1. Ecology—A branch of Biology
1. Ecology is the study of the interactions of organisms with each other and with their physical environments.

2. 2. The Earth is a single living system of living globe that has been named the biosphere. The biosphere is the portion of the Earth that supports life.
Biosphere

3. 3. All of the living organisms that inhabit an environment are called biotic factors.
4. Abiotic factors are the non-living parts of the environment such as light, temperature, rainfall, soil type, wind, nutrients, and location on the Earth.

4. BIOTIC FACTORS
ABIOTIC FACTORS

5. 5. Ecologist study interactions among organisms different levels
5. Ecologist study interactions among organisms different levels. The lowest level is an Individual. Next is a population, which is a group of organisms that interbreed and live in the same place at the same time.

6. 6. The next higher level is the community, which is a collection of interacting populations. A change in one population in a community will cause changes in other populations.

7. 7. An ecosystem, the next higher level of organization, is made up of interactions among populations in a community and the community’s physical surroundings, or abiotic factors.

8. 8. Large groups of ecosystems that share the same kind of climax community (where no changes are occurring) are known as biomes. Each land biome is characterized by a particular type of climate and physical features.

9. Biome 11 biomes in the biosphere DESERT DECIDUOUS FOREST
TEMPERATE RAINFOREST

10. 9. The highest of all levels then, is the biosphere and ecologists are concerned with all interactions within the biosphere.

11. Ecological Interactions
Individual (smallest)
Population
Community
Ecosystem
Biome
Biosphere (largest)