Ben Siggery

•Biodiversity Net Gain policy will be a mandatory requirement for urban development.•Its benefits for biodiversity can be maximized by considering functional connectivity.•The potential of electric circuit theory to fill this policy gap is explored.•The challenges that practitioners may face are addressed.•Omniscape was found to be a promising tool in the policy context.

It is widely recognised that palaeoecology holds great potential to inform and support nature conservation, but that there are difficulties in knowledge exchange between academia and practitioners that inhibit the operationalisation of research. To facilitate the integration of palaeoecology into the conservation toolkit, it is essential to understand perspectives of the practitioners themselves and the contexts in which they work. This paper reports the results of a survey of 153 UK-based conservation practitioners, concerning their perceptions of palaeoecology, the barriers to its use and potential solutions for making palaeoecological insights more accessible in conservation practice. The survey was conducted online over a period of 3 months; closed question responses were analysed for statistical trends and thematic analysis was done on open question responses. The majority of respondents were strongly positive about the role palaeoecological research could play, though they also exhibited a limited understanding of how and why one might implement it. They identified time constraints as the biggest barrier to using palaeoecology within their work, and also flagged concerns around financial resources and the accessibility of the research. Access to applied case studies and a centralised database were the most favoured solutions among respondents. Respondents with prior experience of working with palaeoecology were generally more optimistic about its incorporation. This paper makes several key recommendations to progress the integration of palaeoecology into conservation, including improving data accessibility, aligning research design with conservation and policy drivers, and increasing both respective groups’ understanding of the other.

The introduction of the signal crayfish Pacifastacus leniusculus to British rivers has led to ecological degradation and the decline of the native white-clawed crayfish Austropotamobius pallipes. To manage and mitigate the impact of the signal crayfish, conservation agencies and government bodies employ multiple conservation strategies. These take the form of proactive native crayfish breeding and stocking programs and reactive invasive crayfish control programs. Here, we used eDNA to assess the populations of native and invasive crayfish species across 50 sites in 10 river catchments in Norfolk, United Kingdom (UK). The sites were chosen to enable assessment of the potential of eDNA to inform proactive and reactive crayfish conservation strategies. Three of the catchments sampled were selected to assess the success of recent A. pallipes reintroduction, whereas the remaining seven were selected to better understand the distribution of each species at the landscape scale. Combining results of eDNA-based methods with net searches within an occupancy model enabled us to confidently determine the presence of P. leniusculus at eight sites, and A. pallipes at three sites, which was more than visual searches alone (five and two study sites, respectively). Neither eDNA nor net searches detected A. pallipes at sites where A. pallipes had been reintroduced. We recommend that practitioners using eDNA-based surveys for management and conservation of crayfish should consider: (1) designing eDNA surveys with an emphasis on large spatial scales to comprehensively describe the distributions of native and invasive crayfish in a region of interest; (2) work with local conservation organizations and/or government bodies to inform the selection of study sites to generate results that are meaningful to real-world conservation actions; and (3) use results from eDNA-based crayfish surveys to target limited conservation resources to appropriate proactive and/or reactive conservation actions.

Rewilding is a conservation concept and practice which has gained traction over the past two decades, and is often perceived as a powerful tool to reverse anthropogenic ecological degradation. In the UK, Environmental Land Management Schemes (ELMS) have introduced the idea of ‘public money for public goods’, making some rewilding initiatives more viable for landholders. Many conservation organisations work with landholders to promote rewilding as part of local conservation strategies, but there remains a lack of understanding of landholder perceptions and attitudes towards rewilding. This research used semi-structured interviews based on the gaps identified in the literature to explore these aspects in a sample population of 8 landholders in Surrey, UK. Thematic analysis interpreted the importance of emergent patterns and implications in relation to existing literature. This research found that landholders associate many different meanings towards rewilding. These perceptions fall along two spectra, ranging from passive to active forms of rewilding and with different levels of impact on human activities. Landholder valuations of rewilding are profoundly influenced by their perceptions of its meaning, with more favourable attitudes expressed towards ‘low-impact’, active forms of rewilding. Concern was expressed about the need to balance rewilding goals with food security. This emphasises that understanding local views is essential to improve consideration of practical constraints, whilst helping to reduce polarisation and mistrust about rewilding. Conservation organisations should facilitate collaboration among landholders to kickstart the implementation of acceptable and context-specific forms of rewilding, playing a key role in achieving local and national nature recovery targets.