Ecosystems Chapter 21

Definition All of the living and nonliving elements in a particular place. Living elements: incude plants, animals, and people Nonliving elements; include sunlight, soil, air, water, and temperature.

Ecosystems Large and Small The planet, the ocean, a forest Small: A puddle, a tree, a flower

Divisions within an Ecosystem Organisms: found within populations Ex: one rabbit Community: groups of plants and animals adapted to similar conditions Populations: found within communities Ex: rabbits

Changes in Ecosystems Balanced ecosystems: Unbalanced ecosystem: Population sizes of different species don’t change relative to each other Unbalanced ecosystem: A change in predator or prey population

Whole System Affected A change in one feature can affect the whole system Ex: forest fire, nonative species, deforestation The good: ecosystems eventually return to original conditions

Short Term Changes Are easily reversed Seasonal changes: birds migrating, trees lose leaves, animals hibernate

Long Term Changes Harder to reverse Examples: volcanic activity, global warming, melting ice caps How can these change ecosystems?

Changes by Human Activity Growing crops, constructing roads and buildings, and building dams. How can these affect ecosystems?

Nonnative Species Starlings, zebra mussels, dandelions Organisms that are from another ecosystem Compete with native species for food and shelter