1. Review- By what two processes is water cycled from land to the atmosphere Sequence- Describe one way in which water from Lake Superior may make one complete cycle through the atmosphere and make it back to Lake Superior 2. Review- Why do living organisms need nutrients Predict- Based on your knowledge of the carbon cycle, what do you think might happen if humans were to continue to clear and burn vast areas of forests for building 3. Explanation- Describe how oxygen moves through the biosphere as part of the carbon cycle. Include a description of the various forms that oxygen takes.

Ch 3 The Biosphere 3.4 Cycles if Matter

Biogeochemical Cycles Elements pass from one organism to another and among parts of the biosphere through closed loops Powered by the flow of energy.

Biogeochemical Cycles Involve biological processes, geological processes, and chemical processes Matter moves through these cycles, it is never created or destroyed.

Biogeochemical Cycles Biological Processes All activities performed by living organisms Eating, breathing, “burning” food, and eliminating waste products.

Biogeochemical Cycles Geological Processes Include volcanic eruptions, the formation and breakdown of rock, and major movements of matter within and below the surface of the earth.

Biogeochemical Cycles Chemical and Physical Processes Include the formation of clouds and precipitation, the flow of running water, and the action of lightning.

Biogeochemical Cycles Human Activity Include the mining and burning of fossil fuels, the clearing of land for building and farming, the burning of forests, and the manufacture and use of fertilizers.

The Water Cycle Enters atmosphere due to evaporation or transpiration in plants In atmosphere, water vapor condenses to form clouds and if they become large enough will fall as precipitation.

The Water Cycle Precipitation can become ground water if it absorbed into the soil or flow along the surface until it enters a stream or lake Ground water can enter plant’s roots, flow into streams or lakes, or can become an underground reservoir.

Nutrient Cycles Carbon Nitrogen Phosphorous.

Carbon Cycle Plants take in CO2 during photosynthesis and use the carbon to build carbohydrates Carbohydrates then pass through food webs to consumers.

Carbon Cycle Organisms release carbon in the form of carbon dioxide gas by respiration When organisms die, decomposers break down the bodies, releasing carbon to the environment.

Carbon Cycle Geologic forces can turn accumulated carbon into carbon-containing rocks or fossil fuels CO2 is released into the atmosphere by volcanic activity or by human activities.

The Nitrogen Cycle Need nitrogen to make amino acids (proteins) and nucleic acids (DNA & RNA) Nitrogen gas (N2) makes up 78 percent of Earth’s atmosphere.

The Nitrogen Cycle Ammonia (NH3), nitrate ions (NO3), and nitrite ions (NO2) are found in soil, in the wastes produced by many organisms, and in dead and decaying organic matter.

Nitrogen Cycle Dissolved nitrogen exists in several forms in the ocean and other large water bodies.

Nitrogen Cycle Nitrogen Fixation Bacteria convert nitrogen gas into ammonia.

Nitrogen Cycle Other bacteria convert ammonia into nitrates and nitrites that producers can use Consumers eat the producers and reuse nitrogen to make what they need Decomposers release nitrogen from waste and dead organisms as ammonia, nitrates, and nitrites.

Nitrogen Cycle Denitrification Bacteria obtain energy by converting nitrates into nitrogen gas, which is released into the atmosphere.

Nitrogen Cycle Nitrogen Fixation Nitrogen gas is converted to usable forms by lightning.

Nitrogen Cycle Humans make and use fertilizers Excess fertilizer is often carried into surface water or groundwater.

The Phosphorus Cycle Used in DNA & RNA and other molecules Very important but not abundant Land- Inorganic phosphate as rocks and soil minerals Ocean- Dissolved phosphate and sediments.

The Phosphorus Cycle Rocks and sediments wear down, phosphate is released May stay on land and cycle between organisms and soil.

The Phosphorus Cycle Plants bind phosphate into organic compounds from soil and water Organic phosphate moves through the food web, from producers to consumers.

The Phosphorus Cycle Phosphate my dissolve in water and flow through rivers to oceans and be incorporated into marine organisms.

Limiting Nutrient Primary Productivity Nutrient whose supply limits productivity Primary Productivity Rate at which primary producers create organic material.

Nutrient Limitation in Soil Fertilizers contain large amounts of nitrogen, phosphorus, and potassium Plants acquire carbon dioxide from the atmosphere Micronutrients such as calcium, magnesium, sulfur, iron, and manganese are necessary in relatively small amounts.

Nutrient Limitation in Water Saltwater Nitrogen is often the limiting nutrient Freshwater Phosphorus is typically the limiting nutrient.

Nutrient Limitation in Water Aquatic ecosystem can receive a large input of a limiting nutrient Runoff from heavily fertilized fields.

Nutrient Limitation in Water Can result in “Algae blooms” May not be enough consumers May disrupt the ecosystem.