In the face of global biodiversity loss, improving connectivity remains a key strategy for conserving and restoring ecosystems. Connectivity can help biodiversity by enabling dispersal, promoting gene flow, and supporting larger, more resilient populations, especially in fragmented habitats.
However, while connectivity is widely endorsed in policy, there’s limited empirical evidence across diverse species that support its effectiveness. Conservation efforts such as habitat restoration could yield greater benefits if connectivity effects were better understood.
Cunningham, C.A., Beale, C.M., Bowler, D.E., Pocock, M.J., Hutchinson, R., White, P.C., Hunt, M., Maskell, L. and Hill, J.K. 2025. Connectivity benefits most woodland invertebrate species but only in landscapes with low woodland cover. Ecology Letters 28(5): e70131.
A new study aims to fill this gap by quantifying how woodland connectivity affects invertebrate species across the UK, where woodland cover remains low (13%). The study analyzed more than 18 million citizen science records and included over 800 broadleaf woodland-associated invertebrate species, ranging from moths and beetles to spiders and hoverflies. Using high-resolution spatial models and two decades of land cover data (1990–2015), the authors tested how forest cover and connectivity interact to shape species occurrence patterns.
The results show that woodland connectivity offers a measurable boost to biodiversity – but only in the right context. While overall woodland cover had the strongest effect on species presence, connectivity also played a positive role for 39% of species, with only 3% showing a negative response. Crucially, the benefits of connectivity were strongest in landscapes with low levels of woodland cover, which is typical across much of the UK. In high-cover areas, connectivity either had little effect or was associated with slight declines in occurrence, suggesting diminishing returns.
This nuanced pattern reflects both ecological processes and landscape history. In fragmented, low-woodland landscapes, connectivity likely facilitates dispersal and recolonization, buffering against local extinctions. Conversely, in woodland-rich areas, other factors, such as habitat quality or microclimate, may play a more dominant role. Not all species responded equally: moths, spiders, and hoverflies benefited most from increased connectivity, while aquatic or semi-aquatic species like dragonflies and caddisflies showed limited sensitivity, likely due to habitat mismatches.
The results provide evidence that woodland restoration and creation policies should be spatially targeted to maximize connectivity in low-cover landscapes. This strategy can enhance biodiversity outcomes under current restoration and climate adaptation goals. However, a one-size-fits-all approach is unlikely to work: connectivity benefits vary among species and depend heavily on broader landscape context.
This research is particularly relevant for guiding restoration strategies that move beyond just increasing habitat area to also considering how those habitats are spatially arranged. For conservation practitioners and planners, it underscores a key message: connectivity does not have a universal impact, but when thoughtfully applied in the right settings, it can significantly support forest biodiversity. The future of landscape design will depend not just on how much we plant – but where and how we connect it.
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