Honors BiologyHonors Biology

CH. 24 p. 634-647CH. 24 p. 634-647

CH. 25 p. 652-659, 663-668, 673-677CH. 25 p. 652-659, 663-668, 673-677

Ecology Ecology

EcologyEcology

Ecology is the study of organisms within Ecology is the study of organisms within their environment. their environment. Matter cyclesMatter cycles Energy flowsEnergy flows

The sun is the ultimate source of energy The sun is the ultimate source of energy on earthon earth

Trophic level- one step in a food chain Trophic level- one step in a food chain or pyramidor pyramid

Ecology termsEcology terms

HabitatHabitat- the place where a population of a - the place where a population of a species livesspecies lives

CommunityCommunity- the different species that live - the different species that live within the habitatwithin the habitat

EcosystemEcosystem- the biotic and abiotic factors of - the biotic and abiotic factors of a habitata habitat AbioticAbiotic- the physical aspects of a habitat (soil, - the physical aspects of a habitat (soil,

air, water)air, water) BioticBiotic- the living things in a habitat - the living things in a habitat

Food ChainsFood Chains

Producers- photosynthetic organisms that Producers- photosynthetic organisms that capture energy from the sun. capture energy from the sun.

Consumers- organisms that consume Consumers- organisms that consume plants or other organisms to obtain energy. plants or other organisms to obtain energy.

Decomposer- Bacteria and fungi that eat Decomposer- Bacteria and fungi that eat decayed organisms.decayed organisms.

Food ChainsFood Chains

Herbivores- animals that eat plants and Herbivores- animals that eat plants and other producersother producers

Carnivores- animals that eat other animalsCarnivores- animals that eat other animals Omnivores- animals that eat both plants Omnivores- animals that eat both plants

and animalsand animals Detritivores- organisms that eat organic Detritivores- organisms that eat organic

wastes from dead organismswastes from dead organisms

Energy PyramidEnergy Pyramid

10% Rule10% Rule

Only 10% of the energy from one trophic Only 10% of the energy from one trophic level moves up to the next.level moves up to the next.

90% of the energy is lost -- given off as 90% of the energy is lost -- given off as heat or wasted energy.heat or wasted energy.

Biogeochemical cyclesBiogeochemical cycles The Water cycleThe Water cycle

Evaporation- water heated to water vaporEvaporation- water heated to water vapor Condensation- water vapor becomes cloudsCondensation- water vapor becomes clouds Precipitation- Rain, Hail, Snow, Sleet etc.Precipitation- Rain, Hail, Snow, Sleet etc. Runoff- drains into streams, rivers, lakes, Runoff- drains into streams, rivers, lakes,

oceansoceans Percolation- water goes into soil with ground Percolation- water goes into soil with ground

waterwater

Transpiration- water released from plantsTranspiration- water released from plants

The Water Cycle The Water Cycle

Carbon CycleCarbon Cycle

Photosynthesis- plants fix COPhotosynthesis- plants fix CO22 in the air to in the air to make organic materials.make organic materials.

Respiration- plants and animals through Respiration- plants and animals through cellular respiration release COcellular respiration release CO22 into the air. into the air.

Combustion- when plants, wood, and fossil Combustion- when plants, wood, and fossil fuels (organic materials turned into coal, oil, fuels (organic materials turned into coal, oil, and gas) are burned COand gas) are burned CO22 is released into the is released into the atmosphere.atmosphere.

Erosion- exposed limestone will release COErosion- exposed limestone will release CO2 2

into the water or air. into the water or air.

Greenhouse EffectGreenhouse Effect

Greenhouse gases- HGreenhouse gases- H22O, CHO, CH44, CO, CO22, NO, , NO, OO33, and CFC’s absorb solar energy that is , and CFC’s absorb solar energy that is reflected by the earth the atmospherereflected by the earth the atmosphere

The Greenhouse Effect keeps the earth’s The Greenhouse Effect keeps the earth’s surface temperature stable. surface temperature stable.

But the concentration of COBut the concentration of CO2 2 increases increases due to combustion causing rises in the due to combustion causing rises in the temperature of the earth.temperature of the earth.

The Nitrogen CycleThe Nitrogen Cycle NN22 gas in the atmosphere is fixed in the soil by gas in the atmosphere is fixed in the soil by

lightning and nitrogen fixing bacteria.lightning and nitrogen fixing bacteria. Plant roots take in nitrogen in the form of Plant roots take in nitrogen in the form of

ammonia (NHammonia (NH33) nitrates (NO) nitrates (NO33-1-1) to make ) to make

proteins.proteins. Animals obtain nitrogen from there food. Animals obtain nitrogen from there food. Decomposition of dead organisms and wastes Decomposition of dead organisms and wastes

returns nitrogen to the soilreturns nitrogen to the soil Denitrifying bacteria returns nitrogen in the soil Denitrifying bacteria returns nitrogen in the soil

back into Nback into N22 gas in the atmosphere. gas in the atmosphere.

The Nitrogen CycleThe Nitrogen Cycle ~78% of the atmosphere is unusable N~78% of the atmosphere is unusable N22. . Living things need nitrogen to build amino acids and Living things need nitrogen to build amino acids and

nucleic acidsnucleic acids Nitrogen fixationNitrogen fixation- N- N22 gas is fixed in the soil by lightning gas is fixed in the soil by lightning

and nitrogen fixing bacteria.and nitrogen fixing bacteria. Ammonification- Ammonification- bacteria in the soil convert bacteria in the soil convert

decomposing organic materials into NHdecomposing organic materials into NH33. . Nitrification- Nitrification- ammonia is converted to to nitrites and ammonia is converted to to nitrites and

nitratesnitrates Assimilation- Assimilation- Plant roots take in nitrogen in the form of Plant roots take in nitrogen in the form of

ammonia (NHammonia (NH33) nitrates (NO) nitrates (NO33-1-1) to make proteins) to make proteins

DenitrificationDenitrification- reduction of nitrates by bacteria into - reduction of nitrates by bacteria into nitrogen gas.nitrogen gas.

Limiting FactorsLimiting Factors Limiting Factors- an environmental factor such Limiting Factors- an environmental factor such

as food, temperature, water, or sunlight that as food, temperature, water, or sunlight that restricts growth, metabolism or population size. restricts growth, metabolism or population size.

Productivity of ecosystems and their organisms Productivity of ecosystems and their organisms is affected by limiting factors.is affected by limiting factors.

A resource in short supply keeps growth in A resource in short supply keeps growth in check. check.

Competition for an abundant resource can keep Competition for an abundant resource can keep individual populations in check. individual populations in check.

Population Density- the number of individuals in Population Density- the number of individuals in an area.an area.

Density Independent Density Independent FactorsFactors

Limiting Factor that is not affected by size Limiting Factor that is not affected by size of the populationof the population

Most important:Most important: WeatherWeather ClimateClimate

Density Dependent FactorsDensity Dependent Factors Limiting Factor that is more effective as Limiting Factor that is more effective as

population density increasespopulation density increases Especially affects long lived organismsEspecially affects long lived organisms

Competition for food and other resourcesCompetition for food and other resources PredationPredation ParasitismParasitism

Exponential GrowthExponential Growth

If there is little competition for a resource, If there is little competition for a resource, the population may experience a period of the population may experience a period of exponential growth. exponential growth.

Logistic GrowthLogistic Growth

As population density (and competition) As population density (and competition) increases, growth becomes logistic and increases, growth becomes logistic and levels of at the carrying capacity. levels of at the carrying capacity.

Carrying Capacity (k)- the maximum Carrying Capacity (k)- the maximum population size that can be supported by population size that can be supported by the available resources in a given area. the available resources in a given area.

Exponential (J-Curve) vs. Exponential (J-Curve) vs. Logistic Growth (S-Curve)Logistic Growth (S-Curve)

Boom and Bust CycleBoom and Bust Cycle If growth is exponential If growth is exponential

until the carrying until the carrying capacity is reached capacity is reached (and overshot), a (and overshot), a massive death rate will massive death rate will follow.follow.

Predator-Prey CyclePredator-Prey Cycle

If the limiting factor is inconsistent, If the limiting factor is inconsistent, population size emulates the fluctuations population size emulates the fluctuations with a bit of a lag with a bit of a lag

Predator Prey CyclePredator Prey Cycle

Human Population GrowthHuman Population Growth

Why doesn’t environmental Why doesn’t environmental resistance take effect?resistance take effect? Altering the environmentAltering the environment Technological advances inTechnological advances in

CultureCulture AgricultureAgriculture Industry Industry MedicineMedicine

Ozone LayerOzone Layer Earth’s atmosphere is divided into several layers, the Earth’s atmosphere is divided into several layers, the

lowest layer is called the troposphere, and next layer lowest layer is called the troposphere, and next layer is called the stratosphereis called the stratosphere

The Ozone Layer is not an actual layer but a The Ozone Layer is not an actual layer but a concentration of Oconcentration of O33 molecules, located in the molecules, located in the stratosphere, which is about 15-30km above Earthstratosphere, which is about 15-30km above Earth

The ozone layer absorbs a portion of the radiation The ozone layer absorbs a portion of the radiation from the sun, preventing it from reaching the planet’s from the sun, preventing it from reaching the planet’s surface.surface.

Most importantly it absorbs the portion of ultraviolet Most importantly it absorbs the portion of ultraviolet light called UVBlight called UVB

Ozone DepletionOzone Depletion In the early 1970’s, researchers began to investigate In the early 1970’s, researchers began to investigate

the effects of CFC’s (chlorofluorocarbons) on the the effects of CFC’s (chlorofluorocarbons) on the ozoneozone

CFC’s contain chlorine, and are found in aerosol CFC’s contain chlorine, and are found in aerosol propellants, refrigerants, solvents, and many other propellants, refrigerants, solvents, and many other productsproducts

CFC’s are so stable only exposure to strong UV CFC’s are so stable only exposure to strong UV radiation breaks them down; once CFC’s are broken radiation breaks them down; once CFC’s are broken down chlorine is releaseddown chlorine is released

One chlorine atom can destroy over 100,000 ozone One chlorine atom can destroy over 100,000 ozone moleculesmolecules

There is no actual “hole”, but a low concentration of OThere is no actual “hole”, but a low concentration of O33

Ozone DepletionOzone Depletion

Ultra Violent BUltra Violent B UVB has been linked to skin cancer, cataracts, crop UVB has been linked to skin cancer, cataracts, crop

damage, and harm some forms of marine lifedamage, and harm some forms of marine life

Montreal ProtocolMontreal Protocol

International Treaty to phase out and ban International Treaty to phase out and ban the use of CFC’sthe use of CFC’s

Opened for signatures in 1989, by 2009 all Opened for signatures in 1989, by 2009 all 196 countries of the United Nations had 196 countries of the United Nations had signed. signed.

SymbiosisSymbiosis SymbiosisSymbiosis- relationship of species that live - relationship of species that live

together in a close, long term association. together in a close, long term association. Secondary compounds- Secondary compounds- defensive defensive

chemicals in plants or animalschemicals in plants or animals NicheNiche- the role a species plays within an - the role a species plays within an

ecosystemecosystem Fundamental nicheFundamental niche Realized nicheRealized niche

Biodiversity- Biodiversity- the variety of organisms and the variety of organisms and species within an ecosystem. species within an ecosystem.

Symbiotic RelationshipsSymbiotic Relationships CompetitionCompetition (- ,- ) (- ,- ) species using the same resources.species using the same resources. Predation Predation (+,-) one organism kills another for food. (+,-) one organism kills another for food. Parasitism Parasitism (-,+) (-,+) a parasite benefits and a host is a parasite benefits and a host is

harmed. harmed. MutualismMutualism(+,+) (+,+) symbiosis where both species symbiosis where both species

benefit.benefit. CommensalismCommensalism(+, 0) (+, 0) - relationship where one - relationship where one

species benefits and the other is neither harmed or species benefits and the other is neither harmed or helped.helped.

http://www.nearctica.com/ecology/pops/symbiote.htm http://www.nearctica.com/ecology/pops/symbiote.htm

Biomes Biomes Biome- Biome- a large area with a type of climate a large area with a type of climate

and certain types of plants and animals. and certain types of plants and animals. ClimateClimate- the physical conditions and - the physical conditions and

average weather conditions of a particular average weather conditions of a particular area over a long period of time.area over a long period of time. MoistureMoisture TemperatureTemperature

Terrestrial BiomesTerrestrial Biomes Tropical Rain Forest Tropical Rain Forest SavannasSavannas TaigaTaiga DesertsDeserts Temperate GrasslandTemperate Grassland Temperate Deciduous ForestTemperate Deciduous Forest Temperate Evergreen (Coniferous) Forest Temperate Evergreen (Coniferous) Forest TundraTundra

http://www.mbgnet.net/index.htmlhttp://www.mbgnet.net/index.html

Convection CellsConvection Cells

Location of the Worlds Location of the Worlds BiomesBiomes

Tropical Rainforest will be located around Tropical Rainforest will be located around the Equator due to hot, humid air from the Equator due to hot, humid air from Hadley Cell. Hadley Cell.

Deserts will be located around 30° N and Deserts will be located around 30° N and 30° S due to cool dry air from the Hadley 30° S due to cool dry air from the Hadley Cell and Ferrel CellCell and Ferrel Cell

Taiga will be located around 60° N due to Taiga will be located around 60° N due to wet air from the Ferrel and Polar Cell wet air from the Ferrel and Polar Cell

Mountain EffectMountain Effect

On the windward side of a mountain, warm On the windward side of a mountain, warm wet air from prevailing winds will rise, cool wet air from prevailing winds will rise, cool and condense causing precipitation. and condense causing precipitation.

On the leeward side of a mountain, air that On the leeward side of a mountain, air that travels over the mountain will be cool and travels over the mountain will be cool and very dry. very dry.

Dry biomes like deserts and grasslands Dry biomes like deserts and grasslands can be created on the leeward side of the can be created on the leeward side of the mountain. mountain.

Mountain EffectMountain Effect

SuccessionSuccession

Ecosystems change over time as species Ecosystems change over time as species are introduced by natural means or abiotic are introduced by natural means or abiotic factors.factors.

Pioneer species are organism that are first Pioneer species are organism that are first to live in an area. to live in an area.

Climax Community- a stable, self Climax Community- a stable, self perpetuating plant and animal community perpetuating plant and animal community established by succession.established by succession.

Primary SuccessionPrimary Succession Ecosystems change over time as species are Ecosystems change over time as species are

introduced by natural means or abiotic factors.introduced by natural means or abiotic factors. Primary Succession occurs in an area with Primary Succession occurs in an area with

newly exposed rock, lava, or sand, where life newly exposed rock, lava, or sand, where life has not lived before. has not lived before. retreated glacierretreated glacier lava coolinglava cooling new beach formsnew beach forms Etc.Etc.

Primary SuccessionPrimary Succession Primary Succession begins with bare rock, and Primary Succession begins with bare rock, and

pioneer species like lichen, mosses, and or small pioneer species like lichen, mosses, and or small annual grasses- which enriches the soil. annual grasses- which enriches the soil.

Secondary SuccessionSecondary Succession Secondary Succession- the sequential Secondary Succession- the sequential

replacement of species after a major disruption replacement of species after a major disruption in a community where there has been life in a community where there has been life before. before. forest fireforest fire floodflood climate change climate change cultivationcultivation plowed fieldplowed field clearcut forest, etc.clearcut forest, etc.

Secondary SuccessionSecondary Succession If fertile soil is present secondary succession If fertile soil is present secondary succession

replace established species as new species replace established species as new species become more competitive.become more competitive.

Invasive Species Invasive Species Natural Selection favors organisms that can Natural Selection favors organisms that can

disperse and then colonize new territory. disperse and then colonize new territory. Plants use wind and animals for dispersal, Plants use wind and animals for dispersal,

animals can move great distances. animals can move great distances. Barriers like continents, mountains, and Barriers like continents, mountains, and

inhospitable conditions provide barriers for inhospitable conditions provide barriers for exotic species.exotic species.

Exotic (Invasive) Species that overcome natural Exotic (Invasive) Species that overcome natural barriers can damage ecosystems. barriers can damage ecosystems.

The ecosystem has no checks on the exotic The ecosystem has no checks on the exotic species- which upset balance. species- which upset balance.