Pollination Ecology of Flowering Plants
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http://en.spii.ir/seSPII/default.aspx?page=Document&app=Documents&docId=11507 University Lectures, 30. 5. 2016 Invited by Prof. Behzad Ghareyazie, Founder of ABRII Prof. em. Klaus Ammann, University of Bern, Switzerland Lecture 6 in Teheran Pollination Ecology of Flowering Plants [email protected] Pollination Ecology http://en.wikipedia.org/wiki/Pollination_syndrome http://www.cas.vanderbilt.edu/bioimages/pages/pollination.htm Fenster, C.B., Armbruster, W.S., Wilson, P., Dudash, M.R., & Thomson, J.D. (2004) Pollination syndromes and floral specialization. Annual Review of Ecology Evolution and Systematics, 35, pp 375-403 http://www.ask-force.org/web/Pollination/Fenster-Pollination-Syndromes-2004.pdf 1.6.1. incentive: Sources of nectar and pollen INCENTIVES FOR VISITING FLOWERS Plants can not move from one location to another, thus many flowers have evolved to attract animals to transfer pollen between individuals in dispersed populations. Flowers that are insect-pollinated are called entomophilous; literally "insect-loving" in Latin. They can be highly modified along with the pollinating insects by co-evolution. Flowers commonly have glands called nectaries on various parts that attract animals looking for nutritious nectar. Birds and bees have color vision, enabling them to seek out "colorful" flowers. Some flowers have patterns, called nectar guides, that show pollinators where to look for nectar; they may be visible only under ultraviolet light, which is visible to bees and some other insects. Flowers also attract pollinators by scent and some of those scents are pleasant to our sense of smell. Not all flower scents are appealing to humans, a number of flowers are pollinated by insects that are attracted to rotten flesh and have flowers that smell like dead animals, often called Carrion flowers including Rafflesia, the titan arum, and the North American pawpaw (Asimina triloba). Flowers pollinated by night visitors, including bats and moths, are likely to concentrate on scent to attract pollinators and most such flowers are white. Still other flowers use mimicry to attract pollinators. Some species of orchids, for example, produce flowers resembling female bees in color, shape, and scent. Male bees move from one such flower to another in search of a mate. http://en.wikipedia.org/wiki/Flower#Attraction_methods Hedera helix, Ivy Nectar presented in open disk * Allgemeines Hedera helix, Efeu, Araliaceae Nektarsuche Hedera Parnassia palustris, Saxifragaceae attractive pseudo-glands offered, no nectar Nektarsuche Hedera Parnassia palustris Studentenröschen Saxifragaceae Parnassia palustris, Pseudonektarien, schlussendlich Selbstbestäubung Ranunculus bulbosus Ranunculaceae yellow Corolla actually flower-shaped nectaries green perianth, the actual flower * Ranunculus bulbosus Ranunculus bulbosus, nektaries flower shaped, Ranunculaceae * Ranunculus bulbosus, Nektarien Ranunculus repens normal spectrum seen by humans ultraviolett spectrum seen by insects Ranunculus repens, Nektarmal in UV various shapes of nectaries with Ranunculaceae Nektarien Ranunculaceae Aquilegia vulgaris, Akelei, Ranunculaceae corolla and nectaries Aquilegia vulgaris Aquilegia vulgaris nectaries only Ranunculaceae Aquilegia vulgaris Aconitum napellus Ranunculacaee Aconitum napellus Aconitum paniculatum, Ranunculaceae, view from the side Aconitum paniculatum Aconitum paniculatum frontal view Ranunculaceae Aconitum paniculatum Aconitum paniculatum Ranunculaceae Nectaries prepared Aconitum paniculatum Nektarien Aconitum septentrionale Ranunculaceae Aconitum septentrionale Aconitum vulparia gelber Eisenhut Ranunculaceae Bumblebees digging holes in helmet of flowers in order to steal the pollen from the anthers Aconitum vulparia, Hummelbesuch Manfredini, F., Beani, L., Taormina, M., & Vannini, L. (2010) Parasitic infection protects wasp larvae against a bacterial challenge. Microbes and Infection, 12, 10, pp 727- 735 <Go to ISI>://WOS:000282906000005 Examples of the amazing breadth of pollination ecology: The dove tree (Davidia involucrata ) has “naked” flowers that lack a perianth but are surrounded by two large bracts. These turn from green (a) to white (b) when flowers open which increases pollinator attraction Sun, J.F., Gong, Y.B., Renner, Susanne S., & Huang, S.Q. (2008) Multifunctional Bracts in the Dove Tree Davidia involucrata (Nyssaceae: Cornales): Rain Protection and Pollinator Attraction, Vol. 171, pp. 119-124. The University of Chicago Press for The American Society of Naturalists, http://www.ask-force.org/web/Pollination/Sun-Davidia-Multifunctional-Bracts-2008.pdf Examples of the amazing breadth of pollination ecology: Calypso bulbosa (c), a rewardless orchid, has evolved to deceive naïve bumblebees in the early spring to effect pollination without payment in nectar Dafni, A. (1983) Pollination of Orchis Caspia--A Nectarless Plant which Deceives the Pollinators of Nectariferous Species from other Plant Families. Journal of Ecology, 71, 2, pp 467-474 http://www.ask- force.org/web/Pollination/Dafni- Pollination-Orchis-Deceives-1983.pdf Ackermann, J.D. (1981) Pollination Biology of Calypso bulbosa var. occidentalis (Orchidaceae), a Food Deception System. Madrono, 28, 3, pp 101-110 http://www.ask-force.org/web/Pollination/Ackermann- Calypso-bulbosa-Food-Deception-1981.pdf The perennial vine, Gelsemium sempervirens (d), contains alkaloids in all plant parts including corollas and nectar which deter floral herbivores and nectar robbers but - in high concentrations - also pollinators Adler, L.S. & Irwin, R.E. (2005) Ecological costs and benefits of defenses in nectar. Ecology, 86, 11, pp 2968-2978 http://www.ask- force.org/web/Pollination/Adler- http://alabamaplants.com/Yellowopp/Gelsemi Ecological-Costs-Benefits-2005.pdf um_sempervirens_page.html Adler, L.S. & Irwin, R.E. (2005) Ecological costs and benefits of defenses in nectar. Ecology, 86, 11, pp 2968-2978 http://www.ask-force.org/web/Pollination/Adler-Ecological-Costs-Benefits-2005.pdf Conclusion Secondary compounds in nectar are widespread (Baker 1977, Adler 2000); however, the relationship between these compounds and plant fitness has remained poorly understood. Here we provide experimental evidence that secondary compounds in the nectar of Gelsemium generally decreased the proportion of flowers probed and time spent per flower for most floral visitors. Nectar alkaloids decreased an estimate of male plant reproduction and had little consistent effect on estimates of female reproduction. If nectar secondary compounds provide more fitness costs than benefits in Gelsemium, what maintains variation in this trait? If nectar secondary compounds are heritable, variation could be maintained through a number of mechanisms, including spatiotemporal variation in selection driven by variation in the abundance of pollinators vs. nectar robbers (Thompson and Cunningham 2002). Alternatively, the presence of alkaloids in nectar may be a pleiotropic consequence of their production in other plant tissues and transport through the phloem. To address the possibility that links between defense levels in different tissues constrain the ability of plants to evolve optimal solutions in the context of interactions with multiple antagonists and mutualists, studies of the genetic and environmental factors that determine defense expression across multiple plant tissues, including roots, leaves, stems, flowers, nectar, and fruits, will provide the most constructive ecological and evolutionary insights. Adler, L.S. & Irwin, R.E. (2005) Ecological costs and benefits of defenses in nectar. Ecology, 86, 11, pp 2968-2978 http://www.ask-force.org/web/Pollination/Adler-Ecological-Costs-Benefits-2005.pdf Hoverflies (e) visit flowers in a large range of habitats, they even pollinate cultivated plants. Though they are numerous, species-rich and wide-spread, their role as pollinators is often still neglected. Mayer, C.A., Lynn; Armbruster, W. Scott; Dafni, Amots; Eardley, Connal; Huang, Shuang-Quan; Kevan, Peter G.; Ollerton, Jeff; Packer, Laurence; Ssymank, Axel; Stout, Jane C.; Potts, Simon G. (2011) Pollination ecology in the 21st Century: Key questions for future research. Journal of Pollination Ecology, 3, pp 8-23 http://www.ask- force.org/web/Pollination/Mayer- Pollination-Ecology-21fst-Century- Future-2011.pdf Rhododendron ponticum (h) is a highly invasive plant in Ireland. Though it provides food resources for generalist bumblebees, effects on native plant pollinator interactions vary with intensity of invasion. Mayer, C.A., Lynn; Armbruster, W. Scott; Dafni, Amots; Eardley, Connal; Huang, Shuang-Quan; Kevan, Peter G.; Ollerton, Jeff; Packer, Laurence; Ssymank, Axel; Stout, Jane C.; Potts, Simon G. (2011) Pollination ecology in the 21st Century: Key questions for future research. Journal of Pollination Ecology, 3, pp 8-23 http://www.ask- force.org/web/Pollination/Mayer- Pollination-Ecology-21fst-Century- Future-2011.pdf Heterochelus chiriagricus (Striped monkey beetle), 10mm. [image by M. Picker & C. Griffiths ©, from Field Guide to Insects of South Africa, used with permission]. http://www.biodiversityexplorer.org/beetles/scarabaeidae/r utelinae/hopliini.htm In the Succulent Karoo of South Mayer, C., Soka, G., & Picker, M. (2006) Africa, monkey beetles (Hopliini) The importance of monkey beetle (Scarabaeidae : Hopliini) pollination for Aizoaceae and Asteraceae in grazed and are important pollinators of many ungrazed areas at Paulshoek, Succulent Karoo, South Africa. plant species Journal of Insect Conservation, 10, 4, pp 323-333