1. Ecosystem Recycling

2. Ecosystem Recycling Matter must be recycled and reused
Substances pass between living and nonliving worlds
Water, carbon, nitrogen, calcium, phosphorus
Biogeochemical cycles

3. Water Cycle Water is crucial to life Cells contain 70-90 percent water
Dissolves a variety of compounds
Filters out UV light from the sun
Expands as it freezes
Liquid over a wide temperature range
Changes temperature slowly
Requires large amounts of energy to evaporate

4. Water Cycle Where water is found Water vapor (atmosphere)
Groundwater (in soil or underground formations of porous rock)
Trapped within living things
Bodies of water
Lakes, rivers, streams, oceans (substantial %)

5. Water Cycle Movement of water (water cycle) Evaporation Transpiration
Adds water as vapor to the atmosphere
Transpiration
Plants release water through leaves
Animals release water when they breathe, sweat, or excrete
Precipitation
Water leaving the atmosphere
Amount depends on abiotic factors (temperature & air pressure)

6. Fig. 3-18, p. 54 Global warming Condensation Ice and snow Condensation
Transpiration
from plants
Evaporation
from land
Evaporation
from ocean
Precipitation
to land
Surface runoff
Increased
flooding
from wetland
destruction
Precipitation
to ocean
Runoff
Lakes and
reservoirs
Reduced recharge of
aquifers and flooding
from covering land with crops and buildings
Point
source
pollution
Infiltration
and percolation
into aquifer
Surface
runoff
Figure 3.18: Natural capital: simplified model of the hydrologic cycle with major harmful impacts of human activities shown by red arrows and boxes.
Question: What are three ways in which your lifestyle directly or indirectly affects the hydrologic cycle?
See an animation based on this figure at ThomsonNOW.
Ocean
Groundwater
movement (slow)
Aquifer
depletion from
overpumping
Fig. 3-18, p. 54

7. Carbon Cycle Carbon dioxide
Greenhouse gas; traps heat in the atmosphere.
Without it the Earth would be a frozen world.
There is ~30% more carbon dioxide in the air today than there was 150 years ago
Humans burning more fuel
Greenhouse gases are causing our planet to become warmer.

8. Carbon Cycle Autotrophs use carbon dioxide (CO2) to make carbohydrates
Major parts of the cycle
Aerobic respiration (plants & animals)
Photosynthesis (plants)
Forest fires
Fossil fuels add CO2 to the atmosphere
Burning coal, oil, and natural gas

9. Carbon dioxide
in atmosphere
Respiration
Photosynthesis
Burning
fossil fuels
Forest fires
Diffusion
Animals
(consumers)
Deforestation
Plants
(producers)
Carbon
in plants
(producers)
Transportation
Respiration
Carbon
in animals
(consumers)
Carbon dioxide
dissolved in ocean
Marine food webs
Producers, consumers,
decomposers
Decomposition
Carbon fossil fuels on
Figure 3.19: Natural capital: simplified model of the global carbon cycle, with major harmful impacts of human activities shown by red arrows.
Question: What are three ways in which you directly or indirectly affect the carbon cycle?
See an animation based on this figure at ThomsonNOW.
Carbon
in limestone or
dolomite sediments
Compaction

10. Nitrogen Cycle
Nitrogen is needed to make proteins and nucleic acids (DNA)
Nitrogen gas makes up ~78%
Multicellular plants and animals cannot utilize atmospheric nitrogen
Needs to go through nitrogen fixation
Nitrogen fixation
Converting nitrogen gas to nitrate
Nitrogen-fixing bacteria
Transforms nitrogen gas into usable form

12. Nitrogen Cycle Ammonification Nitrification
Decomposers breaking down dead organisms, urine and dung to release the nitrogen in the form of ammonium (NH3)
Nitrification
Soil bacteria take the ammonium & oxidize (add oxygen) it into nitrites
Plants use nitrites to form amino acids

13. Fig. 3-20, p. 57 Nitrogen in atmosphere Denitrification by bacteria
Electrical
storms
Nitrogen
in animals
(consumers)
Nitrogen oxides
from burning fuel
Volcanic
activity
Nitrification
by bacteria
Nitrogen
in plants
(producers)
Nitrates
from fertilizer
runoff and
decomposition
Decomposition
Uptake by plants
Figure 3.20: Natural capital: simplified model of the nitrogen cycle in a terrestrial ecosystem, with major harmful human impacts shown by red arrows.
Question: What are three ways in which you directly or indirectly affect the nitrogen cycle?
See an animation based on this figure at ThomsonNOW.
Nitrate
in soil
Nitrogen
loss to deep
ocean sediments
Nitrogen
in ocean
sediments
Bacteria
Ammonia
in soil
Fig. 3-20, p. 57

14. Phosphorus Cycle Does not cycle through the atmosphere
Obtained from terrestrial rock formations
Limiting factor on land and in freshwater ecosystems
Biologically important for producers and consumers
Phosphorus Cycle
Movement of phosphorus from the environment to organisms and back to the environment

15. Phosphorus Cycle Phosphorus is essential
Needed in animals to form bones, teeth, molecules such as DNA & RNA
Plants get phosphorous from soil & water
Animals get phosphorous from eating plants or animals

16. Fig. 3-21, p. 58 Phosphates in sewage Fertilizer phosphates Plate
tectonics
Phosphates
in mining waste
Runoff
Runoff
Sea
birds
Runoff
Phosphate
in rock
(fossil bones,
guano)
Erosion
Ocean
food chain
Animals
(consumers)
Phosphate
dissolved in
water
Phosphate
in shallow
ocean sediments
Figure 3.21: Natural capital: simplified model of the phosphorus cycle, with major harmful human impacts shown by red arrows.
Question: What are three ways in which you directly or indirectly affect the phosphorus cycle?
Phosphate
in deep ocean
sediments
Plants
(producers)
Bacteria
Fig. 3-21, p. 58

17. http://www. drippytheraindrop