Bren School of Environmental Science and Management, University of California Santa Barbara, Santa Barbara, CA, USA.
Conservation Science Group, Department of Zoology, University of Cambridge, Cambridge, UK.
Glob Chang Biol. 2017 Dec;23(12):5260-5272. doi: 10.1111/gcb.13791. Epub 2017 Jul 10.
Balancing the production of food, particularly meat, with preserving biodiversity and maintaining ecosystem services is a major societal challenge. Research into the contrasting strategies of land sparing and land sharing has suggested that land sparing-combining high-yield agriculture with the protection or restoration of natural habitats on nonfarmed land-will have lower environmental impacts than other strategies. Ecosystems with long histories of habitat disturbance, however, could be resilient to low-yield agriculture and thus fare better under land sharing. Using a wider suite of species (birds, dung beetles and trees) and a wider range of livestock-production systems than previous studies, we investigated the probable impacts of different land-use strategies on biodiversity and aboveground carbon stocks in the Yucatán Peninsula, Mexico-a region with a long history of habitat disturbance. By modelling the production of multiple products from interdependent land uses, we found that land sparing would allow larger estimated populations of most species and larger carbon stocks to persist than would land sharing or any intermediate strategy. This result held across all agricultural production targets despite the history of disturbance and despite species richness in low- and medium-yielding agriculture being not much lower than that in natural habitats. This highlights the importance, in evaluating the biodiversity impacts of land use, of measuring population densities of individual species, rather than simple species richness. The benefits of land sparing for both biodiversity and carbon storage suggest that safeguarding natural habitats for biodiversity protection and carbon storage alongside promoting areas of high-yield cattle production would be desirable. However, delivering such landscapes will probably require the explicit linkage of livestock yield increases with habitat protection or restoration, as well as a deeper understanding of the long-term sustainability of yields, and research into how other societal outcomes vary across land-use strategies.
在保持生物多样性和维护生态系统服务的同时，平衡粮食生产，尤其是肉类生产，是一个重大的社会挑战。关于土地保护和土地共享两种相反策略的研究表明，与其他策略相比，土地保护（将高产量农业与非农业土地上的自然栖息地的保护或恢复相结合）的环境影响更低。然而，那些具有长期生境干扰历史的生态系统可能对低产农业具有弹性，因此在土地共享下表现更好。与之前的研究相比，我们使用了更广泛的物种（鸟类、蜣螂和树木）和更广泛的牲畜生产系统来研究不同土地利用策略对生物多样性和地上碳储量的可能影响，我们在墨西哥尤卡坦半岛进行了这项研究，该地区具有悠久的生境干扰历史。通过对相互依存的土地利用的多种产品进行建模，我们发现与土地共享或任何中间策略相比，土地保护将允许更多的大多数物种的估计种群和更大的碳储量持续存在。尽管存在干扰历史，尽管低产和中产农业的物种丰富度并不比自然栖息地低多少，但这一结果在所有农业生产目标中都成立。这突出表明，在评估土地利用对生物多样性的影响时，衡量个别物种的种群密度比简单地衡量物种丰富度更为重要。土地保护对生物多样性和碳储存都有好处，这表明保护自然栖息地以保护生物多样性和储存碳，同时促进高产量牛生产区的发展是可取的。然而，要实现这种景观，可能需要明确将牲畜产量的提高与生境保护或恢复联系起来，还需要更深入地了解产量的长期可持续性，并研究其他社会成果如何因土地利用策略而异。
