Interactions and Interactions and EcosystemsEcosystems

Grade 7 ScienceGrade 7 Science

Topic 1: Interactions Within Topic 1: Interactions Within EcosystemsEcosystems

• Ecology:Ecology: The study of the The study of the relationships between living relationships between living organisms and their environment.organisms and their environment.

• Scientists who study these Scientists who study these relationships are called relationships are called ecologistsecologists..

The Needs of Living ThingsThe Needs of Living Things

• All living things from spiders, to All living things from spiders, to sunflowers, to humans need…sunflowers, to humans need…

1)1) FoodFood

2)2) WaterWater

3)3) HabitatHabitat

4)4) Air (gas exchange)Air (gas exchange)

Adaptation Adaptation

• AdaptationAdaptation: is an inherited : is an inherited characteristic that helps an organism characteristic that helps an organism survive and reproduce in its survive and reproduce in its environment.environment.

• E.g. A duck has webbed feet so it can E.g. A duck has webbed feet so it can swim wellswim well

• E.g. Many birds have hollow bones so E.g. Many birds have hollow bones so they can fly easily.they can fly easily.

Continued…Continued…

• There are however many characteristics There are however many characteristics that help animals survive in their that help animals survive in their environment that are learned.environment that are learned.

• E.g. Humans learn to look both ways E.g. Humans learn to look both ways before crossing the street.before crossing the street.

• These however, are These however, are notnot adaptations. adaptations.

EcosystemsEcosystems

• An An ecosystemecosystem is the interactions between living is the interactions between living and non-living things in a particular environment.and non-living things in a particular environment.

• E.g. A rotting log is an example of an ecosystem. The organisms E.g. A rotting log is an example of an ecosystem. The organisms living in and on the log and the soil, temperature, and other non-living in and on the log and the soil, temperature, and other non-living features around the log are interacting.living features around the log are interacting.

Interactions Between Living Interactions Between Living Things in an EcosystemThings in an Ecosystem

• SymbiosisSymbiosis: Occurs when two : Occurs when two species live closely together in a species live closely together in a relationship that lasts over time.relationship that lasts over time.

• Can you think of any examples??Can you think of any examples??

3 Types of Symbiosis3 Types of Symbiosis

• MutualismMutualism: Each partner benefits : Each partner benefits from the relationship!from the relationship!

• e.g. The remora fish uses suckers on its e.g. The remora fish uses suckers on its head to attach itself to a shark. It then head to attach itself to a shark. It then eats the bacteria living on the shark’s skin.eats the bacteria living on the shark’s skin.

• Other examples??Other examples??

Continued…Continued…

• ParasitismParasitism: One partner benefits : One partner benefits from the relationship and the other is from the relationship and the other is harmed.harmed.

• Which is which?? Parasite or host??Which is which?? Parasite or host??

Examples: tapeworm, mosquito, leechExamples: tapeworm, mosquito, leech

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• Commensalism:Commensalism: One partner One partner benefits and the other appears to be benefits and the other appears to be unaffectedunaffected

• The orchid plant lives high up attached to the The orchid plant lives high up attached to the trunks of trees. The orchid benefits by having a trunks of trees. The orchid benefits by having a safe place to live, the tree does not benefit or safe place to live, the tree does not benefit or suffer.suffer.

• Other Examples???Other Examples???

Impacts on EcosystemsImpacts on Ecosystems

• Relationships exist between the Relationships exist between the living and non-living. These can have living and non-living. These can have a major impact on an environment.a major impact on an environment.

• The beaver can have a dramatic impact on water The beaver can have a dramatic impact on water and change the environment around them by and change the environment around them by building dams.building dams.

• Other examples??Other examples??

Topic 2: Human Impacts on Topic 2: Human Impacts on EcosystemsEcosystems

• Humans have a more dramatic and often Humans have a more dramatic and often more devastating effect on the Earth’s more devastating effect on the Earth’s ecosystems than any other animal.ecosystems than any other animal.

Natural ResourcesNatural Resources

• We rely on the ecosystem around us, just We rely on the ecosystem around us, just like all living things do. We use natural like all living things do. We use natural resources to meet our basic needs.resources to meet our basic needs.

• Natural Resources:Natural Resources: The materials and The materials and products that are found in nature.products that are found in nature.

• Examples???Examples???

People and Nature: A Changing People and Nature: A Changing RelationshipRelationship

• How have the ways people interact with How have the ways people interact with the environment changed over time??the environment changed over time??

• Gathering Food in AlbertaGathering Food in Alberta

Buffalo HuntBuffalo Hunt → Small Farms → Feedlots→ Small Farms → Feedlots

How has this affected the environment??How has this affected the environment??

Other Examples??Other Examples??

Needs vs. WantsNeeds vs. Wants

• NeedNeed: Something you need to : Something you need to survivesurvive

• Want:Want: Things that make our lives Things that make our lives more enjoyablemore enjoyable

Topic 3: Environmental Topic 3: Environmental ChoicesChoices• Ecological Footprint:Ecological Footprint: Is a calculation of the Is a calculation of the

total area of land and water needed to supply all total area of land and water needed to supply all of the materials and energy that you use as well of the materials and energy that you use as well as absorb all of the waste you produce.as absorb all of the waste you produce.

• What does that mean??What does that mean??

SustainabilitySustainability

• SustainabilitySustainability: A system where the : A system where the resources are being renewed as resources are being renewed as quickly as they are being used. All quickly as they are being used. All wastes are able to be completely wastes are able to be completely absorbed.absorbed.

Ways to Help the Ways to Help the EnvironmentEnvironment• The 3 R’s:The 3 R’s:

• Reduce:Reduce: The amount of garbage you The amount of garbage you produceproduce

• Reuse:Reuse: Products rather than throwing Products rather than throwing them awaythem away

• Recycle:Recycle: Find other ways to make use Find other ways to make use of products if they cannot be reused.of products if they cannot be reused.

Topic 4: How Organisms Topic 4: How Organisms InteractInteract

• There are both living and non-living There are both living and non-living parts of an ecosystem.parts of an ecosystem.

• BioticBiotic: living parts of the ecosystem: living parts of the ecosystem• Abiotic: Abiotic: non-living parts of the non-living parts of the

ecosystem (have never been living). ecosystem (have never been living).

• Examples??Examples??

The Roles of Organisms in an The Roles of Organisms in an EcosystemEcosystem

• NicheNiche: The role of an organism in its : The role of an organism in its ecosystem.ecosystem.

• To determine an organism’s niche, To determine an organism’s niche, you must look at what it eats, where you must look at what it eats, where it lives, and how it interacts with it lives, and how it interacts with other organisms in its ecosystem.other organisms in its ecosystem.

Types of Niches…Types of Niches…

• ProducersProducers: make food for themselves : make food for themselves using the sun’s energy through a using the sun’s energy through a process called photosynthesis. process called photosynthesis.

• Examples???Examples???

• Producers make life possible for all Producers make life possible for all other organisms on Earth.other organisms on Earth.

Continued…Continued…

• Consumers:Consumers: Consumers eat the food Consumers eat the food made by producers. Consumers can made by producers. Consumers can eat producers or other consumers.eat producers or other consumers.

• HerbivoresHerbivores: Eat producers only and fill the plant-: Eat producers only and fill the plant-eating niche. E.g. cows, deer, horses…eating niche. E.g. cows, deer, horses…

• Carnivores:Carnivores: Eat other consumers and fill the Eat other consumers and fill the meat-eating niche. E.g. wolves, coyotes, sharks…meat-eating niche. E.g. wolves, coyotes, sharks…

• PredatorsPredators: Kill and eat other animals (cougar): Kill and eat other animals (cougar)

• Prey: Prey: Get killed an eaten by predators (mouse)Get killed an eaten by predators (mouse)

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• OmnivoresOmnivores: Eat both producers and consumers. : Eat both producers and consumers. E.g. raccoons, skunks and humansE.g. raccoons, skunks and humans

• Food Chain:Food Chain: is a model that shows how the is a model that shows how the energy stored in food is passed from organism to energy stored in food is passed from organism to organism.organism.

Food WebsFood Webs

• Food WebsFood Webs: Are more complex than food chains. : Are more complex than food chains. They show all of the relationships between They show all of the relationships between predator and prey in an ecosystem. (They are a predator and prey in an ecosystem. (They are a combination of several food chains)combination of several food chains)

Pyramid of NumbersPyramid of Numbers• Food Chains and Food Webs show how food energy moves Food Chains and Food Webs show how food energy moves

throughout a system but not how many organisms it involves. throughout a system but not how many organisms it involves. To solve this, scientists invented the To solve this, scientists invented the pyramid of numberspyramid of numbers..

• Biomass: Biomass: The total mass of all the organisms in an ecosystemThe total mass of all the organisms in an ecosystem

The Order of ConsumersThe Order of Consumers

• There are There are PrimaryPrimary, , SecondarySecondary and and Tertiary Tertiary Consumers. Explain…Consumers. Explain…

The Clean-up SquadThe Clean-up Squad

• Scavengers:Scavengers: Are organisms that feed on dead or Are organisms that feed on dead or decaying plant and animal matter.decaying plant and animal matter.

• Examples??Examples??

• Decomposers: Decomposers: Don’t actually eat dead material, Don’t actually eat dead material, instead they grow on or in dead material, instead they grow on or in dead material, absorbing some nutrients into their own cells.absorbing some nutrients into their own cells.

• Examples??Examples??

Topic 5: Cycles in the Topic 5: Cycles in the EnvironmentEnvironment

• The Carbon CycleThe Carbon Cycle

The Water CycleThe Water Cycle

Parts of the Water CycleParts of the Water Cycle• EvaporationEvaporation: is the process in which a liquid changes : is the process in which a liquid changes

into water vapor.into water vapor.• TranspirationTranspiration: is the process in which water that is : is the process in which water that is

taken in through plants roots evaporates from the taken in through plants roots evaporates from the plant’s leaves, stems and flowersplant’s leaves, stems and flowers

• CondensationCondensation: is the process in which water vapor : is the process in which water vapor changes into liquid.changes into liquid.

• PrecipitationPrecipitation: is the process in which liquid water : is the process in which liquid water forms from condensation inside clouds and falls as forms from condensation inside clouds and falls as rain, sleet, snow and hail.rain, sleet, snow and hail.

• Ground WaterGround Water: is water in the soil. Plant roots can : is water in the soil. Plant roots can grow down to reach ground water.grow down to reach ground water.

• Run-offRun-off: Is water that runs off the ground into lakes, : Is water that runs off the ground into lakes, rivers or streams.rivers or streams.

Pollution in the EnvironmentPollution in the Environment

• PollutionPollution: occurs when a substance is : occurs when a substance is added to the environment at such a fast added to the environment at such a fast rate that it cannot be broken down, stored rate that it cannot be broken down, stored or recycled in the air, land or water in a or recycled in the air, land or water in a non-damaging form.non-damaging form.

• Acid RainAcid Rain: occurs when pollutants : occurs when pollutants containing sulfur and nitrogen are found in containing sulfur and nitrogen are found in high levels in the air.high levels in the air.

Movement of Pollution Movement of Pollution

• Chemicals can take a very long time to Chemicals can take a very long time to breakdown causing a great deal of damage to breakdown causing a great deal of damage to plants and animals.plants and animals.

• Bioaccumulation:Bioaccumulation: When pollutants move from When pollutants move from level to level in the food chain.level to level in the food chain.

Topic 6: Succession and Topic 6: Succession and Change in an Ecosystem.Change in an Ecosystem.

• Have you ever noticed grasses or plant growing in Have you ever noticed grasses or plant growing in vacant lot near your home? How does this vacant lot near your home? How does this process happen?process happen?

• Succession:Succession: the gradual process by which some the gradual process by which some species replace others in an ecosystem.species replace others in an ecosystem.

• Primary SuccessionPrimary Succession: The gradual growth of : The gradual growth of organisms in an area that was bare, such as rock.organisms in an area that was bare, such as rock.

• E.g. Ferns and mosses growing on rocksE.g. Ferns and mosses growing on rocks

Primary SuccessionPrimary Succession

Secondary SuccessionSecondary Succession

• Secondary SuccessionSecondary Succession: The gradual growth of : The gradual growth of organisms in an area that previously had a organisms in an area that previously had a number of organisms. E.g. A burnt forest areanumber of organisms. E.g. A burnt forest area

Biological ControlBiological Control

• Biological ControlBiological Control: Controlling pests using their : Controlling pests using their natural enemies.natural enemies.

• Examples??Examples??• Introduced SpeciesIntroduced Species: When exotic species are : When exotic species are

introduced into an environment.introduced into an environment.• They often have no natural enemies and survive They often have no natural enemies and survive

and reproduce better than naturally occurring and reproduce better than naturally occurring species. They can take over an ecosystem.species. They can take over an ecosystem.

• E.g. Zebra mussel, Purple Loosestrife, Scotch E.g. Zebra mussel, Purple Loosestrife, Scotch BroomBroom

• ExtinctionExtinction: When a species no longer exists.: When a species no longer exists.

Topic 7: Environmental Topic 7: Environmental MonitoringMonitoring• Ecosystem MonitoringEcosystem Monitoring (also called Environmental (also called Environmental

Monitoring): Is a way to check the condition of an Monitoring): Is a way to check the condition of an ecosystem by comparing the results of investigations ecosystem by comparing the results of investigations done at different times.done at different times.

• Physical Monitoring:Physical Monitoring: Uses satellites to track Uses satellites to track changes in landscape over time.changes in landscape over time.

• Environmental Monitoring: Environmental Monitoring: Tracks changes in Tracks changes in climate, temperature and weather patterns.climate, temperature and weather patterns.

• Chemical MonitoringChemical Monitoring: Assesses air, soil and water : Assesses air, soil and water quality.quality.

• Biological Monitoring:Biological Monitoring: Tracks changes in Tracks changes in organisms and populations of organisms over time.organisms and populations of organisms over time.

Long-Term MonitoringLong-Term Monitoring

• Indicator SpeciesIndicator Species: A species that is sensitive to : A species that is sensitive to environmental change and is the first to be environmental change and is the first to be affected; they help to monitor the overall health affected; they help to monitor the overall health

of our environment.of our environment. • What would be some good indicator species??What would be some good indicator species??

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• Baseline Data:Baseline Data: A starting point of data A starting point of data that allows scientists to go back and see if that allows scientists to go back and see if changes have occurred.changes have occurred.

• Permanent Plots:Permanent Plots: Study areas that Study areas that scientists always return to.scientists always return to.

• A report that outlines how an activity will A report that outlines how an activity will affect the environment is called an affect the environment is called an environmental impact assessment.environmental impact assessment.