Ecology UnitEcology Unit

2.1 Organisms & Their 2.1 Organisms & Their EnvironmentEnvironment

EcologyEcology What does –ology mean on the end of any What does –ology mean on the end of any

word? word? The study ofThe study of

What word does eco- remind you of? What word does eco- remind you of?

EcosystemEcosystem

DefinitionDefinition::Ecology is the study of how organisms Ecology is the study of how organisms interact with each other and their interact with each other and their environment.environment.

The environment has abiotic and biotic The environment has abiotic and biotic factors.factors.

Remember: Remember:

The prefix a- in front of any The prefix a- in front of any word word means no or not.means no or not.

The prefix bio- mean life or The prefix bio- mean life or livingliving

Definitions:Definitions:

Abiotic factors – nonliving things in the Abiotic factors – nonliving things in the environment.environment.

Biotic factors – living things in the Biotic factors – living things in the environment.environment.

Label the following items as Label the following items as biotic or abiotic.biotic or abiotic.

1.1. AirAir

2.2. CatCat

3.3. TemperatureTemperature

4.4. MoistureMoisture

5.5. PlantPlant

6.6. MushroomMushroom

7.7. LightLight

8.8. SoilSoil

9.9. WaterWater

10.10. SeedsSeeds

1.1. AbioticAbiotic

2.2. BioticBiotic

3.3. AbioticAbiotic

4.4. AbioticAbiotic

5.5. BioticBiotic

6.6. BioticBiotic

7.7. AbioticAbiotic

8.8. AbioticAbiotic

9.9. AbioticAbiotic

10.10. BioticBiotic

Circle the biotic factor(s) and Circle the biotic factor(s) and underline the abiotic factor(s)underline the abiotic factor(s)

in the following studies:in the following studies: Example #1 – Study of the life cycle Example #1 – Study of the life cycle

of trout to observe whether they of trout to observe whether they need to lay their eggs on rocky need to lay their eggs on rocky bottomed streams or sandy bottom bottomed streams or sandy bottom streams.streams.

Example #2 – Study of moles and Example #2 – Study of moles and observe which soil types the animals observe which soil types the animals prefer to dig their tunnels in.prefer to dig their tunnels in.

Levels of OrganizationLevels of Organization(smallest to largest)(smallest to largest)

1. 1. OrganismOrganism – an individual living thing – an individual living thing

2. 2. PopulationPopulation – a group of organism (all – a group of organism (all of one species) that breed with each of one species) that breed with each other & live in the same place.other & live in the same place.

3. Community3. Community (or Biological Community) (or Biological Community) – all populations of different species – all populations of different species that live in the same place.that live in the same place.

4. 4. EcosystemEcosystem – all the biotic & abitoic factors – all the biotic & abitoic factors that interact with each other in a given that interact with each other in a given area.area.

Two major types of ecosystems:Two major types of ecosystems:

1.1. Terrestrial – ecosystems located on landTerrestrial – ecosystems located on land

2.2. Aquatic - ecosystems located in fresh or salt Aquatic - ecosystems located in fresh or salt waterwater

Definitions:Definitions:

Habitat – a place where an organism lives its Habitat – a place where an organism lives its life life

- can change or disappear- can change or disappear

- example: a tree, ocean, soil, pond- example: a tree, ocean, soil, pond

Niche (neesh) – how organisms interact with Niche (neesh) – how organisms interact with their biotic and abiotic parts of the habitattheir biotic and abiotic parts of the habitat

It is an advantage for a species to It is an advantage for a species to occupy a niche different from other occupy a niche different from other species in the same habitat. species in the same habitat.

Two species can’t exist for long in the Two species can’t exist for long in the same community of their niches are same community of their niches are the same (leads to competition & the same (leads to competition & reduces resources such as food).reduces resources such as food).

5. 5. BiosphereBiosphere – the portion of Earth – the portion of Earth that supports lifethat supports life

www.ux1.eiu.edu/~cfruf/bio3002/levels_ecology.htm www.chesterfield.k12.sc.us/.../BiologyICP.htmlRemove frame 

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Do all organisms get along Do all organisms get along with each other?with each other?

How organisms live together in an How organisms live together in an ecosystem is called ecosystem is called symbiosissymbiosis..

There are 3 types of symbiosis:There are 3 types of symbiosis:1.1. MutualismMutualism

2.2. CommensalismCommensalism

3.3. ParasitismParasitism

MutualismMutualism Both species benefit from each other.Both species benefit from each other. Example – ants and acacia treesExample – ants and acacia trees

Ants protect the acacia tree from other Ants protect the acacia tree from other animals that might eat the tree. The animals that might eat the tree. The tree provides nectar and a home for the tree provides nectar and a home for the ant. They both benefit from each other!ant. They both benefit from each other!

CommensalismCommensalism One species benefits One species benefits

and the other species and the other species is neither harmed nor is neither harmed nor benefited.benefited.

Example – Spanish Example – Spanish moss growing on moss growing on treestrees Spanish moss has a Spanish moss has a

place to live on the place to live on the trees but the trees are trees but the trees are not harmed by the not harmed by the moss or get nutrients moss or get nutrients from the moss. Only from the moss. Only one benefits and the one benefits and the other does not. other does not.

ParasitismParasitism One species benefits at the expense of One species benefits at the expense of

another species.another species. Parasites usually don’t kill their host (the Parasites usually don’t kill their host (the

animal they live on). Why would you kill animal they live on). Why would you kill the person that is providing you food & a the person that is providing you food & a home???home???

Example – ticks on a dogExample – ticks on a dog Tick is a parasite that feeds off the nutrients in Tick is a parasite that feeds off the nutrients in

the dog’s blood. The dog doesn’t get the the dog’s blood. The dog doesn’t get the nutrients so it is harmed. nutrients so it is harmed.

Tapeworm & roundworms work the same way Tapeworm & roundworms work the same way as tick but they are inside the host’s body.as tick but they are inside the host’s body.

Predator – Prey relationshipPredator – Prey relationship

Predator – found in all ecosystems and Predator – found in all ecosystems and eat plants and/or animals. Predators are eat plants and/or animals. Predators are a type of consumer that seek out and a type of consumer that seek out and eat other organisms.eat other organisms.

Prey – the animal that the predator eats.Prey – the animal that the predator eats.

Example – cat & mouse; lion & antelopeExample – cat & mouse; lion & antelope

In order to be living, one of the In order to be living, one of the characteristics of life is to use characteristics of life is to use energy. How is that energy obtained energy. How is that energy obtained by organisms? It varies on the by organisms? It varies on the organism.organism.

AutotrophsAutotrophs – make their own food – make their own food Autotrophs are called producers. Think Autotrophs are called producers. Think

about the definition! Autotrophs produce about the definition! Autotrophs produce their own food so called producers. their own food so called producers.

Example – grass, trees, green algae Example – grass, trees, green algae which is a unicellular organism which is a unicellular organism

Section 2.2 Nutrition & Energy Flow

Heterotroph – can not make their Heterotroph – can not make their own food; instead have to eat food to own food; instead have to eat food to get energy. get energy. Heterotrophs are called consumers. Heterotrophs are called consumers.

Think about the definition! Heterotrophs Think about the definition! Heterotrophs consume food so called consumers. consume food so called consumers.

Example – deer eating leaves; bison Example – deer eating leaves; bison eats grass; owl eats a mouseeats grass; owl eats a mouse

Heterotroph Relationships:Heterotroph Relationships:

1.1. HerbivoreHerbivore – consumers (heterotrophs) – consumers (heterotrophs) that eat producers (autotrophs) that eat producers (autotrophs)

Example – rabbits, grasshoppers, Example – rabbits, grasshoppers, beavers, squirrels, bees, elephants, batsbeavers, squirrels, bees, elephants, bats

2. 2. CarnivoresCarnivores – consumers (heterotrophs) – consumers (heterotrophs) eat consumers (heterotrophs)eat consumers (heterotrophs)

Example – lion kills another lionExample – lion kills another lion

3. 3. OmnivoresOmnivores – consumers (heterotrophs) – consumers (heterotrophs) that eat a variety of foods (plant or that eat a variety of foods (plant or animal)animal)

Example – raccoons, opossum, bears, Example – raccoons, opossum, bears, humanshumans

4. Others4. Others

Scavengers – do not kill for food; eat Scavengers – do not kill for food; eat animals that are already deadanimals that are already dead

Example - vulturesExample - vultures

Decomposers – break down dead Decomposers – break down dead decaying plants and animals.decaying plants and animals.

Example – bacteria & fungiExample – bacteria & fungi

Flow of Matter & EnergyFlow of Matter & Energy Food Chain is a simple model that Food Chain is a simple model that

shows how matter & energy moves shows how matter & energy moves through an ecosystem.through an ecosystem.

Arrows indicate the direction in which Arrows indicate the direction in which energy is transferred from one energy is transferred from one organism to the next.organism to the next.Example – Example –

Berries (autotroph)Berries (autotroph) Mice (first Mice (first order heterotroph) order heterotroph) Hawk (second Hawk (second order heterotrophorder heterotroph

http://www.umaine.edu/umext/earthconnections/images/foodchain.gif

http://www.bcgrasslands.org/SiteCM/i/upload/4D9BB688B89B4092F9D10BDAEF83EC41E762FBDB.jpg

http://kentsimmons.uwinnipeg.ca/16cm05/1116/53-10-FoodChains-L.jpg

Trophic level – a feeding step in the Trophic level – a feeding step in the passage of energy & materialspassage of energy & materials First order heterotroph – organism that First order heterotroph – organism that

feeds on plantsfeeds on plants Second order heterotroph – organism Second order heterotroph – organism

that feeds on a first order heterotrophthat feeds on a first order heterotroph

http://www.mlms.logan.k12.ut.us/~mlowe/EnergyPyramid.gif

http://www.utc.edu/Faculty/Deborah-McAllister/educ575/wq04MichaelKavur/image002.jpg

Food webs – show many food chains Food webs – show many food chains that can occur in a community.that can occur in a community.

Ecological pyramids show how Ecological pyramids show how energy flows through an ecosystem energy flows through an ecosystem in a pyramid form. in a pyramid form.

Base is always the autotrophs (first Base is always the autotrophs (first trophic level).trophic level).

Next layers build upon each layer for Next layers build upon each layer for higher trophic levels.higher trophic levels.

http://cmore.soest.hawaii.edu/cruises/operex/images/terrestrial_food_web_full.jpg

3.1 Communities3.1 Communities Various combinations of abiotic and Various combinations of abiotic and

biotic factors interact in different places biotic factors interact in different places around the world which results in around the world which results in conditions in one part of the world are conditions in one part of the world are suitable or certain life and not others.suitable or certain life and not others.

Limiting factorsLimiting factors – any biotic or abiotic – any biotic or abiotic factor that restricts (or limits) the factor that restricts (or limits) the existence, numbers, reproduction, or existence, numbers, reproduction, or distribution, or distribution of distribution, or distribution of organisms. organisms.

Examples of limiting factors:Examples of limiting factors: Availability of water & food would affect how Availability of water & food would affect how

many, if any, organisms can live in an areamany, if any, organisms can live in an area Predators to an area would affect the Predators to an area would affect the

number of organisms (prey) living in the number of organisms (prey) living in the areaarea

Temperature of the area affect which Temperature of the area affect which animals live there (polar bear will not be in a animals live there (polar bear will not be in a desert)desert)

List of common limiting factors: amount of List of common limiting factors: amount of sunlight, climate, temperature, water, sunlight, climate, temperature, water, nutrients/food, fire, soil, chemistry, space, nutrients/food, fire, soil, chemistry, space, other organismsother organisms

Factors that limit one population in a Factors that limit one population in a community may also have an indirect community may also have an indirect effect on another population.effect on another population.

Example – lack of water limits the Example – lack of water limits the growth of grass growth of grass lack of grass limits lack of grass limits the seeds produced the seeds produced lack of seeds lack of seeds limits the mouse population limits the mouse population lack lack of mice limits the hawk populationof mice limits the hawk population

Tolerance – ability of an organism to Tolerance – ability of an organism to withstand many biotic and abiotic withstand many biotic and abiotic factors.factors. Different species have different ranges Different species have different ranges

of toleranceof tolerance

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SuccessionSuccession Natural changes & species replacements Natural changes & species replacements

that take place in the community of an that take place in the community of an ecosystem. ecosystem. Occurs in stages and at each stage different Occurs in stages and at each stage different

species of plants and animals may be presentspecies of plants and animals may be present At each stage of succession, new organisms At each stage of succession, new organisms

may move in, others may die or move outmay move in, others may die or move out Difficult to observe because takes decades or Difficult to observe because takes decades or

more to go to the next stagemore to go to the next stage Two types of succession: Primary & SecondaryTwo types of succession: Primary & Secondary

Primary SuccessionPrimary Succession

Colonization of barren land by Colonization of barren land by communities of organisms.communities of organisms. Takes place in land where nothing lived Takes place in land where nothing lived

beforebefore

Example – after a volcanoExample – after a volcano First species to grow in the area are First species to grow in the area are

called called pioneer speciespioneer species

Example - lichensExample - lichens

LICHENS

http://botit.botany.wisc.edu/images/332/Lichens/Foliose_lichens_130_d.gif

Pioneer species eventually die making the Pioneer species eventually die making the first stage of soil for other organisms to first stage of soil for other organisms to livelive

Example – small ferns, fungi, & insectsExample – small ferns, fungi, & insects These organisms die & more soil builds. These organisms die & more soil builds.

Seeds carried or blown in will start to growSeeds carried or blown in will start to grow After time, the are will become more After time, the are will become more

stable. A stable, mature community that stable. A stable, mature community that undergoes little or no change is called a undergoes little or no change is called a climax community.climax community. Can last 100’s of yearsCan last 100’s of years Change DOES occur in a community but Change DOES occur in a community but

changes are balanced.changes are balanced.

http://www.life.illinois.edu/bio100/lectures/s97lects/05Succession/rockSuccession.GIF

http://tinyurl.com/y95bfk9

Volcanic Eruption

Primary Succession

Secondary Succession

Secondary SuccessionSecondary Succession

The sequence of changes that takes The sequence of changes that takes place after an existing community is place after an existing community is severely disrupted in some wayseverely disrupted in some way

Example – forest fire, field is not Example – forest fire, field is not replanted, tear down a building and replanted, tear down a building and leave itleave it Are gradually changed over timeAre gradually changed over time Soil already exists in a secondary Soil already exists in a secondary

succession so takes less time than primary succession so takes less time than primary succession to reach a climax community.succession to reach a climax community.

http://www.ck12.org/ck12/images?id=113572

Years after a forest fire.

http://images.google.com/imgres?imgurl=http://biology.clc.uc.edu/graphics/bio303/wetland.jpg&imgrefurl=http://biology.clc.uc.edu/Courses/bio303/succession.htm&usg=__Q0_2nL72qKCEi_kxV7HCsux1_NM=&h=300&w=571&sz=126&hl=en&start=16&tbnid=IPIoNmJGqcPCQM:&tbnh=70&tbnw=134&prev=/images%3Fq%3Dstages%2Bof%2Bsecondary%2Bsuccession%26gbv%3D2%26hl%3Den

Stages of secondary successsion

Chapter 4 Population Chapter 4 Population BiologyBiologySection 4.1 Population DynamicsSection 4.1 Population Dynamics

Principles of Population GrowthPrinciples of Population Growth Populations typically form a “J” shape Populations typically form a “J” shape

curvecurve

http://peer.tamu.edu/curriculum_modules/ecosystems/images/exponential.jpg

This “J” shaped curve is called Exponential Growth – means that as a population gets larger, it also grows at a faster rate.

Initial increase in the number of Initial increase in the number of organisms is slow because of the organisms is slow because of the number of reproducing organisms is number of reproducing organisms is small.small.

Rate of growth will increase because Rate of growth will increase because number of individuals able to number of individuals able to reproduce has increased.reproduce has increased.

Can a population grow indefinitely Can a population grow indefinitely (meaning forever)? (meaning forever)? NONO Populations have limiting factors! Populations have limiting factors!

See Chapt. 3 for the list of limiting See Chapt. 3 for the list of limiting factors. Because of these limiting factors. Because of these limiting factors the population may form an “S” factors the population may form an “S” shape growth curve.shape growth curve.

http://www.saburchill.com/IBbiology/images/140106009.jpg

Carrying capacity – number of organisms of one species that an environment can support indefinitely (forever).

QuestionsQuestions1.1. What happens to a population when there What happens to a population when there

are more births than deaths?are more births than deaths?

2.2. What happens to a population when there What happens to a population when there are more deaths than births?are more deaths than births?

3.3. What happens to a population when the What happens to a population when the number of deaths equal (or close to equal) number of deaths equal (or close to equal) the number of births?the number of births?

4.4. When the population overshoots the When the population overshoots the carrying capacity, the ________ take over carrying capacity, the ________ take over to bring the population into check.to bring the population into check.

5.5. Why can a population fluctuate (go up and Why can a population fluctuate (go up and down) once it reaches carrying capacity? down) once it reaches carrying capacity?

AnswersAnswers1.1. IncreasesIncreases2.2. DecreasesDecreases3.3. Stays the sameStays the same4.4. Limiting factors Limiting factors 5.5. The population can go up and the The population can go up and the

limiting factors take over and bring limiting factors take over and bring it back down into check. The it back down into check. The population can go down and the population can go down and the amount of resources (food) goes up amount of resources (food) goes up and the population will go up.and the population will go up.

Reproduction PatternsReproduction Patterns

Life–history pattern – an organism’s Life–history pattern – an organism’s reproductive patternreproductive pattern Can be studied by population biologists to Can be studied by population biologists to

determine if carrying capacity has been determine if carrying capacity has been reachedreached

Two types of reproductive patterns:Two types of reproductive patterns: Rapid life history patternRapid life history pattern Slow life history patternSlow life history pattern

Rapid Life History PatternRapid Life History Pattern

Meaning the organism can reproduce rapidlyMeaning the organism can reproduce rapidly Typically increase rapidly & then declines Typically increase rapidly & then declines

when environmental conditions change when environmental conditions change Example-mosquitoes grow and reproduce Example-mosquitoes grow and reproduce quickly in the summer but not in the winter.quickly in the summer but not in the winter. Usually have:Usually have:

Small body sizeSmall body size Mature rapidlyMature rapidly Reproduce earlyReproduce early Have a short life spanHave a short life span

Slow Life History PatternSlow Life History Pattern

Meaning the organism reproduces Meaning the organism reproduces slowlyslowly Typically live in a more stable Typically live in a more stable

environmentenvironment Opposite of all the things listed in rapid Opposite of all the things listed in rapid

life history patternslife history patterns Maintain population sizes at or near Maintain population sizes at or near

carrying capacitycarrying capacity Example – elephants, bears, whales, humansExample – elephants, bears, whales, humans

3 Ways Organisms Are 3 Ways Organisms Are DispersedDispersed

1. Random – often seen (ex. 1. Random – often seen (ex. Dandelions)Dandelions)

2. Clumped – most common2. Clumped – most common

3. Uniform – least common (visible 3. Uniform – least common (visible with birds on a wire)with birds on a wire)

Uniform

There are 2 kinds of limiting factors when it There are 2 kinds of limiting factors when it comes to dispersal:comes to dispersal:

Density-dependent factorsDensity-dependent factors – include – include disease, competition, predators, parasites, disease, competition, predators, parasites, & food& food

-these factors have an increasing -these factors have an increasing effect effect as the population increasesas the population increases

Density-Independent factorsDensity-Independent factors – mostly – mostly abiotic factors like volcanic eruptions, abiotic factors like volcanic eruptions, temperature, storms, floods, droughtstemperature, storms, floods, droughts

-all populations can be affected by -all populations can be affected by these these factors, small organisms are most factors, small organisms are most vulnerablevulnerable

What can limit a population What can limit a population size?size?

1 – Predation affects population size.1 – Predation affects population size. If number of predators decrease then If number of predators decrease then

the number of prey increasesthe number of prey increases If number of prey increases then the If number of prey increases then the

number of predators will increase over number of predators will increase over time & then eventually will decrease time & then eventually will decrease because to many predators for the because to many predators for the amount of food available.amount of food available.

What can limit a population What can limit a population size?size?

2 – Competition within a population2 – Competition within a population When resources (food, water, shelter) When resources (food, water, shelter)

are plentiful, the population will increaseare plentiful, the population will increase But when resources are not plentiful, But when resources are not plentiful,

competition will occur or those competition will occur or those resources & the population will decreaseresources & the population will decrease

What can limit a population What can limit a population size?size?

3 – The effects of crowding & stress3 – The effects of crowding & stress Some organisms will show symptoms of Some organisms will show symptoms of

stress when in crowded situationsstress when in crowded situations Increase in population can cause stress Increase in population can cause stress

symptoms such as: aggression, symptoms such as: aggression, decrease in parental care, decreased decrease in parental care, decreased fertility, & decreased resistance to fertility, & decreased resistance to disease which can lead to a decrease in disease which can lead to a decrease in populationpopulation