Population genetic theory predicts that individuals with higher genetic variation and hybrids among populations should have higher fitness. We tested these two hypotheses by analyzing individual and population-scale data for westslope cutthroat trout (Oncorhynchus clarkii lewisi) in four mixed-source reintroductions. We observed more hybrid and fewer nonhybrid offspring than expected across four independent mixed-source reintroductions. We also found clear evidence that heterozygosity influenced individual reproductive and relative population fitness. Overall, we found a strong, positive relationship between genetic variation, hybridization, and transplant fitness, emphasizing the importance of genetic variation and population mixing in conservation.

Rigorous scientific practice relies on the tenet of transparency. However, despite regular transparency in areas such as data availability and methodological practice, the influence of personal and professional values in research design and dissemination is often not disclosed or discussed in conservation science. Conservation scientists are increasingly driven to work in collaboration with communities where their work takes place, which raises important questions about the research process, especially as the field remains largely represented by a Western scientific worldview. The process of reflexivity, and the creation of positionality statements as one form of a reflexive practice, is an important component of transparency, rigor, and best practice in contemporary conservation science. In our own professional practices, however, we have found that guidance on how to produce positionality statements and maintain reflexivity throughout the lifecycle of research is too often lacking. In response, we build on existing literature and our own experience to offer a primer as a starting point to the practice of reflexivity. Rather than being prescriptive, we seek to demonstrate flexible approaches that researchers may consider when communicating reflexive practice to enhance research transparency. We explore the challenges and potential pitfalls in a reflexive practice and offer considerations and advice based on our collective professional experience.

Hydropower expansion is increasingly responsible for connectivity and biodiversity loss in freshwater ecosystems. The Amazon basin, which supports the highest level of freshwater biodiversity globally, faces such unplanned expansion. Here, we demonstrate and quantify the impacts of two major hydroelectric dams on the Madeira River on the trans-Amazonian movements of one apex predatory catfish (Brachyplatystoma rousseauxii) performing the longest migration known in freshwaters. Using otolith microchemistry, we show that above the dams, the former basin-wide homing migration between the breeding grounds in the upper Madeira and the nursery in the Amazon estuary has now been replaced by residency. We found evidence suggesting downstream migration of juvenile fish past dams into the Amazon estuary and that some of them home back to the Madeira. However, we did not find evidence that the fish homing back from the estuary can access their breeding grounds in the upper Madeira; they remain blocked below the dams. Our results provide undisputable evidence that the conservation of the species primarily requires the reestablishment of connectivity with the construction of efficient fishways.

The Kunming-Montreal Global Biodiversity Framework lays out an ambitious set of goals and targets aimed at halting and reversing biodiversity loss. The extent of natural ecosystems has been selected as one of a small set of headline indicators against which countries will report progress under this framework. We evaluate the effectiveness with which this indicator is expected to capture the overall scope of the ecosystem-focused component of Goal A, and interlinkages with the species-focused component of this same goal, using extensive global data on the integrity, connectivity, and plant species composition of forests. Results generated for all forest-supporting countries demonstrate that consideration of these additional factors can profoundly alter understanding of the state of forest biodiversity relative to that based on extent alone. Employment of ecosystem extent as a headline indicator must therefore be augmented by appropriate use of component and complementary indicators addressing other key dimensions of ecosystem change.

Information about species’ locations can influence what happens to them—from supporting habitat protection to exposing poaching targets. Debate about releasing locations when new species are found highlights the trade-off between the risk of loss and the benefits of funding and public support. No research so far has collected data on how such decisions are made, and no decision tools easily compare a range of decision-making scenarios. Here, we present a method to compare the costs and benefits of decisions about the disclosure of information about newly discovered species and populations. We implement our method for seven species where information is completely or partially secret. We ask decision-makers to estimate the costs and benefits associated with these case studies and apply our method. Results show a range of implications from choices that are always better, to others that depend on risk attitude, and demonstrate that the process of decision-making can be transparent and easily communicated.

There is limited quantitative evidence of the effects of socio-economic shocks on biological resource use. Focusing on wild meat hunting, a substantial livelihood and food source in tropical regions, we evaluated the impacts of the shock from Nigeria's coronavirus disease (COVID-19) lockdown on species exploitation around a global biodiversity hotspot. Using a 3-year quantitative dataset collected during and after the lockdown (covering 1008 hunter-months) and matching by time of year, we found that successful hunting trip rates were more frequent during the lockdown, with a corresponding increase in the monthly number, mass, and value of animals caught. Moreover, hunters consumed a larger proportion of wild meat and sold less during lockdown, compared to non-lockdown periods. These results suggest that local communities relied on wild meat to supplement reduced food and income during the lockdown, buffering the COVID-19's socio-economic shock. Our findings also indicate that wild species may be especially vulnerable to increased hunting pressure during socio-economic shocks.

The EU Biodiversity Strategy 2030 aims to better protect natural ecosystems with high biodiversity and climate change mitigation potential. To achieve this goal, it is crucial to identify forests worth protecting, such as those characterized by long continuity and old age. Here, we propose a robust approach that combines historical maps from the mid-19th century with remote sensing data to identify areas that have been forested for over 150 years, aiming to reduce the need for detailed and time-consuming field investigations in potential conservation areas. We tested this approach in a 20,000 km² region in the Polish Carpathians, an area likely containing many unprotected forests of high conservation value, where historical maps from the mid-19th century are representative of much of Central Europe. Our results showed that an area of approximately 4200 km² has been continuously forested since at least the mid-19th century. Currently, 50% of these forests are outside protected areas, representing an important conservation opportunity. More generally, our approach can support the identification of valuable forests worth protecting before they are lost and provide useful insights for policymakers and stakeholders in the ongoing debate on the challenges of improving forest conservation in the Carpathians, and Europe more widely.