Pollination of a flower occurs when pollen is transferred from the anther (the male part) to the stigma (the female part).
Self-pollination (Autogamy) occurs within individual flowers without the help of an agent to move the pollen. The anther simply opens and the pollen falls on the stigma.
Cross-pollination occurs when pollen from a flower on one plant is transferred to the stigma of a flower on a different plant of the same species.
Pollination can be accomplished either by natural, but non-living (abiotic) forces, such as wind and water, or by living (biotic) organisms. While wind commonly pollinates grasses, conifers, and many deciduous trees, and water provides pollination for aquatic plants, these two abiotic vectors supply only about 20% of the pollination required by flowering plants. That leaves nearly 80% of flowering plants in need of a biotic pollinating agent or vector. Biotic vectors (or pollinators) include:
Insects
* bees, wasps, and occasionally ants
* beetles
* moths and butterflies
* flies
Vertebrates
* birds (hummingbirds, honeyeaters, sunbirds, spider hunters)
* mammals (bats, bears, rabbits, deer, rodents, monkeys, marsupials, lemurs)
* lizards
Why Should We Care About Pollination?
¨ Because much of our food supply depends on it!
¨ Up to 1/3 of our food needs biotic pollinators.
¨ Although some staple crops, like grains, are pollinated by the wind, many other foods we depend on are either directly or indirectly affected by the work of biotic pollinators.
* Directly affected – tomatoes, melons, cucumbers, blueberries and many other fruiting crops
¨ Many plants that we rely on for our beverages, fibres, spices, and medicines also need biotic pollinators in order to produce these goods.
¨ Our economy depends on pollinators too - over one billion dollars worth of produce in Canada is dependent on pollination by insects!
¨ Many species, besides humans, also depend on pollination for survival and without the activities of bees and other pollinators, the world would be a very different – and much less diverse – place to live.
Pollinators are in desperate need of our help!
Largely due to human activity…
Their habitat is decreasing
Their populations are declining
Self-pollination (Geitonogamy) occurs between the anther of one flower and the stigma of another on the same plant. This may require the help of a pollinating agent, or can be achieved by gravity.
Image: www.tutorvista.com
Types of Pollination
* Indirectly affected – eggs, dairy products, and meat from animals whose feed (like alfalfa, clover, and various seeds) depends on pollinators