ECOLOGY ECOLOGY CHAPTERS 18-23CHAPTERS 18-23

Study of the interactions between organisms & the living & non-living components of their environment.

Today’s EnvironmentToday’s EnvironmentEcological problems

◦Exploding human population◦Mass Extinction◦Thinning ozone layer◦Climatic changes

Ecological ResearchEcological ResearchConducted using three basic

principles:◦Observing ◦Experimenting◦Modeling

Energy FlowEnergy FlowMain energy source for life on

earth◦SUN

Autotrophs◦Make food by means of

photosynthesis or chemosynthesis◦PRODUCERS

Heterotrophs◦Rely on other organisms

for food◦CONSUMERS

Types of HeterotrophsTypes of HeterotrophsHerbivores: eat plantsCarnivores: eat animalsOmnivores: eat both

(plants/animals)Detritovores: eat dead matter

◦Ex. EarthwormsDecomposers: break down

organic matter◦Ex. Fungi

Food Chains & Food WebsFood Chains & Food WebsFood Chain

◦Shows how living things transfer energy by eating & being eaten

Food Web◦Links all food chains in an ecosystem

together◦Shows a network of complex

interactions

Levels of OrganizationLevels of OrganizationLevels of

OrganizationDescription

Biosphere •Broadest, most inclusive level•Thin volume of earth & its atmosphere that supports life

Ecosystem •Includes all living & non-living components found in a particular place•Pond: fish, turtle, water, etc.

Community •All interacting organisms living in an area•May contain thousands of species

Population •All members of a species that live in one place at one time

Organism •Simplest level of organization

Ecosystem RecyclingEcosystem RecyclingThe Water Cycle

Nitrogen Cycle

Carbon Cycle

Biosphere CyclesBiosphere CyclesClick on diagram to play a video on Biosphere Cycles…

Ecology of OrganismsEcology of OrganismsHabitat

◦Where an organism livesBiotic Factors

◦Living components of an environmentAbiotic Factors

◦Physical & chemical (non-living) characteristics of an environment

◦Temperature, light, humidity, pH, salinity, O2 concentration, precipitation, etc

◦Abiotic factors are not constant

BiomesBiomesTropical Rain ForestDesertTundraTaigaGrasslandSavannaTemperate Deciduous ForestChapparal

Biomes of the WorldBiomes of the World

Tolerance CurveTolerance CurveGraph of performance vs. values

of an environmental variable, such as temp.

TermsTermsAcclimation

◦An organism’s ability to adjust their tolerance to abiotic factors, such as high elevation

Conformers◦Do no regulate internal conditions

Regulators◦Use energy to control some internal

conditionsDormancy

◦State of reduced activityMigration

◦Movement to a more favorable environment

NicheNicheA species’ way of life; the role it

plays in its environmentFundamental Niche

◦Range of conditions a species can potentially tolerate & range of resources it can potentially use

Realized Niche◦Range of resources a species

actually uses

Generalists vs. SpecialistsGeneralist

◦Species with a broad niche◦Virginia opossum (feeds on anything)

Specialist◦Species with narrow niches◦Koala bear (eats

only leaves of eucalyptus tree)

Community EcologySymbiosis: Relationships among species

◦ Predation Predator kills & consumes prey

◦ Parasitism One organism benefits & other is harmed

◦ Competition Species compete for same resources

◦ Mutualism Cooperative relationship in which both species

benefit

◦ Commensalism One organism benefits & the other is not affected

SuccessionThe gradual, sequential regrowth of a

species in an area.◦ Primary succession

Development of a community in an area that has not supported life previously, such as bare rock, sand dunes, or an island formed from volcanic eruption.

◦ Secondary succession Sequential replacement of species that follows

disruption of an existing community.

◦ Pioneer species: species that predominate early in succession

◦ Climax community: Stable end point following succession

Environmental ScienceA field of science that uses

biological principles to look at the relationships between humans & the earth.

Human Effects on EnvironmentDeclining ozoneGreenhouse Effect

◦CO2 Blanket; increase temperature

Human Population Growth

Effect of Rising PopulationBurn more fossil fuelsLess fresh drinking waterDecrease in undeveloped landExtinction of many speciesIncrease in human wasteLess foodMore disease & deathPotentially more natural disasters

Taking Action!!Conservation

BiologyAn area of science

which tries to identify & maintain natural areas

Restoration BiologyAn attempt at

saving a devastated area