Invasive social bees can alter plant-pollinator interactions with detrimental effects on both partners. However, most studies have focused on one invasive bee species, while the interactions among two or more species remain poorly understood. Also, many study sites had a history of invasive bees, being hard to find sites with historical low abundances. In Patagonia, Bombus ruderatus (F.) invasion begun in 1993 and B. terrestris (L.) in 2006. Though honey bees (Apis mellifera L.) introduction started in 1859, their density is still low in some parts. By experimentally increasing honey bee densities, we evaluated the effect of honey bees and bumblebees floral visitation on native pollinator floral visitation, pollen deposition, and reproductive success of three plant species in mixed Nothofagus antarctica forests of northern Patagonia: Oxalis valdiviensis, Mutisia spinosa and Cirsium vulgare. Our results show that exotic bees became the main floral visitors. No negative association was found between invasive bee and native pollinator visitation rates, but there was evidence of potential competition between honey bees and bumblebees. Floral neighborhood diversity played an important role in pollinator behavior. Conspecific pollen deposition was high for all species, while deposition of heterospecific pollen was very high in M. spinosa and C. vulgare. Not as expected, honey bees visitation rate had a negative effect on heterospecific pollen deposition in C. vulgare. For O. valdiviensis, exotic visitation rates increased conspecific pollen deposition, which was positively related to reproductive success. Although exotic bees became main floral visitors, their contribution to reproductive success was only clear for one species.

中文翻译：

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入侵蜜蜂对南极非霍夫古斯混交林中植物-授粉媒介相互作用和植物物种繁殖成功的影响。

侵入性的社会蜜蜂可以改变植物与传粉者的相互作用，对双方都有不利影响。但是，大多数研究都集中在一种侵入性蜜蜂物种上，而对两种或多种物种之间的相互作用仍然知之甚少。另外，许多研究场所都有入侵蜜蜂的历史，很难找到具有较低历史丰度的场所。在巴塔哥尼亚，Bombus ruderatus（F.）入侵始于1993年，而B. terrestris（L .）入侵始于2006年。尽管蜜蜂（Apis melliferaL.）的介绍始于1859年，在某些地方它们的密度仍然很低。通过实验性提高蜜蜂的密度，我们评估了蜜蜂和大黄蜂的花期访问对巴塔哥尼亚北部混合南极南极森林中三种授粉植物的花粉传粉者花期访问，花粉沉积和繁殖成功的影响：Oxalis valdiviensis，Mutisia spinosa和Cirsium庸俗的。我们的结果表明，外来蜜蜂成为主要的花卉访客。入侵性蜜蜂与本地传粉者的访视率之间未发现负相关，但有证据表明蜜蜂与大黄蜂之间存在潜在竞争。花邻里多样性在授粉媒介行为中起着重要作用。同种的花粉沉积是高的所有物种，而异种花粉的沉积是在非常高的M.刺和C.大麦。出乎意料的是，蜜蜂的探访率对小球藻的异种花粉沉积有负面影响。对于瓦尔迪沃斯，外来访问率增加了特定花粉的沉积，这与生殖成功成正相关。尽管外来蜜蜂成为主要的花卉访客，但它们对繁殖成功的贡献仅在一个物种中很明显。