I. Recycling in the Biosphere * Biogeochemical cycles- a process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another.

Classification of Biogeochemical processes a. Biological- activities performed by organisms including: eating , breathing, burning food, waste elimination b. Geological- activities performed by the earth: volcanic eruptions, rock formation and degradation c. Chemical/Physical- formation of clouds and rain, flow of running water and the action of lightning

Biogeochemical processes (cont.) d. Human Activity- mining, farming, fertilizer use, and burning of fossil fuels affects the cycles of matter.

Cycles Transforming energy into usable forms Biogeochemical cycle- exchange of matter through the biosphere. *Matter cannot be created or destroyed!!!* Cycling of nutrients in the biosphere involves: Matter in living organisms Physical processes found in the environment Transforming energy into usable forms

Water Cycle Water is constantly evaporating into atmosphere (water vapor) Vapor rises, cools, forms clouds (condensation): 90% of water vapor evaporates from ocean, 10% from surface of plants (transpiration). Water falls from clouds in form of precipitation

Water cycle -water is constantly evaporating into atmosphere (water vapor) -vapor rises, cools, forms clouds -water falls from clouds in form of precipitation -90% of water vapor evaporates from ocean, 10% from surface of plants (transpiration).

https://www.youtube.com/watch?v=2D7hZpIYlCA

Nitrogen Cycle *Nitrogen enters the food web when plants absorb nitrogen compounds from soil* Consumers get nitrogen by eating plants or animals that contain nitrogen. 8

Atmospheric nitrogen (N2) Nitrates (NO3) Nitrogen – needed to make proteins Conversion of nitrogen into a form that is useable by plants is called nitrogen fixation. -animals and plants cannot use nitrogen directly from the atmosphere -nitrogen gas captured by bacteria, convert into usable form THE GOAL! Atmospheric nitrogen (N2) Nitrates (NO3) 9

Nitrogen Cycle (cont.) Nitrogen is returned to the soil in several ways: 1. Animals urinate 2. Organisms die (decomposers!) 3. Lightning Organisms convert ammonia into usable nitrogen compounds. (Nitrification) Fixed nitrogen converted back to gas and reenters atmosphere (Denitrification) In the soil

https://www.youtube.com/watch?v=leHy-Y_8nRs

The Carbon Cycle Carbon Contained within… Major part of organic molecules Carbohydrates, proteins, fats, and nucleic acids. Contained within… animal skeletons rocks the atmosphere (CO2) dissolved in oceans fossil fuels (coal, natural gas, oil)

Carbon Cycle http://blogs. dickinson

Human Impact Fossil fuels release carbon stores very slowly Burning anything releases more carbon into atmosphere — especially fossil fuels Increased carbon dioxide in atmosphere increases global warming Fewer plants mean less CO2 removed from atmosphere

https://www.youtube.com/watch?v=2D7hZpIYlCA

Phosphorous Cycle Phosphorous essential to organisms as it is part of molecules such as DNA and RNA. Remains mostly on land and in the ocean as inorganic phosphate- usually in rocks or soils. Rocks and sediments release phosphate as they wear down

* Plants bind phosphate into organic compounds when they absorb it from the soil or water. * Organic phosphates make their way through the food web to the rest of the ecosystem

Phosphorus Cycle

https://www.youtube.com/watch?v=leHy-Y_8nRs

IV. Nutrient Limitation Primary productivity is the rate at which primary producers (plants) create organic material. If one essential nutrient in an ecosystem runs short, then primary productivity will be limited

A. Nutrient limitation in soils * In farming, growth of crop plants is limited by a lack of one or more nutrients in the soil, which is why fertilizers are used * Fertilizers usually contain: nitrogen, phosphorous, and potassium

* Micronutrients are nutrients that are needed in smaller amounts: calcium, magnesium, sulfur, iron, and manganese Soybean plant showing manganese deficiency Iron deficiency in leaves of melon plant

All nutrient cycles work together like interlocking gears * All nutrient cycles work together like interlocking gears. If one gear slows down (one nutrient runs short), the whole system slows down or even stops.

B. Nutrient limitation in aquatic ecosystems * The open oceans are relatively nutrient poor when compared to many land areas * In saltwater environments, nitrogen is typically the limiting nutrient * In freshwater environments, phosphorous is typically the limiting nutrient

* Heavy rains can bring fertilizer runoff from agricultural fields into aquatic environments and causes dramatic effects such as, algal blooms.