Presentation is loading. Please wait.

Presentation is loading. Please wait.

Cycles in Nature Chapter 25, Section 2. Cycles of Matter The biosphere contains a fixed amount of water, carbon, nitrogen, oxygen, and other materials.

Similar presentations


Presentation on theme: "Cycles in Nature Chapter 25, Section 2. Cycles of Matter The biosphere contains a fixed amount of water, carbon, nitrogen, oxygen, and other materials."— Presentation transcript:

1 Cycles in Nature Chapter 25, Section 2

2 Cycles of Matter The biosphere contains a fixed amount of water, carbon, nitrogen, oxygen, and other materials required for life. The biosphere contains a fixed amount of water, carbon, nitrogen, oxygen, and other materials required for life. These materials are cycled through the biosphere and used by many different organisms. These materials are cycled through the biosphere and used by many different organisms.

3 Water Cycle A model that describes how water moves from the surface of the earth to the atmosphere and back to the surface again. A model that describes how water moves from the surface of the earth to the atmosphere and back to the surface again.

4 Water Cycle Processes that add water to the air: Processes that add water to the air: Evaporation Evaporation Occurs when liquid water turns into water vapor (gas). Occurs when liquid water turns into water vapor (gas). Transpiration Transpiration Occurs when plants release water into the air. Occurs when plants release water into the air. Respiration Respiration Releases water vapor to the air. Releases water vapor to the air. Animal Wastes Animal Wastes Returns water to the environment. Returns water to the environment.

5 Water Cycle Processes that subtract water from the air. Processes that subtract water from the air. Condensation Condensation Occurs when water vapor changes to a liquid. Occurs when water vapor changes to a liquid. Clouds Clouds When water vapor cools, it condenses on tiny particles of matter (like dust) in the air and forms tiny droplets. When water vapor cools, it condenses on tiny particles of matter (like dust) in the air and forms tiny droplets. Precipitation Precipitation Eventually the cloud droplets become so heavy that they fall to the earth as precipitation. Eventually the cloud droplets become so heavy that they fall to the earth as precipitation.

6 Water Cycle Affects on the cycle by humans: Affects on the cycle by humans: Water use by humans (households, factories, agriculture, etc) can reduce the amount of water that evaporates into the atmosphere and limits the amount of water available to plants and animals. Water use by humans (households, factories, agriculture, etc) can reduce the amount of water that evaporates into the atmosphere and limits the amount of water available to plants and animals.

7 Nitrogen Cycle Nitrogen Cycle Nitrogen Cycle A model that describes how nitrogen moves from the atmosphere to the soil to living organisms and back again. A model that describes how nitrogen moves from the atmosphere to the soil to living organisms and back again.

8 Nitrogen Cycle Importance of nitrogen Importance of nitrogen Needed to build proteins (building blocks of cells). Needed to build proteins (building blocks of cells). Essential part of DNA. Essential part of DNA.

9 Nitrogen Cycle Processes that remove nitrogen from the atmosphere: Processes that remove nitrogen from the atmosphere: Nitrogen fixation: Nitrogen fixation: Plants cannot use nitrogen directly from the air. So, bacteria in soil convert the nitrogen from the air into compounds that plants can use. Animals get the nitrogen they need by eating plants.

10 Nitrogen Cycle Processes that return nitrogen to the soil: Processes that return nitrogen to the soil: Animal wastes. Animal wastes. Dead and decaying organisms. Dead and decaying organisms.

11 Nitrogen Cycle Affects on the cycle by humans: Affects on the cycle by humans: Removing crops from the land removes any nitrogen that would be added to the soil through the decay of the plants. Removing crops from the land removes any nitrogen that would be added to the soil through the decay of the plants. Adding fertilizer, compost, or animal manure returns nitrogen to the soil. Adding fertilizer, compost, or animal manure returns nitrogen to the soil. Planting nitrogen-fixing crops (such as peas, clover, and beans) adds nitrogen to the soil. Planting nitrogen-fixing crops (such as peas, clover, and beans) adds nitrogen to the soil. Nitrogen-fixing crops have roots with nodules that contain nitrogen-fixing bacteria.

12 Carbon Cycle Carbon Cycle Carbon Cycle A model that describes how carbon moves from living to non-living things. A model that describes how carbon moves from living to non-living things.

13 Carbon Cycle Carbon Cycle Carbon Cycle Carbon is located in humus in the soil and as part of carbon dioxide in the atmosphere. Carbon is located in humus in the soil and as part of carbon dioxide in the atmosphere.

14 Carbon Cycle Processes that remove carbon from the atmosphere: Processes that remove carbon from the atmosphere: Photosynthesis Photosynthesis Uses carbon dioxide, water, and sunlight to produce sugars.

15 Carbon Cycle Processes that add carbon to the atmosphere: Processes that add carbon to the atmosphere: Respiration Respiration Uses oxygen and releases carbon dioxide.

16 Carbon Cycle Affects on the cycle by humans: Affects on the cycle by humans: Carbon dioxide is released into the air when humans burn fossil fuels (gas, coal, oil, etc), which are the remains of once-living organisms. Carbon dioxide is released into the air when humans burn fossil fuels (gas, coal, oil, etc), which are the remains of once-living organisms. Use of trees for fuel or for building reduces the number of plants that remove carbon dioxide from the air. Use of trees for fuel or for building reduces the number of plants that remove carbon dioxide from the air.


Download ppt "Cycles in Nature Chapter 25, Section 2. Cycles of Matter The biosphere contains a fixed amount of water, carbon, nitrogen, oxygen, and other materials."

Similar presentations


Ads by Google