2.2 - Nutrient Cycles. Carbon Cycle

Transcription

1 2.2 - Nutrient Cycles Carbon Cycle

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3 Nutrients What are nutrients? Chemicals (C,O, N, P, H...) needed for life There is a constant amount of these nutrients on Earth and they are stored in different places. Nutrient stores on Earth include...

4 Oceans

5 Land

6 Atmosphere

7 Marine Sediments/ Sedimentary Rock How do sediments form? Little pieces of Earth are broken down and worn away by water. These little bits are washed downstream and settle in the bottom of rivers, lakes & oceans. Layer after layer of eroded earth is deposited, pressing down on each other. Over time, the bottom layers turn into ROCK! The same thing happens in the ocean as plants and animals, shells decompose and sink to the ocean floor!

8 Nutrient/ Mineral Rich Rocks Chert formed from microscopic skeletons on the deep sea floor Iron ore..laid down in the days when Earth s air had no O 2 Coal remains of ancient plants

9 Nutrient cycles are the flow of nutrients in and out of these stores. Human activity has shifted the natural balance

10 The 5 Essential Elements for Life

11 Pg A

12 Carbon stores are also known as carbon sinks.

13 CARBON STORES (SINKS) Short-term carbon stores include: Animals & plants (on land and in oceans) Decaying organic matter In the atmosphere as CO 2 CO 2 (dissolved) in the top layer of ocean

14 CARBON STORES (SINKS) Long-term carbon stores (ocean) Sinks to the floor and remains for ~500 yrs (eventually used by bacteria and released again)

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16 CARBON STORES (SINKS) Long-term carbon stores (land) Coal, Oil, Natural Gas Deposits (Fossil Fuels) These are found deep underground. They are formed from dead plants and animals.

17 CARBON STORES (SINKS) Marine Sediments/ Sedimentary Rock (largest long-term C stores) CaCO 3 (calcium carbonate) Limestone (rock)

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19 THE CARBON CYCLE Ways that carbon is cycled through ecosystems: Photosynthesis Respiration Decomposition Ocean processes Volcanic Eruptions Forest Fires

20 PHOTOSYNTHESIS Plants and some micro-organisms (cyanobacteria) undergo photosynthesis: Energy + Carbon dioxide + Water Glucose + Oxygen Energy + 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2

21 Plants remove CO2 and Produce O2

22 *Side Note: the carbohydrates also provide energy for animals... When animals eat plants, they take carbon into their cells...

23 CELLULAR RESPIRATION This process occurs in both plants and animals (in the mitochondria of their cells) ENERGY is released in the cell for growth, repair or reproduction... (Opposite of photosynthesis!) Glucose + Oxygen Energy + Carbon dioxide + Water C 6 H 12 O 6 + 6O 2 Energy + 6CO 2 + 6H 2 O Released to atmosphere

24 CO 2 is released by respiration...

25 DECOMPOSITION Another way that CO 2 is released into the atmosphere is by decomposers... When they break down dead plants (organic matter) they convert cellulose (type of carbohydrate) back into CO 2

26 OCEAN PROCESSES OCEAN MIXING: CO 2 dissolves in cold ocean waters and SINKS Ocean currents slowly move the CO 2 towards the tropics... Water warms and rises. CO 2 released to atmosphere Ocean currents near surface carry C back to high latitudes...

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28 VOLCANIC ERUPTIONS Sometimes CO 2 is released from volcanoes! MAGMA = Molten sedimentary rock

29 Lava going into the ocean at Hawaii s Volcanoes National Park

30 FOREST FIRES CO 2 is rapidly released during forest fires

31 HUMAN ACTIVITIES Since 1850 (Industrial Revolution), humans have increased the CO 2 in the atmosphere:

32 CO 2 on the rise in the atmosphere For the past years, the increase in CO 2 was 1-3 % Since 1850, the increase has been 30% Scientists estimate that carbon stores in the atmosphere will rise by at least 1/3 by the end of the century.

33 Burning Fossil Fuels (oil, gas, coal)

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36 Greenhouse Gases and Climate Change Greenhouse gases = CO 2, CH 4, N 2 O, H 2 O... Collect in atmosphere Sunlight hits Earth Some light is re-radiated back towards space as heat Gases absorb this radiation and trap the heat in the atmosphere If concentrations stay stable... Energy sent from Sun to Earth = Energy sent back into space Earth s temperature stays constant

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38 HUMAN ACTIVITIES adding CO 2 to atmosphere