ECOLOGYInteractions of Living Things

I. Ecology

• Ecology: The study of the interactions between organisms and their environment.

• Environment: Anything that affects the organism.

II. Biotic vs. Abiotic

• Biotic: living factors in the environment. – Plants– Bacteria– Animals– Fungi– Protists

• Abiotic: Non-living factors affecting the environment. – Water– Soil– Light– Temperature– natural disasters – pH

III. 4 Levels of Environment

• Organism/Species

• Population

• Community

• Ecosystem

IV. Energy Uptake

• Producers – Make own food• Consumers – Eat other things

– Herbivore – Eat plants– Carnivore – Eat animals– Omnivore – Eat plants and animals– Scavenger – Live off remains of dead

organisms

• Decomposers – Recycle dead matter

Producers

Consumers Herbivores

ConsumersCarnivores

ConsumersOmnivores

ConsumersScavengers

Decomposers

V. Flow of Energy

• Food Chains – simple, show direct relationships

• Food Webs – Complex, show all possible relationships

• Energy Pyramid – Shows ecosystems loss of energy. Each level uses 90% of energy obtained leaving only 10% available to the next level

Food Chains

Food Web

Energy Pyramid

VI. Habitat vs. Niche• Habitat: The environment

in which an organism lives.

• Niche: An organism’s way of life within an ecosystem. (includes its habitat, its food, its predators and the organisms with which it competes.

VII. Competition

• Organisms try to use the same limited resource.

• Use by one organism decreases the amount available to other organisms.

VIII. Predator/prey

One organism (the predator) eats the other organism (the prey).

IX. Symbiosis – Two organisms live in close association with one another

1.) Mutualisms: Both organisms benefit

Symbiosis

2. Commensalism

• Sharks and remoras

One organism benefits and the other organism is unaffected

Symbiosis

3. Parasitism

• Parasite: organism that benefits

• Host: organism that is harmed and sometimes dies

• Examples:Ticks Tapeworms

One organism benefits while the other organism is harmed.

X. Carrying Capacity

• Largest population an environment can support