2. Chapter 3
Communities, Biomes, and Ecosystems
Various substances or elements on Earth move through long-term and short-term biogeochemical cycles as they become part of different aspects of the biosphere. The amount of a substance that is involved in a long-term cycle has an effect on the availability of that substance for use by humans and other organisms on Earth.
Choose a substance or element that you know is involved in both long-term and short-term biogeochemical cycles. In a well-organized essay, describe how it moves through both types of cycles, and how these cycles affect its availability to humans and other organisms.

3. Chapter 3 Communities, Biomes,
and Ecosystems
Section 1: Community Ecology
Section 2: Terrestrial Biomes
Section 3: Aquatic Ecosystems

4. Chapter 3
Communities, Biomes, and Ecosystems
3.1 Community Ecology
Communities
A biological community is a group of interacting populations that occupy the same area at the same time.
Oasis

5. Chapter 3
Communities, Biomes, and Ecosystems
3.1 Community Ecology
Limiting Factors
Any abiotic factor or biotic factor that restricts the numbers, reproduction, or distribution of organisms is called a limiting factor.
Includes sunlight, climate, temperature, water, nutrients, fire, soil chemistry, and space, and other living things

6. 3.1 Community Ecology Range of Tolerance
Chapter 3
Communities, Biomes, and Ecosystems
3.1 Community Ecology
Range of Tolerance
An upper limit and lower limit that define the conditions in which an organism can survive
The ability of any organism to survive when subjected to abiotic factors or biotic factors is called tolerance.
Zones in which organisms cannot survive are considered the range of intolerance.

7. Ecological Succession
Chapter 3
Communities, Biomes, and Ecosystems
3.1 Community Ecology
Ecological Succession
The change in an ecosystem that happens when one community replaces another as a result of changing abiotic and biotic factors is ecological succession.
There are two types of ecological succession—primary succession and secondary succession.

8. Chapter 3
Communities, Biomes, and Ecosystems
3.1 Community Ecology
The establishment of a community in an area of exposed rock that does not have any topsoil is primary succession.

9. Pioneer species are the species that first occupy an area.
Chapter 3
Communities, Biomes, and Ecosystems
3.1 Community Ecology
Pioneer species are the species that first occupy an area.
They help to create soil by secreting acids that help to break down rocks.

10. Chapter 3
Communities, Biomes, and Ecosystems
3.1 Community Ecology
The orderly and predictable change that takes place after a community of organisms has been removed but the soil has remained intact is secondary succession.

11. Chapter 3
Communities, Biomes, and Ecosystems
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