Weeks 1 & 2 - Introduction, Ecosystems, Symbiotic Relationships, and Human Impacts

1 Introduction

 Introduction


Introduction: Activity 02 - An Overview of the Module
INTRODUCTION
Have you ever watched the birds fly overhead in the summer and wondered where they came from and where they were going to spend the night? We all wonder about the world around us. For this module, we will ask the questions ecologists ask, but not just about birds.

As ecologists, we will try to understand why all living things live in the places that they do. We will also explore how we as humans interact in the global ecosystem.

In the introduction to this module, "Interactions and Ecosystems", you will complete 2 exercises and a pretest.

Copyright © 2001, the Crown in Right of Alberta, as represented by the Minister of Learning, Alberta Learning, 11160 Jasper Avenue, Edmonton, Alberta T5K 0L2

Picture and Photos:( For specific picture reference view page source.)
Copyright © 2000-2001 www.arttoday.com, Copyright © 2001 Jeannie Charrois, Copyright © The Essentials Clip Art CD, MaGlas-l.gif.

Lesson 1


Introduction: Activity 02 - An Overview of the Module
Discussion
Unlike any other organisms on the Earth, humans have the greatest ability to change their environment. Through the creation of tools, humans have been altering their environment in ways thought to improve life. Do these changes help all those living things in the ecosystem? Past history and current concerns over global warming, acid rain, and the destruction of forests would suggest that this is not always so! What we do in the name of "progress" is often more destructive to the global environment.

In recent years, the impact of humans has caused a number of dramatic changes to a variety of ecosystems found on the Earth. Humans use and modify natural ecosystems through agriculture, forestry, recreation, urbanization, and industry. The most obvious impact of humans on ecosystems is the loss of biodiversity. If we understand our interactions with the environment, we can take steps to keep the Earth a fit place for all organisms to live. We all have an impact on the environment. Think about how you are affecting your environment.

Picture and Photos:( For specific picture reference view page source.)
Copyright © 2000-2001 www.arttoday.com, Copyright © 2001 Jeannie Charrois, Copyright © The Essentials Clip Art CD, MaGlas-l.gif.Copyright © 2001, the Crown in Right of Alberta, as represented by the Minister of Learning, Alberta Learning, 11160 Jasper Avenue, Edmonton, Alberta T5K 0L2

 Lesson 1


Activity 03 - LESSON 1: Defining an Ecosystem and Learning about Basic Needs
ACTIVITY A: Ecosystems


Textbook Readings

Science in Action 7
page 11
or

Science Focus 7
page 13

Living things cannot exist on their own. Every living thing must interact with its environment in order to survive. Organisms continually interact with their environment by creating or taking in energy in the form of food and releasing waste materials which are recycled by the ecosystem. As energy can neither be created nor destroyed, energy in the ecosystem is moved around through the ability of living things to consume others or to be consumed themselves.

An ecosystem can be compared to a huge factory with many moving parts, producing many different products. This environment will function the best when all the supplies are in balance - when organisms, materials, and energy interact together in a single system. However, when a part of the factory breaks down, or the supplies that make the products run out, the effects are felt throughout the factory. In the same way, when our ecosystem is altered, the effects are felt not only by the organism which caused the change, but by all those organisms which rely on that part of the ecosystem.

The Earth contains many ecosystems. Each of the ecosystems can be divided into smaller communities and populations. Living in each of these smaller categories are individual species. Think about the meaning of each of these highlighted words as you complete the activity below.



KeTextbook Readings

Science in Action 7
page 8 and 10
or

Science Focus 7
page 38

ACTIVITY B: Biotic and Abiotic Factors

Why is it that you cannot hold your breath forever? After only a minute or so you feel like your lungs will burst and you need to take a breath. As a member of the animal kingdom you need oxygen in order to survive. Oxygen is a non-living or abiotic component of life on Earth.

One way to take a closer look at an ecosystem is to divide the environment into living and non-living parts. The terms we use to describe these components are biotic and abiotic. Biotic is used to describe living things such as plants, animals and micro-organisms. Abiotic is the term given to describe the parts of the environment which are non-living. This would include things such as oxygen, sunlight, water, soil, temperature, wind speed, and the contours of the land. All these factors affect how organisms must function and adapt to their environments in order to survive.

By examining your current surroundings, you already know many of the ways in which different parts of the environment interact. If you go outside and find an ant eating a leaf, you would say this is two biotic factors interacting- the ant and the leaf. If you are looking at a plant growing in a sunny window you are viewing the process of photosynthesis. Photosynthesis is an interaction between a biotic component (the green plant) and many abiotic components (sunlight, water, and carbon dioxide). Through this interaction, the plant is able to produce its own food and give off an abiotic product called oxygen. An area's ecosystem is the network of all the biotic and abiotic components and the relationship between them.

HOW DO I KNOW IT IS ALIVE(BIOTIC)?
We often wonder if something is really living, non-living, or dead. If something is considered to be living it will have all of the characteristics list below. Don't be fooled-many non-living things may appear to have characteristics of living things, but if something does not have all the characteristics, it is not considered to be biotic or alive.
1. All organisms grow. Just like you will grow to approximately the same size and shape as your parents, all other living things grow to resemble the adults in their species as well.
2. All organisms move. An animal's movement from place to place can be obvious. Movement by other organisms may appear to be less obvious, but a plant's growth towards the sunlight, or small movements such as breathing, are evidence that an organism is alive.
3. All organisms reproduce. By reproducing organisms ensure their species will continue to survive. Organisms use a variety of ways to reproduce.
4. All organisms produce or take in food. All living things need energy to remain living. Animals receive their energy from food which they eat. Animals must eat other living things to get food. Plants are able to produce their own food through the process of photosynthesis. They use the Sun's energy to make food from carbon dioxide and water.
5. All organisms respond to stimuli in their environment. Organisms have the ability to react to a stimulus. A tulip which opens its petals on a sunny day or a dog who comes when called are responding to stimulus
6. All organisms are made up of cells. If you had a microscope and you looked at a living organism under it, you would see that all living things are made up of tiny units called cells. Even those things which were once living and are now dead will still be made up of cells. When we say something is "dead", we mean it once had life. Cork comes from Oak trees. If you were to look closely at a cork from a bottle, you would still be able to see where the cells used to be, even though the wood is now considered to be dead.
7. All organisms have a common chemical make-up. The shape of the organism does not matter. All organisms are made up of the same chemicals-carbon, hydrogen, nitrogen, and oxygen. Many organisms may contain additional chemicals, but these four chemicals are common to all living things.

Exercise 1.1: Biotic/Abiotic/Dead



ACTIVITY C: Basic Needs and Range of Tolerance

Imagine you have become a castaway on a deserted island in the South Pacific. When you wash up on shore there is no one else there with you. You are wearing little more than a t-shirt and jeans. All your luggage has been lost. The island has abundant vegetation and there are birds singing in the trees. The ocean water surrounding the island appears to be teeming with life.

Once you realize you are alone on a deserted island you panic! You now must put some of your science training to action if you are going to survive. You remember that all living things have a few basic needs. Do you remember what these are?


Textbook Readings

Science in Action 7
page 12 to 14
or

Science Focus 7
page 6 to 8

While you are gone, your neighbourhood friend, Cindy, has offered to look after your plant collection which consisted of tropical plants, ferns, and a cactus. Cindy wants to make sure the plants are healthy and decides to make sure they are well watered. When you finally return, you find your favourite cactus is rotting and dying. What could have caused this? Tropical plants and ferns thrive in a shady and moist environment. Cacti have adapted to grow best in warm, sunny, and dry environments. When Cindy watered the plants, she over-watered the cactus causing the cactus to die.
In the wild, most species appear to be limited in at least part of their geographic range by abiotic factors such as temperature, moisture availability and soil nutrients. For example, a plant may die if the temperature drops below 0° C or goes above 40°C. The range within which an organism can survive is called the organism's range of tolerance. No species has adapted to survive under all conditions found on the Earth. All species have specific limits of tolerance to physical factors that directly affect their survival or reproductive success. An abiotic factor's range of variation in which a species can survive and function is commonly defined as the range of tolerance. The level within the range of tolerance at which a species or population can function most efficiently is termed the optimum.
Copyright © 2001, the Crown in Right of Alberta, as represented by the Minister of Learning, Alberta Learning, 11160 Jasper Avenue, Edmonton, Alberta T5K 0L2

Picture and Photos:( For specific picture reference view page source.)
Copyright © 2000-2001 www.arttoday.com, Copyright © 2001 Jeannie Charrois, Copyright © The Essentials Clip Art CD, MaGlas-l.gif.