Kevin J. Gaston

This article explores the relations between biodiversity science and policy, and how the former most effectively contributes to the latter. Given the present biodiversity crisis, and the interlinked risks this poses to the global human population, natural resources, and economy, it is vital that the science–policy interface operates well. Most critically there needs to be good understanding amongst biodiversity scientists about the realities of policy making, and amongst policy makers and advisors about the realities of biodiversity science. There can be significant misconceptions on both sides, and their resolution is enhanced both by shared understanding of the opportunities and constraints and by critical interpretive skills. The article highlights some of the key issues.

The scientific community is increasingly delegating trust and responsibility to data sources and tools that it cannot control or fully understand. When their functioning cannot be independently inspected, evaluated, or reproduced, such systems effectively operate as scientific black boxes.

People and Nature is a ‘journal of relational thinking’. This editorial explores what relational thinking can mean and how it might be operationalized in the context of humans and the environment. Relational thinking may seem intuitive because it recognizes the world's inherent interconnectedness. However, the question of how to operationalize relational thinking in social‐ecological research is rich and multifaceted. This is because doing research that embraces and advances relational thinking can be complex, particularly when research expands beyond social science to human–nature relationships with diverse organisms and ecological systems. This editorial offers one synthesis of existing work on relational thinking and outlines practical suggestions for how to recognize and implement deeper relationality in research. It synthesizes nine themes that can offer guidance for researchers who aim to clarify and strengthen how their research employs and advances relational thinking.

Biodiversity is under threat from human activities globally. The implications for human–nature interactions may be driving a vicious cycle—whereby less biodiversity means fewer human–nature interactions, less awareness of the importance of biodiversity and therefore greater human impacts. Understanding and quantifying an individual's nature interactions, or personalised ecologies, could help understand changes in human–nature interactions. Here we report the piloting of a Personalised Ecology Index (PEI), a novel measure which aims to quantify multiple aspects of an individual's direct sensory interactions with nature into a numeric score. To construct and evaluate the PEI, we used two national surveys in the United Kingdom that explore the interactions between people and nature. Using Partial Least Squares Structural Equation Modelling, we show that four proposed axes of the PEI—frequency, duration, diversity and intensity of exposure to nature—demonstrate a valid formative construct. We further demonstrate the robustness of the index to variation in its constituent questions, both in terms of their composition and temporal recall period. Finally, we demonstrate construct validity in terms of the association of PEI scores with the rural–urban classification of participants' residential area and perceived greenspace availability, and discriminant validity with a measure of nature connectedness. Further exploration of the dynamic, bidirectional relationship between people's interactions with nature will help to inform wider environmental and infrastructural policy measures. This may be critical for curbing and reversing the biodiversity crisis. Read the free Plain Language Summary for this article on the Journal blog.

The IUCN Red List of Threatened Species, the most widely used global system for assessing species’ extinction risk, has become a foundational source of information for conservation management, policy and research. Since the adoption of quantitative extinction risk criteria more than three decades ago, the Red List has expanded substantially in scope and influence, informing decisions ranging from species conservation and protected area designation to international agreements, corporate risk assessments and global biodiversity indicators. Given its central role, maintaining scientific rigour, transparency and trust in the Red List system is essential. Feedback from users, emerging from evolving applications and scientific advances, has shaped the Red List throughout. At the same time, the Red List has been subject to recurring critiques, some of which stem from persistent misconceptions about its purpose, design and appropriate use. To address these, we review the history and development of the Red List system, clarify the strengths of its design, delineate the contexts for which the system was and was not intended, and elucidate the circumstances under which it may be modified. Finally, we outline pathways for researchers and users to contribute to ongoing improvements and discuss potential future directions for evolution of the Red List.

To halt and reverse the ongoing biodiversity crisis, substantial changes in human behaviour will be required. One important challenge in achieving such changes is the ‘extinction of experience’ – the progressive loss of direct human interactions with nature (hereafter ‘personalised ecologies’). Diminished personalised ecologies can erode emotional ties to nature, weaken pro-conservation attitudes and reduce engagement in the diverse actions needed to support biodiversity. Although the extent of this decline has increasingly been documented, far less attention has been paid to the processes through which it unfolds over time, particularly across generations. In this Perspective, we examine how the extinction of experience may become entrenched within societies. We propose a conceptual framework, drawing on ideas from behavioural genetics, to explore how personalised ecologies could be transmitted across generations through genetic, environmental and interactive pathways. We then use this framework to consider why, once initiated, the extinction of experience may persist and intensify over time. Finally, we outline potential strategies to help disrupt this cycle of disconnection and to foster more positive, self-reinforcing trajectories of human–nature interactions. Achieving this will likely require coordinated efforts across sectors, including conservation organisations, education systems, urban planning and public health initiatives.

Anthropogenic/artificial light at night (ALAN) may have detrimental effects on individual organisms, ecosystem structure and integrity, and human sleep and circadian rhythms. The wavelength dependence of diverse biological photosensory systems is thus an appropriate consideration when quantifying ALAN. We propose spectral weighting functions for biological detection in animals (BA(λ)) and all organisms (BE(λ)) based on established features of biological spectral sensitivity. Light metrics employing B(λ) provide a biologically relevant way to measure ALAN and evaluate solutions to reduce it through spectral tuning.

Nocturnal moths are severely affected by light pollution, most notoriously through fatal attraction to artificial lights, yet flight-to-light is not their only response. To investigate how artificial lights impact flight behaviour, we exposed over 1200 wild-caught moths of 62 species to LED lights with different characteristics, under varying background lighting conditions, and tracked over 500 flight paths in three dimensions. Flight-to-light behaviour and flight tortuosity both increased with light intensity, irrespective of spectrum, though tortuosity was affected by lower levels of white than amber light, suggesting white LEDs could impact moth trajectories from greater distances. Flight tortuosity was also higher upon exposure to a single light versus three producing equivalent illuminance. Conversely, higher background light levels led to reductions in both flight-to-light and tortuosity, but moths were also less likely to take flight in these conditions, suggesting that both point sources and diffuse background lighting disrupt moth movement. Finally, moths caught using light traps were less likely to fly and, if they did, more likely to fly towards light sources than those caught with butterfly nets. These findings suggest mitigation policies for light pollution should prioritize reducing light intensity, and point to new directions for future research.

Artificial light at night (ALAN), from streetlights and other sources, is ubiquitous across modern towns and cities and has wide-ranging impacts upon the natural environment. The extent, spectra and timing of light influence the physiology, behaviour and fitness of individuals of many species, shape the structure of ecological communities and the functioning of ecosystems. To date, however, it has been challenging to characterize this lighting at sufficiently fine spatial resolutions across city-wide extents. Here, we apply a Monte Carlo radiative transfer model to simulate in three dimensions the light environment resulting from emission from streetlights using the city of Exeter, UK, as an exemplar. We show that this technique can model the evolving lighting landscape of modern cities at scales, and through observables, suitable for both ecological studies and lighting professionals. We estimate measures of melatonin suppression, induced photosynthesis and phytochrome photostationary state from our models, probing how the transition towards light-emitting diode street lighting impacts physiological processes in plants and animals throughout the city. Our simulations illustrate that although the area lit by ALAN is decreasing overall at metre scales, which is lit is becoming more hostile towards many organisms.