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What are the essential questions to ask about ecosystems?
- 1. what limits the production in ecosystems? (nutrients, light, temp, etc)
- 2. How do nutrients move throught the ecosystem? (cycles- nitrogen, water, etc)
- 3. How does energy move through the ecosystem? (flows, exits in heat form)
What is an ecosystem? What do the organisms in an ecosystem do?
- All the organisms in a community plus abiotic factors
- the organisms in an ecosystem transform energy and process matter.
- self sustaining
- ---->autotrophs capture energy, energy is transfered by consumption, and nutrients cycle
As matter is cycled....
your going to lose a lot of energy in the form of heat
Matter nor energy can...
be created nor destroyed
Explain generalized nutrient cycling
there is an abiotic reservoir where the nutrients stay until the energy enters the food chain and is made available to a producer who captures it. Then consumers eat the producers and get the transferred energy. Decomposers eat dead things and connect all trophic levels and after decomposers the nutrients once again enter the abiotic reservoir
Explain the carbon cycle
Carbon also begins in an abiotic reservoir. It enters the atmosphere and enters the food chain by being used for photosynthesis. The plants that use it for photosynthesis then give off oxygen used by animals who then go through respiration and give off carbon dioxide. There is also carbon from combustion of fuels. These return the carbon to the abiotic reservoir. Some of this carbon goes back to the plants, some stays in the atmosphere, and some is used by deposition of dead material. It is then transferred to fossil fuels in the ground.
Explain the Nitrogen cycle.
It starts as N in the atmosphere. Then nitrogen fixing backteria on plant roots and in the soil convert it into different types of nitrogen such as ammonium for other plants to use. Once again, carnivores eat the plants obtaining nutrients. It is recycled by decomposing and nitrifying bacteria and returned to the abiotic reservoir by denitrifying bacteria
Why is nitrogen important?
- it is the element found in essential amino acids and protiens
- ---->adenine, guanine, cytocine, thymine
What can nitrogen fixing bacteria do?
convert nitrogen into a type usable by plants such as ammonium
Explain the phosphorus cycle.
Phosphorus starts in abiotic reservoir such as rocks, minerals and soil. It enters the food chain and erosion releases soluble phospate and plants uptake it. Deocomposing bacteria and fungi help to recycle it by consuming animal tissues and feces and the N2 returns to the abiotic reservoir by loss to ocean sediment
Explain the water cycle
Water is in the abiotic reservoir at the surface and atmosphere water. It enters the food chain by precipitation and root uptake by plants. It then goes through transpiration (the movement of water across the leaves of plants)and returns to the reservoir by evaporation into the air and runoff back to the surface of waterbodies
What are the 3 major things phospate is needed for?
- DNA backbone
- lipid phospates
What did Hubbard Brook do? What did he learn?
He deforested 38 acres and crated a v-notion. As it rained over a 50 or so year period they collected water. Over about 1 year the nitrogen started to increase bc trees werent maintaining the nitrogen levels anymore. There was also a loss in calcium. He learned that trees control nitrogen levels. Evenutally the water was not even drinkable anymore
What is utrification?
- dying of a place like a lake
- somewhere looses all life
What breaks the water cycle?
- ---->groundwater is not transpired, and precipiation is not created
What are the effects of deforestation?
- 40% increase in runoff
- ---->loss of water
- 60x loss in nitrogen into runoff
- 10x loss in calcium
What is the 2nd law of thermodynamics?
as energy degrades, entropy (chaos) increases
What are trophic levels?
- feeding relationships
- they start with energy from the sun then are captured by plants
Plants are what level.. of all food chains
food chains usually go up about
- only 4 or 5 levels
- ---->inefficiency of energy transfer
Explain the loss of energy between levels of the food chain... and cost of living
- 17% of energy used for growth
- 33% used for cellular respiration
- 50% is waste
- only the 17% moves onto the next level, cost of living way higher than whats passed on
How can humans get more energy?
go vegitarian, get 10% of first hand instead of 2nd hand energy