Ecology

The study of the interaction of living things with their environment.

Cycles

• Water cycle• Carbon cycle• Nitrogen cycle

Water

Water Cycle

1. Evaporation is the process in which liquid bodies of water, such as ponds, lakes, rivers, and oceans, change into water vapor.

2. Transpiration is the evaporation of water from plant leaves.

3. Condensation is the process where water vapor changes to liquid or ice. (cloud formation)

4. Precipitation is when the water condenses so much that it falls to the ground in the form of rain, snow, or hail.

5. Once the precipitation falls to the ground, the water may flow onto the ground or underground. The process starts all over again.

Carbon

Carbon Cycle1. Carbon begins in the atmosphere as carbon dioxide.2. Plants on land, and algae in the water, take in the carbon

dioxide during the process of photosynthesis. They use this carbon dioxide to make their own food.

3. Animals eat the plants and get the carbon from the plants during feeding.

4. Both animals and plants die, and the carbon from their bodies goes back into the soil during decomposition. OR Animals breathe out carbon dioxide during the process of respiration.

5. Over millions of years, the carbon in their bodies can change into fossil fuels like coal, oil, and natural gas.

6. When people drive cars, or burn fossil fuels, the carbon is converted back to carbon dioxide gas and released into the atmosphere.

Nitrogen Cycle

Nitrogen Cycle1. Nitrogen gas is found in the atmosphere.2. Nitrogen gas cannot be used by animals or plants so it has to be changed

into a solid form. This is done one of two ways…a) Nitrogen gas is taken in by bacteria in the soil during the process of

nitrogen fixation, and the nitrogen gas is converted to ammoniab) Nitrogen gas is converted to ammonia when lightening takes it from

the atmosphere and puts it into soil.3. The ammonia is then converted into nitrates by nitrifying bacteria.4. The nitrates are then taken in by plants to build their DNA and proteins.5. Animals eat the plants and get the nitrogen they need.6. Animals and plants die and excrete wastes. Their bodies and waste can be

converted back to ammonia, through the process of decomposition7. Finally, the ammonia is converted back to nitrogen gas in the atmosphere

by the process of denitrification.

Biotic vs. Abiotic

Biotic

–Bacteria–Protists–Plants–Animals–Fungi

Abiotic

–Water–Gases–Weather–Temperature–Soil

Levels of Organization• Biosphere• Biome• Ecosystem• Community• Population• Individual/organism• Organ system• Organ• Tissue• Cell• Organelle• Molecule• atom

Most inclusive M

ost Exclusive

Biosphere

• Habitat ~ Area in which a particular organism lives. Must have physical and biotic factors necessary for survival.

• Ecological Niche ~ The job an organism carries out in its ecosystem. How the organism affects the environment.

The Sun

• Source of all energy for the biosphere

Obtaining Food

• Autotroph– Producer

• Heterotroph– Consumer– Herbivore– Carnivore– Omnivore

Food Chain

• One way flow of energy through an ecosystem• First Step ~ Producers• Primary consumer (1°)• Secondary consumer (2°)• Tertiary consumer (3°)

Grass→Rabbit→Fox→Mountain Lion

Food Web

• Shows all of the possible food chains in an ecosystem.

• Arrows always point toward the consumer.

• Identify two possible food chains shown.

Food Web Construction Lab

• Complete the Food Web Construction and Manipulation lab provided by Mrs. Fairweather.

Ecological Pyramid

• Trophic Levels• 10% Rule

Energy Pyramid

Shows the available energy available at a specific trophic level.

Biomass Pyramid

Shows all the available mass at a specific trophic level.

Pyramid of Numbers• Shows total number of

organisms available on that trophic level

Community Interactions

• Symbiosis: relationship in which 2 species live closely together – Mutualism: both species benefit– Commensalism: one member of the association benefits and the

other is neither helped nor harmed– Parasitism: one organism lives on or inside another and harms it

• Predation: one organism captures and feeds on another organism– Predator– Prey

• Competition: organisms of the same or different species attempt to use an ecological resource in the same place at the same time

Mutualism

Commensalism

Parasitism

Predator-Prey Relationship

Techniques of Field Ecology

• If you were in charge of a team given the responsibility to determine the number of sunfish in Horseshoe Lake, discuss with your partner how would you accomplish this task.

• Write a paragraph, in the appropriate space, on your “Techniques of Field Ecology” worksheet.

Techniques of Field Ecology

• Random Sampling – the organisms in a few small areas are counted and projected to the entire area

• Quadrant Studies – tracking changes in a small section of the environment

• Mark & Recapture – marking a number of individuals in a natural population, returning them to that population, recapturing some of them, then using a formula to determine total number of individuals in population

Techniques of Field Ecology

• Complete the random sampling and mark and recapture studies.

Population Ecology – Linear Growth Curves

• Linear growth. • In other words, growth in a straight line. • Your hourly wage would grow linearly.

Population Ecology – Logistic Growth Curve

• Logistic growth curve. Natural populations grow this way!!! This is also known as an s-shaped growth curve.

Be sure you can label each part of the graph!!

Population Ecology – Saw-tooth Growth Curve

• Predator – prey

Population Ecology - Exponential Growth Curve

• Exponential growth. This is also known as a J-shaped growth curve.

Histograms

Positive Population Growth

The children outnumber the adults of child-bearing age. More than two children per family.

Zero Population Growth

The children are fairly equal to the number of child-bearing adults. Average of two children per family.

Negative Population Growth

The children are outnumbered by the adults. Average of less than two children per family.

Positive Growth

Developing countries usually show positive growth.

•The aged make up a very small population.

•Health care may be inaccessible to many, or may be of poor quality.

•Economy may not be stable.

•Most of population lives at poverty level.

•War may be a factor that affects young adult and male population

Positive Growth

Zero Growth

The population is relatively stable, neither growing nor shrinking.

•Developed countries

•Good health care.

•Good sized elderly population

•Stable economy

•Most families are middle-class

Zero Growth

Negative Growth

Population will experience decrease in near future due to fewer children being born.

•Well developed countries.

•Larger elderly population

•Typically “rich” country.

•Future may be economically iffy – aging population relies on government health and pension programs that are supported by taxes of working people.

Population Growth

Affected by 3 things:• Number of births• Number of deaths• Number or individuals that enter or leave a

population.