That is the question Associate Editor, Gavin Siriwardena (British Trust for Ornithology) invites you to explore at a new Interactive Session during this year’s British Ecological Society Annual Meeting. Here he offers an insight into ‘When and how are land-sparing and land-sharing appropriate for environmental management’? Find out how you can get involved here.

Recent studies have proposed land-sparing as an optimal solution for biodiversity conservation: removing areas from agricultural production or protecting them from anthropogenic influence, while production or development is focused elsewhere. Conversely, land-sharing sees the integration of environmental management with human activity.

Depending upon the system and the target species, ‘spared’ land could be unmanaged, natural habitat, a specifically created habitat or low-intensity farmland – essentially, subsidised production.

However, species conservation isn’t everything … Land under environmental management might also need to do things like promoting clean water and giving people opportunities to interact with nature near to where they live. Conversely, sequestering carbon can happen anywhere, while specific, relatively remote areas may be needed to protect the habitats of threatened species.

It may not be possible to square the circle of these potentially conflicting priorities, but I would like the British Ecological Society to try! Hence, I am convening one of the newly launched Interactive Oral Sessions (a structured discussion, in other words) on this subject at the BES Annual Meeting in Birmingham. The aim is to get a group of interested ecologists together to work towards a consensus on how and when to recommend different solutions, without a dogmatic focus on a particular approach. Ideally, we will then have a framework in which to provide consistent policy advice.

Considering scale might be one way to find common ground: the same pattern of land-use could consist of sharing at one scale and sparing at another. For example, an uncropped field margin around an arable field is spared land habitat for some small and sedentary species, but the field as a whole is shared and larger, more mobile species are likely to perceive it as such. Hence, the debate can largely be about the scale at which land is spared.

Conversely, differences are likely to arise from the scale at which decisions are focused. If you want high diversity on your farm, you need a mixture of habitats, which probably means some spared land within the farm, or the whole farm being shared, depending upon the scale at which you look at it. If you want high diversity for a country, it may not matter if the spared land is hundreds of kilometres from the productive, or developed, area.

Given that economics is always likely to be an important driver, the pressure from outside conservation circles will be to maximize production or development.  If your focus is on preventing extinction at a national scale, it may be fine to retain species in a few, remote nature reserves that are spared from development. However, a focus on abundance or healthy populations of target species may mean that a few spared areas are insufficient, so either networks of linked areas or more integration of shared and spared land (sharing, in other words) are needed. At this point, ecosystem service concepts come in: is it enough for the ‘cultural service’ of biodiversity to be delivered by its ‘existence value’ somewhere in the country, or do people to experience key species directly?

Clearly, there are complex issues here, some of which research is trying to address. However, subjective judgements and policy priorities will also affect the conclusions that policymakers reach.

The BES can’t solve everything, but we can feed useful advice into the debate …

The Interactive Session is a new feature at the 2018 British Ecological Society Annual Meeting in Birmingham. ‘When and how are land-sparing and land-sharing appropriate for environmental management?’ takes place on Tuesday 18 December, 15:00-17:00, Hall 5.

The session will begin with a general introduction and three short presentations giving different perspectives on the issue. These will be followed by a facilitated discussion, with others suggested by participants before the conference (email: gavin.siriwardena@bto.org). The aim is to reach a consensus as to when to recommend different solutions, avoiding a dogmatic focus on a particular approach, leading to a published output as a’ perspectives’ piece in our new sister journal, People and Nature. Volunteers to get more involved with the session, chairing discussion groups or taking notes, or with preparing the paper afterwards, are welcome.