With so much of our land taken up for farming and producing food for our growing population, wildlife has suffered as a result. Interventions to balance the needs of humanity and nature are often implemented on farmland, and a new study aims to show which measures could be more favourable to wildlife while also being better for your bank account.
The increasing global population and subsequent need for greater food production are at odds with the limited space on our planet. Human activity linked to food production is the biggest threat to biodiversity worldwide, contributing to over a third of all carbon emissions and taking up half of our habitable land [1, 2]. Leaving enough room for nature is important, but whether to take a land-sharing or land-sparing approach has resulted in much debate. Land-sharing is where agricultural and urban land are adapted to allow wildlife to survive alongside people; think of grass roofs on large buildings in cities. Land-sparing, on the other hand, involves leaving a piece of land entirely to wildlife while reducing human interactions; for example, nature reserves. Sharing measures take up less space and don’t compromise new human expansion but land-sparing interventions are typically considered better for wildlife diversity [3].
The team of scientists worked with farmers across Britain to model land-sharing and sparing measures aimed at achieving various conservation targets on arable farmland. Their aim was to assess the effectiveness of these measures and their potential costs to the government, and consequently, the taxpayer. These targets were, over the proposed 20-year period, to reduce carbon emissions and increase biodiversity. Yellowhammers, bullfinches, and lapwings were selected as good indicators of overall biodiversity, due to their different adaptability to, and abundance on farmland. The researchers surveyed over 100 farmers to explore their preferences for land-sharing or sparing schemes and to estimate the overall costs to implement and monitor them on their land. Land-sharing measures were split into either in-field sharing, e.g. stubble fields to provide cover for wildlife as well as food for over-wintering birds; or field-edge sharing, with the creation of hedgerows for species like the bullfinch to benefit from. The proposed sparing measures involved the production of the target species’ preferred habitat, e.g. a wet grassland for lapwings.
The scientists found in their models that sharing and sparing measures differ in how much they cost to implement. Land sparing required more compensation to the farmer for the same area of land, due to the greater loss in crop or livestock yield than sharing measures would result in [4]. However, spared land requires far less monitoring and upkeep costs than sharing measures, which have to provide resources for wildlife as well as farmers. Spared land is designed to not be used for farming at all.
Overall, the researchers found that land-sparing reduced carbon emissions and increased target bird populations, all while costing taxpayers less than half of land-sharing alternatives. This was mostly thanks to the drastic reduction in monitoring and initial set-up costs of sparing compared to sharing. Land-sparing provided better habitats for the target species, and the researchers suggest that even greater benefits to wildlife would be achieved if sparing measures were targeted towards other species too, especially those not as well suited to farmland. Nevertheless, not all research findings agree with this study, and the costs and ease of implementation will differ depending on the location, the crops grown and the species of native wildlife.
How to Find Another Way
The scientists showcased here how sparing some land not only benefits the wildlife of the area, but can also be better for the taxpayer. Why not see how you can implement land-sharing or sparing around your own home? Maybe leave the lawn untouched for No Mow May, or just keep a small portion dedicated to wildflowers for our bees and butterflies. Sharing your window with the birds by attaching a feeder in the winter is another great way to help make a difference for wildlife in your area!
Article by Fin Mills
Photo credit: Geoff McKay/Flickr
References:
Study paper: Collas L, Crastes dit Sourd R, Finch T, Green R, Hanley N, Balmford A. (2023) ‘The costs of delivering environmental outcomes with land sharing and land sparing,’ People and Nature, 5(1).
[1] Crippa M, Solazzo E, Guizzardi D, Monforti-Ferrario F, Tubiello FN, Leip AJ. (2021) ‘Food systems are responsible for a third of global anthropogenic GHG emissions,’ Nature Food, 2(3).
[2] Tilman D, Clark M, Williams DR, Kimmel K, Polasky S, Packer C. (2017) ‘Future threats to biodiversity and pathways to their prevention,’ Nature, 546(7656).
[3] Cannon PG, Gilroy JJ, Tobias JA, Anderson A, Haugaasen T, Edwards DP. (2019) ‘Land‐sparing agriculture sustains higher levels of avian functional diversity than land sharing,’ Global Change Biology, 25(5).
[4] Green RE, Cornell SJ, Scharlemann JP, Balmford A. (2005) ‘Farming and the fate of wild nature,’ Science, 307(5709).
