ECOLOGY 2

ECOLOGY

ECOLOGY (ORGANISMS AND THEIR ENVIRONMENT)

What is ecology?
Ecology is the scientific study of how living things interact with the environment

Autotrophs are producers and producers are organisms thatmake their own food (glucose). They are the only organisms that can convert solar energy into chemical energy or food (organic compound). They carry out autotrophic nutrition. Plants and algae are autotrophs.

Auto: means self

Troph: means feeder

Autotrophs are self-feeders

PLANTS ARE AUTOTROPHS. (They make their own food)

ALGAE ARE AUTOTROPHS (They make their own food)

Scientists estimated that about 65 - 85% of the oxygen we breathe comes from algae.

Heterotrophs are consumers and consumers are organisms that eat or obtain nutrients made by autotrophs. They depend onautotrophs for food. Horses, cows, lions and humans areheterotrophs.

Herbivores are heterotrophs that eat plants only, EX. COWS .

A COW IS A HERBIVORE.

Carnivores are heterotrophs that eat meat only, ex. lions.

A LION IS A CARNIVORE.

Omnivores are heterotrophs that eat both meat and plants, ex. humans.

HUMANS ARE OMNIVORES.

Decomposers are organisms that break down dead organisms and return them to the soil. They recycle nutrients. Ex. ofdecomposers are fungi and bacteria.

MUSHROOMS ARE DECOMPOSERS. (mushrooms are fungi)
Predators are organism that kill other organisms for food, ex. a lion is a predator.

Prey are organisms that are killed and eaten by other organism, ex. deers are killed and eaten by lions. Deers are preys.

Scavengers are heterotrophs that eat dead organisms, Ex. vultures.
Biotic are living things. Ex. plants, humans, cows and mushrooms are biotic factors

Abiotic are nonliving. Ex. sun, water, oxygen and temperature are abiotic factors

Niche is the role that the organism play in the environment. For example, a lion's role is "predator"

Habitat is the place where organisms live.

Carrying Capacity refers to the maximum number of organism a habitat can support. Once the number of organisms reaches the carrying capacity, it levels out or stop growing.

Limiting Factors: refers to any biotic or abiotic aspect of the environment that affect population growth. For example, in a desert, water and temperature areabiotic limiting factors; food, prey, and predator are biotic factors that can affect population growth.

Species: Two organisms are of the same species if the can reproduce (make babies or offspring) and their babies are fertile. That is their babies can also make babies. 

Population: Organisms of the same species living at the same place at the same time, for example a population of dogs, a population of cats.

Community: Different populations living at the same place and at the same time. For example, we live in a community made up of people, cats, dogs, trees, other animals and plants.

Ecosystem consist of the living and the nonliving


The Food Chain And The Food Web show how energy moves through the ecosystem.

EXAMPLE OF FOOD CHAINEnergy for this food web comes from the sun.


THINK! The arrow in the food chain or the food web represents energy. The caterpillar is receiving its energy from the flowers by eating them.

• What happens to the owl population if the snake population is removed from the food chain?

• How is the caterpillar population affected by the removal of the snake population?

EXAMPLE OF FOOD WEB

THINK!

• How is the rabbit population affected if the deer population is removed from the food web?

INTERACTIVE FOOD WEB 1

INTERACTIVE FOOOD WEB 2

INTERACTIVE FOOD WEB 3

-The first organism in the food chain or the food web is always a plant because only plants can convert sunlight into food.

-In the next level in the food chain or web are the herbivores because herbivores eat plants.

-Carnivores are found on the third level or higher because they eat herbivores or other carnivores.

-The arrow in the food chain or food web represents energy

-Energy decreases as it goes through the ecosystem because energy is used for life functions and energy is lost as heat.

- If you remove an organism from the environment, the environment becomes less stable.

- The greater the biodiversity, the more stable the environment.

Questions

• Why are plants at the bottom of the food pyramid?
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• What happens to energy as it goes through the ecosystem?

• In the food web, how come no arrow is pointed toward the plant?

• What is the role of decomposers?
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• Identify two organisms that carry out decomposition.
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• What does the arrow represent in the food web?

• At what level of the energy pyramid would you find the largest amount of biomass?

Answers

• Plants are at the bottom of the food pyramid because they can convert sunlight into food for animals.
• As energy goes through the ecosystem it decreases because it is used by organisms for life functions and it is lost as heat.
• Plants do not receive energy from other organisms.
• The decomposers recycle nutrients, or break down dead organisms and return them into the soil so that they can be used by plants.
• Fungi and bacteria carry out decomposition
• In the food web, the arrow represents energy.

• The largest amount of biomass is found at the bottom of the energy pyramid.

Remember
Living things depend on biotic factors such as food and abiotic factors like oxygen, soil, temperature, light and water.

Ecological succession refers to the orderly changes that take place in an ecosystem, where one group or organisms is being replaced by another.

Renewable resources are resources that can recycle themselves within a short amount of time. Example: trees, animals, humans, water, oxygen are renewable resources.

Nonrenewable resources are resources that cannot recycle themselves in a short amount of time, and therefore efforts must be made to conserve them. Fossil fuel like gasoline, coal and cooking gas are nonrenewable resources.

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