Wild bees are key ecosystem components making their decline a cause for concern. An effective measure to increase wild bee diversity is to enhance plant diversity. However, the effect on bee diversity of augmenting plant diversity depends on site-specific environmental conditions. We aimed to make spatial predictions of where: (a) environmental conditions maximize bee diversity, so that such areas can be prioritized for augmenting plant diversity; and (b) populations of threatened wild bee species are most likely to occur. We surveyed bee communities in traditionally managed hay meadows in SE Norway and modelled bee diversity as a function of climate, habitat area, and distance to nesting substrates. We used independent data to validate our predictions and found that plant and predicted bee species richness together explained 76% and 69% of the variation in observed solitary bee species richness in forested and agricultural ecosystems, respectively. In urban areas, the predicted bee species richness alone explained 31% of the variation in observed solitary bee species richness. Using data from online species occurrence records, we found that – compared to species of lower conservation concern – threatened solitary bee species were more typically recorded in areas with a high predicted solitary bee species richness. We show that spatial predictions of bee diversity can identify sites where augmenting plant diversity is likely to be most effective. Maps of predicted bee diversity can guide species surveys and monitoring projects and increase the chances of locating populations of threatened bees.

野生蜜蜂是生态系统的关键组成部分，因此它们的数量减少令人担忧。增加野生蜜蜂多样性的有效措施是提高植物多样性。然而，增加植物多样性对蜜蜂多样性的影响取决于特定地点的环境条件。我们的目标是对以下位置进行空间预测：(a) 环境条件使蜜蜂多样性最大化，以便可以优先考虑这些区域以增加植物多样性；(b) 受威胁的野生蜜蜂种群最有可能出现。我们调查了挪威东南部传统管理的干草草地中的蜜蜂群落，并将蜜蜂多样性建模为气候、栖息地面积和与筑巢基质距离的函数。我们使用独立数据来验证我们的预测，并发现植物和预测的蜜蜂物种丰富度共同解释了森林和农业生态系统中观察到的单独蜜蜂物种丰富度的 76% 和 69% 的变化。在城市地区，仅预测的蜜蜂物种丰富度就解释了观察到的独居蜜蜂物种丰富度的 31% 变化。使用来自在线物种发生记录的数据，我们发现——与较低保护关注的物种相比——受威胁的孤蜂物种更常记录在预测孤蜂物种丰富度高的地区。我们表明，蜜蜂多样性的空间预测可以确定增加植物多样性可能最有效的地点。预测的蜜蜂多样性地图可以指导物种调查和监测项目，并增加定位受威胁蜜蜂种群的机会。