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Chapter 13: Plants: Uses, Form and Function

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1 Chapter 13: Plants: Uses, Form and Function
13.1 Plants as Valuable Bioresources

2 Agenda Take up homework Lesson 13.1 Plants as Valuable Bioresources Read p Vocabulary Handout

3 Learning Goals Students will define the following terms: photosynthesis, cellulose, agriculture, food security, sustainable agriculture, textile, timber, biofuel. Students will describe how the biosphere depends on plants. Students will describe the importance of agriculture to Canadian society. Students will explain the relationship between the “Three Sisters” Students will list important food crops in Canada. Students will discuss monocultures and sustainable agriculture and their role in food security. Students will explain the role of plants as a source of biochemicals, in erosion control, and in recreation and ecotourism.

4 Plants as Valuable Bioresources
People depend on plants to provide food, clothing, shelter, and medicine, as well as the oxygen we breathe. Some plants, such as Echinacea purpurea , are used for medicinal purposes.

5 The Biosphere Depends on Plants
Plants are essential to the health and functioning of the biosphere. Plants provide many important ecosystem services: providing food for other organisms providing habitats producing oxygen through photosynthesis providing fibre for humans to make clothing and structures reducing soil erosion providing fuel sources Two of the most important ecosystem services of plants are that: They carry out photosynthesis. They contain cellulose.

6 Photosynthesis: A Life-Sustaining Process
The conversion of solar energy into chemical energy is one of the factors that permit life as we know it to exist on Earth. Photosynthesis occurs in plants, some bacteria, and some protists. plants use light energy to convert water and carbon dioxide into glucose and oxygen. Glucose is the food that supplies plants and, any consumer along a food chain with energy to perform all other activities. plants as producers make up the base of the food chain in many ecosystems. most of the oxygen oxygen produced by plants and other photosynthetic organisms is released into the atmosphere and used by other organisms for their own cellular respiration. About 50 percent of the oxygen in the atmosphere is produced by plants.

7 The Many Uses of Cellulose
Plants contain cellulose, a large and complex carbohydrate. Cellulose is the main component of cell walls in plants. Humans use cellulose in many different ways: cellulose from cotton plants is used to make fabric cellulose from wood pulp is used to make paper and cardboard. The heat generated when wood and other plant materials are burned comes from the chemical energy stored in cellulose.

8 Plants as a Source of Food
Throughout history, plants have been a primary source of food for humans. Agriculture: farming or forestry practices that produce food and goods. Humans use about 150 of the edible plant species on Earth. The average human diet is made up of only about 20 crop plants. Three of these crops—wheat, rice, and corn (maize)—make up about 60 percent of the calories that humans consume directly from plants. Other crops that are important to humans include sugar cane, potatoes, sugar beets, soybeans, and barley.

9 The Importance of Agriculture to Canadian Society
One in seven jobs in Canada is in the agricultural industry. The agriculture and food industries account for almost 10 percent of Canada’s gross domestic product (GDP). Canada’s agricultural products are exported to countries all over the world including: United States Japan China Exports of maple sugar and maple syrup are worth over 200 million dollars every year.

10 Aboriginal Agriculture
In some North American Aboriginal societies, corn, climbing beans, and squash are known as “the three sisters.” These crops have been planted together by Aboriginal farmers across North America for thousands of years. The three crops benefit each other, growing most successfully when they are all planted together. The corn acts as a vertical structure for the beans to climb. When the bean plant dies and decays, it adds nitrogen to the soil. The squash, grows horizontally along the ground and acts as a ground cover which helps to protect the corn and the beans from dehydration, weeds, and other pests.


12 Important Food Crops in Canada
Canada’s grain crops, include: wheat, barley, oats, and rye used to produce food products worldwide. soybeans and flaxseed used to produce food oils

13 Crops with the Highest Production in Canada in 2008
Production (thousands of tonnes) Food Products Wheat 28 611 Flour used to make pasta, bread, cereal, cakes and cookies Canola 12 642 canola oil Barley 11 781 can be added to soups, salads, and stews • flour used to make baked goods Grain corn 10 592 cornmeal, cereal, and tortilla chips Oats 4 272 oatmeal and oat bran • flour used to make cereal, muffins, and cookies Peas 3 571 eaten alone or in soups, salads, and stews Soybeans 3 335 soybeans, tofu, and soy milk Lentils 1 043 Flaxseed 861 flaxseeds and flaxseed oil Rye 316 flour for cereal, bread, and other baked goods

14 Food Security Scientists predict that by 2030 the global population of humans will rise to over 8 billion. A critical issue for today’s human population and all future individuals on Earth is how to achieve food security. Food security: The state where all people, at all times, have access to enough safe and nutritious food to meet their dietary needs and preferences and allow them to lead an active and healthy life

15 Monoculture Today most agriculture is based on monocultures.
Monocultures allow larger and more productive crops to grow. Hundreds of hectares of one type of plant are grown in place of the natural ecosystem. Benefits of monocultures Similar treatment and care The same fertilizer, and pesticides can be used. Negative environmental and economic consequences Planting a single crop on the same area of soil repeatedly can deplete the soil of valuable nutrients. requires the input of synthetic fertilizers. often vulnerable to crop-specific pests. This has led to an increase in the use of pesticides. The farmer must pay for the fertilizers and pesticides. Water quality in ground water, streams, and rivers is usually decreased when synthetic fertilizers and pesticides are used.


17 Sustainable Agriculture
Sustainable agriculture: an approach to agricultural production that integrates economics, the environment, and society in meeting the nutritional needs of the world. The goal is to produce enough food to feed the world while taking into account the economy, society, and the environment in an integrated way.

18 In sustainable agriculture, farming methods aim to balance high yields with sustainable practices.
Crop rotation helps keep soil healthy and reduces the need for synthetic fertilizers. The use of natural predators helps keep pest populations under control, reducing the need for pesticides. Hand-pulling of weeds reduces the use of machinery, which reduces the need for petroleum-based fuels. Hiring people to help with some aspects of production, local communities benefit socially and economically. Sustainable agriculture practices try to model natural ecological processes, reducing impacts to the environment. The economic and social impacts of food production are integrated into the approach as well.

19 Plants as a Source of Fibres and Building Materials
Plants have provided resources that humans have used as building materials throughout time. Thatch roofs Thatch is a natural reed and grass which, when properly cut, dried, and installed, forms a waterproof roof. Traditionally thatchers use locally available materials. If local farmers were growing wheat, then wheat reed or straw was used. Sod houses The sod house or "soddy" was a successor to the log cabin during frontier settlement of Canada and the United States. The prairie lacked standard building materials such as wood or stone; however, sod from thickly-rooted prairie grass was abundant.

20 Wood is the most popular building material worldwide
Wood is the most popular building material worldwide. Timber is wood that is intended to be used for carpentry or construction. Wood is also the raw material used to make furniture and other items, such as musical instruments.

21 Many wood products such as plywood, chipboard/particleboard, and fibreboard are also used in construction. Plywood is an engineered wood product made up of sheets of wood veneer. The wood veneer boards are pressed and bonded together to create one solid piece. 

22 Particle board is a waste-wood product made by heat pressing wood chips, sawmill shavings, or even sawdust and resin together. After the resin, chemicals, and wood scraps have been mixed together, the liquid mixture is made into a sheet.  Fiberboard is an engineered wood composite made up of wood fibers. The making of the composite uses the fibers, glue, and heat to create a tight bonding board.

23 Plant fibres have been used for thousands of years
Plant fibres have been used for thousands of years. Products include paper, cords, rope and textiles. Textiles are fabrics or a flexible material made from natural or synthetic fibres, threads, or yarns. Type of Material Description Paper Paper is made from wood chips, fibrous crops such as rice, and recycled paper that is ground down, producing a material called pulp. Pulp is then mixed with water into a soft mass that is mashed and pressed into a thin sheet. Cardboard Cardboard is high-quality paper that still contains some lignin. Lignin is a substance in plants that holds strands inside cellulose molecules together. Cardboard is stiff and brown because the lignin has not been removed from it. Rope Cords and rope are plant fibre products that are used for tying, building, and hauling. Fibres from a plant called Indian hemp (Apocynum cannabinum) are used to make the highest quality rope and cord in the world. Fabric Fibres can be intertwined to make fabrics and cloths that are used in the textile industry. Textiles are used worldwide for clothing, household products, and shelters. Cotton is produced in the largest volumes of any textile worldwide. Flax plants produce one of the most valuable textiles in the world—linen. Flax fibres are made into linen textiles such as bed sheets and lace.

24 Plants as a Source of Biochemicals
Plants produce chemical compounds for many different purposes. to either attract pollinators to repel threats, such as fungi, insects, and other herbivores. Long before current technology and mass production, humans were extracting the chemicals from plants for: medicines perfumes dyes Lichen is used to make dyes.

25 Medicinal Uses Aboriginal peoples in North America and around the world have used, and continue to use, plants and plant extracts for a variety of medicinal purposes. Tea made from blackberry plants is used to treat diarrhea and other stomach ailments. Evergreen bark and needles, primarily from coniferous hemlocks and pines, were boiled to make a tea rich in Vitamin C. Approximately 25 percent of all prescription medicines contain plant extracts. These extracts are either isolated from or synthesized from plants, and then manufactured.

26 The pharmaceutical industry is constantly testing new plant extracts to discover potential applications in medicines. However, the deforestation of many rainforests is causing loss of biodiversity and threatening undiscovered species that might help fight many conditions that are currently untreatable. The rosy periwinkle contains two compounds that are used to treat childhood leukemia and Hodgkin’s disease. The survival rate of individuals suffering from Hodgkin’s disease shifted from less than 20 percent to greater than 90 percent after these compounds were discovered. The rosy periwinkle, however, is native to rainforests in Madagascar, and is at risk due to rapid deforestation in that region.

27 Ginseng is used to improve the function of
the immune system. Goldenseal is used to fight colds and as a mouthwash to treat sore gums and sore throats.

28 Plants as a Source of Fuel
Burning the woody parts of plants has provided energy for cooking and heating for thousands of years. Coal used today was formed over millions of years as partially decomposed plant material was buried deeper and deeper under Earth’s surface. Canada is becoming a significant leader in the production of biofuels. Biofuels: fuels produced from renewable biological sources such as crops and crop residues. Biofuels have the potential to provide an alternative energy source to fossil fuels.

29 Plants and Erosion Control
Soil erosion is a naturally occurring process in which the actions of wind and water remove the top layers of soil. Plants play a key role in controlling erosion and reducing the negative effects of flooding. The loss of soil is a significant in agricultural regions where the fertile topsoil can be lost. Eroded soil can wash down embankments and make roads impassable, and it can redirect streams. One key way to help reduce soil erosion is to cover the area with appropriate plants. Plants slow down the movement of water on the surface of the soil This allows the excess water to penetrate into the soil rather than washing over and carrying the topsoil with it.

30 Plants, Recreation, and Ecotourism
Local parks, conservation areas, provincial parks, national parks, and even backyards provide environments filled with plant life where we can: exercise, camp, hike, boat, picnic, cycle, and climb, learn about nature, and relax. Ecotourism is also a significant industry in Canada. Tourists come from all over the world to visit Canadian landscapes: temperate rainforests on the west coast the sweeping prairies the boreal forests deciduous forests of eastern Canada the tundra Canadians also visit other countries to experience the tropical rainforests of Costa Rica, the jungles of South America, and the wild grasslands of Africa.

31 Section Summary Plants are important because they transform the Sun’s energy into glucose and release oxygen into the atmosphere through the process of photosynthesis. Cellulose is an important molecule found in the cell walls of plants, and it is used by humans in many ways. Plants are a source of food, fibres, building materials, biochemicals, fuel, flood and erosion control, recreation, and ecotourism

32 Success Criteria I am able to define the following terms: photosynthesis, cellulose, agriculture, food security, sustainable agriculture, textile, timber, biofuel. I am able to describe how the biosphere depends on plants. I am able to describe the importance of agriculture to Canadian society. I am able to explain the relationship between the “Three Sisters” I am able to list important food crops in Canada. I am able to discuss monocultures and sustainable agriculture and their role in food security. I am able to explain the role of plants as a source of biochemicals, in erosion control, and in recreation and ecotourism.

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