Department of Environmental Conservation, University of Massachusetts, 160 Holdsworth Way, Amherst, MA 01003, USA.
Conserv Biol. 2013 Aug;27(4):785-95. doi: 10.1111/cobi.12046. Epub 2013 Apr 2.
Two contrasting strategies have been proposed for conserving biological diversity while meeting the increasing demand for agricultural products: land sparing and land sharing production systems. Land sparing involves increasing yield to reduce the amount of land needed for agriculture, whereas land-sharing agricultural practices incorporate elements of native ecosystems into the production system itself. Although the conservation value of these systems has been extensively debated, empirical studies are lacking. We compared bird communities in shade coffee, a widely practiced land-sharing system in which shade trees are maintained within the coffee plantation, with bird communities in a novel, small-scale, land-sparing coffee-production system (integrated open canopy or IOC coffee) in which farmers obtain higher yields under little or no shade while conserving an area of forest equal to the area under cultivation. Species richness and diversity of forest-dependent birds were higher in the IOC coffee farms than in the shade coffee farms, and community composition was more similar between IOC coffee and primary forest than between shade coffee and primary forest. Our study represents the first empirical comparison of well-defined land sparing and land sharing production systems. Because IOC coffee farms can be established by allowing forest to regenerate on degraded land, widespread adoption of this system could lead to substantial increases in forest cover and carbon sequestration without compromising agricultural yield or threatening the livelihoods of traditional small farmers. However, we studied small farms (<5 ha); thus, our results may not generalize to large-scale land-sharing systems. Furthermore, rather than concluding that land sparing is generally superior to land sharing, we suggest that the optimal approach depends on the crop, local climate, and existing land-use patterns.
为了在满足对农产品日益增长的需求的同时保护生物多样性,人们提出了两种截然不同的策略:保护地和共享地生产系统。保护地策略涉及提高产量以减少农业所需的土地面积,而共享地农业实践则将自然生态系统的元素纳入生产系统本身。尽管这些系统的保护价值已经被广泛讨论,但实证研究却很缺乏。我们比较了遮荫咖啡中的鸟类群落,遮荫咖啡是一种广泛实践的共享地系统,在这种系统中,咖啡种植园内保留了遮荫树,与一种新颖的、小规模的、节约地的咖啡生产系统(集成开放式树冠或 IOC 咖啡)中的鸟类群落进行了比较,在这种系统中,农民在几乎没有遮荫的情况下获得更高的产量,同时保护与种植面积相等的森林面积。依赖森林的鸟类的物种丰富度和多样性在 IOC 咖啡农场中高于遮荫咖啡农场,而 IOC 咖啡与原生林之间的群落组成比遮荫咖啡与原生林之间更相似。我们的研究代表了对明确的节约地和共享地生产系统的首次实证比较。由于 IOC 咖啡农场可以通过允许森林在退化土地上再生来建立,因此广泛采用这种系统可以在不影响农业产量或威胁传统小农生计的情况下,大幅增加森林覆盖和碳封存。然而,我们研究的是小农场(<5 公顷);因此,我们的结果可能不适用于大规模的共享地系统。此外,我们并不是得出节约地总体上优于共享地的结论,而是建议最佳方法取决于作物、当地气候和现有土地利用模式。