The multifunctional role of shade trees for conservation of biodiversity and ecosystem services in natural forests and agroforests is well documented, yet we lack insights into the impact of shade tree species identity on pest and disease dynamics on agroforestry crops such as coffee and cacao, and its implications for management. We conducted two surveys on the impact of shade tree species identity and canopy cover on pests, diseases and a fungal hyperparasite on Arabica coffee in southwestern Ethiopia, which is one of the areas of origin of Arabica coffee. One survey was in a commercial plantation, and the other along a management gradient from only little managed coffee growing in the natural forest to intensively managed commercial plantations. To link these findings to current shade tree selection criteria, we complemented these surveys by interviews with farmers and managers. Shade tree species identity left a weak imprint on insect pest levels, and insect pests levels differed strongly in the strength and direction of their response to canopy cover. In contrast to the insect pests, the incidence of coffee leaf rust and its hyperparasite, as well as coffee berry disease, differed among shade tree species, with particularly high levels of coffee leaf rust and the hyperparasite underneath the canopy of the shade trees Acacia abyssinica and Croton macrostachyus, and coffee berry disease underneath the canopy of Acacia abyssinica and Polyscias fulva. Smallholder farmers used many criteria for selecting shade trees, such as leaf traits and competition for soil moisture, but low priority is given to the effect of shade tree species identity on pests and diseases. Our findings help to understand spatial variation in pest and disease dynamics in natural forests and agroforests, and may inform the selection of shade tree species by coffee producers and thereby contribute to ecologically-informed pest and disease management. Importantly, our finding highlight the potential for using tree identity for the sustainable management of pests and diseases, with relevance for global agroforestry systems.

遮荫树在保护天然林和混农林中的生物多样性和生态系统服务方面的多功能作用已得到充分证明，但我们缺乏对遮荫树物种特性对咖啡和可可等农林作物病虫害动态的影响及其影响的深入了解。对管理的影响。我们在埃塞俄比亚西南部的阿拉比卡咖啡原产地之一，就遮荫树种特性和树冠覆盖对病虫害和真菌超寄生虫的影响进行了两次调查。一项调查是在商业种植园中进行的，另一项调查是沿着管理梯度从仅在天然林中种植的少量管理咖啡到集约管理的商业种植园进行的。为了将这些发现与当前的遮荫树选择标准联系起来，我们通过采访农民和管理者来补充这些调查。遮荫树种的特性在害虫水平上留下了微弱的印记，害虫水平在它们对冠层覆盖的反应强度和方向上存在很大差异。与害虫相比，遮荫树种的咖啡叶锈病及其超寄生虫以及咖啡浆果病的发生率不同，其中遮荫树冠层下的咖啡叶锈病和超寄生虫水平特别高大穗金合欢和大穗巴豆，以及金合欢和富丽花树冠下的咖啡浆果病. 小农使用许多标准来选择遮荫树，例如叶片性状和对土壤水分的竞争，但对遮荫树物种特性对病虫害的影响的重视程度较低。我们的研究结果有助于了解天然林和混农林中病虫害动态的空间变化，并可能为咖啡生产者选择遮荫树种提供信息，从而有助于以生态学为基础的病虫害管理。重要的是，我们的发现强调了使用树木身份来可持续管理病虫害的潜力，这与全球农林业系统相关。