While top-down control plays an important role in shaping both natural and agricultural food webs, we lack insights into how top-down control effects vary across spatial scales. We used a multi-scale survey of top-down control of coffee pests and diseases by arboreal ants to examine if colony location creates a small-scale mosaic in top-down control around trees and if the strength of that control varies between sites at the landscape scale. We investigated pest and disease levels on coffee shrubs at different distances from shade trees with and without a Crematogaster spp. ant colony in 59 sites along a coffee management intensity gradient in southwestern Ethiopia. Within sites, ants significantly suppressed herbivory and coffee leaf rust at distances less than 10 m from nesting trees. Top-down control varied between sites, with stronger top-down control of free-feeding herbivory near ant colonies at sites with lower management intensity and stronger top-down control of a skeletonizer at sites with higher canopy cover. We conclude that the strength of top-down control by ants is highly heterogeneous across spatial scales, as a consequence of the biology of the predator at the small scale and herbivore density or changes in herbivore–ant interactions at the landscape scale.

中文翻译：

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从天然咖啡林到种植园的蚂蚁自上而下害虫防治中的多尺度马赛克

虽然自上而下的控制在塑造自然和农业食物网方面发挥着重要作用，但我们缺乏对自上而下控制效果如何在空间尺度上变化的深入了解。我们对树栖蚂蚁对咖啡病虫害的自上而下控制进行了多尺度调查，以检查群体位置是否在树木周围自上而下的控制中形成了小规模的马赛克，以及该控制的强度是否因不同地点的不同而有所不同。景观尺度。我们调查了距离遮荫树不同距离的咖啡灌木的病虫害水平，有和没有火葬炉属 埃塞俄比亚西南部咖啡管理强度梯度沿线 59 个地点的蚁群。在站点内，蚂蚁在距筑巢树木不到 10 m 的距离内显着抑制了食草动物和咖啡叶锈病。自上而下的控制因地点而异，在管理强度较低的地点对蚁群附近自由觅食的食草动物进行更强的自上而下控制，而在冠层覆盖率较高的地点对挖骨机的自上而下控制更强。我们得出结论，蚂蚁自上而下控制的强度在空间尺度上是高度异质的，这是小尺度捕食者生物学和食草动物密度或景观尺度食草动物-蚂蚁相互作用变化的结果。