Standard II-1, part 3- Biogeochemical Processes Science AHSGE Standard II-1, part 3- Biogeochemical Processes

Nutrients Nutrient- Substance necessary for life Must obtain from the environment to sustain life and carry out life processes Examples: Oxygen, water, carbon, nitrogen and phorphorous Obtained in the form of elements and compounds from air, water, food, or soil Biogeochemical Cycle- Involves living organisms (bio), geological processes (geo) and chemical processes (chemical)

Water Cycle Hydrology- Study of water and the cycling of it through the environment Sources: River, ocean, ponds/lakes, streams, aquifers, ice caps, or glaciers Two types: Salt (ocean), fresh water (ponds, lakes, rivers, streams), brackish water (swamps, anywhere rivers empty into ocean)

Water Cycle Two ways to get liquid from vapor: precipitation (snow, rain, sleet, hail), condensation (gas to a liquid) Two ways to get water vapor from liquid: evaporation (liquid to a gas) and transpiration (loss of water from a plant through the stomata) Runoff- Surface water continually moves until it reaches a water source Infiltration- Water soaking into the ground Water table- Point of saturation under the ground

Carbon and Oxygen Cycles All living things composed of molecules containing carbon Organic- Any substance containing carbon and oxygen Carbon and oxygen are recycled quickly through living things Autotrophs/producers- photosynthesis Consumers/decomposers/heterotrophs- cellular (aerobic) respiration

Carbon and Oxygen Cycles Carbon enters into cycle long term when buried underground and converted to peat, coal, oil, or natural gas deposits (millions of years) Released back to the atmosphere as CO2 when fossil fuels are burned Carbon and oxygen can enter a long-term cycle in the form of calcium carbonate (chalk) or limestone Remain trapped in deposits until erosion occurs

Carbon and Oxygen Cycles

Nitrogen Cycle Element needed to produce proteins Plants and animals can not use directly from atmosphere Nitrogen Fixation Nitrogen gas is captured by bacteria in air, soil, water and on the roots of some plants (legumes) Converted into a useful form for plants Nitrate- Inorganic nitrogen compound converted from ammonia Energy from lightning bolts can also convert

Nitrogen Cycle Plants absorb nitrates from soil and convert to proteins Consumers get nitrogen from eating plants or other animals Fixed nitrogen is in limited supply, so this element is a factor that limits the growth of producers

Nitrogen Cycle Nitrogen returns to soil: Animal urination Decomposers break down dead organisms into the nitrogen compound ammonia Organisms in the soil convert ammonia into nitrogen compounds to be used by plants Denitrification- Soil bacteria convert fixed nitrogen compounds back into nitrogen gas, which returns to the atmosphere

Phosphorus Cycle Essential for growth and development of organisms Found in various compounds of cells Large amounts concentrated in bones and teeth Phosphorus, in the form of phosphates, are present in small amounts in soil and water Often a factor that limits the growth of producers

Phosphorus Cycle Short-term cycle Long-term cycle Cycled from soil to producers and then to consumers Organisms die returning phosphorus to soil to be used again Long-term cycle Weathering or erosion of rocks containing phosphorus slowly add to the cycle

Phosphorus Cycle