Biology 20 -Unit 1 Slides

Biology 20Biology 20

Chapter 1 – The Biosphere as a Closed Chapter 1 – The Biosphere as a Closed SystemSystem

A A closed systemclosed system exchanges energy with exchanges energy with the surroundings but not the surroundings but not matter.matter.

The earth is in a state of The earth is in a state of dynamic equilibriumdynamic equilibrium.There .There are continuous changes are continuous changes but the whole system but the whole system remains undisturbedremains undisturbed

The BiosphereThe Biosphere

The The biospherebiosphere is the narrow zone of Earth that is the narrow zone of Earth that contains life.contains life.

It’s composed of the It’s composed of the lithospherelithosphere (land), (land), atmosphereatmosphere (air) and (air) and hydrospherehydrosphere (water) (water)

Living parts are called Living parts are called bioticbiotic factors. factors. Non-living parts are called Non-living parts are called abioticabiotic factors. factors.

Organization in the BiosphereOrganization in the Biosphere

For an organism For the biosphere

cell --------- individual

tissue------ population

organ ------community

system ----ecosystem

organism ---biosphere

DefinitionsDefinitions

AA population population includes a group of includes a group of individuals of the individuals of the same speciessame species occupying a specific area at a given time.occupying a specific area at a given time.

A A communitycommunity includes all the populations includes all the populations of of all speciesall species that occupy a given area that occupy a given area

An An ecosystemecosystem is called the functional unit is called the functional unit of the biosphere where the biotic and of the biosphere where the biotic and abiotic factors interact with each other.abiotic factors interact with each other.

Biodiversity:Biodiversity:

The number of The number of organisms in an organisms in an ecosystem.ecosystem.

The greater the The greater the biodiversity the biodiversity the healthier the healthier the ecosystemecosystem

The loss of one The loss of one organism from a food organism from a food chain can cause a chain can cause a collapse of the entire collapse of the entire chain.chain.

Equilibrium UnbalancedEquilibrium Unbalanced If the changes to an ecosystem are too severe If the changes to an ecosystem are too severe

the health of an ecosystem suffers.the health of an ecosystem suffers. It may cause:It may cause: extinctionextinction of a species worldwide of a species worldwide extirpationextirpation (local extiction of a species) (local extiction of a species) endangeredendangered species (close to extinction) species (close to extinction) threatenedthreatened species (likely to be endangered) species (likely to be endangered) special concernspecial concern – a species at risk – a species at risk P. 11 shows Canadian species at riskP. 11 shows Canadian species at risk

Factors that affect organism survivalFactors that affect organism survival Indicator speciesIndicator species are organisms that are are organisms that are

sensitive to changes in the ecosystem. If these sensitive to changes in the ecosystem. If these species decline the whole ecosystem is in species decline the whole ecosystem is in trouble.trouble.

E.g. Frogs, Grizzly BearsE.g. Frogs, Grizzly Bears

Reasons for declining populationsReasons for declining populations Loss of habitatLoss of habitat Air and Water QualityAir and Water Quality Climate ChangeClimate Change Ultraviolet Radiation (UV), loss of ozoneUltraviolet Radiation (UV), loss of ozone

The Earth’s Heat Budget. (p. 20)The Earth’s Heat Budget. (p. 20)

Only 0.023% of the sun’s energy is used in photosynth.

All of life on Earth depends on this captured energy.

Food Chain/Web VocabularyFood Chain/Web Vocabulary

Trophic LevelsTrophic Levels are the relative positions of are the relative positions of energy use in food chain.energy use in food chain.

AutotrophsAutotrophs sit on the 1 sit on the 1stst trophic level and can trophic level and can make their own food from the sun’s energy.make their own food from the sun’s energy. ProducersProducers use photosynthesis use photosynthesis

Primary consumersPrimary consumers rely on autotrophs for food rely on autotrophs for food 22ndnd trophic level trophic level Also called Also called herbivoresherbivores

Secondary consumersSecondary consumers rely on primary rely on primary consumers for foodconsumers for food 33rdrd trophic level trophic level Also called Also called carnivorescarnivores OmnivoresOmnivores will consume autotrophs as well. will consume autotrophs as well.

Tertiary consumers etc. are possibleTertiary consumers etc. are possible Food chains are limited to Food chains are limited to 55 trophic levels. trophic levels.

Chains vs. WebsChains vs. Webs Food Chains show a one way flow of energy from Food Chains show a one way flow of energy from

producer to top carnivore (last consumer in a chain)producer to top carnivore (last consumer in a chain) Food Webs are more realistic feeding relationships. Food Webs are more realistic feeding relationships.

They show the interlocking food chains between each They show the interlocking food chains between each organism in the ecosystem.organism in the ecosystem.

The more The more complex complex the food the food web the web the healthier healthier the the ecosystem.ecosystem.

PhotosynthesisPhotosynthesis The process where plants convert inorganic The process where plants convert inorganic

molecules into organic food energy called molecules into organic food energy called glucoseglucose..

Cellular Respiration•All organisms including plants break down the glucose to release the energy used in cells (ATP)

ChemosynthesisChemosynthesis In some ecosystems where light is not available In some ecosystems where light is not available

ie. Caves, deep ocean etc. extracting energy ie. Caves, deep ocean etc. extracting energy from chemicals is possible.from chemicals is possible.

•Bacteria are capable of forming organic molecules from chemicals like hydrogen sulphide, ammonia, and sulphur.

•These bacteria are called chemoautotrophs

Laws of ThermodynamicsLaws of Thermodynamics The study of energy transformationsThe study of energy transformations

First lawFirst law Energy can’t be created or destroyed it can Energy can’t be created or destroyed it can

only change forms.only change forms.

Second lawSecond law In any energy transformation, “waste” energy In any energy transformation, “waste” energy

in the form of heat is produced.in the form of heat is produced. This means there is always less energy This means there is always less energy

available as you move up the food chain.available as you move up the food chain.

Ecological Pyramids – models of energyEcological Pyramids – models of energy

Pyramid of BiomassPyramid of Biomass

includes the total includes the total dry dry massmass of all the living of all the living matter in a trophic matter in a trophic levellevel

There is always less There is always less biomass in each biomass in each higher trophic levelhigher trophic level

Standard pyramidStandard pyramid

Pyramid of NumbersPyramid of Numbers

The number of The number of organisms is counted organisms is counted in the ecosystem.in the ecosystem.

The shape can be a The shape can be a standard pyramid but standard pyramid but due to an organism’s due to an organism’s size it can be unusual.size it can be unusual.

Pyramid of EnergyPyramid of Energy

The joule is the metric unit of energyThe joule is the metric unit of energy

The total energy in joules can be determined for The total energy in joules can be determined for each trophic level.each trophic level.

This pyramid takes into account the energy This pyramid takes into account the energy expenditure of an organism, such as the energy expenditure of an organism, such as the energy used for hunting etc.used for hunting etc.

Always a standard pyramidAlways a standard pyramid

Human Energy Effects on the EcosystemHuman Energy Effects on the Ecosystem

We can be primary, sec, tert, consumersWe can be primary, sec, tert, consumers Burning wood releases energy stored by Burning wood releases energy stored by

photosyn.photosyn.

Large scale effectsLarge scale effects

1. Hunting and Fishing1. Hunting and Fishing Some species have been extirpated (wolves/bison)Some species have been extirpated (wolves/bison)

2. Monocultures2. Monocultures Single food crops have replaced biodiverse regionsSingle food crops have replaced biodiverse regions Rainforests are destroyed for crops not suited for the Rainforests are destroyed for crops not suited for the

soil conditions.soil conditions.

The trade off is short term economic gain for The trade off is short term economic gain for long term economic collapse.long term economic collapse.

The Water MoleculeThe Water Molecule H20 consists of one atom of H20 consists of one atom of

oxygen bound to two atoms of oxygen bound to two atoms of hydrogen.hydrogen.

The water molecule has a The water molecule has a positive charge on the side of positive charge on the side of hydrogen atoms and a negative hydrogen atoms and a negative charge on the other side. charge on the other side. Therefore it’s called a Therefore it’s called a polar polar molecule.molecule.

Water molecules tend to attract Water molecules tend to attract each other because the positive each other because the positive ends attract to the negative ends attract to the negative ends. This is called ends. This is called hydrogen hydrogen bonding.bonding.

Water is a “universal Water is a “universal solvent: solvent:

it takes up valuable it takes up valuable chemicals, minerals and chemicals, minerals and nutrients.nutrients.

Moderates tempsModerates temps

Absorbs and releases Absorbs and releases thermal energythermal energy

Makes up 60% of a cellMakes up 60% of a cell

Provides surface Provides surface tension.tension.

Water’s properties

Arguably the most important natural phenomenon on Earth, the water cycle, also known as the hydrologic cycle, describes the constant movement and endless recycling of water between the atmosphere, land surface, and under the ground. The hydrologic cycle supplies the force needed for most natural processes, thus supporting life itself.

CondensationCondensation

The change from a liquid to a The change from a liquid to a gas. In the water cycle, the gas. In the water cycle, the change from water to water change from water to water

vapor.vapor.

Condensation Condensation & Convection& Convection

Warm air risesWarm air rises Air cools and Air cools and

can no longer can no longer hold vaporhold vapor

Process known Process known as as CONVECTIONCONVECTION

Condensation & Condensation & Cloud Cloud

FormationFormation Cooling of water Cooling of water vapor forms vapor forms CLOUDSCLOUDS

Other ways Other ways clouds are formedclouds are formed ConvergenceConvergence Lifting of air by Lifting of air by

frontsfronts

Freshwater StorageFreshwater Storage Water may be Water may be

stored temporarily stored temporarily in the ground, in the ground, oceans, lakes, oceans, lakes, rivers, and ion ice rivers, and ion ice caps and glaciers.caps and glaciers.

The world’s two The world’s two main reservoirs of main reservoirs of fresh water are the fresh water are the great polar ice caps, great polar ice caps, and the ground.and the ground.

If all of the ice in the If all of the ice in the ice caps and other ice caps and other glaciers melted, it glaciers melted, it would raise the sea would raise the sea level by about 260 ft.level by about 260 ft.

In temperate In temperate climates, water is climates, water is found in depression found in depression storage or surface storage or surface water puddles, water puddles, ditches, and ditches, and anywhere else that anywhere else that runoff water can runoff water can gather. This is a gather. This is a temporary form oftemporary form of storagestorage

A hydrologist is A hydrologist is particularly particularly interested in interested in stream flow -- the stream flow -- the 31% of 31% of precipitation precipitation which runs off into which runs off into rivers, streams rivers, streams and lakes. and lakes.

About 3% of this About 3% of this water will seep water will seep underground underground

About 31% will run About 31% will run off into rivers, off into rivers, streams and lakes streams and lakes

About 66% of the About 66% of the water returns to the water returns to the atmosphere atmosphere through through evaporation and evaporation and transpirationtranspiration

Surface RunoffSurface Runoff When When

precipitation rate precipitation rate exceeds exceeds infiltration rate, or infiltration rate, or when soil is when soil is saturated, water saturated, water begins to move begins to move down slope on down slope on ground surface.ground surface.

Surface RunoffSurface Runoff surface runoff surface runoff

gradually flows into gradually flows into gullies, streams, gullies, streams, lakes, or rivers. lakes, or rivers. Water in streams Water in streams and rivers flows to and rivers flows to the ocean, seeps the ocean, seeps into the ground, or into the ground, or evaporates back evaporates back into the atmosphere.into the atmosphere.

Water Storage in Water Storage in OceansOceans

The largest The largest reservoir is the reservoir is the oceans. There oceans. There is about 50 is about 50 times as much times as much water in the water in the oceans than in oceans than in the next largest the next largest reservoir, polar reservoir, polar ice and glaciers.ice and glaciers.

-Rain water soaks into ground through soil and underlying rock layer.

•Percolation is the term for movement of water through the soil.

•Leaching is the removal of soluble materials by percolation.-Water cleaned as

impurities filtered

•The water table is the top level below the ground that is saturated with water.

-then stored underground in rock crevices and in the pores of geologic materials that make up the Earth's crust

- water seeps downward underground into soil and rock crevices

-Water storage under the ground largely depends on the geologic features related to the types of soil and the types of rocks present at the storage locations.

-underground storage occurs in the soil, in aquifers, and in the crevices of rock formations

TranspirationTranspirationThe process of The process of

evaporation evaporation from plants. from plants. Basically, Basically, plants plants sweating.sweating.

Transpiration Cont.Transpiration Cont.Environmental Environmental

factors that affect factors that affect transpiration:transpiration:

LightLight TemperatureTemperature HumidityHumidity WindWind Soil waterSoil water

Good For Plants!!Good For Plants!! Transpiration is the Transpiration is the

“engine” of plant life, “engine” of plant life, pulling water up pulling water up from the roots. This from the roots. This allows for allows for photosynthesis, photosynthesis, brings minerals from brings minerals from the roots to the rest the roots to the rest of the plant, and of the plant, and cools the leaves. cools the leaves.

Biogeochemical Cycles:Biogeochemical Cycles:Reservoirs & PathwaysReservoirs & Pathways

Atmosphere

HydrosphereLithosphere

Biosphere

Some Major Cycles of Some Major Cycles of MatterMatter

•Water Cycle•Rock Cycle•Chemical Cycles

•Carbon•Nitrogen•Phosphorous•Sulfur

Carbon CycleCarbon Cycle

Atmosphere

HydrosphereLithosphere

Biosphere

Carbon Cycle: Carbon Cycle: ReservoirsReservoirs

Atmosphere

HydrosphereLithosphere

Biosphere

1x(= 7.3x1017 grams

carbon)

3x

55x35,000x

Carbon CycleCarbon Cycle

Atmosphere

HydrosphereLithosphere

Biosphere

Photosynthesis

Respiration& Decay

Carbon CycleCarbon Cycle

Atmosphere

HydrosphereLithosphere

Biosphere

Photosynthesis

Respiration& Decay

Burial &Lithification

Weathering& Volcanism

Dissolution

PhotosynthesisBurial &Lithification

Exsolution

Carbon CycleCarbon Cycle

Atmosphere

HydrosphereLithosphere

Biosphere

HumanImpacts

Burning fossil fuels:Increased combustion

Deforestation:Decrease Photosynthesis

Increase Respiration

Net Effect:Increase in Carbonin Atmosphere

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northernsummer

northernwinter

Carbon ReservoirsCarbon Reservoirs

InorganicInorganic The atmosphere in the form of COThe atmosphere in the form of CO22

The oceans (COThe oceans (CO22)) The Earth’s crust as fossil fuels and The Earth’s crust as fossil fuels and

carbonates like limestonecarbonates like limestone

OrganicOrganic The bodies of living thingsThe bodies of living things Peat – dead plant material Peat – dead plant material coal coal

Human Impact on the Carbon CycleHuman Impact on the Carbon Cycle

The Greenhouse EffectThe Greenhouse Effect

Without the greenhouse effect avg temp = -18o C

Too much of this can lead to global warming.

Levels of CO2 is 3X in 40 yr

The balance between photosyn and cell resp. is changing.

The Greenhouse Effect traps heat inside the Earth’s atmosphere. This causes our climate increasing in temperature. This is known as Global Warming.

Global warming could cause:Global warming could cause:

flooding as polar ice caps melt, flooding as polar ice caps melt, raising sea levelsraising sea levels

extreme weather events due to extreme weather events due to shifting ocean currentsshifting ocean currents

deserts to spread across Europe deserts to spread across Europe as land dries upas land dries up

Albedo EffectAlbedo Effect

Albedo refers to the reflective ability of a material.

The higher the albedo the greater the reflection of solar radiation.

Global warming could cause a lower albedo which in turn causes more global warming and so on.

Nitrogen CycleNitrogen Cycle

Atmosphere

HydrosphereLithosphere

Biosphere

Nitrogen fixation:• bacteria• lightning

Waste &Decomposition

Denitification:bacteria

Erosion

Absorption

Nitrogen-Fixing Nitrogen-Fixing Bacteria in Root Bacteria in Root

NodulesNodules

Nitrogen Fixation

•N2 is converted to nitrate (NO3) in 2 ways

•by lightning

•by bacteria in the soil

•Once in nitrate form N can enter plants in the water.

•Denitrification

•During decay, bacteria can convert and release nitrates to nitrites and then back into N2 gas for the atmosphere.

Phosphorous CyclePhosphorous Cycle

Atmosphere

HydrosphereLithosphere

Biosphere

Never enters the atmosphere

Waste &Decomposition

Weathering & Erosion

Absorption

SedimentationAbsorption

Phosphorous CyclePhosphorous Cycle

HydrosphereLithosphere

Biosphere

Mining, use (fertilizer, detergent, etc.)& increased runoff

Net Effect:Increase in phosphorous in water &“algal blooms”; Depletion in soils

More Phos. for organismsLong Cycle

Short Cycle

Short time involves living things

Involves geologic processes