1. Introduction to Ecology

2. Ecology
The study of interactions among organisms and their environment.
Biosphere: combined portions of the planet.

3. Levels of Organization
Species: group of very similar organisms.
Populations: animal groups living in the same area.
Communities: groups of different populations.
Ecosystem: groups of communities including nonliving things.
Biomes: groups of ecosystems with similar environments

4. Sunlight
The main source of energy for life on Earth.

5. Autotrophs use energy from the environment to make own food.
Also called producers  produce their own food.
Includes plants.
Photosynthesis: autotrophs use sunlight, CO2, and water to produce O2 and sugar.

6. Heterotroph
Also called consumers because they rely on other organisms for energy and food supply.
Herbivores: eat plants only
Carnivores: eat meat only (eat animals)
Omnivores: eat plants and animals
Decomposers: break down organic matter

7. Energy Flow Energy flows through an ecosystem in one direction:
From the SUN  PRODUCERS  CONSUMERS
Represented by:
Food chain
Food web

8. Food Chain
A series of steps in which organisms transfer energy by eating and being eaten.
Trophic level: each step in the
food chain.

9. Food Web
Linkage of food chains; animals can eat more than one thing and be eaten by more than one thing.

10. Ecological Pyramids Only about 10% of energy is passed at each level.
Biomass: total amount of living tissue with in a trophic level.