1. Cycling of Materials in Ecosystems
Cycles within an Ecosystem
Water Cycle
Carbon Cycle
Phosphorous and Nitrogen Cycle

2. Cycles within Ecosystems
Almost everything within an ecosystem is recycled.
Water, carbon, nitrogen & phosphorus pass from the nonliving environment to living organisms & then back to the environment.

3. Water Cycle
Water is the most important, non-living component of the ecosystem.
Nonliving cycle: involves condensation, precipitation, & evaporation.
Living cycle: involves plants in a process called transpiration.

4. Water Cycle Nonliving portion: Living portion:
Water vapor, as it cools, condenses in the form of clouds and falls to the Earth’s surface as precipitation (as rain, snow, etc)
Then water evaporates (turning from a liquid to a gas) and re-enters the atmosphere
Living portion:
Water is absorbed by roots of plants
After passing through the plant, the water evaporates from the leaves in a process called transpiration

6. Carbon Cycle
Carbon dioxide in the air (or dissolved water) is used by photosynthesizing plants, algae and bacteria as raw material to build organic molecules.
What does that mean? Autotrophs take in carbon dioxide to help make food in order to grow and survive
Involves:
Respiration (breathing where CO2 is a by product)
Combustion (burning)
Erosion (limestone)

8. Phosphorous and Nitrogen Cycle
You need phosphorous and nitrogen to build proteins and nucleic acids (part of DNA)
Since more organisms are unable to use nitrogen gas (N2), nitrogen fixing bacteria bind nitrogen with hydrogen to form ammonia (NH3)
What does that mean? We need nitrogen, but we can’t use pure nitrogen gas (N2) so certain bacteria convert N2 into a usable forms (ammonia)

9. Phosphorous and Nitrogen Cycle
Stages:
Assimilation (absorption of nitrogen gas,N2, by plants)
Ammonification (production of ammonia, NH3, by bacteria during organism decay)
Nitrification (production of nitrate from ammonia)
Denitrification (conversion of nitrate to N2)