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Morales, C. L. (2007). "Introducción de abejorros (<i>Bombus</i>) no
nativos: causas, consecuencias ecológicas y perspectivas [Introduction of
non-native bumblebees (<i>Bombus</i>): causes, ecological consequences
and perspectives]." <u>Ecologia Austral</u> <b>17</b>: 51-65.<br>
<x-tab> </x-tab>The
invasion of non-native pollinators might have considerable impacts on
native pollinators, native and introduced plants. In this article I
analyze the causes of introduction of bumblebees (Bombus), the factors
favoring the invasion and the distribution of introduced species. I also
review the studies about their ecological impact, discussing the
limitations of those studies, and the main gaps in knowledge. Five
bumblebee species are established outside their native ranges, as a
consequence of intentional releases and the trade of colonies.
Introduced bumblebees are highly polylecthic and could acquire high
abundances in invaded areas, dominating in some cases the anthophyllous
communities. In general, they gather resources more efficiently than
natives, and despite a substantial overlap in the use of floral
resources, in general both groups mutually exclude in time and space,
suggesting the potential for competition; nevertheless no study has
experimentally tested this hypothesis. The introduction of bumblebees
could favor the introduction and transmission of pathogens. Non native
bumblebees are less efficient pollinators of some native plants than
natives and, in general, they prefer non native plant species,
contributing to the pollination of important weeds, although their
influence on weed invasion process has not been tested. Under
experimental conditions some species of non native bumblebees can mate
with native congeners; nevertheless no hybridization has been reported in
the wild. The evidence of the impact of non native bumblebees on
native ecosystems is scarce, fragmented and preliminary. In spite of
them, considering the overall available evidence I strongly recommend the
application of the precautionary principle to analyze potential future
introductions.<br><br>
This is part of a special section in the journal about pollinators:
<br><br>
The journal Ecología Austral from Argentina has recently published a
special <br>
section on "Threats to Pollinators". It has contributions from
Marcelo Aizen, <br>
Diego Vázquez and many others. The articles can be downloaded freely from
the <br>
journal's web:
<a href="http://www.ecologiaaustral.com.ar/ingles/index2.php" eudora="autourl">
http://www.ecologiaaustral.com.ar/ingles/index2.php<br>
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