TOPIC 6 - ECOLOGY

Ecology

The study of how organisms interact with the living and non-living things

Biotic factors

Living parts of the ecosystem (EX: plants and animals)

Abiotic factors

Non living parts of the environment (EX: Rocks, air, pH, sunlight)

Niche

A species’ role in it’s environment (It’s job and what it eats)

Population

All the organism of a species that live in the same area

Community

All the different populations in an area

Biosphere

All of earth’s ecosystems

Competition

The struggle for resources among organisms

Limiting factors

The living and non living things in the environment that limit the size of populations (EX: Food, shelter, sun, space, oxygen)

Carrying capacity

The maximum population (# of organisms of any species) that an ecosystem can support

Predators

Kill and eat other organisms called prey

Autotrophs

(producers) make their own food by photosynthesis

Heterotrophs

Must eat something for food (consumers)

Herbivores

Can only eat plants

Carnivores

Can only eat animals

Omnivores

Can eat plants and animals

Consumers

Same as heterotrophs

Decomposers

Break organisms down and return nutrients to the soil. They are the recyclers in the ecosystem

Scavengers

Eat dead organisms that they did NOT kill themselves (EX: Vultures)

Parasites

They live off of another organism. They do not kill them usually (the parasite benefits, the host is harmed)

Producers

Same as autotrophs

Food chain

A diagram of the linear feeding relationship of organisms in an ecosystem

Rules in Drawing One:

1. All food chains begin with a Producer (Autotroph or Plant)

2. All food chains end with a Decomposer

3. Arrows in a food chain show the direction of the energy flow

Grass → Grasshopper → Frog → Snake → Hawk → Decomposer

Food web

A diagram composed of many interlocking food chains. It is more accurate than a food chain because most organisms eat more than one type of food in their environment)

Sun

The primary source of life’s energy on earth

Energy pyramid

A diagram showing the energy available at each trophic level. The bottom layer (Producers) has the greatest amount of energy and the amount of energy Decreases by 90% at each level as you move UP though the pyramid. Where does the energy go? Into the environment (Lost as heat)

Self sustaining ecosystem requires:

1. A constant source of energy (usually the SUN)

2. A process to capture the energy and store it in organic molecules. (Photosynthesis)

3. A way to recycle elements back to the ecosystem. (Decomposers)

Ecological Succession

The orderly sequence of changes in the communities living in a given ecosystem over time.

Pioneer Organisms to Climax Community