Peer-reviewed publications

Ensuring that companies can assess and manage their impacts on biodiversity will be crucial to solving the current biodiversity crisis, and regulatory and public pressure to disclose these impacts is increasing. Top-down intactness metrics (e.g., Mean Species Abundance) can be valuable for generating high-level or first-tier assessments of impact risk but do not provide sufficient precision or guidance for companies, regulators, or third-party assessors. New metrics based on bottom-up assessments of biodiversity (e.g., the Species Threat Abatement and Restoration metric) can accommodate spatial variation of biodiversity and provide more specific guidance for actions to avoid, reduce, remediate, and compensate for impacts and to identify positive opportunities.

In 2022, 196 government parties to the Convention on Biological Diversity (CBD) agreed to update and redesign their national biodiversity strategies and action plans (NBSAPs) by the end of 2024. This process offers an opportunity to influence the implementation of the Kunming-Montréal Global Biodiversity Framework and to shape how countries frame and address biodiversity–health interlinkages for the next decade. 1 Historically, NBSAPs have not drawn on available health expertise in their implementation. This is the time to prioritise fundamental gaps in the knowledge-to-policy interface and to improve policy coordination to advance systems-level, holistic health approaches to implementation. We propose recommendations for aligning NBSAPs to optimise outcomes for biodiversity and health.

Freshwater connectivity and the associated flow regime are critical components of the health of freshwater ecosystems. When freshwater ecosystems are fragmented, movements and flows of species, nutrients, sediments, and water are altered, changing the natural dynamics of freshwater ecosystems. The consequences of these changes include declines and loss of freshwater species populations and freshwater ecosystems, and alterations in the delivery of certain ecosystem services, such as fisheries, buffering of flood events, healthy deltas, recreational and cultural values, and others. Measures exist that can maintain and restore connectivity or mitigate against its loss in the face of constructed barriers or other habitat alterations. These measures include system-scale planning for energy and water resources that includes options for limiting loss of freshwater connectivity; putting in place protections for keeping critically important freshwater habitats connected; mitigating impacts on freshwater ecosystems via barrier design, fish passage or implementation of environmental flows; restoring freshwaters via barrier removal and reconnection of rivers, wetlands and floodplains and via active management of groundwater recharge. We present case studies of measures applied in Europe, Asia, Africa and the Americas and reflect on the next generation of innovation needed to further enhance and advance the implementation of restoration and protection and the mitigation of freshwater connectivity impacts.

The conservation of natural and cultural resources shared between countries is a significant challenge that can be addressed through the establishment of transboundary conservation areas (TBCAs). TBCAs enable countries to harmonize cross-border governance and management, increase protected area (PA) coverage, and strengthen relationships between neighbouring countries and communities. In Africa, many ecosystems and species ranges span multiple countries, making TBCAs a crucial tool for biodiversity conservation. However, there is a lack of research on where TBCAs can be established or need to be established. To address this gap, we conducted a study to identify opportunities for establishing TBCAs in Africa. We first compiled an up-to-date list of existing TBCAs on the continent. Then, we identified potential TBCAs by identifying protected areas next to country borders that are adjacent to other protected areas in a neighbouring country. We also evaluated the functional connectivity between these PA pairs and prioritized potential TBCAs based on size, connectivity, and ease of establishment. We identified 27 existing TBCAs and 8,481 potential TBCAs in Africa composed of various possible combinations of 2,326 individual PAs. Our results provide a baseline of existing TBCAs and offer a better understanding of where transboundary conservation might be established or strengthened. We also highlight areas where future transboundary conservation efforts could safeguard PA connectivity. This information can guide policy and decision-making processes towards promoting conservation and sustainable use of natural and cultural resources shared between countries in Africa.

We thank Scholte, Kamgang, & Sabuhoro (2023) and Hausmann (2023) for their perceptive commentaries on our study of what attracts ecotourists to Sub-Saharan African protected areas (Eyster, Naidoo, & Chan, 2022).

Mangrove forests support unique biodiversity and provide a suite of ecosystem services (ES) that benefit people. Decades of continual mangrove loss and degradation have necessitated global efforts to protect and restore this important ecosystem. Generating and evaluating asset maps of biodiversity and ES is an important precursor to identifying locations that can deliver conservation outcomes across varying scales, such as maximising the co-occurrence of specific ES. We bring together global datasets on mangrove-affiliated biodiversity, carbon stocks, fish and invertebrate production, and coastal protection to provide insight into potential trade-offs, synergies and opportunities from mangrove conservation. We map opportunities where high ES provision co-occurs with these areas that could be leveraged in conservation planning, and identify potential high-value opportunities for single ES that might otherwise be missed with a biodiversity focus. Hotspots of single ES, co-occurrence of multiple ES, and opportunities to simultaneously leverage biodiversity and ES occurred throughout the world. For example, efforts that focus on conserving or restoring mangroves to store carbon can be targed to deliver multiple ES benefits. Some nations, such as Vietnam, Oman, Ecuador and China, showed consistent (although not necessarily strong) correlations between ES pairs. A lack of clear or consistent spatial trends elsewhere suggests that some nations will likely benefit more from complementarity-based approaches that focus on multiple sites with high provision of different services. Individual sites within these nations, however, such as Laguna de Terminos in Mexico still provide valuable opportunities to leverage co-benefits. Ensuring that an ES focused approach is complemented by strategic spatial planning is a priority, and our analyses provide a precursor towards decisions about where and how to invest.

Based on a review of >50,000 academic publications, policy documents, and Indigenous and local knowledge sources, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) Values Assessment examined current knowledge on the diversity of nature’s values and valuation methods to gain insights into their role in policymaking and to their fuller integration into decisions. It presents an inclusive typology of the multiple conceptualizations of nature’s values and their interrelationships, and shows global patterns of where and how valuation studies have been conducted. It reveals that >50 well established valuation methods from diverse disciplines and traditions are available to decision makers. Yet, <5% of published studies document uptake of values information into decisions, and few valuation efforts adequately represent or engage stakeholder diversity in valuation processes. Furthermore, evidence shows that people and nature benefit when nature’s multiple values are considered in the design and implementation of biodiversity conservation and territorial management policies (e.g., protected areas, payments for ecosystem services). Theassessment concludes that combinations of values-centred approaches can leverage transformative changes towards more just and sustainable futures.

Monitoring of terrestrial and aquatic species assemblages at large spatial scales based on environmental DNA (eDNA) has the potential to enable evidence-based environmental policymaking. The spatial coverage of eDNA-based studies varies substantially, and the ability of eDNA metabarcoding to capture regional biodiversity remains to be assessed; thus, questions about best practices in the sampling design of entire landscapes remain open. We tested the extent to which eDNA sampling can capture the diversity of a region with highly heterogeneous habitat patches across a wide elevation gradient for five days through multiple hydrological catchments of the Swiss Alps. Using peristaltic pumps, we filtered 60 L of water at five sites per catchment for a total volume of 1800 L. Using an eDNA metabarcoding approach focusing on vertebrates and plants, we detected 86 vertebrate taxa spanning 41 families and 263 plant taxa spanning 79 families across ten catchments. For mammals, fishes, amphibians and plants, the detected taxa covered some of the most common species in the region according to long-term records while including a few more rare taxa. We found marked turnover among samples from distinct elevational classes indicating that the biological signal in alpine rivers remains relatively localised and is not aggregated downstream. Accordingly, species compositions differed between catchments and correlated with catchment-level forest and grassland cover. Biomonitoring schemes based on capturing eDNA across rivers within biologically integrated catchments may pave the way toward a spatially comprehensive estimation of biodiversity.

Study Region: The Kwando (Cuando) River and the western headwaters of the Zambezi River, which are data-scarce basins of southern Africa. Study Focus: A comparative analysis of the performance of two fundamentally different hydrological modelling approaches (a conceptual model and a theory guided machine learning model) in a data-sparse region. New Hydrological Insights for the Region: The machine learning model (HydroForecast) generally performs better – in terms of statistical fit between simulated and observed flows – than the conceptual model (Pitman). For the Kwando River, the conceptual model explicitly simulates the expected attenuation effects of a large floodplain, while the machine learning model represents this and other processes implicitly. The two models quantify the Kwando sub-basin flow contributions differently, with the conceptual model calibrated manually to align with the available qualitative information that suggests that the majority of the runoff is generated in the upstream sub-basin and then attenuated in the downstream floodplain. Generally, this work offers insight into how the two very different models can simulate historical flows in a large basin when streamflow observations and the forcing rainfall data are limited and of unknown quality, and suggests that a machine learning model better leverages information from multiple training parameters to reproduce the measured streamflows.

Over the past few decades, the use of camera-traps has revolutionized our ability to monitor populations of wild terrestrial mammals. While methods to estimate abundance from individually-identifiable animals are well-established, they are mostly restricted to species with clear natural markings or else necessitate invasive and often costly animal tagging campaigns. Estimating abundance or density from unmarked animals remains challenging. Several models recently developed to deal with this issue are promising, but are not widely used by field ecologists. Here, we developed a framework for applying the Space-To-Event (STE) model—originally designed to be used with time-lapse images—on motion-triggered camera-trap data. Our approach involves performing bootstrap resampling on the photographic dataset to generate multiple datasets that are then used as input to the STE model. We tested our approach on 29 datasets, including 17 ungulate species from eight sites, in six different countries and various ecosystems. Then, we conducted a regression analysis to evaluate how variations in ecological and sampling conditions across studies affected the bias and precision of our STE density estimates. Our study shows that with a bootstrap resampling approach and information on animal activity and effective detection distances to animals, the STE model can be used to analyze motion-trigger datasets and provide population density estimates that are similar to those from other methods. We found that measuring the camera viewshed was critical to prevent major negative biases in density estimates. Moreover, using a 1-s sampling window was important to avoid the positive bias that results from violating the instantaneous-sampling assumption. We found that precision increased with greater sampling effort and higher density populations. Based on these results, we highlight several issues from past studies that have applied the original timelapse-based STE to motion-trigger datasets, issues that our bootstrap resampling approach addresses. We caution that the STE model, whether applied to timelapse or motion-triggered datasets, relies on strict assumptions. Any violations of these assumptions, such as non-instantaneous sampling or the application of angle and distance of detection provided by the camera manufacturer, can cause biases in multiple directions that may be difficult to differentiate.