Empirical evidence supports neither land sparing nor land sharing as the main strategy to manage agriculture–biodiversity tradeoffs

Summary

Agricultural land-use change is a key driver of biodiversity loss. Two alternative strategies have been discussed to align biodiversity conservation with agricultural production in landscapes containing agriculture: (i) land sparing, with intensive agriculture strictly separated from natural land, and (ii) land sharing, a mosaic of low-intensity agriculture and natural elements. Sparing builds on high-yielding intensive production to provide more area for natural habitats; sharing aims to support biodiversity within agricultural landscapes by employing wildlife-friendly farming practices. A considerable body of literature addresses conceptual aspects of these strategies, but empirical evidence on how they support biodiversity is scarce. We assessed the empirical evidence by analyzing 57 peer-reviewed articles identified in a systematic literature review, of which only 17 allowed a comparison of the strategies. These 17 articles contained 27 cases of comparisons, of which 52% reported that context-specific solutions combining sharing and sparing performed best, and exclusively focusing on one strategy cannot balance the competing demands of food production and biodiversity. In 41% cases, land sparing performed best and in 7% land sharing. However, these 17 studies almost exclusively focus on specific contexts and metrics (e.g. species population density of tropical forest birds) and the other 40 studies lack important elements for a comparison, such as the assessment of agricultural production performance. The empirical basis is thus sparse and does not support statements claiming that, in general, either land sharing or land sparing strategies are unequivocally better. It rather highlights the importance of context-specific solutions for aligning agricultural production and biodiversity conservation.