How Human Activities Affect Our Ecosystem

A Lesson Plan for Science Grade 8 Patricia Ann R. Empleo DLC: Suggested ways to minimize the impact of human to the environment. I. Objective:

At the end of the lesson, students are expected to: a. identify the diferent human activities that affect the ecosystem b. assume the responsibility for environmental care c. create a slogan about protecting the ecosystem II. Subject Matter/ Topic: How does Human Activities Affect the Ecosystem? Materials: Visual Aids Cartolina Colored Paper White Board Marker Masking Tape Pictures Short Bond paper Pentel Pens

III.

References: BOOK: Ching, Johnny A. (2007). General Biology. Mandaluyong City. pg.304 WEBSITES: How do human activities affect ecosystems? http://www.mheducation.ca/school/learningcentres/file.php/9780070726901/ olc2/dl/699403/1_5.pdf Human Activities that Affect the Ecosystem http://classroom.synonym.com/human-activities-affect-ecosystem-9189.html Science Module Grade 8 http://www.slideshare.net/nicogranada31/k-to-12-grade-8-science-learnermodule Value to be integrated: Environmental Care (Physical Dimension)

IV. Motivational Activity: Direction: Write in the circles the reason why the pictures in the box occur.

Processing Questions: 1. Who do you think are responsible for the following disaster? 2. Are you affected by this? Why? Why not? 3. What do you think will happen if the following reasons why the disaster occur continue to happen?

V. Main Activity: Brainstorming: Predict The Consequences 1. The class will be divided into 3 groups. Choose one of the activities listed below. • logging • farming • fishing 2. Brainstorm at least three consequences of the activity you chose. Be sure to think about things that could affect the environment. 3. Choose a representative to present your group’s answers. Processing Questions: 1. How do you find the activity is it easy or hard for you to come up with these consequences? 2. Is this really happening right now? 3. Did you experience these consequences? 4. What do you feel after knowing these activities affect our environment? 5. What should you do to help avoid these consequences? 6. Can you give ways to avoid these? VI. Abstraction/Lesson Proper: How do Human Activities Affect the Ecosystem? Ecosystem refers to a community of living organisms and their interactions with the environment. Most human activities, such as agriculture, industry, fishing and mining affect the ecosystem in a negative way, especially when performed in an excessive and unsustainable way. Global warming, pollution and extinction of species are some of the consequences of such human behavior. Humans are the top consumers in many food pyramids. To increase food production, they use methods that have an effect on food chains and food webs. Some of the farming practices are described as follows: 1. Monoculture. This is the cultivation of a single crop in large areas. Vast tracts of land are converted to rice farms, sugar farms, and coconut farms. By limiting the cultivation of different kinds of plants, people also deprive

many animals of their food and home. These animals, some of which feed on insect pests, move to other places. Only the insect pests that eat the monocrop remain in the area. If uncontrolled, these pests can totally wipe out the monocrop in a short time. Some soil microorganisms depend on specific plants for food. Eliminating these plants is harmful to the microorganisms. Since microorganisms are responsible for returning plant nutrients to the soil, the cycling of nutrients for reuse of the plants is disturbed. 2. Herbicides and Insecticides. Farmers spray their crops with insecticides to kill insect pests, and with herbicides to kill weeds. However, the chemicals also destroy other organisms, including beneficial insects and soil organisms which help in decay. Insecticides move up the food pyramid and accumulate in the body of organisms. The smallest concentration of the chemical is at the base of the pyramid occupied by producers. The amount increases towards the top. The greatest concentration is found in the top consumers such as birds, mammals, and humans. Many insect pests become resistant to chemicals. This may lead to the use of increased amounts of pesticide. 3. Chemical Fertilizers. Monocrops usually require large amounts of chemical fertilizers. Continuous and uncontrolled use of chemical fertilizers may increase soil acidity, thus destroying soil structure. Findings show that more fertilizers are needed for the same amount of yield after years of monoculture. Fertilizers may run off to rivers, ponds, and lakes. Accumulation of fertilizers may cause the death of these bodies of water. Fertilizers in the water will cause increased growth of algae and other water plants. They cover the water’s surface and block the passage of oxygen. Thus, less oxygen is dissolved in water. Furthermore, when algae and aquatic plants die, decay microorganisms use oxygen. Dissolved oxygen becomes insufficient, causing fish and other aquatic animals to die.

To conserve the environment, some desirable practices are described below: 1. Grow a variety of crops instead of only one crop. 2. Use insects to fight other insects. This is known as biological control of insect pests. 3. Instead of chemical fertilizers, try organic farming using natural fertilizers for crops. Some natural fertilizers are compost and animal manure.

VII.

Application: In short bond paper, make a slogan about protecting the ecosystem.

VIII. Evaluation: I. TRUE OR FALSE: Write T if the statement is correct and F if not. __________ 1. Farmers spray their crops with herbicides to kill insect pests, and with

insecticides to kill weeds. __________ 2. To conserve the environment the farmer should grow a variety of crops instead of only one crop. __________ 3. Mang Tano use insecticides kill pest, this helps to protect our ecosystem. __________ 4. To help protect our environment, Mang Tenor use insects to fight other insects. __________ 5. Chemical Fertilizer helps to protect our ecosystem. II. ESSAY Discuss the following desirable practices the farmers should do to conserve the environment. Explain why it is important to the ecosystem. ANSWER KEY: 1. F 2. T 3. F 4. T 5. F IX.

Assignment: Look for current research about the farmer’s practices and identify if they follow the following desirable farmer practices to conserve the environment.