Informing nature recovery in England by analysing "bottlenecks" in broad habitats.

Published online
26 May 2024
Published by
Natural England
Content type

Gutierrez-Arellano, C. & Crick, H. & Cowling, D. & Drake, L. & Hawkins, V. & Newland, L. & Taylor, S. & Travers, T. & Hodgson, J.
Contact email(s)

Publication language
England & UK


This study aimed to identify key areas where connectivity bottlenecks occur (where connectivity is restricted) at the national scale in England, UK, and assess the extent to which these areas match with bottlenecks identified in three focal nature recovery projects (NRPs) for three broad habitats: grassland, heathland and wetlands. The decision support tool Condatis was used to identify bottleneck areas. The movement of generic species with moderate-low (1 km) and moderate-high dispersal abilities (3.4 km) across the landscape in four possible directions (north-south, east-west, northeast-southwest and northwest-southeast) was determined. A scoring system applicable across different landscapes and spatial scales was developed to categorize bottlenecks into severe, major and minor and to rank the areas within these categories. National maps of the most significant bottlenecks in the three broad habitats were produced. The maps were used alongside other relevant spatial information (e.g. topographic, infrastructure or land use maps) to identify sites where restoration to improve connectivity is feasible. Severe bottleneck areas of the three broad habitats covered 7.3% of land and were mostly concentrated in the midlands. Fewer and mostly minor bottlenecks in NRP areas were identified because habitat availability and connectivity were better in these areas than the national average. The project areas were relatively small in a national context (13,490-62,070 ha; 0.1-0.5% of England's land area), so their chance of overlapping a major or severe bottleneck (if they had been randomly selected) was low. Additionally, these areas were not chosen with a specific remit to address nationally significant gaps to secure habitat networks. There were some advantages and disadvantages of running Condatis analyses at the national and local scales. National analyses set an important context which can inform every local area and show options that species have for using alternative routes through the networks. However, there were computational limitations in the modelling of short-distance dispersers (<1km). In contrast, local analyses can be run at a finer spatial resolution and can consider shorter dispersal abilities. They can inform on the functioning of local habitat networks, but may not provide a long term, large-scale perspective. Modelling at an intermediate scale such as region, county or several landscape character areas is recommended to get an overview of multi-generation movement potential, and to set local priorities in that context. Initiatives such as the local nature recovery strategies (LNRS) which focus on mapping key areas for restoration at county-level scales, could find this approach highly informative. To maximize the benefit of this study, further work would usefully include engaging with the NRP and LNRS teams to help them with the use of the project's spatial outputs.

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