Data from: The effect of repeated, lethal sampling on wild bee abundance and diversity

1. Bee pollinators provide a critical ecosystem service to wild and agricultural plants but are reported to be declining world-wide due to anthropogenic change. Long-term data on bee abundance and diversity are scarce, and the need for additional quantitative sampling using repeatable methods has been emphasized. Recently, monitoring programmes have begun using a standardized method that employs a combination of pan traps and sweep netting, resulting in lethal sampling of bees. This standardized method can remove a large number of bees from sites during each sampling day, raising concern that the sampling itself could have a negative effect on bee populations. 2. We conducted an experiment to assess whether lethal sampling for bees using pan traps and netting affected bee abundance and diversity when done every two weeks throughout a season and over multiple years. We compared bee abundance, richness, evenness and functional group composition between sites that had been sampled every two weeks from 2009 to 2012 to similar sites not previously sampled. 3. We found that the standardized method for sampling bees, with specimens from 132 morphospecies, did not affect bee communities in terms of abundance, rarefied richness, evenness, or functional group composition. Thus, our results indicate that the bee communities we sampled are robust to such sampling efforts, despite removing an average of 2862 bees per season. 4. We discuss several explanations for why sampling did not affect bee abundance or community structure, including a density-dependent response to reduced competition for resources. 5. These results suggest that bee monitoring programmes sampling once every two weeks with pan traps and netting will not affect bee community structure. We urge researchers monitoring bees to utilize standardized protocols so that results can be compared across space and time.

1. 传粉蜜蜂为野生植物与农业作物提供了至关重要的生态系统服务，但据报道，受人为活动变化影响，全球范围内的蜜蜂种群均呈现下降趋势。当前关于蜜蜂种群丰度与多样性的长期数据仍较为匮乏，学界也一再强调需采用可重复的方法开展补充定量采样。近年来，部分蜜蜂监测项目开始采用标准化采样方案，该方案结合了色盘诱捕器（pan traps）与扫网采样法（sweep netting），属于对蜜蜂的致死性采样。这种标准化方法在单次采样日即可从样地中移除大量个体，引发了学界对采样行为本身可能对蜜蜂种群造成负面影响的担忧。
2. 本研究开展了一项控制实验，以评估在整个生长季内每两周开展一次、且持续多年的色盘诱捕器与扫网致死采样，是否会对蜜蜂种群丰度与多样性造成影响。我们将2009年至2012年间每两周采样一次的样地，与此前未开展过采样的匹配样地进行对比，分析二者的蜜蜂丰度、物种丰富度、均匀度以及功能群组成差异。
3. 本研究共采集到132个形态种的蜜蜂标本，结果显示，该标准化采样方法并未对蜜蜂群落的丰度、稀疏化物种丰富度、均匀度以及功能群组成产生显著影响。因此，尽管单次生长季平均移除了2862只蜜蜂，但本研究采样的蜜蜂群落对这类采样活动具有较强的耐受性。
4. 针对采样未对蜜蜂丰度与群落结构造成影响这一结果，本研究探讨了多种可能的解释机制，其中包括资源竞争减弱后引发的密度依赖响应。
5. 本研究结果表明，采用色盘诱捕器与扫网法每两周开展一次采样的蜜蜂监测项目，并不会对蜜蜂群落结构造成负面影响。我们呼吁开展蜜蜂监测的研究者采用标准化采样方案，以便不同时空尺度下的监测结果能够实现横向与纵向比较。