CYCLES IN NATURE -Energy in an ecosystem is replenished by the sun. -Matter in an ecosystem has to be recycled. -Atoms making up organisms today are the same as those present when life on Earth began.

Water Cycle

The Water Cycle ◦Precipitation ◦Evaporation ◦Condensation ◦Transpiration ◦Runoff ◦Groundwater

Liquid to vapor … ◦Evaporation: This is when the sun heats up water in rivers or lakes or the ocean and turns it into vapor or steam. ◦Transpiration: This is kind of like plant sweat. Transpiration is the process by which plants lose water out of their leaves. ◦Respiration: When animals breathe out they release CO2 and water vapor.

Water turning from vapor back to liquid … ◦Condensation: This is when the water vapor in the air gets cold and changes back into liquid, forming clouds. ◦Precipitation: Precipitation occurs when so much water has condensed that the air cannot hold it anymore. The clouds get heavy and water falls back to the earth in the form of rain, hail, sleet or snow.

Collection of water on the ground … ◦Infiltration: when water soaks into the soil. Once in the ground the water can be evaporated, absorbed by plants or continue down to the water table (kind of like an underground river). ◦Run off: water that doesn’t get absorbed into the soil, or did not evaporate, and therefore made its way from the ground surface into places that water collect. Runoff causes erosion, and also carry chemicals and substances on the ground surface along to the rivers where the water ends up. It can cause water pollution too. ◦Only about 35% of precipitation ends up in the sea or ocean. The other 65% is absorbed into the soil. Some of it too is evaporated.

Water Cycle

Carbon Cycle

Respiration (yellow lines): A byproduct of cell respiration. You breath out carbon dioxide every time you exhale. Plants also release carbon dioxide Combustion (red line): This is when organic materials are burned. It can happen naturally in forest fires but the vast majority of it is due to humans burning fossil fuels in our factories and cars.

Photosynthesis (Blue line): This is when producers (like plants) take in carbon dioxide to make sugar (carbohydrates). Carbon dioxide is absorbed by producers (also known as autotrophs - these are organisms that make their own food e.g. plants)

Herbivores and omnivores eat the plants and take in the carbon that the plants used to make sugar. Most of the carbon is then exhaled (as mentioned in step 1) but some of it is also released as solid waste and the rest is released when the animal (or plant) dies.

The dead organisms (dead animals and plants) are decomposed or turned into fossil fuels. Decomposed: Dead organisms are broken down by decomposers (fungi and bacteria). The carbon that was in their bodies is then returned to the atmosphere as carbon dioxide. Creation of Fossil Fuels: In some circumstances the process of decomposition is prevented. The remains of the plants and animals may then be compressed and heated transforming it into fossil fuels (oil, coal, or natural gas) that can be used in the future for combustion.

The Carbon Cycle Atmosphere Photosynthesis Respiration Wastes Soil Fuel Pollution

Nitrogen cycle

The Nitrogen Cycle  Amino acids and proteins  Atmosphere  Lightning  Bacteria  Waste  Runoff

Nitrogen Fixing Nodules -The bacteria converts the nitrogen that can’t be used by the plants into a useable form. What kind of symbiotic relationship would this be?

Nitrogen cycle