Abstract1. Rewilding, here defined as "the reorganisation of biota and ecosystem processes to set an identified social-ecological system on a preferred trajectory, leading to the self-sustaining provision of ecosystem services with minimal ongoing management," is increasingly considered as an environmental management option, with potential for enhancing both biodiversity and ecosystem services.2. Despite burgeoning interest in the concept, there are uncertainties and difficulties associated with the practical implementation of rewilding projects, while the evidence available for facilitating sound decision-making for rewilding initiatives remains elusive.3. We identify five key research areas to inform the implementation of future rewilding initiatives: increased understanding of the links between actions and impacts; improved risk assessment processes, through, for example, better definition and quantification of ecological risks; improved predictions of spatio-temporal variation in potential economic costs and associated benefits; better identification and characterisation of the likely social impacts of a given rewilding project; and facilitated emergence of a comprehensive and practical framework for the monitoring and evaluation of rewilding projects. Policy implications.Environmental legislation is commonly based on a "compositionalist" paradigm itself predicated on the preservation of historical conditions characterised by the presence of particular species assemblages and habitat types.However, global environmental change is driving some ecosystems beyond their limits so that restoration to historical benchmarks or modern likely equivalents may no longer be an option. This means that the current environmental policy context could present barriers to the broad implementation of rewilding projects. To progress the global rewilding agenda, a better appreciation of current policy opportunities and constraints is required. This, together with a clear definition of rewilding and a scientifically robust rationale for its local implementation, is a prerequisite to engage governments in revising legislation where required to facilitate the operationalisation of rewilding.

We present the results of our eighth annual horizon scan of emerging issues likely to affect global biological diversity, the environment, and conservation efforts in the future. The potential effects of these novel issues might not yet be fully recognized or understood by the global conservation community, and the issues can be regarded as both opportunities and risks. A diverse international team with collective expertise in horizon scanning, science communication, and conservation research, practice, and policy reviewed 100 potential issues and identified 15 that qualified as emerging, with potential substantial global effects. These issues include new developments in energy storage and fuel production, sand extraction, potential solutions to combat coral bleaching and invasive marine species, and blockchain technology. Aims of Horizon ScanningWe have conducted an annual horizon scan of global conservation issues since 2010 with the aim of highlighting, by consensus, emerging topics that are not yet widely known in the conservation community but could have substantial effects on biological diversity worldwide in the medium to long term. Our iterative, transferable process of horizon scanning, which is designed to be both transparent and democratic, is carried out by a team with a wide range of experiences and areas of expertise.Our aim has been to focus attention and stimulate debate about these subjects, potentially leading to new research foci, policy developments, or business innovations. These responses should help to facilitate better-informed forward-planning. It is difficult to gauge the direct effects of our horizon scans on the research, policy, or business communities, except through personal communication and hearsay. However, several topics recognized in our previous horizon scans Trends This is the eighth such annual horizon scan.An international team with expertise in horizon scanning, science communication, and conservation research, practice, and policy identified 15 issues, following widespread consultation and a Delphi-like scoring process to identify the most important.The issues were wide ranging, and include sand extraction, blockchain technology, use of robotics to combat invasive species, and new developments in energy storage and fuel production. There is now substantial action on this issue internationally, with several governments, including those of the USA and the UK, introducing legislative bans on microbeads in cosmetics and detergents, and many cosmetics companies voluntarily committing to halt their use of microplastics by 2020 [2,3]. New research on the effects of microbeads has revealed biological responses in both terrestrial and aquatic environments, with evidence demonstrating that microplastics reduce the survival and fitness of earthworms Lumbricus terrestris [4] and facilitate the accumulation of sorbed organic pollutants in fish [5]. Discussion of the use of gene editing to control invasive species or disease vectors, raised in our 2014 horizon scan [6], has increased...

We present the results of our eighth annual horizon scan of emerging issues likely to affect global biological diversity, the environment, and conservation efforts in the future. The potential effects of these novel issues might not yet be fully recognized or understood by the global conservation community, and the issues can be regarded as both opportunities and risks. A diverse international team with collective expertise in horizon scanning, science communication, and conservation research, practice, and policy reviewed 100 potential issues and identified 15 that qualified as emerging, with potential substantial global effects. These issues include new developments in energy storage and fuel production, sand extraction, potential solutions to combat coral bleaching and invasive marine species, and blockchain technology.

Planning for nature conservation has increasingly emphasised the concepts of resilience and spatial networks. Although the importance of habitat networks for individual species is clear, their significance for long‐term ecological resilience and multi‐species conservation strategies is less established. Referencing spatial network theory, we describe the conceptual basis for defining and assessing a network of wildlife areas that supports species’ resilience to multiple forms of perturbations and pressures. We explore actions that could enhance network resilience at a range of scales, based on ecological principles, with reference to four well‐established strategies for intervention in a spatial network (“Better, Bigger, More and Joined”) from the influential Making Space for Nature report by Lawton et al. (). Building existing theory into useable and scalable approaches applicable to large numbers of species is challenging but tractable. We illustrate the policy context, describe the elements of a long‐term adaptive management plan and provide example actions, metrics and targets for early implementation using England as a case study, where there is an opportunity to include large‐scale ecological planning in a newly launched 25‐year environment plan. Policy implications. The concept of resilient ecological networks has attracted scientific and political support, but there is no consensus on what a resilient network would look like, or how to assess it. Therefore, it is unclear whether existing targets for action will be sufficient to achieve network resilience. We show that the scientific principles to place resilience and network theory at the heart of large‐scale and long‐term environmental planning are established and ready to implement in practice. Delivering a resilient network to support nature recovery is achievable and can be integrated with ongoing conservation actions and targets, by assessing their effectiveness on properties of the entire network. England's 25 Year Environment Plan promises to deliver a natural environment that is protected and enhanced for the future and so provides the ideal testbed.