Ecosystems & CommunitiesEcosystems & Communities

Climate WeatherClimate Weather

• The average, year-The average, year-after-year conditionsafter-year conditions

of temperature and of temperature and precipitation in a precipitation in a particular region.particular region.

• The latitude, winds, The latitude, winds, shape and elevation shape and elevation of the land determine of the land determine the climate.the climate.

• The day-to-day The day-to-day condition of the condition of the atmosphere at a atmosphere at a particular time and particular time and place.place.

Three Main Climate ZonesThree Main Climate Zones

• Polar Polar • TemperateTemperate• TropicalTropical

At the poles, it's bitterly cold--below freezing all the time, and very dry. At the equator (at sea level), it's always hot and usually rainy, but it never freezes. At mid latitudes, climates are in between these two extremes.

Which area of Which area of earth receives earth receives the most direct the most direct sunlight?sunlight?

Ozone Ozone • Ozone layer traps heat energy and helps maintain Ozone layer traps heat energy and helps maintain

warm temperature on earth.warm temperature on earth.• Ozone layer acts as protective layer by filtering out UV Ozone layer acts as protective layer by filtering out UV

rays.rays.• Chlorofluorohydrocarbons or CFCs (found in Chlorofluorohydrocarbons or CFCs (found in

refrigerants & aerosol propellants) reach the ozone refrigerants & aerosol propellants) reach the ozone layer and react with the ozone, breaking it down. layer and react with the ozone, breaking it down.

• CFC’s were banned in 1987.CFC’s were banned in 1987.

BalanceBalance• Too many greenhouse gases = too much heating, Too many greenhouse gases = too much heating,

global warmingglobal warming• Too little ozone = exposure to UV radiationToo little ozone = exposure to UV radiation

Global WarmingGlobal Warming

• Global warming Global warming is the increase in the is the increase in the average temperature of the biosphere.average temperature of the biosphere.

• Global warmingGlobal warming may be due to human may be due to human activities that are adding more carbon activities that are adding more carbon dioxide to the atmosphere than the dioxide to the atmosphere than the carbon cycle can remove. carbon cycle can remove. • Burning of fossil fuelsBurning of fossil fuels• Cutting and burning of the rainforestCutting and burning of the rainforest

How could a worldwide increase in temperature affect organisms?

Niche Niche • The ecological niche is every function and The ecological niche is every function and

relationship that links a particular species to all its relationship that links a particular species to all its environment (which includes both other living environment (which includes both other living beings and abiotic factors). beings and abiotic factors).

• where the species lives• at what times it is active• how its activities

change• what does it eat • what feeds upon it

(trophic relationships)

• what other living beings interact with it (competition, parasitism, cooperation, symbiosis, etc)• what are its tolerance ranges for environmental factors (temperature, humidity, precipitations, sunlight, etc).

SymbiosisSymbiosis

• Any relationship in which two species Any relationship in which two species live closely together. live closely together.

• MutualismMutualism: both species benefit: both species benefit• CommensalismCommensalism: one benefits and the : one benefits and the

other is neither helped or harmed.other is neither helped or harmed.• ParisitismParisitism: one organism lives on or inside : one organism lives on or inside

another organism and harms it.another organism and harms it.

MutualismMutualism

Coral polyps, colored by the algae that live in a mutualism within the cells of the coral organism.

CommensalismCommensalism

Parasitic RelationshipsParasitic Relationships

malaria parasites inside red blood cells (a) and outside the cells

Population GrowthPopulation Growth

Three factors affect population sizeThree factors affect population size• The number of birthsThe number of births• The number of deathsThe number of deaths• The number of individuals that enter or leave the population.The number of individuals that enter or leave the population.

Two types of Growth:Two types of Growth:Exponential GrowthExponential Growth – with unlimited resources, a population will – with unlimited resources, a population will

reproduce until it approaches an infinitely large size.reproduce until it approaches an infinitely large size.

Logistic GrowthLogistic Growth – as resources beome less available, the growth – as resources beome less available, the growth

of the population slows or stops.of the population slows or stops.

Population GrowthPopulation GrowthExponential Growth of the Population Logistic Growth of the Population

Bacteria Seals

Limits to Population GrowthLimits to Population Growth

Density-DependentDensity-Dependent

FactorsFactors• Competition for food, Competition for food,

water, space, sunlight, water, space, sunlight, matesmates

• PredationPredation• ParasitismParasitism

Density-Independent Density-Independent FactorsFactors

• Climate extremes Climate extremes (drought, flood, global (drought, flood, global warming)warming)

• Human Disturbances Human Disturbances (Clear-cutting forests, (Clear-cutting forests, building housing building housing developments)developments)

Predator Prey RelationshipsPredator Prey Relationships

Predators hunt their prey to consume them.

Predation affects Population GrowthPredation affects Population Growth

How are the increases and decreases in the moose population

related to the changes in the wolf population?

Renewable & Nonrenewable Renewable & Nonrenewable ResourcesResources• Renewable Renewable

resourcesresources can can regenerate or be regenerate or be recycled.recycled.

• Renewal takes time.Renewal takes time.• Renewable does not Renewable does not

mean unlimited.mean unlimited.• Examples: A tree, Examples: A tree,

water, oxygen.water, oxygen.

• Non renewable Non renewable resourcesresources cannot cannot be replenished.be replenished.

• Examples: Fossil Examples: Fossil fuelsfuels

Human Activities that affect Human Activities that affect ResourcesResources• Deforestation- cutting down of forest for Deforestation- cutting down of forest for

logging, farming, buildinglogging, farming, building• Overfishing- commercial harvesting of fishOverfishing- commercial harvesting of fish• Pollution- burning of fossil fuels, industry Pollution- burning of fossil fuels, industry

(smog & acid rain)(smog & acid rain)• Water pollution- improper disposal of waste Water pollution- improper disposal of waste

and chemicalsand chemicals

Think about it• How are environmental resources related to How are environmental resources related to

human health?human health?

BiodiversityBiodiversity

• Biodiversity Biodiversity is the sum variety of all is the sum variety of all organisms in the biosphere. organisms in the biosphere.

• Biodiversity is one of Earth’s greatest Biodiversity is one of Earth’s greatest natural resource. natural resource.

Human activities that threaten Human activities that threaten biodiversitybiodiversity • Altering habitatsAltering habitats• HuntingHunting• Pollution—biological magnification (top Pollution—biological magnification (top

consumer gets the most poison)consumer gets the most poison)• Introduction of non-native species—Introduction of non-native species—

foreign species can take over a new foreign species can take over a new habitat and cause endangerment of native habitat and cause endangerment of native speciesspecies

Think about it• Why is biodiversity important to humans?Why is biodiversity important to humans?

Endangered SpeciesEndangered Species• An An endangered speciesendangered species is a species is a species

whose population size is declining and whose population size is declining and is danger of extinction.is danger of extinction.

• If all the plants or animals of a certain If all the plants or animals of a certain species die, that species becomes species die, that species becomes extinct.extinct.

• When any extinction occurs, When any extinction occurs, it affects the planet's it affects the planet's biodiversity negatively and biodiversity negatively and irreversibly.irreversibly.

Endangered SpeciesEndangered Species