ECOLOGY

What is Ecology?

• Ecology is the scientific study of the relationship between organisms and their environment

• Ecologists study these relationships

What is the Biosphere?

• Living things can be found in the air, on land, and in both fresh and salt water.

• The biosphere is the surface of the Earth that supports life.

• The biosphere extends from the high atmosphere to the bottom of the ocean.

What Are Abiotic Factors?

• The non-living parts of an organism’s environment

• Examples are:

Air, water, sunlight, soil, humidity, temperature

Why do you think ecologists study these features?

How might these factors affect living things?

What Are Biotic Factors?

• All of the living organisms in an environment are biotic factors

• Living organisms affect other organisms

• Living things compete against one another

• Ecologists study how living things interact with both biotic and abiotic factors

• All organisms are interdependent – they can’t exist alone

Levels of Organization in Ecology“Populations”

“Communities” are collections of interacting populations

Forest Community

Pond Community

Desert Community

Grassland Community

Rainforest Communities

Ecosystems

• An ecosystem is made up of a community interacting with its environment

• Three kinds of ecosystems:

1. Terrestrial: Located on land

2. Freshwater aquatic

3. Salt water aquatic

Habitat

• Habitat is the place where an organism lives out its life.

• Habitats have specific biotic and abiotic factors that an organism needs to survive and reproduce.

• Habitats may change or disappear due to natural causes or interference by man.

What kind of habitat would a frog need?

The Niche

• A niche is the role and position a species has in its environment.

• Includes all its interactions with biotic and abiotic parts of its habitat.

• Species in different niches don’t compete for the same resources.

• Competition is reduced.

Symbiosis

• Relationships between organisms can be classified.

• Close and permanent relationship is called a symbiosis.

• Three main types:

1. Commensalism

2. Mutualism

3. Parasitism

Commensalism

Mutualism

Parasitism

Modes of Nutrition

AUTOTROPHS HETEROTROPHS

Scavengers

Decomposers

Food Chains

Food Webs

Food Pyramid

Pyramid of Energy

Pyramid of Biomass

http://resources.emb.gov.hk/biology/english/environment/ecology/pyramid.html