Ecology Notes: Part 1

What is Ecology?• Ecology: the study of how organisms interact

with each other and with their environment.

Eco logyeco = interactionslogy = the study of

The study of how organisms interact with each other and

with their environment

Biotic Factors in Ecosystems:

• Biotic Factors – all the living things that interact or come into contact with an organism.

Biotic Factors in Ecosystems:

Biotic factors of a Bullfrog:

Plants it eats as a tadpole

Herons who eat frogs

Red Legged Frog who competes with it for food

Insects eaten by bullfrogs

Abiotic Factors in Ecosystems:

• Abiotic Factors – All the physical or non-livingthings that have an effect on an organism.

Abiotic Factors in Ecosystems:

Examples:

• Wind

• Available Nutrients

• Soil Type

• Sunlight

• Temperature

• Humidity

• Precipitation

• Elevation

Energy Flow

• Sunlight is the main source of Energy for life on Earth.

- Of all the sun that reaches Earth, only 1% of it is used by living things

Autotrophs• Autotrophs: living things that get their energy

from the Sun or from thermal vents. They can use this energy to make their own food.

• Producers: same thing as an Autotroph.

Two Processes to Capturing Energy from the Environment:

Examples of Autotrophs

• Some examples of autotrophs are:

- Photosynthetic bacteria

- Chemosynthetic bacteria

- Algae - Protista

- Kelp - Grass

- Trees - Flowers

Heterotroph• If an organism does not get it’s energy directly

from the sun, nor from thermal vents, they must get energy by CONSUMING something else.

• Heterotroph: organisms that eat other organisms for their energy and food supply.

• Consumers: same thing as a Heterotroph.

Some examples of Heterotrophs are:

Herbivores: eat only plants.

Carnivores: eat only other animals.

Omnivores: eat plants and animals.

Scavengers: animals that consume the carcasses of other animals

Decomposers: feed by chemically breaking down decaying plants and animals.

Detritivores: eat the particles of decaying plants or the decomposers that live in decaying organic matter

Energy Flow• Energy flows through an ecosystem in

one direction

Sun producers consumers

Feeding Relationships

• Food Chain: a single series of energy transfers where organisms are eating and being eaten.

• Most feeding relationships in an ecosystem are more complex than just 1 food chain.

Feeding Relationships• Food Web: a complex network of energy

transfers among the living things in an ecosystem.

An ecological pyramid is a model that shows the interactions between organisms in an ecosystem.

Feeding Relationships• Each step in a food chain

or food web is called a Trophic Level

- Producers make up the first trophic level

- Consumers make up all the higher trophic levels.

- Each consumer depends on the trophic level below it for energy.

E

Producers

• What is another name for a producer?

Where are producers found on a ecological pyramid?

Autotrophs!

Consumers

What is another name for a consumer?

Secondary Consumers: the second level of organisms above producers.

They are the second consumers to get energy and are mostly smallcarnivores and omnivores.

Primary Consumers: the first level of organisms above producers.

They are the first consumers to get energy and are mostly herbivores.

Where are primary consumers found on the ecological pyramid?

Tertiary Consumers: the third level of organisms above producers. They are the last organisms to get energy and are mostly largecarnivores and omnivores.

Heterotrophs!

Where are secondary consumers found on the ecological pyramid?

Where are tertiary consumers found on the ecological pyramid?

Energy Pyramid:Ecological pyramids also show the amount of energy at each trophic level in an ecosystem. Approximately 10% of energy is passed to the next trophic level. The rest of the energy is used during life processes or lost as heat.

Heat!!!

Ecological Pyramid

6,000 kcal

600 kcal

60 kcal

6 kcal