Decreased availability of forage, as well as increased pesticide exposure, are important factors in the decline of honey bee health. Here, we isolate land cover transitions and their effect on honey production at 160 commercial apiaries in the Northern Great Plains. We found that land cover changes from 2008 to 2012 caused an annual decline in honey yields of 0.9% in the study area. Transitions from grassland to soybean (but not corn) were particularly detrimental to honey yields, potentially due to bee contact with pesticides within and around agricultural fields. When our results are applied to known apiary locations across all of North Dakota (U.S.A.), we estimate a 2.5% (1.6 million USD) decline in 2012 honey yields due to land cover changes occurring between 2008 and 2012. Even when controlling for changes in land cover, we found that on average colonies in the study area experienced a 14% annual decline in honey yields. We discuss possible explanations for these non-land-cover-related honey yield declines, including changing economic conditions (e.g. pollination services), changes in land management (e.g. pesticides), and increases in pests or diseases.

饲料供应减少以及农药暴露增加是蜜蜂健康下降的重要因素。在这里，我们隔离了大平原北部 160 个商业养蜂场的土地覆盖变化及其对蜂蜜生产的影响。我们发现，2008 年至 2012 年的土地覆盖变化导致研究区域的蜂蜜产量每年下降 0.9%。从草地到大豆（但不是玉米）的过渡对蜂蜜产量特别有害，这可能是由于蜜蜂在农田内和农田周围接触了杀虫剂。当我们的结果应用于整个北达科他州（美国）的已知养蜂场时，我们估计由于 2008 年至 2012 年发生的土地覆盖变化，2012 年蜂蜜产量将下降 2.5%（160 万美元）。土地覆盖，我们发现，研究区域内的蜂群平均每年的蜂蜜产量下降 14%。我们讨论了这些与土地覆盖无关的蜂蜜产量下降的可能解释，包括经济条件的变化（例如授粉服务）、土地管理的变化（例如杀虫剂）以及病虫害的增加。