Chapter 10

Ecosystems

Section 1: Living Things and the Environment

• The study of how living things interact with each other and their environment is called ecology.

• An ecosystem is made up of the living things in an area, and their nonliving surroundings.

Habitat

• A habitat is where an organism lives and finds the things it needs to live, grow, and reproduce.

Biotic Factors

• A biotic factor is a living part of a habitat.– Plants– Animals– Seed, nuts, berries– Worms, fungi, bacteria

Abiotic Factors

• Abiotic factors are nonliving parts of an organism’s habitat:– Water– Sunlight– Oxygen and other gases– Temperature and weather– Soil and rocks

4 Levels of Organization

• 1. The biggest level is the ecosystem or biome, which includes biotic and abiotic factors.

4 Levels of Organization

• 2. The next biggest is community, all the the living things in an area.

4 Levels of Organization

• 3. Next is population, all the members of one species (can mate and reproduce) in an area.

4 Levels of Organization

• 4. The smallest level is an organism, or individual living thing.

Levels of Organization Ladder

• Create a ladder showing the levels of organization.– Lowest rung: organism– 2nd rung: population– 3rd rung: community– Top rung: ecosystem or biome

– Include a label, the definition, and a drawing for each rung of your ladder.

– If you finish early, do questions 1-3 on page 396.

Section 2: Populations

• Populations change in size when new members join the population or when members leave the population.

Births and deaths

• The birth rate of a population is the number of births in a population in a certain amount of time.

Births and deaths

• The death rate is the number of deaths in a population in a certain amount of time.

The Population Statement

• If birth rate > death rate, population size increases.

• If death rate > birth rate, population size decreases.

Immigration and Emigration

• Immigration means moving into a population.

• Emigration means leaving a population.

Limiting Factors

• The largest population that an area can support is called its carrying capacity.

Limiting Factors

• A limiting factor is an environmental factor that causes a population to stop growing.– Food– Water– Space– Light– Soil– Weather

Population Graphing

• Complete and turn in the graphing activity.

• If you finish early, do questions 1-3 on page 403 (PQA).

Section 3: Energy Flow in Ecosystems

• Each of the organisms in an ecosystem fills the energy role of producer, consumer, or decomposer.

Producer

• An organism that can make its own food is a producer (plants, algae, bacteria)

Consumer

• A consumer gets energy by eating another organism.– Herbivores eat only plants– Carnivores eat only animals– Omnivores eat plants and animals– Scavengers eat dead organisms

Decomposer

• A decomposer breaks down waste and dead organisms (mushrooms and bacteria)

Food chains and Food webs• A food chain is a series of events in which one

organism eats another and gets energy

• A food web is made of many food chains put together.

Energy Pyramid

• A diagram called an energy pyramid shows the amount of energy that moves from one feeding level to another in a food web.

Create a food web

• Follow the directions on your worksheet to cut and paste the producers, consumers, and decomposers.

• Draw lines showing the flow of energy FROM producers TO consumers.

• Don’t forget to include the sun!

Section 4: Interactions Among Living Things

• Every organism has a variety of adaptations that are suited to its specific living conditions.

• An adaptation is a behavior or physical characteristic that allow organisms to be successful

Predation

• An interaction in which one organism kills another for food is called predation.– The organism that does the killing is the predator.– The organism that is killed is the prey.

3 Types of Symbiosis

• Symbiosis is a close relationship between two species that benefits at least one of the species.

3 Types of Symbiosis

• 1. A relationship in which both species benefit is called mutualism. (saguaro and bat)

3 Types of Symbiosis

• 2. A relationship in which one species benefits and the other is not affected is commensalism (hawk and saguaro)

3 Types of Symbiosis

• 3. Parasitism involves one organism living on or inside another organism and harming it.– The organism that benefits is the parasite (tick)– The organism it lives on is the host (dog)

Create a food web

• You will be assigned an ecosystem.• Look at the animals and plants included.• Draw a food web showing how they are

connected.• Draw lines showing the flow of energy.• Include the sun and decomposers.

Section 5: Cycles of Matter

• Matter in an ecosystem is transferred from one organism to another and to the environment in a cycle.

Water Cycle

• The processes of evaporation, condensation, and precipitation make up the water cycle.

The Carbon Cycle

• Plants use carbon dioxide gas to make sugar and oxygen.

• Animals use oxygen and sugar to make carbon dioxide gas.

The Oxygen Cycle

• Plants make oxygen through photosynthesis.

• Animals use oxygen when they breathe and move.

The Nitrogen Cycle• In the nitrogen cycle, nitrogen moves from the

air to the soil, into living things, and back into the air.

• The process of changing free nitrogen into a useable form of nitrogen is called nitrogen fixation and is done by bacteria.

Illustrate the cycles 4 square

• Using your notes and the textbook for guidance, create a 4 square showing the following cycles:– Water– Carbon – Oxygen– Nitrogen

Section 6: Changes in Communities

• The series of predictable changes that occur in a community over time is called succession.

Primary Succession• Primary succession is the series of changes

that occur in an area where no soil or organisms exist. (volcanic eruption)

• The first species to populate the area are called pioneer species.

Secondary Succession

• Secondary succession is the series of changes that occur in an area where the ecosystem has been disturbed, but where soil and organisms still exist (forest fire).

Succession Video

• Write down 10 facts you learned (or already knew) while watching this video.

Chapter 10 Review

• Write and answer questions 1-10 on page 429• Complete the questions on the back of the

worksheet.

• Answer questions 11-25 on page 430. PQA and do these in your notebooks.