1. Cycles in Nature
Spring 2017

2. Question
How does matter move among the living and nonliving parts of an ecosystem?
ANSWER
Matter is recycled within and between ecosystems through biogeochemical cycles.

3. Cycles in Nature Biogeochemical cycles-
Elements, compounds, and other forms of matter are passed from one organism to another.
Also passed from one part of the biosphere to another
They connect these aspects:
Biological
Geological
Chemical

4. The Water Cycle
Water is constantly moving between the atmosphere and Earth!

5. The Carbon Cycle Carbon plays many roles 4 main processes move carbon
Biological processes, such as photosynthesis, respiration and decomposition
Burial and decomposition of dead organisms and their conversion under pressure (fossil fuel)
Geochemical processes such as erosion and volcanic activity release CO₂
Mining, cutting and burning forests, burning fossil fuels

6. The Nitrogen Cycle The atmosphere is the main reservoir of nitrogen.
It also cycles through the soil and tissues of living organisms.

7. The Nitrogen Cycle Nitrogen fixation Denitrification
Bacteria that live in the soil and on the roots of certain plants
Convert nitrogen gas into ammonia, nitrates and nitrites
Primary producers make them into proteins and nucleic acids
Denitrification
Other soil bacteria obtain energy by converting nitrates into nitrogen gas
Gas is released back into the atmosphere

8. The Nitrogen Cycle Plants that add nitrogen
Peanuts
Peas
Legumes (beans, alfalfa)
Why do plants need nitrogen?
It’s a major component in chlorophyll
Roots perform more efficiently, drawing in more water
Yellow leaves? Not enough nitrogen
Too much nitrogen causes nitrogen toxicity.

9. The Phosphorous Cycle Phosphorous in the biosphere cycles among
The land
Ocean sediments
Living organisms

10. The Phosphorous Cycle Not abundant in the atmosphere
Mined, turned into fertilizer and applied to crops.
Taken up by primary producers, reused by consumers.
Released by excretion and decomposing matter.
Geological activity washes from rock into the ocean.

11. The Carbon and Nitrogen Cycles Amoeba Sisters
LwL0Myd7Dk1F0iQPGrjehze3eDpco1eVz&index=36
Video Review Handout
Worth 100 points
Due at the end of the video
This video plays through ONLY 1 time.