Turley Nash E, Biddinger David J, Joshi Neelendra K, López-Uribe Margarita M
Department of Entomology, Center for Pollinator Research The Pennsylvania State University Pennsylvania USA.
Intercollege Graduate Degree Program in Ecology The Pennsylvania State University Pennsylvania USA.
Ecol Evol. 2022 Aug 12;12(8):e9190. doi: 10.1002/ece3.9190. eCollection 2022 Aug.
Wild bees form diverse communities that pollinate plants in both native and agricultural ecosystems making them both ecologically and economically important. The growing evidence of bee declines has sparked increased interest in monitoring bee community and population dynamics using standardized methods. Here, we studied the dynamics of bee biodiversity within and across years by monitoring wild bees adjacent to four apple orchard locations in Southern Pennsylvania, USA. We collected bees using passive Blue Vane traps continuously from April to October for 6 years (2014-2019) amassing over 26,000 bees representing 144 species. We quantified total abundance, richness, diversity, composition, and phylogenetic structure. There were large seasonal changes in all measures of biodiversity with month explaining an average of 72% of the variation in our models. Changes over time were less dramatic with years explaining an average of 44% of the variation in biodiversity metrics. We found declines in all measures of biodiversity especially in the last 3 years, though additional years of sampling are needed to say if changes over time are part of a larger trend. Analyses of population dynamics over time for the 40 most abundant species indicate that about one third of species showed at least some evidence for declines in abundance. Bee family explained variation in species-level seasonal patterns but we found no consistent family-level patterns in declines, though bumble bees and sweat bees were groups that declined the most. Overall, our results show that season-wide standardized sampling across multiple years can reveal nuanced patterns in bee biodiversity, phenological patterns of bees, and population trends over time of many co-occurring species. These datasets could be used to quantify the relative effects that different aspects of environmental change have on bee communities and to help identify species of conservation concern.
野生蜜蜂形成了多样的群落，为原生生态系统和农业生态系统中的植物授粉，这使它们在生态和经济方面都具有重要意义。越来越多的证据表明蜜蜂数量在减少，这引发了人们对使用标准化方法监测蜜蜂群落和种群动态的兴趣增加。在这里，我们通过监测美国宾夕法尼亚州南部四个苹果园地点附近的野生蜜蜂，研究了多年间以及不同年份间蜜蜂生物多样性的动态变化。我们在2014年至2019年的6年时间里，从4月到10月持续使用被动式蓝色风向标诱捕器收集蜜蜂，共收集到超过26000只蜜蜂，代表144个物种。我们对总丰度、丰富度、多样性、组成和系统发育结构进行了量化。生物多样性的所有指标都有很大的季节性变化，月份平均解释了我们模型中72%的变异。随时间的变化则不那么显著，年份平均解释了生物多样性指标中44%的变异。我们发现所有生物多样性指标都在下降，尤其是在过去3年，不过还需要更多年份的采样才能确定随时间的变化是否是更大趋势的一部分。对40种最丰富物种随时间的种群动态分析表明，约三分之一的物种至少有一些数量下降的证据。蜜蜂科解释了物种水平季节性模式的变异，但我们没有发现一致的科水平下降模式，尽管熊蜂和汗蜂是下降最多的群体。总体而言，我们的结果表明，多年来全季节的标准化采样可以揭示蜜蜂生物多样性的细微模式、蜜蜂的物候模式以及许多共存物种随时间的种群趋势。这些数据集可用于量化环境变化不同方面对蜜蜂群落的相对影响，并有助于识别需要保护的物种。
