Chapter 18 Section 4Ecosystem Recycling

Interview… Interview 2 of your peers using the following

question:

How could the local drinking water become polluted or contaminated?

Human or Animal wastePesticidesToxic run-off from manufacturing

plants

The Water Cycle Where can water be found? Lakes, rivers, streams, oceans, vapor, in

the ground.

When you open a new bottle of water do you think it is brand new water?

The movement of water between these reservoirs is known as the water cycle.

The Water Cycle Made up of 3 Processes…

1. Evaporation- adds water as vapor to the atmosphere How does this happen?

The Water Cycle 2. Transpiration- the process when water

evaporates from the leaves of plants in terrestrial ecosystems.

The Water Cycle 3. Precipitation- the process by which

water leaves the atmosphere and abiotic factors play a role.

Time for Questions… What is the main power source behind

the water cycle?

What does the water cycle have to do with the weather?

Carbon Cycle Photosynthesis- plants and other

autotrophs use carbon dioxide, solar energy, and water to make carbohydrates.

Carbon Cycle Cellular Respiration- processes that

takes place in the cells and tissues during which energy is released and carbon dioxide is produced.

Organisms use the oxygen released to help breakdown carbohydrates.

Carbon Cycle Decomposition- decomposers release

carbon dioxide back into the atmosphere when they break down organic material.

Questions Time… How might the removal of vegetation

affect oxygen levels in the atmosphere?

Nitrogen Cycle The way nitrogen flows through the ecosystem. Where can nitrogen be found? Nitrogen Gas- 78% of the atmosphere Plants can only use nitrogen in the form of nitrate. Nitrogen Fixation- process of converting nitrogen

gas into nitrate. Nitrogen Fixing Bacteria- convert nitrogen gas into

usable form. Live in the soil Inside swellings on the roots of plants: beans, peas Plant provide Carbohydrates and the bacteria

provide the usable nitrogen. Example: Farmers plant legumes

Nitrogen Cycle Decomposers- break down dead plants

and animals that contain nitrogen. Dung and Urine also contain nitrogen

that are decomposed, releasing Carbon Dioxide back into the atmosphere.

Time for Questions… Identify the role of bacteria in the

Nitrogen Cycle and tell their role.

What are the mutual benefits in the association between nitrogen-fixing bacteria and the plants they inhabit.

Water Trivia Game Only 3% of Earth’s water is fresh water. 97% of the water on Earth is salt

water. The water found at the Earth’s surface in lakes, rivers, streams, ponds, and

swamps makes up only 0.3% of the world’s fresh water. 68.7% of the fresh water on Earth is trapped in glaciers. 30% of fresh water is in the ground. More than 25% of bottled water comes from a municipal water supply, the

same place that tap water comes from. A ten meter rise in sea levels due to melting glaciers would flood 25% of the

population of the United States. There is more fresh water in the atmosphere than in all of the rivers on the

planet combined. If all of the water vapor in the Earth’s atmosphere fell at once, distributed

evenly, it would only cover the earth with about an inch of water. Approximately 400 billion gallons of water are used in the United States per

day. It takes six and a half years for the average American residence to use the

amount of water required to fill an Olympic-sized swimming pool (660,000 gallons).

American residents use about 100 gallons of water per day. Americans use more water each day by flushing the toilet than they do by

showering or any other activity.[ii]