Unit 4: Interactions Within Ecosystems
The Big Idea:
“Everything is Interconnected”
Mrs. L Hinrichs
Unit 4: Interactions Within Ecosystems
The Big Idea:
“Everything is Interconnected”
Mrs. L Hinrichs
1 gallon milk jugs needed!!!!
We will need 3 milk jugs later on in the unit.
YouTube Opener
What a Wonderful World
BBC with David Attenborough
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What is an Ecosystem?
Look at the pictures on the next slide of the various ecosystems. Answer the following questions on your worksheet. (“What is an ecosystem”)
What characteristics are common to all of the pictures?
Name the type of ecosystem
Write your own definition of an ecosystem.
a
b
c
d
e
f
g
h
i
Ecosystem Awareness
Which of the following are ecosystems?
On a piece of paper, list which of the following you believe are ecosystems by definition.
After 2 minutes, Mrs. Hinrichs will ask you to compare your list with that of a classmate. Revise and discuss to create a new list.
After 2 minutes the class will get into 2 groups and compare lists.
The a single master list will be share on the white board!
Puddle
Barrel of rain water
Vacant lot
Carberry Desert
Field of Wheat
Canadian Shield
North America
Earth
What is an Ecosystem?
National geographic definition of an ecosystem.
A geographic area where plants, animals, other organisms, as well as weather and the physical landscape work together to form a bubble of life. (living and non living)
Every factor in an ecosystem depends on every other factor, either directly or indirectly.
E.g. a change in temperature will often affect what plants will grow. Animals that then depend on the plants for food and shelter will have to adapt, move, or die.
Therefore, the plants are directly affected by the temperature, and the animals are indirectly affected by the temperature as it corresponds to food/shelter.
Living & Non-Living Factors
In any ecosystem there will be some things that are living and some things that are non-living
Abiotic Factors
“non-living”
may have been living at one time, but are NOT alive anymore
BUT we can’t call them “dead” because that suggests that they were once living
Examples of abiotic factors:
Air, water, sunlight, rocks, and parts of soil
Living & Non-Living Factors
Biotic Factors
“living”
Latin word “bio” means “life”
Examples of biotic factors:
Birds, bears, bees, bacteria, bunnies, balsam trees, and blades of grass
Characteristics of Living Things
Is fire a living thing? WHY?
Based on what you know right now, answer that question in your notes. The most important part of the question is ‘WHY?’.
How do we know if something is alive? What are the characteristics of all living things?
Hint: This has been taught from grade 1-6.
Hint: There are 6!
Characteristics of Living Things
Respond to our Environment
All made of cells (DNA or RNA)
Use Energy (food, water, nutrients)
We all die/have a lifespan
We all Grow and Reproduce
Produce Waste
Types of Interactions in Ecosystems
Abiotic – Biotic Interactions
Example: a fish (living) swimming in water (non-lving)
Biotic – Biotic Interactions
Example: a snow shoe hare (biotic) being consumed by a lynx (also biotic)
Abiotic – Abiotic Interactions
Example: The wind (abiotic) creating waves in the water (abiotic)
*All these interactions make up an ecosystem!
Mini Field Trip!!!
Next class we will be going down to the bridge to observe the river ecosystem.
You will be drawing and describing what you see.
Describe the biotic and abiotic factors that you see.
Describe their relationship
Bring pencils, pencil crayons, erasers, etc…
(Reminder: Mrs. Hinrichs… get clipboards!)
Assignment
Complete the worksheet “Abiotic & Biotic Interactions” during the mini field trip.
Due next class
Changing Ecosystems
Ecological Succession
the gradual process by which ecosystems change and develop over time and certain species replace other species in an ecosystem
Happens in stages
At each stage of succession the organisms that are present change the environment in some way to allow another species to move in.
Any changes that take place during succession depend on environmental factors: amount of moisture, temperature, and wind.
Types of Succession
Primary succession
takes place on an area that is originally completely empty of life
Example:
an area that has been covered by a flow of lava
Secondary succession
occurs in an area where life once existed but has then been destroyed (far more common)
Example: a forest that has been destroyed by a wildfire
NOTE: Both processes can last hundreds or thousands of years
Stages of Primary Succession
Simple “pioneer” plants (lichens and mosses) grow in tiny cracks in rock where water and minerals collect
Pioneer plants decompose and begin to form soil in which more complex plants can begin to grow
Grasses, herbs (dandelions), and small shrubs called “opportunist” species begin to grow
they devote a great deal of energy producing huge numbers of seeds (to ensure species survival) and may live only one year
Stages of Primary Succession
Opportunist plants also die, decompose, and contribute to the growing layer of soil
Eventually, the soil is able to support more complex plants, such as larger shrubs and small trees including aspen, black spruce, and jack pine
Larger plants gradually take over from earlier communities since they are taller, have more leaves, and can capture more sunlight
Taller trees begin to grow and block out the sunlight needed by smaller trees and replace them
The final stage is the climax community; large and long-living species such as spruce, birch and fir trees
Primary Succession
Stages of Secondary Succession
Similar to stages for primary succession
Example: a forest has been cleared for agriculture and then abandoned at a later date
a pioneer community consisting of lichens and mosses is not needed because soil is already available
Annual plants (living one year) appear first; often weeds, such as crabgrass
Annual plants are replaced by perennial (live year after year) plants
Perennial plants are replaced by shrubs and trees
These are replaced by a climax community of large, long-living trees
Secondary Succession
ecological succession
Assignment
Complete the worksheet “Ecological Succession”.
DUE DATE: Next Class
Human Impact On Ecosystems
Human intervention can speed up or damage the natural process of succession in some areas
Examples: Over fertilizing, clear cutting forested areas…
Negative Human Impacts on Ecosystems
Preventing natural forest/bush fires
Introducing non-indigenous species to areas
Draining wetlands for agriculture or housing
Deforestation/destruction of rainforests
Pollution (water, soil, ground, air)
Positive Humans Impacts on Ecosystems
Protecting habitats
Reintroducing species
Protection of wildlife/endangered species
Reclamation of logging/mining lands
Reforestation/replanting of trees
Click
Sum of the Parts Activity
We will be doing an activity called Sum of the Parts in order to demonstrate how we all contribute to the pollution in a river, lake, or stream.
Page 283, Project wet book
Climate
The average weather pattern for a region
involves looking at the long term weather that an area usually gets
considers precipitation and temperature as well as other factors
gives a general description of the normal patterns for an area at a certain time of the year
Weather
local conditions that change from day to day
Short term information
Example: in Winnipeg it may be sunny one day with a high temperature, but the next day it may be rainy with a high temperature.
This does not mean that this place has a “hot climate”
Weather considers things like:
Temperature
Precipitation
Wind speed
Atmospheric pressure
Humans and Ecological Successions
In a group of 2 or 3, describe, in as much detail as possible a situation where humans have had a role in ecological succession. (good or bad)
You can make a chart (flow chart, diagram, etc…)
Draw pictures
Describe in words
You will share your example/story with the class.
Introduced or “Invasive” Species
Invasive species are organisms not native to a region that when introduced, either die out leaving no permanent impact, or out-compete the native species for available resources.
Plants, animals, viruses, bacteria, parasites, etc…
Introduced or “Invasive” Species
Examples of invasive species in Canada:
Dutch elm disease
purple loosestrife
zebra mussels
Emerald ash borers
It is estimated that 800 of the 5000 plant species in Canada were introduced species and successful enough to develop populations in the wild!
Mini Research Presentation
You will choose one the in many invasive species that are present in Manitoba from the Invasive Species of Manitoba web site.
Choose a species. (a species can only be chosen once)
Research the species
Create a Poster
Create a short presentation
Educate your classmates!
Endangered Species
Some species in Canada are in danger of extinction
There are so few of the species that they may not be able to reproduce enough to replace themselves
Sometimes species disappear completely from an area (extirpated species)
Any species that are near extinction or are extirpated are placed on the endangered species list
Canada has special laws to protect species on this list
Canadian Endangered Species
Sei whale
Blue whale
North Atlantic and Pacific Right whale
Wolverine
Bottlenose Whale
American Marten
Woodland Caribou
Killer Whale
American Badger
Swift Fox
Threatened Classification
Protecting our Environment
What is Sustainable Development?
A way of making decisions that balances the needs of today without sacrificing the ability of future generations to meet their needs.
The goal is for humans to make daily decisions which consider probable consequences to the environment, the economy and human health.
Money Down the Drain
Next class we will be in the lab to perform an experiment to look at and calculate the cost of a dripping faucet.
Pg. 351 in Project wet book.
Thinking Ahead…
We must make decisions that ensure a good quality of life for the next SEVEN generations.
We are ALL responsible to take care of all life on earth.
What can we do?
Work in a group of 2-3 to create a master list of things that you can do to help create a sustainable environment.
Think about the different goals and what you can do for each one.
Think about…
At home (inside/outside)
At school
In our community
In our province
In our country
Eg. Use rain barrels to collect rainwater to water plants
Make a commitment
Do you want to commit to doing 1 of your sustainable development ideas?
Write it on a paper with your name and SIGN IT!
QUIZ!
Quiz next class on everything in the until up until this point.
Journey 2050
Journey 2050
Energy Transfer in Ecosystems
All living things need energy in order to survive.
The BIG QUESTION is…
Where does all the energy for all living things come from?
Priestly Experiment
Joseph Priestly was an English clergyman and scientist. He noticed that if he put a burning candle in a jar, the candle went out after a few minutes and when he put a mouse in the jar, the mouse died. When Priestly added a green plant to the jar the candle did not go out as quickly and the mouse survived.
What substance was given off by the plant?
Energy Transfer in Ecosystems
If animals and plants get their energy from the food they use…
HOW DOES THE ENERGY GET INTO THE FOOD?
ANSWER: From the Sun!
Energy Transfer in Ecosystems
The Sun is the primary source of all energy for all living things
But animals and plants can’t use the energy from the sun directly…
Energy Transfer in Ecosystems
The Sun’s “light” energy must first be changed or converted into “useful” energy for plants.
Through a process called “photosynthesis”
“Photo” = light
“synthesis” = put together
Photosynthesis
The process of photosynthesis takes energy from sunlight and changes it into energy that plants and animals can use.
plants produce their own food (sugar) from the sun’s light energy
Photosynthesis
Inputs
The roots of a plant absorb water and use it during photosynthesis
The leaves of a plant absorb carbon dioxide and sunlight
Outputs
Plants give off oxygen and “sugar” through photosynthesis (and some leftover water)
Assignment
Complete the worksheet on photosynthesis
DUE DATE: Next class
From Plants to Animals
How does photosynthesis help animals?
Provides food (sugars in plants)
Provides oxygen for breathing
Animals have their own way of converting energy for their body to use
Cellular respiration
Cellular Respiration
Inputs:
Oxygen
Sugars (food)
Outputs:
Water
Carbon Dioxide
Energy (ATP)
cellular respiration and photosynthesis
Assignment
Complete the worksheet “Cellular Respiration Worksheet”
DUE DATE: Next Class
Roles of Organisms
Different organisms serve different functions or play different parts
If one part is not there, it affects all the others
Three main groups of organisms:
Producers
Consumers
Primary consumers
Secondary consumers
Tertiary consumers
Decomposers
Roles of Organisms
Producers
Produce food for themselves
Always at the start of a food chain
Examples: green plants, algae, and phytoplankton
Consumers
Consume (eat) food produced by the producers
Are found in higher levels within food chains
Examples: humans, rabbits, fish
Decomposers
Breakdown dead material
Can be considered a consumer.
Eg. Worms, fungi, mold
Types of Consumers
Herbivores: plant eating animals
found second in a food chain behind producers
Omnivores: organisms that eat plants and animals
Carnivores: meat eating organisms that feed on other animals
“Top carnivores” are found at the top of all food chains
Scavengers: eat dead or decomposing plant/animal matter
Examples: seagulls, crows, vultures, raccoons
Decomposers: “break up” dead plant and animal matter and return nutrients to the soil
Not always shown in food chains
Roles of Organisms
There are two other categories of consumers:
Predators
Animals that hunt and kill other animals for food
May require specific things to hunt in order to live
Could be small like spiders or large like sharks
Prey
Animals that are hunted and used as food by predators
Herbivores
Lots of omnivores
and carnivores
What is a Niche?
The specific role that an organism plays in a biological community
helps it to survive
Includes:
what it eats
where it lives (habitat)
how it interacts with other organisms
how it uses resources
Adaptations
Activity: Your Meal
Draw a picture of your most recent meal; explain how each piece of food got to your plate.
Remember to include as many herbs and spices as you can, along with some of the main ingredients that you cant see.
Eg. Milk in the mashed potatoes
Eg. Flour in the bread
Eg. Apples in your apple juice
Food Chains, Food Webs & Energy Flow
What is energy flow?
The movement of energy starting with the sun and passing from one living thing to the next
What is a food chain?
A model that shows how energy stored in food passes from one organism to another.
always begin with a producer and end with a consumer.
show different “levels” of consumers and their relationship to each other.
do not accurately show how much of a food item an animal consumes.
Food Chains
Things to remember:
the arrows in a food chain show the direction of energy flow and show which organisms eat which other organisms
They do not show the amounts of food each living thing needs in order to survive
They do not explain or show lost energy in an ecosystem
Your Meal
You created some food chains when you drew and explained your last meal.
Share some examples with the class by putting it on the poster boards at the front.
Activity: Building Food Chains
Complete the food chains for the following ecosystems:
Lawn
Forest
Pond
Use each organism only once.
HINT: think about what each organism would eat
Grass
Floating algae
Robin
Perch (big fish)
Wild cherry tree
Hawk
Grass hopper
Wood thrush (small bird)
Caterpillar
Minnow (small fish)
Mosquito larva
House cat
Activity: Building Food Chains
Food Webs
A food chain is only a simple feeding pathway
In most ecosystems carnivores rely on more than one source for food; they eat many things
Example: a wolf may eat white tail deer, but also mice, ground squirrels, rabbits, birds and their eggs
depends on what’s available at any given time
Herbivores may also eat more than one type of plant
producers get eaten by more than one type of living thing.
Food Webs
These complicated relationships can be shown using a food “web”
Connect each organism with all the organisms that it eats and all the organisms that eat it.
made of many individual interconnected food chains.
more realistic and more complex than food chains.
Energy Flow
At every level of a food chain or web an organism takes in energy (by eating)
Only 3 things can happen to this energy:
Used as fuel for the organism’s activities
gets “burned up” and released as heat
Stored in the organism’s body
Left unused and passes out of the organism as waste
*Each time energy is transferred (passed on through eating) in an ecosystem, some energy is LOST because it is put to use for life processes and activities.
Create a Food Web
As a class, organize the pictures, arrows, and coloured paper into a food web.
Place the coloured paper behind the organism photos.
You might not need all the materials provided.
Green paper producers
Red paper primary consumers
Blue paper secondary consumers
Yellow paper tertiary consumers
Orange paper quaternary consumers
Energy Loss in Ecosystems
Due to energy loss, it takes many mosquitoes to support one dragon fly
This shows how food chains are not accurate models of what happens in ecosystems.
Ecological Pyramids
A graphic way of showing the effects of energy loss through the levels of a food chain
Each level of an ecological pyramid matches a level of producer or consumer in a food chain
Ecological Pyramids
At each level of the ecological pyramid the amount of available energy is less
The number of organisms at each level of the pyramid usually decreases
Why is energy lost through the levels of a pyramid?
3 Types of Ecological Pyramids
Pyramid of Biomass
Shows total mass of organisms at each level.
Corresponds to the amount of energy contained at each level.
Limitations include:
Time of year it is calculated. Breeding season, snow fall affects numbers, etc…
Impossible to accurately measure mass of every single organism at each level.
Pyramid of Numbers
Shows the number of organisms at each level regardless of their size.
Convenient because counting organisms is pretty easy, although some are very hard to count.
Eg. How do you could total number of fungi spores, or earthworms in the ground?
Pyramid of Productivity
Looks at the amount of energy present at each level as well as the loss of energy.
This idea is based on Lindeman’s Ten Percent Law, which states that only about 10% of the energy in a trophic level will go towards creating biomass. The rest is used in respiration, hunting, and other activities, or is lost to the surroundings as heat.
What’s interesting, is that toxins are passed up the pyramid very efficiently, which means that as we go up, the amount of harmful chemicals is more and more concentrated in the organisms’ bodies. This is called biomagnification.
Assignment
Complete the worksheet “Transfer of Energy”
DUE DATE: Next Class
Assignment
We are going to complete two Gizmos.
Ecosystems Gizmo
Food Chain Gizmo
Biomagnification
The process that causes increasing concentrations of harmful toxins at each higher level of a food chain.
Examples: pesticides, mercury, herbicides, toxic wastes
How does this happen?
Harmful toxins get trapped in living things
As these organisms get eaten, the trapped material stays inside each organism that eats it, and it passes from organism to organism
Animals at the tops of the food chains end up with very high concentrations of this toxin.
Bioaccumulation
The accumulation of chemicals in a single organisms body over the course of its lifetime by ingesting contaminated materials.
Mercury enters water through industrial processes. Marine life ingest and absorb the mercury in small amount continuously which ‘accumulates’ in their bodies over time.
National Geographic
Bioaccumulation activity
If time permits, we will do a larger final project. Total required time: 10 hours.
Mini Bioaccumulation Activity
Next class, we will be in the lab to perform a mini activity.
Micro-Organisms
What is a micro-organism?
An organism (living thing) that is too small to see with the human eye
Micro-organisms (or microbes) play many different roles in ecosystems and living things
Aid in digestion (animals)
Help with composting decaying material
Can cause food to spoil or rot
Used to make vaccines
Can carry and cause disease
Used to make food (like yogurt)
Microorganisms
Microscopes
Food Preservation
How can we protect our food from micro-organisms?
Throughout history, humans have preserved food using a variety of methods:
Salting – absorbs and removes moisture through osmosis
Freezing – slows down growth of organisms (too cold) and removes moisture by forming ice
Drying – removes moisture
Pasteurizing – heating and then quickly cooling kills most disease-carrying microorganisms
Adding sugar – absorbs and removes moisture through osmosis
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Final Exam
You final exam is worth 10% of your final grade.
It will include multiple choice, short answer, and long answer. It could also include matching, or fill in the blank.
All material that I, Mrs. Hinrichs has taught is fair game for the exam.