Download Matter Cycles and Nutrient Recycling: Carbon and Nitrogen and more Schemes and Mind Maps Fossil Fuels in PDF only on Docsity!
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In order to continually use the same area of land foragriculture, some farmers apply fertilizers to improve the levelof nitrates in the soil. An alternative to this intensive use offertilizer is to plow the roots of the leguminous plants backinto the soil and leave the area unplanted for a season. Whywould a farmer use this alternative method and what would bethe benefit of turning over the soil and leaving the old plantroots?
Leguminous plants have a symbiotic relationship with N-fixing
bacteria held in nodules on their roots. They can capturenitrogen from the atmosphere and turn it into nitrates – a formplants can use. By plowing these roots into the soil, thenitrogen content in the soil would increase.^ Make a chart or graphic organizer of the three types ofmatter we have discussed here.
Where is each stored (sinks),
where does each enter the food web? How do consumers get thismatter? What happens to each type of matter once an organismdies?
1
Matter Cycles
How are nutrients recycled through ecosystems?
Why? We have learned the importance of recycling our trash. It allows us to usesomething again for another purpose and prevents the loss of naturalresources. But what happens to the waste in nature? Why aren’t we up toour necks in natural refuse? Why is there always a supply of water? Whyis there oxygen to breathe and carbon dioxide for photosynthesis? Thebiological molecules in nature are also recycled. This recycling processconverts
the
complex
organic
compounds
to
simple,
inorganic
compounds, which then can be returned to nature to be used again andagain.^ Activating Prior Knowledge
(In the space below, brainstorm everything you know—or think youknow—about matter cycles such as carbon, nitrogen and phosphorous).
cv Model 1 – The Carbon Cycle 2
(
Diagram adapted from U.S. DOE, Biological and Environmental Research Information System. -
http://earthobservatory.nasa.gov/Features/CarbonCycle/
May 6, 2012)
Model 1 shows the cycling of what type of matter? Carbon
Carbon is often in the form of carbon dioxide in certain stages ofthe matter cycle. What is the chemical formula for carbondioxide?
CO
2
Places where matter is stored are called
sinks
.Where is the
largest carbon sink?
In the deep ocean
(
Bacteria and fungi
)
Fossil fuels
(coal, oil, peat, gas)
Combustion of
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What happens when these organisms die?
Decomposers that eat them use up even more oxygen from the water
Why is there less oxygen when water plants die?
Plants make oxygen during photosynthesis
What can ultimately happen to a lake, river or marineenvironment if the algae blooms happen repeatedly?
The ecosysten collapses and most organisms including fish die
Why is it important to be careful about the detergents used inhomes?
Phosphorous in the detergent can make its way to water
where it will cause an algae bloom.
Plants and animals are part of all of the nutrient cycles throughthe foods they eat and what eats them (food chains and foodwebs). Name the three classes of organic compounds(containing carbon) we have talked about so far and explain howthe carbon cycle and nitrogen cycle contribute to the usablesupplies of these macromolecules.
Carbon in the atmosphere is incorporated into plants through
photosynthesis. Consumers then eat the plants and so on. Carbonis the main atom in carbohydrates, lipids and proteins.
Nitrogen is needed in proteins. Plants take it up from the soil due to
decomposition of organisms, lightning or legumes – all madepossible by bacteria. Consumers eat plants or other animals toget their nitrogen.
4
c.
Speculate: In what form is carbon returned to the atmosphere? Carbon dioxide or CO
2
d.
What would happen if decomposition did not occur? Dead organisms would pile up and no carbon would be availableto new organisms.
10.Not all dead organisms are acted on by decomposers. Instead of
being immediately recycled, the carbon from some organismsis kept in a type of long-term storage, or
carbon sink
. Using
Model 2, answer the questions below about this long-termstorage.
a.
What are the two biggest carbon sinks and howmany gigatons does each store?
Deep ocean (37,000 GT) and fossil fuels (10,000 GT) b.
What is the collective term for the carbon sinkmaterials in the earth?
Fossil fuels c.
How do humans use the materials in that part ofthe carbon sink?
Burn it to heat, run factories, make electricity… d.
What is the scientific name for the process listedin question 8
c
Combustion
List five examples of the process from 8.d in your everyday life.
Cars, heating, cooking, lights, electronics
How is the majority of electricity generated in the area where you live? Does the process involve the combustion of coal?Check with your teacher if you are not sure.
60% fossil fuels,
30% hydroelectric, 10% other mostly renewables.
Many of the carbon-based fuels are categorized as fossil fuelsbecause they formed from decayed organisms over millions of
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b.
Model 4 indicates the main source of phosphates come from whatgeologic feature?
Rocks
c.
How do plants get phosphorous?
They absorb phosphate in the soil
through their roots
d.
How do you think consumers get their phosphorous?
Through their food
e.
Phosphorous makes up the backbone of DNA, a major part of cellmembranes and lots of it is in ATP – the energy molecule cells use.Speculate, is there life without phosphorous?
No!
Read This!
Nitrogen
and
phosphorous
are in very low supply in marine and
freshwater ecosystems. These ecosystems have evolved around having alimited amount of these elements which limits producer growth. Too manyproducers cause problems.In addition to sources mentioned below, phosphorous is often found inhigh levels in laundry and dishwashing detergent. These household usesoften make their way to water. Recently, Washington State lowered theallowable amount of phosphorous in detergents to help our waterecosystems.
Model 3- The Phosphorus Cycle 8
Model 3 illustrates how nature recycles what type of matter?
Phosphorous
Phosphorus exists on earth in the form of phosphates (PO
4
).
a.
Unlike the other forms of matter cycling shown in Models 1-3, in whatpart of the environment is phosphorus
not
found?
The atmosphere (air)
5
years. List as many examples of fossil fuels as you can.
Coal, natural gas, oil and its products gas and diesel
W
hich process appears to mostly balance the process of
photosynthesis?
respiration
15.Does the ocean appear to mostly balance the uptake and release
of CO
2
Yes.
16.Which process appears mostly unbalanced?
Combustion due to human use of fossil fuels
How many gigatons of CO
2
enter the atmosphere due to human
activity?
9 GT per year
What processes are taking up some of the CO
2
human activity?
Photosynthesis (3 GT) and air sea exchange (2 GT)
Is it enough to balance human CO
2
output?
No.
Read This!
Carbon dioxide (CO
2
) is one of the
greenhouse gases
. These gases hold
heat energy in the atmosphere, which raises the overall temperature ofthe Earth. This helps maintain the Earth’s biosphere, but also has led toenvironmental concerns. The more CO
2
in the atmosphere, the higher
the Earth’s average temperature will be.
20.How much excess carbon dioxide enters the atmosphere per
year due to human activity?
4 GT
21.What are potential global effects of these changes in CO
2
levels?
Warming, sea level rise, mass extinction, crop failure,
extreme weather, drought, fires, desertification,disease
