Wolf Delisting Challenges Demonstrate Need for an Improved Framework for Conserving Intraspecific Variation under the Endangered Species Act

Distribution model transferability for a wide-ranging species, the Gray Wolf

Using existing data can be a reliable and cost-effective way to predict species distributions, and particularly useful for recovering or expanding species. We developed a current gray wolf (Canis lupus) distribution model for the western Great Lakes region, USA, and evaluated the spatial transferability of single-state models to the region. This study is the first assessment of transferability in a wide-ranging carnivore, as well as one of few developed for large spatial extents. We collected 3500 wolf locations from winter surveys in Minnesota (2017–2019), Wisconsin (2019–2020), and Michigan (2017–2020). We included 10 variables: proportion of natural cover, pastures, and crops; distance to natural cover, agriculture, developed land, and water; major and minor road density; and snowfall (1-km res.). We created a regional ensemble distribution by weight-averaging eight models based on their performance. We also developed single-state models, and estimated spatial transferability using two approaches: state cross-validation and extrapolation. We assessed performance by quantifying correlations, receiver operating characteristic curves (ROC), sensitivities, and two niche similarity indices. The regional area estimated to be most suitable for wolves during winter (threshold = maximum sensitivity/specificity) was 106,465 km² (MN = 48,083 km², WI = 27,757 km², MI = 30,625 km²) and correctly predicted 88% of wolf locations analyzed. Increasing natural cover and distance to crops were consistently important for determining regional and single-state wolf distribution. Extrapolation (vs. cross-validation) produced results with the greatest performance metrics, and were most similar to the regional model, yet good internal performance was unrelated to greater extrapolation performance. Factors influencing species distributions are scale-dependent and can vary across areas due to behavioral plasticity. When extending inferences beyond the current occurrence of individuals, assessing variation in ecology such as habitat selection, as well as methodological factors including model performance, will be critical to avoid poor scientific interpretations and develop effective conservation applications. In particular, accurate distribution models for recovering or recovered carnivores can be used to develop plans for habitat management, quantify potential of unoccupied habitat, assess connectivity modeling, and mitigate conflict, facilitating long-term species persistence.

Mainstreaming the Ambition, Coherence, and Comprehensiveness of the Post-2020 Global Biodiversity Framework Into Conservation Policy

Parties to the Convention on Biological Diversity are finalizing a new Global Biodiversity Framework (GBF) to more effectively guide efforts by the world’s nations to address global loss of biodiversity and ecosystem services. Each party is required to mainstream the new framework and its component targets into national conservation strategies. To date, such strategies have been criticized as largely aspirational and lacking clear linkages to national policy mechanisms, which has contributed to the world’s general failure to meet the Convention’s previous targets. We use the United States and European Union as examples to compare and contrast opportunities and barriers for mainstreaming the GBF more effectively into policy. The European Union and United States have unique relationships to the Convention, the former being the only supranational party and the latter, having signed but never ratified the treaty, adopting Convention targets on an ad hoc basis. The contrasting conservation policy frameworks of these two polities illustrate several conceptual issues central to biodiversity conservation and demonstrate how insights from the GBF can strengthen biodiversity policy even in atypical contexts. We focus on three characteristics of the GBF which are essential if policy is to effectively motivate and guide efforts to halt and reverse biodiversity loss: comprehensiveness, coherence, and ambition. Statutes in both the United States and European Union provide a strong foundation for mainstreaming the GBF’s comprehensiveness, coherence, and ambition, but policy development and implementation falls short. We identify six common themes among the reforms needed to successfully achieve targets for reversing biodiversity loss: broadening conservation focus to all levels of biodiversity, better coordinating conservation strategies that protect sites and landscapes with those focused on biodiversity elements (e.g., species), coordinating biodiversity conservation with efforts to safeguard ecosystem services including ecosystem-based climate mitigation and adaptation, more coherent scaling of targets from global to local extents, adoption of a more ambitious vision for recovery of biodiversity, and development of effective tracking and accountability mechanisms.

Modeling Potential Changes in Rare Species Habitat from Planned Timber Harvest in Minnesota, USA

In 2018, the Minnesota Department of Natural Resources conducted the Sustainable Timber Harvest Analysis that resulted in the 10-year Stand Exam List (SEL). The SEL includes stands that will be assessed for potential management action from 2021 to 2030, but the location, number, and impact of stands actually harvested remains unknown. This study sought to use modeling to assess potential habitat changes from the SEL for five threatened, endangered, or special concern wildlife species. Three simulation scenarios captured the potential range of harvest from the SEL, and the Wildlife Habitat Indicator for Native Genera and Species model assessed associated habitat changes. The most realistic simulation scenario resulted in statistically insignificant habitat changes of less than ±6%, while two scenarios providing the upper and lower extremes of harvest resulted in statistically significant changes for one species each. Scenarios that resulted in less harvest and more mature forests benefited the five species, reflecting their habitat preferences. The tempering of habitat change values in the most realistic simulation scenario provides evidence for forest management tradeoffs between different wildlife species habitat requirements, as well as other forest resource management objectives.

Maximizing the effectiveness of national commitments to protected area expansion for conserving biodiversity and ecosystem carbon under climate change

Global commitments to protected area expansion should prioritize opportunities to protect climate refugia and ecosystems which store high levels of irrecoverable carbon, as key components of an effective response to biodiversity loss and climate change. The United States and Canada are responsible for one-sixth of global greenhouse gas emissions but hold extensive natural ecosystems that store globally significant above- and below-ground carbon. Canada has initiated a process of protected area network expansion in concert with efforts at reconciliation with Indigenous Peoples, and acknowledged nature-based solutions as a key aspect of climate change mitigation. The US, although not a party to global biodiversity conventions, has recently committed to protecting 30% of its extent by 2030 and achieving the UNFCCC Paris Agreement's mitigation targets. The opportunities afforded by these dual biodiversity conservation and climate commitments require coordinated national and regional policies to ensure that new protected areas maximize biodiversity-focused adaptation and nature-based mitigation opportunities. We address how global commitments can best inform national policy initiatives which build on existing agency mandates for regional planning and species conservation. Previous analyses of global conservation priorities under climate change have been tenuously linked to policy contexts of individual nations and have lacked information on refugia due to limitations of globally available datasets. Comparison and synthesis of predictions from a range of recently developed refugia metrics allow such data to inform planning despite substantial uncertainty arising from contrasting model assumptions and inputs. A case study for endangered species planning for old-forest-associated species in the US Pacific Northwest demonstrates how regional planning can be nested hierarchically within national biodiversity-focused adaptation and nature-based mitigation strategies which integrate refugia, connectivity, and ecosystem carbon metrics to holistically evaluate the role of different land designations and where carbon mitigation and protection of biodiversity's resilience to climate change can be aligned.