Ecosystem Recycling. The Carbon Cycle. Biogeochemical Cycles: Carbon Cycle 11/27/2016

Transcription

1 Ecosystem Recycling Biogeochemical Cycles: Oxygen Carbon Sulfur Nitrogen Phosphorous Calcium While energy flows through an ecosystem, water and minerals are recycled. Water, carbon, oxygen, and nitrogen travels through a biogeochemical cycle, moving from the abiotic parts of an ecosystem into the biotic parts, and back again. Water Carbon Oxygen Nitrogen Temperate rainforests store vast amounts of carbon, both above and below ground. All living things are made up of organic molecules that contain carbon. Just like water, the amount of carbon on Earth has not changed since the formation of Earth, it has just been recycled. 1

2 Plants remove carbon dioxide from the atmosphere, during photosynthesis, and convert it into simple carbohydrates. Consumers break down carbohydrates during cellular respiration and release carbon dioxide back into the atmosphere. Carbon Sinks: 1. Marine viruses and phytoplankton 2. Forests 3. Coral reefs During decomposition of organic wastes, carbon dioxide is also released into the atmosphere. Organic wastes that are not decomposed are buried and converted into fossil fuels. The burning of fossils fuels for mechanical use, during combustion, also releases carbon dioxide into the atmosphere. 2

3 vrs Carbon stink Brazil s rainforests re-cycle carbon faster than any other ecosystem. Carbon sink Today, the earth s atmosphere is accumulating CO 2 faster that it can be sequestered. The earth s core temperature is rising Oxygen Cycle Brazil s forests produce 40% of the earth s atmospheric oxygen 21% of our Atmosphere consists of oxygen gas. Most life forms depend upon oxygen during cellular respiration to help release the energy found in their foods. 3

4 During the day, plants release oxygen into the atmosphere, during photosynthesis. At night, plants take in oxygen from the atmosphere and use it for cellular respiration. During both day and night, animals and fungi take oxygen from atmosphere and use it for cellular respiration. The same processes happen underwater as well. Aquatic plants and phytoplankton release dissolved oxygen into the water during photosynthesis. Animals remove the dissolved oxygen from the water during cellular respiration. Nitrogen is an essential element for all life and used to form proteins and nucleic acids. Like water and carbon, nitrogen is also recycled through ecosystems. 4

5 Nitrogen makes up 78% of the atmosphere. However, it exists as nitrogen gas, N2, and is held together by a triple covalent bond that most organisms cannot break. The only organisms that can break the covalent bonds in atmospheric nitrogen are symbiotic bacteria that live on the roots of legume plants (beans and peanuts). Nitrogen Fixing bacteria, on roots of legumes, fix nitrogen gas into ammonia, nitrate, and nitrite during nitrogen fixation. Plants then take up the nitrogen products and use it to form proteins and nucleic acids. Animals obtain nitrogen by eating plants or other animals that ate plants. Excess nitrogen is released in urine or feces. Anaerobic bacteria break down the nitrogen products in plant and animal wastes into nitrogen gas that is released into the atmosphere during denitrification. 5

6 George Washington Carver The End George Washington Carver was a botanist and teacher that prompted farmers to plant more legumes, especially peanuts, to enrich soils that had become nutrient poor after being used to grow cotton over and over again. (He also invented Peanut Butter) 6