Shrubs as magnets for pollination: A test of facilitation and reciprocity in a shrub-annual facilitation system
Autor: | Ally Ruttan, Stephanie M. Haas, Christopher J. Lortie |
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Rok vydání: | 2020 |
Předmět: |
0106 biological sciences
Polymers and Plastics Pollination ved/biology.organism_classification_rank.species Ambrosia dumosa 010603 evolutionary biology 01 natural sciences Shrub Pollinator Magnet species hypothesis Positive interactions Deserts biology Ecology ved/biology Indirect interactions Understory Bees 15. Life on land biology.organism_classification Pollinator facilitation QL1-991 Facilitation Annual plant Larrea Zoology 010606 plant biology & botany |
Zdroj: | Current Research in Insect Science, Vol 1, Iss, Pp 100008-(2021) |
ISSN: | 2666-5158 |
Popis: | The magnet species hypothesis proposes that flowering plants that are attractive to pollinators can increase the relative pollination rates of neighbouring plants by acting as ‘magnets.’ Here, we test the hypothesis that insect-pollinated shrub species Larrea tridentata and wind-pollinated shrub species Ambrosia dumosa act as magnets for the pollinator visitation of understory annual plant species in an arid ecosystem. As an extension to the magnet species hypothesis, we propose the double magnet species hypothesis in which we further test for reciprocity by the floral island created in the understory of the benefactor shrubs as an additional pollinator magnet for the shrub itself. We used an annual plant placed near each shrub and the open to measure the effect of shrubs on annuals. The double magnet species hypothesis was tested using L. tridentata with and without surrounding annuals. We measured pollinator visitation and visit duration using video and in-situ observation techniques to test whether shrubs increase pollinator visitation to understory annual plants, if insect-pollinated shrubs act as better pollinator magnets than wind-pollinated shrubs (to determine the effects of the floral resource itself), and whether shrubs with annuals in their understory have higher pollinator visitation rates relative to shrubs without annuals. We found that insect-pollinated shrubs increased the visitation rate and duration of visits by pollinators to their understory plants and that wind-pollinated shrubs decreased the duration of visits of some insect visitors, but these relationships varied between years. While the presence of annuals did not change the visitation rate of all possible pollinators to L. tridentata flowers, they did decrease the visitation duration of specifically bees, indicating a negative reciprocal effect of the understory on pollination. Thus, the concentrated floral resources of flowers on insect-pollinated shrubs can act as a magnet that attract pollinators but that in turn provide a cost to pollination of the shrub. However, while wind-pollinated shrubs may provide other benefits, they may provide a cost to the pollination of their understory. These findings support the magnet species hypothesis as an additional mechanism of facilitation by insect-pollinated shrubs to other plant species within arid ecosystems. |
Databáze: | OpenAIRE |
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