2.2 Nutrient Cycles in Ecosystems Name: Date: (Reference: BC Science 10 pp. 68 to 91) Block: NUTRIENT CYCLING IN THE BIOSPHERE nutrients: ____________________________________________ __________________________________________ stores:______________________________________________ __________________________________________ aka _______________ Nutrients are accumulated for short or long periods of time in _________________________________, _____________, and _________________________. Biotic processes, such as _____________________ and abiotic processes, such as __________________________ can cause nutrients to flow in and out of stores. nutrient cycles: _______________________________________ __________________________________________ aka _______________________________ Nutrient cycles are nearly in ________________________; the amount of nutrients flowing ________ the stores are nearly the same as the amounts flowing _________ of the stores. Page 1
Nutrients are accumulated for short or long periods of time in _________________________________, _____________, and _________________________.
Biotic processes, such as _____________________ and abiotic processes, such as __________________________ can cause nutrients to flow in and out of stores.
Nutrient cycles are nearly in ________________________; the amount of nutrients flowing ________ the stores are nearly the same as the amounts flowing _________ of the stores.
Metric measurement units used in the diagrams of nutrient cycles: gigatonne: ________________________________________ megatonne: _______________________________________
Human activities, such as _______________________, ________________________, ______________________________, ___________________, _______________________, and _____________________________________ can
affect a nutrient cycle by increasing the amounts of nutrients in the cycle ______________ than natural biotic and abiotic processes can move them back to the _________________.
What does the term biogeochemical cycles mean?________________________________________________________________________________________________________________________________________________________________________
THE CARBON, NITROGEN, AND PHOSPHORUS CYCLES
Five chemical elements (aka chemical nutrients) that limit the amount and
types of life in ecosystems are:1. _________________________2. _________________________3. _________________________4. _________________________5. _________________________
Which of the five chemical elements are cycled between living organisms and the atmosphere?________________________________________________________________________________________________________________How does phosphorus enter the environment?________________________________________________________Health of the ecosystem depends on a ______________________ of these five nutrients.
THE CARBON CYCLE
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Every living thing contains ______________. Only _________% of the Earth’s crust is carbon.How carbon is stored
Short term: ___________________________________________ ____________________________________________ ____________________________________________ ____________________________________________ ____________________________________________
Long term: ___________________________________________ ____________________________________________ ____________________________________________ ____________________________________________
Refer to THE CARBON CYCLE on p. 8 of your Data Booklet to answer the following.
1. The greatest carbon stores on earth: ______________________________________________________
2. The store that contains the least amount of carbon: ______________________________________________________
3. The greatest carbon exchange (in gigatonnes) and what is responsible : ______________________________________________________
4. The smallest carbon exchange (in gigatonnes) and what is responsible : ______________________________________________________
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5. What process only releases carbon into the cycle? ______________________________________________________
How carbon is cycled through the ecosystemA variety of natural processes move carbon through ecosystems. These include _______________________, _____________________, _________________________, __________________________, and events such as ___________________________ and large scale ______________________________.
Photosynthesis Is an important process in cycling _________________ and
___________________ through ecosystems. A chemical reaction that converts _________________________ into
___________________________. Carbon in the form of ___________________________ in the
atmosphere enters through the leaves of plants and reacts with _______________ in the presence of _____________________ to produce energy-rich ________________ (carbohydrates) and ________________.
o occurs in the _______________________ of plant cells.
The balanced chemical equation for photosynthesis is:
Also occurs in some micro-organisms, such as ____________________. Makes usable energy for _____________________. By eating plants, ___________________ obtain energy and take
_______________ into their cells.
Cellular Respiration the process in which both _________________ and ________________
release ____________________________ back into the atmosphere ________________________ and ________________ are converted into
___________________________ and __________________.Page 4
occurs in the _______________________ of all living cells.
The balanced chemical reaction for cellular respiration is:
DecompositionThe importance of decomposition in the carbon cycle: ________________________________________________________________________________________________________________________________________________________________________
Other ways carbon is cycled through ecosystems The following also play an important part in the carbon cycle, by
releasing CO2 into the atmosphere: the oceans:______________________________________
Land clearing/logging:____________________________________________________________________________________________________________________________________________________________________________________________________________
THE NITROGEN CYCLE
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Nitrogen is an important component of _______ and ____________. DNA is the abbreviation for _________________________ _____. Proteins are essential for ___________ _____________________ within
the __________. In animals, this includes _______________
__________________. In plants, _____________.
How nitrogen is stored The largest store of nitrogen: ___________________________, as
____________________________. Other major stores: ________________,
___________________________________________________. Smaller stores (on land): ________________________, _________,
__________________.
How nitrogen is cycled through ecosystems ______% of the Earth’s atmosphere is nitrogen gas. Most organisms cannot use it in this form, so much of the
nitrogen cycle involves ______ processes to make nitrogen available to plants, and then in turn to animals.
How nitrogen is removed from ecosystems Excess nitrogen dissolves in ___________, enters the
_______________________, and washes into _________and ____________.
The nitrogen compounds eventually become trapped in ____________________________________, and will not be released again until the rock is ________________________.
HUMAN ACTIVITIES AND THE NITROGEN CYCLE Due to human activities, the amount of nitrogen in the
ecosystem has __________________ in the last 50 years.1. _______________________________________ and
_________________________________ releases nitrogen oxide (NO) and nitrogen dioxide (NO2).
Burning also releases nitrogen compounds that increase _____ ______________________ in the form of nitric acid (HNO3).
2. ________________________ often use large amounts of nitrogen-containing ______________________.
Excess nitrogen is washed away, or leached, into the waterways.
This promotes huge growth in aquatic algae = eutrophication: _______________________________________________________________________________________________________________________________
Refer to THE NITROGEN CYCLE on p. 11 of your Data Booklet.
1. What two processes take nitrogen from the atmosphere and where do they occur? ____________________________________________________________________________________________________________
2. Locate the two stages of nitrification. Name organism(s) and ions involved in the process.____________________________________________________________________________________________________________
3. What is involved in uptake? List the ion(s) involved. ____________________________________________________________________________________________________________
4. Locate denitrification on the data table. Name organism(s) and ions involved in the process.____________________________________________________________________________________________________________
5. Locate and name another natural process that adds nitrogen to the cycle. ______________________________________________________
6. Locate and name two human activities that add nitrogen to the cycle. ____________________________________________________________________________________________________________
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THE PHOSPHORUS CYCLEPhosphorus is essential for _______________________ in plants and animals
Phosphorus is a part of the molecule that carries _________ in living cells.
______: adensosine triphosphate
In plants, phosphorus is important for _______________________, _________________________, and ______________________.
In animals, phosphorus and calcium are important for __________ ______________________.
How phosphorus is stored Phosphorus is not stored in the ________________________.
it is trapped in _______________________ (PO43–, HPO42–, H2PO4–) found in __________ (Earth’s Crust) and __________________________ in the ocean.
Refer to THE PHOSPHORUS CYCLE on p. 9 of your Data Booklet.
1. List the five phosphorus sinks, in order, from largest to smallest? __________________________________________________________________________________________________________________________________________________________________
How phosphorus is cycled through ecosystems Weathering: _______________________________________
__________________________________________• Two types of weathering:1. chemical weathering: ____________________________
After weathering, phosphates are absorbed by _____________, which are then eaten by ________________, and _______________________ return them to the soil.
Weathering doesn’t occur until there is geological uplift. Geological uplift: __________________________
Refer to THE PHOSPHORUS CYCLE on p. 9 of your Data Booklet.
1. List the eight processes, in order, from largest to smallest involved in the flow of phosphorus in the phosphorus cycle? __________________________________________________________________________________________________________________________________________________________________
HUMAN ACTIVITIES AND THE PHOSPHORUS CYCLEHuman activities can either add excess phosphorus to the ecosystem or reduce the phosphorus supplies in the ecosystem.
Add excess phosphorus: Mined for commercial fertilizers and
detergents
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Extra phosphorus and potassium is added to the ecosystem ______________ than it can be put back into natural stores.
Can lead to __________________________ Reduce phosphorus supplies:
Slash-and-burn practices Releases phosphate from __________ in the
form of _______. Phosphates accumulate in the soil and is
leached from the ash into the water ways, where is settles and becomes ____________________ to organisms.
HOW CHANGES IN NUTRIENT CYCLES AFFECT BIODIVERSITY
Any significant changes to any of these nutrients (____, _____, ____, _____, and _____) can greatly impact the health and biodiversity in an ecosystem
1. Carbon: contributing to _______________________ _______________ carbon in the atmosphere, slight
temperature changes and changes in water level can all affect ecosystem biodiversity
If one part of the ecosystem is affected/removed, it affects the rest of the food chain/food web.
2. Nitrogen: can seriously affect __________ biodiversity
Some plants better adapted to ______________ nitrogen levels than others and therefore out complete the less tolerant species.
3. Phosphorus: can affect _______ _________ _________________ phosphorus have reduced
algae production in some lakes, which is an important food source for _________________.
**Complete CC p. 91 # 1-7, 9- 11, 17, 18, 19Page 12
