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Sci. 7- Plants: Section 2.0 Quiz

Posljednje ažuriranje 3 months ago

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Using ANY OF your review notes, complete the following Quiz for Section 2.0- Plants play an Essential Role in the Environment and in Meeting Human Needs.

2.0 Plants play an essential role in the environment and in meeting human needs

2.1 The Role of Plants in the Environment

Plants are necessary for all life on Earth. Plants provide many things for the sustainability of life on our planet. Vegetation in Canada is classified into 4 main categories: forest, tundra, barren, and agriculture.

What do plants provide?

As a critical part of the ecosystem, plants provide oxygen for organisms to survive. They can reduce pollution by using carbon dioxide. Plants are also the basis of most food webs as producers of food for herbivores and ultimately carnivores. Plants also provide shelter for animals, clean and filter water, and help prevent soil erosion.

2.2 We Use Plants in Many Ways

Plants For Food

Nearly 75% of the world's food supply is based on seven major crops: wheat, rice, maize (corn), potatoes, barley, cassava, and sorghum.

Cocoa

Canola

Seaweed

Sugar

Chocolate is made from the fruit of the cocoa tree

Cocoa beans

78% of vegetable oil production is from canola

Canola plant

contains iodine and is used in soup broths and sushi

Seaweed

half of the world's sugar comes from sugar beets, located in the sugar beets' roots

Sugar beets

Cocoa beans are roasted, shelled, and then crushed. Cocoa butter and cocoa powder are separated. Cocoa powder is then mixed with milk to make chocolate.

Canola is pressed from the canola seeds and used as salad oil and frying oil

other products from seaweed include: ice cream, chocolate milk, yogurt, whipped cream, pies, jellies, and candies

roots are shredded, heated in running water and the concentrated clear liquid crystallizes to produce sugar similar to sugar cane

Chocolate bar

It is used to make margarine, shortening, baked goods, potato chips, and French fries

Bottles of canola oil

Seaweed products are often used to thicken food (alginate, agar, carrageenan)

Sushi made with seaweed

Sugar crystals

People use plants for things other than food.

Plants for Fibre

Plants also provide fibre, which is the tissue of plants from the stem, leaves, seeds or roots. Plants provide fibres for clothing, paper and shelter. The Aboriginal people from the West Coast wove cloth from the bark of the Western Red Cedar tree. Much of our clothing today comes from synthetic (manufactured) material, such as polyester and nylon. Natural fibres also provide resources for cloth:

Cotton - is a natural fibre that absorbs moisture and then allows it to evaporate easily, making it the world's most important non-edible plant. The cotton fibres come from the plant's seeds. The silky fibres are strong, flexible and have a gradual spiral that causes the strands to interlock when twisted, making them ideal for spinning into thread. The second layer of fibres are shorter and are 'fuzzy' - they are used to make cotton batting, rayon and various types of plastic and paper.
Hemp - Early makers of jeans used hemp, which is the oldest cultivated fibre plant in the world. Other products included the Bible, sails and ropes. Hemp has a less negative effect on the environment, because it uses less land area than trees, can be harvested in a year, lasts longer than paper, can be recycled up to seven times, chokes out weeds naturally and is not prone to insect pests.
Flax - is a food and fibre crop. The flax fibres, which are smooth and straight, are taken from the stem of the plant are are two to three times stronger than cotton fibres. Flax fibre is used for making linen paper, linseed oil - which is used as a drying oil in oil paints and varnish - and in products such as linoleum and printing inks.

Plants for Medicine

An apple a day keeps the doctor away! Many medicines (over 7000) contain ingredients made from plants. Herbal remedies are a common example of how plants are used to prevent illness. Plant medicines include:

tea (made from ginger root) - is used to soothe an upset stomach
tea (made from white spruce and hemlock) to prevent scurvy
white willow bark - is used to ease pain
kinnikinnick (buffalo berry) was used to treat kidney problems
opium poppy's seed pod - thick milky fluid provides a powerful pain medication - morphine
codeine is also found in the poppy - it is used in cough medicines
quinine - which comes from the cinchona tree - is used to prevent malaria.

Plants for Transportation and Construction

Rubber is one of the most important plant products that people use. Natural rubber comes from the Brazilian rubber tree. Synthetic rubber is made from coal and oil by-products - but natural rubber is also an important ingredient.

Canoes were carved from trees by Aboriginal people. Lubricants are provided from coconut and castor bean oils. The construction industry in North America uses wood (softwood lumber from British Columbia) as a building material.

Plants for Fuel

Wood or coal (which is a fossil fuel) are used to heat homes. Sugar can be turned into ethanol and wood can provide methanol (wood alcohol). Fuel from plants is economical, but not energy efficient, because a large amount of energy is needed to grow the plants and a lot of the energy is lost when it is converted to fuel.

We must make sure that our living resources survive and thrive, in order to have them in the future.

2.3 Managing Living Resources

Living resources are organisms that can be used to meet human needs. Managing living resources involves maintaining healthy populations of all living things that make up those resources.

Because we grow more than we consume, Canada exports the excess to other countries around the world. Canada is also a leader in forestry and agricultural research. Changing practices in the use of the living resources the land provides have resulted in certain stresses on these resources. This has led to the need to become better managers of the resources we have and need. Scientists, farmers, and foresters are working together to develop practices that reduce the negative effects sometimes associated with harvesting plants for food and fibre.

Sustainability (an ecological balance) is essential if we are to keep our living resources healthy in the long term.

Agriculture in Alberta

Alberta crops are worth almost $3 Billion. The food industry is second only to oil and gas in terms of earnings.

Agriculture is important, but relatively new as an industry in Alberta. The vast natural resources in Alberta attracted many settlers who cultivated the grasslands for crops and harvested timber for construction, manufacturing, and fuel. Nearly all of the grassland in the prairie provinces was converted to cropland, thus destroying the natural vegetation and native plant species that had been around for a thousand years.

There are ecoregions in Alberta where parkland, grassland, and forests have been converted to crop cultivation (of Alberta's 60 million hectares, over 20 million are now farmland).

Math Note: A hectare of land is equal to square meters of land.

Map of Alberta ecoregions

Forestry in Alberta

Canada has about 10% of the world’s forests. Alberta tree species most valued for lumber and paper include: Lodgepole Pine, White Spruce, Black Spruce, Aspen, Tamarack (Larch), and White Birch. From these forests come lumber, pulp, and paper products. Natural forests have many different kinds of trees, shrubs, and smaller plants. There are many animals that make their homes in, around, and under these plants. A natural ecosystem has a higher diversity, or variety, of plants and animals than a field of wheat or a stand of trees. The species within this ecosystem are all interdependent. Forestry practices can increase forest species diversity through careful cutting that allows more light and air into the forest.

Agencies that manage forest resources establish methods and regulations that foresters must follow when a forest is to be harvested. These regulations govern harvesting. Foresters explore a potential tree-cutting area thoroughly before any work begins. They map the area, indicating which tree species are to be cut and which special features should be noted. They also decide how to cut the trees, either clear cut (removing all the trees), or selective harvesting (removing only selected trees). Foresters attempt to improve the conditions (light, temperature, water, and nutrients) within the forest. Leftover branches (from the logging operations) must be disposed of. They are chopped (shredded) and spread over the forest floor, with some smaller piles burned. Replanting is always done by hand. When the trees begin to grow again, if too many of a particular kind compete for resources, they must be removed through thinning or pruning. Fertilizer is dropped from a helicopter to increase nutrient levels for the young trees. Forest fires are a natural part of forest development, but foresters try to ensure they burn in a controlled manner (as much as possible).