Chapter 3: Ecology

What is Ecology?? The study of interactions that take place between organisms and their environment. It explains how living organisms affect each other and the world they live in.

Habitat & Niche Habitat is the place a plant or animal lives Niche is an organism’s total way of life—habitat and its role in environment

Niches A niche is determined by a limiting factor. Limiting factor- any biotic or abiotic factor that restricts the existence of organisms in a specific environment.

Limiting Factors Examples of limiting factors - Amount of water Amount of food Temperature Amount of space Availability of mates

The Nonliving Environment Abiotic factors- the nonliving parts of an organism’s environment. Examples include air currents, temperature, moisture, light, and soil. Abiotic factors affect an organism’s life.

The Living Environment Biotic factors- all the living organisms that inhabit an environment. All organisms depend on others directly or indirectly for food, shelter, reproduction, or protection.

Abiotic or Biotic? Biotic

Abiotic or Biotic? Abiotic

Abiotic or Biotic? Abiotic

Abiotic or Biotic? Biotic

Levels of Organization in Ecology

What are the Levels? Organism Population Community Ecosystem Biosphere

1st Level of Organization Organism: An individual living thing that is made of cells, uses energy, reproduces, responds, grows, and develops

2nd Level of Organization Population: A group of organisms, all of the same species, which interbreed and live in the same place at the same time.

3rd Level of Organization Community: All the populations of different species that live in the same place at the same time.

4th Level of Organization Ecosystem: Populations of plants and animals that interact with each other in a given area with the abiotic components of that area.

5th Level of Organization Biome: A group of ecosystems with similar climates and organisms Desert Tundra Tropical Dry Forest

6th Level of Organization Biosphere: The portion of Earth that supports life.

The Biosphere Life is found in air, on land, and in fresh and salt water. The BIOSPHERE is the portion of Earth that supports living things.

Human Impact on the Environment

Climate vs. Weather: What’s the Difference? Climate: Long-term averages and patterns of temperature, precipitation, winds, and clouds Weather: Short-term changes in temperature, precipitation, winds, and clouds; can change rapidly

Greenhouse Effect Important parts of the atmosphere are a.) greenhouse gases (carbon dioxide, methane, & water vapor), which trap heat on Earth, and b.) the ozone layer, which shields Earth from UV radiation The greenhouses gases can trap heat from the sun to keep our planet warm; this is called the greenhouse effect. Changes in the concentration of these gases (think CO2) can result in more heat being trapped and our planet being warmer

Greenhouse Effect

Pollution Human activities have affected global ecosystems in ways that harm humans and other species Human impacts range from local pollution to global change in ecosystems Example: -Industrial chemicals called chlorofluorocarbons (CFCs) act as catalysts in chemical reactions that break down O3 molecules in the ozone layer. -Most countries have banned CFCs (Montreal Protocol), and the ozone layer seems to be recovering.

Ozone Hole Over Antarctica

Global Warming The correlation of increasing atmospheric CO2 and rising global temperature suggests a cause-and-effect relationship Many scientists have concluded that increased CO2 levels have caused warmer surface temperatures on Earth **Graph on next slide**

Global Warming