Name:_______________________________ Date:_________________

Biogeochemical Study Guide

1. What drives the biogeochemical cycles?Gravity and Law of Thermodynamics

2. What draws nutrients back to the Earth?Gravity

3. In your own words, explain how the laws of thermodynamics relates to the cycling of nutrients throughout an ecosystem.Energy is neither created nor destroyed; energy is only transformed through solar energy being absorbed by plants where in it is converted to stored chemical energy and there is a loss energy through the release of heat. This occurs when energy is transferred between trophic levels as illustrated in a food web. When one animal feeds off another, there is a loss of heat (energy) in the process. Additional loss of energy occurs during respiration and movement. Hence, more and more energy is lost as one moves up through trophic levels

Hydrologic/water Cycle:Describe the processes in each of the following steps of the water cycle:

1. Transpiration-process by which moisture is carried through plants from roots where it changes to vapor and is released to the atmosphere

2. Evaporation- process of liquid to gas vapor by heat

3. Precipitation-any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation include drizzle, rain, sleet, snow, hail.

4. Condensation-process by which water vapor in the air is changed into liquid water

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Carbon Cycle:

1. Explain how deforestation can affect the carbon cycle.

Because plants are one of the main storage areas for carbon, deforestation reduces the number of trees, and therefore, more carbon (in the form of carbon dioxide) remains in the atmosphere and disrupts the normal carbon cycle. More carbon dioxide traps more of the heat from the sun in the atmosphere, increasing the greenhouse effect and leading to climate change.

2. What are some ways that deforestation could be reduced?Plant more trees, go paperless, less burning of wood and gases, recycling and using recycled products

3. How is carbon returned to the atmosphere?

Organisms return carbon dioxide to the atmosphere by respiration (Animals, plants, algae and microorganisms) Carbon dioxide is also released into the atmosphere when fossil fuels such as coal and oil, and wood, are burned.

4. How does carbon get into living organisms (animals & plants)Plants and certain algae, absorb carbon dioxide through tiny pores in their leaves. The plants

then "fix" or capture the carbon dioxide and are able to convert it into simple sugars like glucose through photosynthesis. Plants store and use this sugar to grow and to reproduce. Animals get the carbon by eating the plants or breathing it.

5. How does the burning of fossil fuels impact the carbon cycle?When humans burn fossil fuels, the stored carbon is released into the atmosphere as carbon dioxide. The carbon is then free to cycle through the Earth and can upset the natural balance of the carbon by contributing to global warming because they trap more of the Sun's energy in the Earth's atmosphere. This smoke is a greenhouse gas.

Nitrogen Cycle:1. Define nitrogen fixation?

a process whereby bacteria in the soil convert atmospheric nitrogen ( N2 gas) into a form that plants can use.

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2. What organism is the nitrogen cycle dependent upon?Nitrogen fixing bacteria

3. How does the use of nitrogen enriched fertilizers impact the nitrogen cycle? Helps crops grow where there may not be enough N in the soil

Phosphorus Cycle:1. In what way is phosphorous a key element to living things?

P provides nutrients for plants and animals; also forms a fundamental component of genes – the DNA and RNA structure that determines what we are; around 85 percent of the phosphorus in our bodies can be found in our teeth and bones.

2. What are the largest reservoirs (storage area) of phosphorous?Rocks, water, and soil

3. How do organisms obtain phosphorus?By eating the plants or drinking the water