Biogeochemical Cycles A BIOGEOCHEMICAL CYCLE is a circuit, or pathway, by which an element or molecule moves through both biotic and abiotic components of an ecosystem. We will study the following biogeochemical cycles: Water Carbon Nitrogen Phosphorus

Water Cycle Water is the basic building block of ALL life on Earth. Water regulates the temperature of the planet and cycles essential nutrients through the biosphere and all living things. The flow of water through the biosphere is called the water cycle.

Water Cycle Important Vocabulary: Condensation Precipitation Evaporation Transpiration

Condensation The transformation of water vapor to liquid water droplets in the air, producing clouds and fog is known as condensation.

Precipitation Condensed water vapor that falls to the Earth's surface is precipitation. Most precipitation occurs as rain, but also includes snow, hail, and sleet.

Evaporation Evaporation is the process by which liquid water is heated by the sun and rises into the atmosphere as water vapor.

Transpiration Transpiration is the evaporation of water from the leaves of plants.

REMEMBER THIS!!! Water enters the atmosphere through evaporation and transpiration. Transpiration is the evaporation of water from plants. Water returns to the earth through precipitation.

Interesting Scientific Fact Changing the solid form of water (ice) to the liquid state of water requires heat. Changing water back into ice gives off heat. Knowing this, orange farmers in southern states spray their orange trees with water to prevent them from freezing during sudden cold snaps. The way it works is simple. As the water begins to freeze on the orange trees, it gives off heat which then prevents the fruit from freezing. The crop is saved.

Water Cycle Summary Now that you have learned about the water cycle, check out the: Water Cycle Animation

Questions??? Question 1: How does water return to the earth? Question 2: What is transpiration? Question 3: How does water enter the earth’s atmosphere?