Science AHSGE 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– 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