Ecology_Unit_PowerPoint_with_Images Powerpoint

Ecology Unit

1. Ecology: How Living Things Interact With Each Other and Their Environment Key Concepts in Population and Ecosystem Dynamics

2. What Is Ecology? Definition: The study of how living things interact with each other and their environment. Examples: Wolves hunting elk, Bees pollinating flowers. Think About: Why do organisms need each other to survive?

3. Population Definition: A group of the same species living in the same area at the same time. Example: All the deer in a forest. Question: What might cause a population to increase or decrease?

4. Ecosystem Definition: All living (biotic) and nonliving (abiotic) things in one area and how they interact. Example: Pond = water, fish, plants, rocks, sunlight. Question: Can an ecosystem exist without sunlight?

5. Carrying Capacity Definition: The largest number of individuals of one species an ecosystem can support over time. Example: A pond can only support a certain number of fish before food runs out. Think About: What happens when there are too many deer and not enough food?

6. Limiting Factors Definition: Things that limit how large a population can grow. Examples: Food, water, space, disease, and predators. Activity: List limiting factors for humans.

7. Keystone Species Definition: A species that has a large effect on its ecosystem even though it may not be the most abundant. Example: Sea otters eat sea urchins, keeping kelp forests healthy. Question: What might happen if a keystone species disappears?

8. Trophic Cascade Definition: A chain reaction that happens when one species (often a keystone) changes or is removed, affecting all other levels. Example: When wolves were reintroduced to Yellowstone, elk numbers dropped, trees regrew, and beavers returned. Think About: How can one predator change a whole landscape?

9. Invasive Species Definition: A non-native species that spreads quickly and causes harm to the environment, economy, or health. Examples: Zebra mussels in the Great Lakes, Asian carp in U.S. rivers. Question: Why do invasive species often have no natural predators?