Background

IN ADVANCE: Prepare a selection of popular foods. Use Canada’s Food Guide or create your own list of foods. See the sample table at the end of this activity if you need ideas. 

THE VALUE OF POLLINATORS IS IMMEASURBLE

Without pollination, many plants could not reproduce. Food webs – and therefore ecosystems – would collapse. We would run out of food, medicine, wood products and almost everything we need to survive. Consider these pollinator products and by-products:

•  FOOD: Many of the foods we love – including bananas, apples, chocolate and more than half the world's supply of dietary fats and oils – is the result of the successful work of pollinators. We also get beverages, fibers, condiments, spices and medicines from plants that rely on pollination. And don't forget that wildlife also benefits from food made possible by pollinators.

• FORESTS: Trees are seed-bearing plants. For example, our maples, ashes and oaks of the Canadian South and East, the giant firs and cedars of the West and the spruces of the Boreal North all rely on the process of pollination to renew themselves. Their success is our success, since we rely on wood for our homes, paper, jobs and recreation.
•  FRESH AIR: Green plants are the Earth's "lungs," taking in carbon dioxide and releasing oxygen. The majority of these plant species rely on pollination to renew themselves.
• · Sparkling Water: Aquatic flowering plants help to purify water by taking up nutrients and contaminants. Their terrestrial cousins, rooted along shorelines and on steep slopes, help to keep soil in place. Even cast-off leaves provide a service, forming a protective litter-layer that buffers soil from the impact of rain as it falls to Earth.
• BIODIVERSITY: Healthy ecosystems rely on biodiversity. The process of pollination contributes on at least two levels:
  •  Genetic diversity (the hereditary differences between members of the same plant species) is made possible by the successful transfer of pollen from one plant to another. A plant population with a diverse genetic make-up is better able to fight off diseases and parasites and can adapt more successfully to changing environmental conditions.
  • The success of seed-producing plants in general increases the species diversity of ecosystems, which, in turn, makes those ecosystems healthier.

It's hard to imagine a world without seed-bearing plants. For eons, wind, water, hummingbirds, bees, flies and a host of other tiny creatures have performed their duties faithfully and with little fanfare. Yet the effectiveness of the pollinating agents, in fact the survival of many biotic pollinators, is put at risk by our activities.

• Loss of habitat for biotic pollinators. Our cities, homes and lawns – even our farm fields – have replaced the natural variety of flowering plants that once made up our landscapes It may seem strange that vast fields of the same flowering crop plants would be considered poor habitat for some pollinators. Consider, however:
  •  Crop fields are huge areas of one type of plant, all maturing at the same time, then being harvested and taken away. All the nectar and pollen – all the food for pollinators – is only available within a short period. This is like having a fridge full of food one day, but the next day it's gone – along with your home! Without habitat for feeding, mating and nesting, the population numbers and diversity of pollinators drop. Diverse landscapes and areas, such as provincial, territorial and national parks in different regions of Canada, help to ensure diverse habitats, which help to increase the variety of pollinators.

•  MONEY: Pollination and its products help keep our economy healthy. It is estimated that insect pollination is responsible for $1 billion worth of fruits and vegetables in Canada every year.

Toxic chemicals. Efforts to combat agricultural pests have vastly increased our use of insecticides and herbicides. Unfortunately, insecticides can also kill beneficial insects, and can stay in the environment for a long time. Even low pesticide levels can affect the memory, navigation and foraging abilities of honeybees. Herbicides, another type of poison aimed at undesired weeds, can destroy food that the pollinators rely on before and after crops have bloomed.                 

Imported parasites and diseases. Domestic honeybee and wild bee populations have been hit hard by the varroa mite. Originally from Asia, it attaches to the outside of the bee and sucks body fluids from its host, eventually causing death.

Climate change. Climate change seems to be affecting all aspects of life on the planet and pollination is no exception. Among the consequences that could be attributed to climate change are:                                                                                                             - More imported parasites may be able to survive and prey upon beneficial pollinators.      -Some insect pollinators may see their ranges reduced. That may lead to a decrease in  pollinator diversity and, eventually, a decrease in plant diversity.                                       -Bloom times of plants or insect activity times may be changed so that pollen production of the plant may not match up seasonally with the pollinator's activity.

NOTES

• · Consider bringing in fresh local produce to reinforce the connection to the human food supply.

SAMPLE FOODS

PRODUCT	PLANT	POLLINATOR	THREATS
Honey	Clover or other flowering plants through honeybees	Honeybee	Pesticides, parasites, colony collapse disorder, climate change
Apples	Apple tree	Mason bee	Pesticides, parasites, loss of habitat, climate change
Almonds	Almond tree	Honeybee	Pesticides, parasites, colony collapse disorder, climate change
Chocolate	Cocoa tree	Midge	Pesticides
Maple syrup	Sugar maple tree	Bumblebee	Pesticides, parasites, loss of habitat, climate change
Wood for house construction	White spruce tree	Wind	Spruce budworm, climate change
Paper	Black spruce tree	Wind	Spruce budworm, climate change
Ketchup	Tomato plant	Halictid bee	Pesticides, parasites, loss of habitat, climate change
French fries	Potato plant	Bumblebee	Pesticides, parasites, loss of habitat, climate change
Jack-o’-lantern	Pumpkin plant	Squash bee	Pesticides, parasites, loss of habitat, climate change
Green salad	Lettuce plant	Flies	Pesticides, parasites, loss of habitat, climate change
Blueberries	Blueberry plant	Digger bee	Pesticides, parasites, loss of habitat, climate change

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Task

1. Discuss with the students:

• Many things we take for granted come from seed-bearing plants.

• This includes food and clothing.

2. Share the selection of popular foods you prepared with the class.

3. Help the students trace which of the foods on your list come directly or indirectly from plants.

DISCUSSION

1. Which of the plants reproduce through flowers (it may be all)?

2. Which of the plants rely on animal pollinators?

3. How would our eating habits have to change if common pollinators were to become endangered?

VARIATIONS

•  Divide the class into groups. Assign a food to each group and have them research whether or not it came from flowering plants. Groups should report their findings to the class. Encourage them to use creative techniques such as dramatic interpretations, an essay or a poster.

EXTENSIONS

1. Identify possible threats to pollinators and predict possible consequences of pollinators becoming endangered or extinct.

2. Discuss how high winds and heavy rain that may be caused by climate change could affect plants relying on windborne pollination. 

3. Develop a mural that illustrates products, plants and pollinators, depicts their interconnections, and shows some of the threats to the pollination process. 

4. Conduct a "where does our food come from?" investigation using Canada's Food Guide and grocery store flyers. 

5. Research the flower emblem of your province or territory. Find out how it is pollinated and how it is protected in Canada.

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Learning Objectives

Students identify the plant origin for a number of common foods and find out which pollinating agent

makes it possible.

1. We can describe the importance and value of the pollination process to humans

2. We can trace the origin of common foods to their plant source

3. We can identify the role of pollinators in renewal of the food sources

4. We can identify possible threats to biotic pollinators

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