Ecology

Ecology The scientific study of interactions between organisms and their environments

The living environment: Biotic Factors As far as we know life exists only on Earth Living things are found in air, on land, and in both fresh and salt water.

Flora- plant life Fauna- animal life

The Biosphere is the portion of Earth that supports life.

The biosphere extends from high in the atmosphere to the bottom of the oceans.

Nitrogen gas makes up most of the Earth’s atmosphere.

All the living organisms that inhabit an environment are called biotic factors.

The nonliving environment: Abiotic Factors Abiotic Factors are the nonliving parts of the environment.

Examples include air currents, temperature, moisture, light, and soil.

Organization of Life Organisms Populations Communities Ecosystems Biosphere

Population A group of organisms of one species living in the same place at the same time that interbreed.

A collection of interacting populations. Community A collection of interacting populations.

Ecosystem Made up of the interactions among the populations in a community and the community’s physical surroundings, or abiotic factors.

Example Population – Giraffe Community – Giraffes, Zebra, Elephants Ecosystem – Animals, Grass, Water, Dirt

Terrestrial Ecosystems Located on land.

Aquatic Ecosystems Occur in either fresh water or salt water Saltwater ecosystems occupy approximately 75% of the Earth’s surface.

The role that a species plays in a community. Niche The role that a species plays in a community.

Place where an organism lives out its life Habitat Place where an organism lives out its life

Autotrophs Producers Make own food through photosynthesis

Heterotrophs Cannot make their own food Consumers

Herbivore A consumer that feeds only on plants

Scavenger Animals that feed on carrion, refuse, and dead organisms

Omnivores Consume a variety of foods that include both animal and plant materials.

Decomposers Break down dead and decaying plants and animals into simpler molecules that can be absorbed.

Decomposer - Mushrooms

Carnivore A consumer that feeds only on other animals

Symbiosis “living together” there are several kinds of symbiotic relationships

1. Commensalism One species benefits and the other neither benefits or is harmed

Another example of Commensalism- Emperor Shrimp and Sea Cucumber- shrimp rides around on the sea cucumber and is able to find more food sources this way; this neither helps or hurts the sea cucumber!!!

2. Mutualism Both species benefit Like lichen (combo of fungus and either algae or bacteria)

More examples of Mutualism: 1. Sea anemone and clown fish- sea anemone provides home for clown fish and clown fish provides food for anemone 2. Ants and aphids- ants protect aphids and aphids produce honeydew which ants feed on

3. Parasitism One organism derives benefit at the expense of the other Like a tapeworm in the human intestine

Food Chain Simple model that scientist use to show how matter and energy move through an ecosystem; consists of producers, consumers, & decomposers

Food Chain Algae - Fish - Heron Usually consist of 3 links but most have no more than 5 links

A link is an organism in a food chain

First Trophic Level Made up of photosynthetic autotrophs - the producers

1st Order Consumers Herbivores Do not eat any other consumer

2nd Order Consumers Carnivores - meat eaters They feed on 1st order consumers

3rd Order Consumers Carnivores that feed on 1st and 2nd order consumers

Food Web All the possible feeding relationships at each trophic level in a community

When moving from one trophic level to a higher trophic level, the amount of usable energy decreases. (10% Rule)

Also, when moving from one trophic level to a higher level, the number of organisms and the biomass decreases.

1. Make a Food Web - Look on page 410 in text to see an example 1. Make a Food Web - Look on page 410 in text to see an example. Be sure to draw your arrows showing how the energy is flowing. Arrows will be drawn from producers to consumer, etc. !!! Seeds, berries, grasses, grasshopper, mouse, squirrel, snake, deer, raccoon, hawk, bear Indicate trophic levels as well as producers, omnivores, herbivores, and carnivores

Assume that you are a decomposer. Write a paragraph that describes a) what you look like b) where you live c) what you are going to have for breakfast, lunch, and dinner, d) what your job is now and what it will be when you grow up.