Universidad Nacional de Río Negro, Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural, Mitre 630, San Carlos de Bariloche, Río Negro, 8400, Argentina.
Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural, Mitre 630, San Carlos de Bariloche, Río Negro, 8400, Argentina.
Ecology. 2021 Dec;102(12):e03526. doi: 10.1002/ecy.3526. Epub 2021 Oct 13.
Invasive species can reach high abundances and dominate native environments. One of the most impressive examples of ecological invasions is the spread of the African subspecies of the honey bee throughout the Americas, starting from its introduction in a single locality in Brazil. The invasive honey bee is expected to more negatively impact bee community abundance and diversity than native dominant species, but this has not been tested previously. We developed a comprehensive and systematic bee sampling scheme, using a protocol deploying 11,520 pan traps across regions and crops for three years in Brazil. We found that invasive honey bees are now the single most dominant bee species. Such dominance has not only negative consequences for abundance and species richness of native bees but also for overall bee abundance (i.e., strong "numerical" effects of honey bees). Contrary to expectations, honey bees did not have stronger negative impacts than other native bees achieving similar levels of dominance (i.e., lack of negative "identity" effects of honey bees). These effects were markedly consistent across crop species, seasons and years, and were independent from land-use effects. Dominance could be a proxy of bee community degradation and more generally of the severity of ecological invasions.
入侵物种可以达到很高的丰度并主导本地环境。生态入侵最令人印象深刻的例子之一是非洲亚种的蜜蜂在整个美洲的传播，从巴西的一个单一地点引入开始。入侵的蜜蜂预计会比本地优势物种更负面地影响蜜蜂群落的丰度和多样性，但这以前没有得到过检验。我们开发了一个全面而系统的蜜蜂采样方案，使用一种协议在巴西的三年时间里，在各个地区和作物中部署了 11520 个捕虫板。我们发现，入侵的蜜蜂现在是单一最占优势的蜜蜂物种。这种优势不仅对本地蜜蜂的丰度和物种丰富度产生负面影响，而且对整体蜜蜂丰度（即蜜蜂的强烈“数量”效应）产生负面影响。与预期相反，蜜蜂的负面影响并不强于其他达到类似优势水平的本地蜜蜂（即蜜蜂没有“身份”效应的负面影响）。这些影响在作物种类、季节和年份之间明显一致，并且与土地利用效应无关。优势可能是蜜蜂群落退化的一个指标，更广泛地说，也是生态入侵严重程度的一个指标。
