Ecosystems and Their Ecosystems and Their InteractionsInteractions

Chapter 6

Lesson 6.1

PA Academic Standards for PA Academic Standards for Environment & EcologyEnvironment & Ecology

Standard 4.6.10.A (Part A)Standard 4.6.10.A (Part A) Explain the biotic and abiotic components of an Explain the biotic and abiotic components of an

ecosystem and their interaction.ecosystem and their interaction.• Identify the major biomes and explain their similarities and Identify the major biomes and explain their similarities and

differences. differences. • Compare and contrast the interactions of biotic and abiotic Compare and contrast the interactions of biotic and abiotic

components in an ecosystem.components in an ecosystem.• Analyze the effects of abiotic factors on specific ecosystems.Analyze the effects of abiotic factors on specific ecosystems.• Describe how the availability of resources affects organisms Describe how the availability of resources affects organisms

in an ecosystem.in an ecosystem.• Explain energy flow in a food chain through an energy Explain energy flow in a food chain through an energy

pyramid.pyramid.• Evaluate the efficiency of energy flow in a food chain. Evaluate the efficiency of energy flow in a food chain.

PA Academic Standards for PA Academic Standards for Environment & EcologyEnvironment & Ecology

Standard 4.6.10.A (Part B)Standard 4.6.10.A (Part B) Explain the biotic and abiotic components of an Explain the biotic and abiotic components of an

ecosystem and their interaction.ecosystem and their interaction.• Explain the concept of carrying capacity in an ecosystem.Explain the concept of carrying capacity in an ecosystem.• ExplainExplain trophic levels.trophic levels.• Identify a specific environmental impact and predict what Identify a specific environmental impact and predict what

change may take place to affect homeostasis.change may take place to affect homeostasis.• Examine and explain how organisms modify their Examine and explain how organisms modify their

environments to sustain their needs.environments to sustain their needs.• Assess the effects of latitude and altitude on biomes. Assess the effects of latitude and altitude on biomes. • Interpret possible causes of population fluctuations.Interpret possible causes of population fluctuations.• Explain how erosion and sedimentation have changed the Explain how erosion and sedimentation have changed the

quality of soil related habitats.quality of soil related habitats.

Learning ObjectivesLearning Objectives• Students will compare the interaction of biotic and abiotic Students will compare the interaction of biotic and abiotic

components in an ecosystem.components in an ecosystem.• Students will analyze the effects of abiotic factors on Students will analyze the effects of abiotic factors on

specific ecosystems.specific ecosystems.• Students will describe how the availability of resources Students will describe how the availability of resources

affects organisms in an ecosystem.affects organisms in an ecosystem.• Students will explain energy flow in a food chain through Students will explain energy flow in a food chain through

an energy pyramid.an energy pyramid.• Students will explain trophic levels.Students will explain trophic levels.• Students will evaluate the efficiency of energy flow in a Students will evaluate the efficiency of energy flow in a

food chain.food chain.• Students will explain how erosion and sedimentation have Students will explain how erosion and sedimentation have

changed the quality of soil-related habitats.changed the quality of soil-related habitats.

Learning ObjectivesLearning Objectives• Students will explain the concept of carrying capacity in an Students will explain the concept of carrying capacity in an

ecosystem.ecosystem.• Students will interpret possible causes of population Students will interpret possible causes of population

fluctuations.fluctuations.• Students will examine and explain how organisms modify Students will examine and explain how organisms modify

their environments to sustain their needs.their environments to sustain their needs.• Students will identify a specific environmental impact and Students will identify a specific environmental impact and

predict what change may take place to affect homeostasis.predict what change may take place to affect homeostasis.• Students will identify the major biomes and explain their Students will identify the major biomes and explain their

similarities and differences.similarities and differences.• Students will assess the effects of latitude and altitude on Students will assess the effects of latitude and altitude on

biomes.biomes.

Theme OutlineTheme OutlineLesson 6.1Lesson 6.1

• EcosystemsEcosystems• Biotic Factors in an EcosystemBiotic Factors in an Ecosystem• Abiotic Factors in an EcosystemAbiotic Factors in an Ecosystem• Matter and Energy in an EcosystemMatter and Energy in an Ecosystem• Soil: An Integral Part of Many EcosystemsSoil: An Integral Part of Many Ecosystems• Carrying Capacity of an EcosystemCarrying Capacity of an Ecosystem• Habitats and NichesHabitats and Niches• Homeostasis in an EcosystemHomeostasis in an Ecosystem• BiomesBiomes

BiosphereBiosphere Definition: Definition: layer of soil, water, and air that sustains life layer of soil, water, and air that sustains life

on Earthon Earth

EcosystemEcosystem Definition: Definition: group of living organisms that interact with group of living organisms that interact with

one another and the nonliving physical environment as one one another and the nonliving physical environment as one unitunit

Factors in an EcosystemFactors in an Ecosystem Biotic factorsBiotic factors

• Living components of an ecosystemLiving components of an ecosystem

Example. Plants (flowers, trees, shrubs)Example. Plants (flowers, trees, shrubs)

Example. Animals (mammals, fish, birds)Example. Animals (mammals, fish, birds) Abiotic factorsAbiotic factors

• Nonliving physical and chemical parts of an ecosystemNonliving physical and chemical parts of an ecosystem

Example. Nonliving things. (sun, clouds, air)Example. Nonliving things. (sun, clouds, air)

Terrestrial EcosystemsTerrestrial Ecosystems Forests, deserts, and grasslandsForests, deserts, and grasslands

Aquatic EcosystemsAquatic Ecosystems• FreshwaterFreshwater

Rivers, streams, lakes, ponds, Rivers, streams, lakes, ponds, wetlandswetlands

• MarineMarine Estuaries, coastal marshes, coral Estuaries, coastal marshes, coral

reefs, and open oceanreefs, and open ocean

Two types of ecosystems…Two types of ecosystems…

Organization of EcosystemsOrganization of Ecosystems

EcosystemsEcosystems

CommunitiesCommunities

PopulationsPopulations

OrganismsOrganisms

OrganismOrganism : : A single living thing, any form of A single living thing, any form of lifelife

Species: Species: AA group of organisms that are alike group of organisms that are alike in several ways, including appearance, and in several ways, including appearance, and genetic makeup, and that can breed with one genetic makeup, and that can breed with one another to produce healthy offspringanother to produce healthy offspring

Population:Population: A group of individuals of the A group of individuals of the same species found in a given area or same species found in a given area or located in the same area at a given timelocated in the same area at a given time

Community:Community: Populations of living organisms Populations of living organisms that interact with one another in an ecosystemthat interact with one another in an ecosystem

Level of Organization

HabitatHabitat Definition :Definition : a place where a particular species lives and a place where a particular species lives and

from which it obtains what it needs for survivalfrom which it obtains what it needs for survival

Abiotic FactorsAbiotic Factors

Definition Definition : : the the nonlivingnonliving physical and chemical parts of physical and chemical parts of an ecosystem. Although they are nonliving, they influence an ecosystem. Although they are nonliving, they influence and support the biotic parts of the ecosystem.and support the biotic parts of the ecosystem.

• On land these factors might include: On land these factors might include: water availability, water availability, amount of sunlight, temperature, altitude, precipitation, soil amount of sunlight, temperature, altitude, precipitation, soil nutrients, windnutrients, wind

• In the water they might include: In the water they might include: temperature, sunlight temperature, sunlight penetration, salinity, nutrient levelspenetration, salinity, nutrient levels

Each species survives best within a certain range of environmental conditions. The conditions that define the physical limits within which an organism can survive are tolerance limits.

Abiotic FactorTemperature, pH, sunlight, etc..

Humans are one of the few organisms that can alter the abiotic factors in their ecosystems to meet their needs. (ex. Too cold … turn up the heat!) However, in the process, they alter the abiotic factors for the other organisms sharing that same environment. In some ways these alterations may actually be beneficial to the other organisms but in many ways the changes we make to the abiotic environment have a negative impact on other life forms.

Examples: Man-made Pollutants, wetland alteration, habitat destruction, etc.

One Example: Dams

Abiotic Factors: DamsAbiotic Factors: Dams

Dams generate Dams generate hydroelectric power.hydroelectric power.

Dams block the flow of Dams block the flow of nutrient-rich sediments.nutrient-rich sediments.

What happens to the What happens to the plants and animals plants and animals downstream that depend downstream that depend on these nutrients?on these nutrients?

Pennsylvania DamsPennsylvania Dams

Fish LaddersFish Ladders

Matter and Energy in an Matter and Energy in an EcosystemEcosystem

All ecosystems do two things:All ecosystems do two things:1. Transfer energy (from sunlight)1. Transfer energy (from sunlight)

2. Cycle Matter (Carbon, water, oxygen, nitrogen)2. Cycle Matter (Carbon, water, oxygen, nitrogen)

The transfer of energy and cycling of matter is The transfer of energy and cycling of matter is accomplished by the different organisms in an ecosystem accomplished by the different organisms in an ecosystem through through production, consumption & decompositionproduction, consumption & decomposition..

Food ChainFood Chain Definition: Definition: transfer of transfer of

energy from one organism energy from one organism to anotherto another

http://www.harcourtschool.com/activity/food/food_menu.html

Food WebFood Web Definition:Definition: network that shows many connected food chainsnetwork that shows many connected food chains

Energy Transfer in an EcosystemEnergy Transfer in an Ecosystem Energy Transfer occurs at several different Energy Transfer occurs at several different

levelslevels Producers Producers ConsumersConsumers Scavengers/DecomposersScavengers/Decomposers

Organisms that make their own food from Organisms that make their own food from inorganic molecules and energyinorganic molecules and energy

• Most common example: PlantsMost common example: Plants• All plants capture energy from the sun and All plants capture energy from the sun and

use it to make food through the process of use it to make food through the process of photosynthesisphotosynthesis

COCO22 + H + H22O CO C66HH1212OO6 6 + O + O22

ProducerProducer Definition:Definition: organism that uses elements from the organism that uses elements from the

environment to make its own foodenvironment to make its own food

Photosynthesis• Accomplished by all plants (land Accomplished by all plants (land

ecosystems)ecosystems)• Accomplished by aquatic algae (aquatic Accomplished by aquatic algae (aquatic

ecosystems)ecosystems)

Chemosynthetic BacteriaChemosynthetic Bacteria

• Certain bacteria do not use sunlight, but use certain inorganic molecules

(Usually live in harsh environments: hot springs, thermal vents on the ocean floor)

ConsumerConsumer Definition:Definition: organism that gets its energy and nutrients organism that gets its energy and nutrients

by feeding on other organismsby feeding on other organisms

Organization with consumer levelOrganization with consumer level Primary consumersPrimary consumers

• HerbivoresHerbivores

Secondary consumersSecondary consumers• CarnivoreCarnivore

• OmnivoreOmnivore

Tertiary consumersTertiary consumers

PrimaryPrimary Consumer Consumer DefinitionDefinition: : herbivore or omnivore that feeds on plantsherbivore or omnivore that feeds on plants

Herbivore Herbivore DefinitionDefinition: : animals that eat only plants; primary animals that eat only plants; primary

consumers in a food chainconsumers in a food chain

Secondary ConsumerSecondary Consumer Definition:Definition: carnivore or omnivore that feeds on carnivore or omnivore that feeds on

primary consumers in an ecosystemprimary consumers in an ecosystem

CarnivoreCarnivore Definition: Definition: animals that consume other animalsanimals that consume other animals

OmnivoreOmnivore DefinitionDefinition: animals that eat both plants and other : animals that eat both plants and other

animals and can be primary and secondary (or higher) animals and can be primary and secondary (or higher) consumers consumers

Tertiary ConsumerTertiary Consumer Definition: Definition: organism that eats secondary and primary organism that eats secondary and primary

consumersconsumers

ScavengerScavenger DefinitionDefinition: : organism that feeds on dead organismsorganism that feeds on dead organisms

DecomposerDecomposer DefinitionDefinition: type of bacteria or fungus that breaks down : type of bacteria or fungus that breaks down

dead organisms and wastesdead organisms and wastes

Energy TransferEnergy Transfer How does energy makes How does energy makes

its way through the its way through the ecosystem?ecosystem?

Trophic LevelTrophic Level Definition: Definition: all organisms all organisms

in a feeding level that are in a feeding level that are the same number of steps the same number of steps away from the sunaway from the sun

Energy PyramidEnergy Pyramid DefinitionDefinition: shows the trophic levels in a food web and : shows the trophic levels in a food web and

the amount of energy that moves from one level up to the the amount of energy that moves from one level up to the nextnext

Energy PyramidEnergy Pyramid

Energy TransferEnergy Transfer

Where does the excess energy go?Where does the excess energy go?

If 10% of the energy is passed from one trophic If 10% of the energy is passed from one trophic level to the next, what happens to the other 90%?level to the next, what happens to the other 90%?

Released as Released as heat heat to the environment. to the environment.

Carrying CapacityCarrying Capacity

Definition: Definition: number of number of organisms that an ecosystem organisms that an ecosystem can support indefinitelycan support indefinitely

• Populations Populations cannotcannot grow indefinitely. grow indefinitely.• Populations are constantly changingPopulations are constantly changing

• GrowthGrowth• Birth of individuals, Immigration into a populationBirth of individuals, Immigration into a population

• DeclineDecline• Death of individuals, Emigration out of a populationDeath of individuals, Emigration out of a population

• StabilizedStabilized• No fluctuation in population size at current timeNo fluctuation in population size at current time

Limiting FactorLimiting Factor

The one factor that is most important in controlling population growth.

Carrying CapacityCarrying Capacity

Exponential Growth “J” curve

“S” curve

Three short clips on human populations

1

2

3

NicheNiche Definition:Definition: role an organism plays within an role an organism plays within an

ecosystem including the food it eats and how it obtains ecosystem including the food it eats and how it obtains that food. that food.

No two species can occupy the same niche in one No two species can occupy the same niche in one ecosystem!ecosystem!

Example: 5 Warbler species

Same food preference

Same tree preference

Different feeding locations within the tree

HomeostasisHomeostasis

Changes occur in ecosystems all the time.Changes occur in ecosystems all the time. Types of disturbancesTypes of disturbances

• Periodic disturbancesPeriodic disturbances• Disturbances that occur at regular intervalsDisturbances that occur at regular intervals

Example: annual snowmelt in the northern latitudesExample: annual snowmelt in the northern latitudes

• Sporadic disturbancesSporadic disturbances• Disturbances that do not occur at irregular intervalsDisturbances that do not occur at irregular intervals

Example: flash flooding due to sudden heavy rainsExample: flash flooding due to sudden heavy rains

DefinitionDefinition:: natural stability in an ecosystem that keeps it natural stability in an ecosystem that keeps it from undergoing radical change and helps it recover when from undergoing radical change and helps it recover when stresses are so great that they cause serious problemsstresses are so great that they cause serious problems

Ecosystems maintain Ecosystems maintain homeostasis because homeostasis because organisms within them have organisms within them have the ability to resists change.the ability to resists change.

Healthy ecosystems maintain Healthy ecosystems maintain this balance of stresses, this balance of stresses, though changes occur though changes occur eventually.eventually.

What happens when natural What happens when natural disasters try and alter this disasters try and alter this delicate balance?delicate balance?

Example: Example: Hurricane AgnesHurricane Agnes (1972)(1972)

Hurricane AgnesHurricane Agnes Landfall was June 19, 1972 in FloridaLandfall was June 19, 1972 in Florida Storm tracked northwardStorm tracked northward

Widespread rain in Pennsylvania lead to widespread Widespread rain in Pennsylvania lead to widespread flooding and destruction of many stable ecosystemsflooding and destruction of many stable ecosystems

Healthy ecosystems returned to their pre-flood stable states Healthy ecosystems returned to their pre-flood stable states after the local flood waters subsidedafter the local flood waters subsided

Biomes of the WorldBiomes of the World