1. Environment Chapter 2: Cycles in Nature
Section 1: The Cycles of Matter

2. Section 1: The Cycles of Nature
Matter- anything that occupies space and has mass
The cycles (water, nitrogen, carbon) move matter among the environment and living things

3. The Water Cycle
Water Cycle: the movement of water among oceans, atmosphere, land, and living things.
Brainpop!

4. Steps of the Water Cycle
Precipitation- water moves from the atmosphere to the land and oceans
Ex: rain, snow, sleet, hail
Evaporation- water moving from the land to the atmosphere
The sun’s heat causes water to change from liquid to vapor
Condensation- when water vapor cools forming a liquid that can fall as precipitation
Transpiration- water evaporates from living things back into the atmosphere
Ex: evaporation from leaves, perspiration from humans
Ground Water- precipitation seeps into the ground where it is stored in underground caverns or in porous rock
Runoff- drainage of water from land after precipitation

5. The Water Cycle

6. The Carbon Cycle
The movement of carbon from the environment into living things and back again
Carbon is essential to all living things because it is part of our molecules.
Brainpop!

7. The Carbon Cycle
Photosynthesis- carbon moves from the environment into living things
Plants use carbon dioxide from the air to make sugar and animals get carbon from eating plants
Respiration- carbon moves from living things back to the environment when sugar molecules are broken down to release energy and carbon dioxide is given off when animals exhale
Decomposition- carbon moving from dead organisms back to the environment
Fungi and bacteria decompose dead organisms
Combustion- the process of burning fossil fuels releases carbon back into the atmosphere

8. The Carbon Cycle

9. The Nitrogen Cycle
The movement of nitrogen from the environment to living things and back again.
78% of our atmosphere is nitrogen gas
Nitrogen fixation- the process of bacteria in soil changing nitrogen gas into usable nitrogen for plants
Animals get nitrogen from eating plants
Video Clips on Nitrogen Cycle

10. Environment Chapter 2: Cycles in Nature
Section 2: Ecological Succession

11. Section 2: Ecological Succession
Succession: a gradual development of a community over time
Two types: Primary and Secondary
Primary Succession- development of a community where nothing has existed before
Ex: New island, where a glacier melted revealing new land
Pioneer species- fast-growing plants that help create soil and create many seeds

12. Primary Succession Steps 1. A retreating glacier exposes bare rock
2. Acids from lichens break down the rocks into small pieces to form soil
3. When the soil is deep enough, mosses grow and small insects begin to live in the community
4. Moss is replaced by ferns, then grasses and wildflowers, then shrubs and small trees
5. After hundreds or thousands of years, a forest develops
Video Clip about Primary Succession (4:24)

13. Secondary Succession
Secondary Succession- the redevelopment of a community after an ecological disturbance (ex: forest fire, abandoned farmland)
Steps
1. First year- weeds grow back (crabgrass)
2. Second year- weedy plants grow back (horseweed)
years- small pine trees grow back
years- a forest forms
5. After pine trees die, hardwood trees (oaks, maples) grow back
Video Clip on Secondary Succession (1:15)