Ecology and Human Impact

Ecology and Human Impact• Ch. 14: Ecosystems (pg. 253-262)• Ch. 16: The Fragile Earth (pg. 289-307) *GREEN UNIT OVERVIEW SHEET*

• http://www.myfoxboston.com/dpp/news/great_white_shark_tagged_off_chatham_090509

What is Ecology?

Ecology – the study of the interactions of organisms with one another and with their physical environment.Biotic Factors – Organisms (living)

ex) animals, plants, bacteria, fungusAbotic Factors – Physical Environment (non-living)

ex) water, air, dirt, rocks

Ch. 14: EcosystemsWhat is an Ecosystem?Ecosystem – self-sustaining collection of

organisms and their physical environment.ex) forest, river, lake.

In your notes: give examples of living (biotic) and non-living (abiotic) factors in a river ecosystem.

Why do we study Ecology?• After watching the video, please answer

this question in your notes. Be prepared to share with the class.

Segment 1http://player.discoveryeducation.com/index.cfm?guidAssetId=1234A409-B01D-4996-AEA6-935BC9D28D02&blnFromSearch=1&productcode=US

Vital for survival of all organisms. The way we use the natural world affects the earth’s ability to provide the resources we need. Ecology tells us that our actions have consequences. Not only for us, but for all organisms that share the earth with us.

How do our actions affect other organisms?

• Please answer this question in your notes. Be ready to share. Feel free to use your “Unit Overview” to help give you clues for your answer.

MERCURY

Food Webs and Energy Transfer

• Organisms obtain the energy they need to live by eating or taking in other sources of energy.

• If the flow of energy is disrupted, it can have disastrous results on the entire ecosystem

• What is the first source of energy for the planet?

Important Terms• Producer/Autotroph (Auto = self, troph = feeder)

– organisms that produce their own food directly from the sun’s energy.

• Take in energy from their surroundings and and store it in complex molecules such as carbohydrates.

• Use the process of photosynthesis to make complex molecules

Ex.

Important Terms• Consumers/Heterotrophs (hetero = other)

– Organisms that obtain energy by consuming other organisms. Feed on others (hetero-troph)

• Feed on producers and other consumers• Can be:

– herbivores– carnivores – omnivores – decomposers

Important Terms• Primary Consumer – Feeds on plants. All

are herbivores. • Secondary Consumer – Feeds on primary

consumers. May be omnivore or carnivore• Tertiary Consumer – Feeds on secondary

consumer. May be omnivore or carnivore• Quaternary Consumer – Feeds on tertiary

consumer. May be omnivore or carnivore.

Identify each organism as a producer or the type of

consumer they are

Food Chain vs. Food Web

Food Chain• Food chain is one series

of energy transfers in an ecosystem

Food Web• Food web is the

interconnected food chains in an ecosystem

Important Terms• Trophic Level – group of organisms whos

energy source (the sun) is the same number of steps away from the sun.

• Energy flows from producer consumer. • Producers are always the 1st trophic level• Heterotrophs (consumers) are always at least

the 2nd trophic level

Trophic levels are different than consumer level

• Level 5

• Level 4

• Level 3

• Level 2

• Level 1

Ecological Pyramids:

graphs which illustrate the trophic levels in a community.

Most ecological pyramids are large at the base and narrow at

the top. This is because every time that an organism is eaten by the next trophic level, some of the energy is lost as heat.

More Energy

Less Energy

3 TYPES OF PYRAMIDS:1. Pyramid of Energy2. Pyramid of Biomass3. Pyramid of Numbers means you do not have to write this

Pyramid of Energy:• Shows the energy available at each trophic

level.– The size of the blocks represents the

proportion of energy– Measured in Joules or Calories

Pyramid of Energy:• Most of the energy available to the community

is in the 1st trophic level.• Only 10-20% of the energy is available to the

next trophic level (≈ 90% lost)

Pyramid of Biomass:• Illustrates the amount of biomass in each trophic

level – Biomass weight is determined after dehydration

• Shows the amount of matter lost between trophic levels.

• Measured in Kg, grams or pounds

Pyramid of Biomass P

yram

id o

f Bio

mas

s

Pyramid of Biomass One problem:They can make a trophic level look like it has more energy than it really does.For example: A bird has a beak, feathers and a skeleton that would count as biomass even though it does not contribute to the overall flow of energy into the next trophic level.

Pyramid of Numbers:• Illustration of the number of organisms at

each level

What kind of Pyramid

is this?

Energy, the trophic levels are measured in Kilocalories

Review Videos• Energy Transfer

• http://player.discoveryeducation.com/index.cfm?guidAssetId=7431DF64-E680-49ED-8908-A92ED5CA2725&blnFromSearch=1&productcode=US

Biogeochemical Cycles• Water Cycle (hydrological)

– How water is transferred from the atmosphere to earth, through organisms and back to the atmosphere

• Carbon Cycle– How carbon dioxide and oxygen are cycled from the

atmosphere through organisms and back to the atmosphere.

• Nitrogen Cycle– How organisms convert (fix) unusable nitrogen in

the atmosphere to usable nitrogen to make proteins

Water CycleTERMS

–Precipitation–Transpiration–Evaporation– Infiltration(seepage)–Ground Water–Run Off–Condensationhttp://www.nwlg.org/pages/resources/geog/hydro_cycle/hydro/cycle.htm

http://techalive.mtu.edu/meec/module01/HydrologicCycleQuiz.htm

CARBON CYCLE

Carbon Cycle

TERMS• Resipiration• Photosynthesis• Combustion• Decomposition• Fossil Fuels

Carbon Cycle

CARBON CYCLETERMS:

• Cellular Respiration• Photosynthesis• Combustion• Decomposition• Fossil Fuels

FOSSIL FUELS• Fossil fuels are made from organisms that

died millions of years ago and were buried• They are “non-renewable”, meaning there

is a limited supply.• Examples:

– Coal, oil and gas

Renewable Resources

• Resources that have unlimited supply.• Often considered “green”• Often do not release harmful pollutants

and/or carbon dioxide• Examples:

– Wind, solar, nuclear, geothermal, hydroelectric (water)

IDENTIFY THE RENEWABLE RESOURCE

• GEOTHERMAL– Uses heat generated

by the earth

IDENTIFY THE RENEWABLE RESOURCE

• SOLAR POWER– Harnesses the energy

from the sun

IDENTIFY THE RENEWABLE RESOURCE

• HYDROELECTRIC – is derived from water

moving downhill and flowing through a dam where it causes a turbine to rotate, which in turn drives a electric generator

IDENTIFY THE RENEWABLE RESOURCE

• WIND ENERGY– Harnesses the power

of the wind to generate energy

IDENTIFY THE RENEWABLE RESOURCE

Millstone – Waterford, CT • NUCLEAR ENERGY– produced by the conversion

of heat into energy via the process of nuclear fission– the splitting apart of atoms. Uranium atoms are used here.

Nitrogen Cycle• Nitrogen is the main component of proteins

and genetic materials that build up all organisms.

• 78% of the atmosphere is Nitrogen– Organisms cannot use nitrogen in the

atmosphere, it needs to be changed (or “fixed”) into a useable form

– This is done by bacteria in the soil and plant roots (legumes)

• Nitrogen in the air and in decaying organisms is fixed by bacteria in the soil

• Plants absorb this for themselves• Heterotrophs obtain their nitrogen from

plants and animals that eat plants

Nitrogen Cycle Terms• Nitrogen Fixation – when bacteria in soil

changes nitrogen to a useable form• Decomposition – when dead organisms

break down and release nitrogen into the soil

• Detritovores – organisms that break down dead material

• Ammonia – a useable form of nitrogen• Legumes - seeds that grow inside pods

whose roots have nitrogen fixing bacteria

Legumes• Legumes are plants

whose roots contain nodules that have nitrogen-fixing bacteria.

• Used in crop rotation to increase nitrogen in nitrogen-depleted soil

Examples: Peanuts, soy, clover

Nitrogen Cycle Info • Your body gets the nitrogen it needs to grow from food. • Most plants get the nitrogen they need from soil after

bacteria have “fixed” the nitrogen.• Many farmers use fertilizers to add nitrogen to the soil to

help plants grow larger and faster. • Both nitrogen fertilizers and forest fires add huge

amounts of nitrogen into the soil and nearby lakes and rivers.

• Water full of nitrogen causes plants and algae to grow very fast and then die all at once when there are too many for the environment to support.

As the human population increases, the toll it takes on the

Earth increases

• Pollution – anything potentially harmful that humans add to the environmentex) vehicle exhaust, pesticides, CFCs,

sulfuric acid, carcinogens

Pollution’s Toll• Too much pollution disrupts the

relationships in an ecosystem. ex) What would happen if a pesticide killed the shrews living in the ecosystem below?

Pollution Endangers Our Water Supply

• When substances like mercury and pesticides enter a river, etc. from factory waste, the entire food web can be destroyed.

• Negative health effects can also occur

Mercury (Hg)• Mercury is a toxic metal that remains

in bodies for long periods of time.• Mercury builds up in animals and

causes nerve and kidney damage.• The larger the animal, the greater the

accumulation of toxic substances. This is biomagnification.

Acid Rain• Acid rain is formed when nitric and

sulfuric acid is released into the atmosphere from coal-burning power plants.

• An increase in the acidity of an ecosystem causes many organisms to die

• Ecosystems downwind from factories experiencethe most acid rain

Global Warming• When fossil fuels are burned to make

energy, they release CO2 and other harmful substances into the atmosphere.

• High levels of CO2 have been linked to increasing temperatures on Earth (Greenhouse Effect)

• Increasing temperatures on Earth will lead to climate changes (Global Warming)

Destroying the Ozone Layer• The ozone layer is a part of our

atmosphere that protects us from carcinogenic (cancer causing) UV rays from the sun.

• Chloroflourocarbons (CFCs) – found in aerosol can products and coolants

• CFCs attack and destroy ozone• Most countries have banned CFCs

Pollution can seriously damage the health of an ecosystem (the living and non-living factors in an area)

• Carcinogens – substance that causes cancer.

ex) benzene, dioxin, mercury

Why is the Ozone Layer Thinning?

• CFCs are active for more than 100 years and will continue to breakdown the ozone layer

Ecosystem development and change

Niche – the sum of an organism’s interactions with its physical environment and with other organisms

Competition – situations in which 2 or more organisms attempt to use the same scarce resources

*Competition and predation drive evolution

Competition for resources

• Limiting factors – any condition of the environment that limits the size of a population

• Carrying capacity – The number of organisms that can be supported by a particular ecosystem

• Overpopulation - the condition of having a population so dense as to cause environmental deterioration, an impaired quality of life, or a population crash

• Although the name 'Mad Hatter' was undoubtedly inspired by the phrase "as mad as a hatter," there is some uncertainty as to the origins of this phrase. As mercury was used in the process of curing felt used in some hats, it was impossible for hatters to avoid inhaling the mercury fumes given off during the hat making process. Hatters and mill workers often suffered mercury poisoning as residual mercury vapor caused neurological damage including confused speech and distorted vision. It was not unusual then for hatters to appear disturbed or mentally confused; many died early as a result of mercury poisoning. However, the Mad Hatter does not exhibit the symptoms of mercury poisoning. Principal symptoms of mercury poisoning are "excessive timidity, diffidence, increasing shyness, loss of self-confidence, anxiety, and a desire to remain unobserved

and unobtrusive."[1]

Human Overpopulation• Birth rate/Death rate

United States 14.1/8.7 Australia 12.7/7.3

Iraq 34.2/6.0 Iran 17.5/5.4 Japan 10.0/8.5 Italy 8.9/10.1

Russia 9.7/13.9 • Emigration/Immigration

– The U.S. population is growing by about 2.5 million people each year. Of that, immigration contributes over one million people to the U.S. population annually.

• Exponential growth rate of human populations

Exponential Growth of Human Population

Human Population Growth

• It requires 10 times as many crops to feed animals being bred for meat consumption as it would to feed the same amount of people on a vegetarian diet!!

• The US could feed 800 million people with the grain that livestock eat.US population: 303 million

How can more people be supported on Earth when there is a limited supply of resources?

Human Population Growth

It depends on what they are eating…

Competition for resources

• Limiting factors – any condition of the environment that limits the size of a population

• Carrying capacity – The number of organisms that can be supported by a particular ecosystem

• Overpopulation - the condition of having a population so dense as to cause environmental deterioration, an impaired quality of life, or a population crash

Human Impact on the Environment• Deforestation• Pollution

– Water supply (fertilizers, pesticides, fungicides, acid rain), depletion of ozone layer, global warming

Environment - US current issues: air pollution resulting in acid rain in both the US and Canada; the US is the largest single emitter of carbon dioxide from the burning of fossil fuels; water pollution from runoff of pesticides and fertilizers; limited natural fresh water resources in much of the western part of the country require careful management; desertification

~CIA.gov

Reducing PollutionBush Calls for Work for Higher Fuel Efficiency

President Bush announced on Monday that he had directed his administration to begin the long process of establishing higher fuel efficiency standards for new cars.

Europe Proposes Binding Limits on Auto Emissions

Japan Urges China to Reduce Pollution

California sues EPA over greenhouse gas regulationsPosted Jan. 2, 2007

2:48 PM Hartford (AP) _ Connecticut is joining a lawsuit against the U.S.

Environmental Protection Agency for denying California's first-in-the-nation greenhouse gas limits on cars, trucks and SUVs. The lawsuit was anticipated after the EPA last month denied California's request for a waiver that was required under the

federal Clean Air Act. Connecticut is among 12 states that have adopted the California

emissions standards. EPA Administrator Stephen L. Johnson denied California a waiver

that it needs under the federal Clean Air Act to move forward with regulating greenhouse gas emissions from new cars and

trucks. A spokesman for EPA says the federal Energy Independence and Security Act is a more beneficial national approach to a national

problem.

Middletown prepares school for fuel cell energyPosted Jan. 3, 2008 5:34 AM

Middletown (AP) _ A state grant is being used to convert part of the power systems at Middletown High School -- fuel cell technology.The fuel cell will generate electricity, heat the swimming pool and state officials say ultimately it will save taxpayers money. Fuel cells generate clean power and are more than twice as efficient as the electrical grid when the fuel cell's exhaust heat is put to work.Middletown officials say the fuel cell is expected to generate about 20 percent of the school's total electrical load at a cost less than buying the electricity off the power grid.

Finding Enough Energy• Fossil fuels are linked to greenhouse

emissions and global warming• Fossil fuels are non-renewable (do not

replenish themselves naturally)• Renewable resources can replenish

themselves naturally (trees) are being looked at as an alternative to fossil fuels

Alternatives to Fossil Fuels

• Nuclear Energy• Geothermal Energy• Wind Energy• Solar Energy

*For homework, please read the articles on each type of alternative and answer the questions that follow.

Energy Conservation

• Using less• Energy efficient appliances

Conserving Nonrenewable Resources

Topsoil– Necessary for high crop yields– Hundreds of years to make 1 inch– Much is being washed away by rain due to

cultivation.– About 24 billion tons are lost each yearWhat can be done?

till cultivation and contour farming

Groundwater

• Accumulates very as it needs to seep through rock

• Wasted on irrigation, washing cars, etc.• Being polluted and pollution in

groundwater is very difficult to treat

Ways to Help• Conserve energy• Recycle• Conserve water