Density-Dependent Effects Of Ants On Selection For Bumble Bee Pollination In Polemonium Viscosum
Mutualisms are commonly exploited by cheater species that usurp rewards without providing reciprocal benefits. Yet most studies of selection between mutualist partners ignore interactions with third species and consequently overlook the impact of cheaters on evolution in the mutualism. Here, we expl...
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ftunivnorthcag:oai:libres.uncg.edu/35303 2024-09-30T14:45:27+00:00 Density-Dependent Effects Of Ants On Selection For Bumble Bee Pollination In Polemonium Viscosum Geib, Jennifer C. NC DOCKS at Appalachian State University 2007 http://libres.uncg.edu/ir/asu/f/Geib_Jennifer_2007_Density Dependent Effects Ants.pdf English eng http://libres.uncg.edu/ir/asu/f/Geib_Jennifer_2007_Density Dependent Effects Ants.pdf 2007 ftunivnorthcag 2024-09-17T15:09:12Z Mutualisms are commonly exploited by cheater species that usurp rewards without providing reciprocal benefits. Yet most studies of selection between mutualist partners ignore interactions with third species and consequently overlook the impact of cheaters on evolution in the mutualism. Here, we explicitly investigate how the abundance of nectar-thieving ants (cheaters) influences selection in a pollination mutualism between bumble bees and the alpine skypilot, Polemonium viscosum. As suggested in past work with this species, bumble bees accounted for most of the seed production (78% ± 6% [mean ± SE]) in our high tundra study population and, in the absence of ants, exerted strong selection for large flowers. We tested for indirect effects of ant abundance on seed set through bumble bee pollination services (pollen delivery and pollen export) and a direct effect through flower damage. Ants reduced seed set per flower by 20% via flower damage. As ant density increased within experimental patches, the rate of flower damage rose, but pollen delivery and export did not vary significantly, showing that indirect effects of increased cheater abundance on pollinator service are negligible in this system. To address how ants affect selection for plant participation in the pollination mutualism we tested the impact of ant abundance on selection for bumble bee-mediated pollination. Results show that the impact of ants on fitness (seed set) accruing under bumble bee pollination is density dependent in P. viscosum. Selection for bumble bee pollination declined with increasing ant abundance in experimental patches, as predicted if cheaters constrain fitness returns of mutualist partner services. We also examined how ant abundance influences selection on flower size, a key component of plant investment in bumble bee pollination. We predicted that direct effects of ants would constrain bumble bee selection for large flowers. However, selection on flower size was significantly positive over a wide range of ant abundance (20–80% of ... Other/Unknown Material Tundra University of North Carolina: NC DOCKS (Digital Online Collection of Knowledge and Scholarship) |
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University of North Carolina: NC DOCKS (Digital Online Collection of Knowledge and Scholarship) |
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ftunivnorthcag |
language |
English |
description |
Mutualisms are commonly exploited by cheater species that usurp rewards without providing reciprocal benefits. Yet most studies of selection between mutualist partners ignore interactions with third species and consequently overlook the impact of cheaters on evolution in the mutualism. Here, we explicitly investigate how the abundance of nectar-thieving ants (cheaters) influences selection in a pollination mutualism between bumble bees and the alpine skypilot, Polemonium viscosum. As suggested in past work with this species, bumble bees accounted for most of the seed production (78% ± 6% [mean ± SE]) in our high tundra study population and, in the absence of ants, exerted strong selection for large flowers. We tested for indirect effects of ant abundance on seed set through bumble bee pollination services (pollen delivery and pollen export) and a direct effect through flower damage. Ants reduced seed set per flower by 20% via flower damage. As ant density increased within experimental patches, the rate of flower damage rose, but pollen delivery and export did not vary significantly, showing that indirect effects of increased cheater abundance on pollinator service are negligible in this system. To address how ants affect selection for plant participation in the pollination mutualism we tested the impact of ant abundance on selection for bumble bee-mediated pollination. Results show that the impact of ants on fitness (seed set) accruing under bumble bee pollination is density dependent in P. viscosum. Selection for bumble bee pollination declined with increasing ant abundance in experimental patches, as predicted if cheaters constrain fitness returns of mutualist partner services. We also examined how ant abundance influences selection on flower size, a key component of plant investment in bumble bee pollination. We predicted that direct effects of ants would constrain bumble bee selection for large flowers. However, selection on flower size was significantly positive over a wide range of ant abundance (20–80% of ... |
author |
Geib, Jennifer C. NC DOCKS at Appalachian State University |
spellingShingle |
Geib, Jennifer C. NC DOCKS at Appalachian State University Density-Dependent Effects Of Ants On Selection For Bumble Bee Pollination In Polemonium Viscosum |
author_facet |
Geib, Jennifer C. NC DOCKS at Appalachian State University |
author_sort |
Geib, Jennifer C. |
title |
Density-Dependent Effects Of Ants On Selection For Bumble Bee Pollination In Polemonium Viscosum |
title_short |
Density-Dependent Effects Of Ants On Selection For Bumble Bee Pollination In Polemonium Viscosum |
title_full |
Density-Dependent Effects Of Ants On Selection For Bumble Bee Pollination In Polemonium Viscosum |
title_fullStr |
Density-Dependent Effects Of Ants On Selection For Bumble Bee Pollination In Polemonium Viscosum |
title_full_unstemmed |
Density-Dependent Effects Of Ants On Selection For Bumble Bee Pollination In Polemonium Viscosum |
title_sort |
density-dependent effects of ants on selection for bumble bee pollination in polemonium viscosum |
publishDate |
2007 |
url |
http://libres.uncg.edu/ir/asu/f/Geib_Jennifer_2007_Density Dependent Effects Ants.pdf |
genre |
Tundra |
genre_facet |
Tundra |
op_relation |
http://libres.uncg.edu/ir/asu/f/Geib_Jennifer_2007_Density Dependent Effects Ants.pdf |
_version_ |
1811646101105672192 |