1. Modified by Beth Roland Jacobs Fork Middle School
Ecology Unit- part 2
Modified by Beth Roland
Jacobs Fork Middle School

2. Biogeochemical Cycles (Matter moving through the environment)
All living organisms need certain elements/compounds for life processes
Ex: your cells need Carbon,Hydrogen,Oxygen,Phosphorus,Nitrogen & Sulfur in order to live and reproduce (make more cells)
Cycles in nature keep these elements “moving” from organisms to organism (and sometimes into the atmosphere)

3. Biogeochemical Cycles (Matter moving through the environment)
The flow of a nutrient from the environment to living organisms and back to the environment
Main reservoir for the nutrient is in the environment
Transfer rates to and from reservoir are usually lower than the rates of exchange between and among organisms.
Matter is recycled through an ecosystem – not one way flow

4. Three Categories Hydrologic cycle Atmospheric cycles
Water
Atmospheric cycles
Nitrogen and carbon
Sedimentary cycles
Phosphorus and sulfur

5. CYCLES IN NATURE

6. Carbon Cycle
Carbon moves through the atmosphere and food webs on its way to and from the ocean, sediments, and rocks
Sediments and rocks are the main reservoir

8. Carbon Cycle diffusion Atmosphere Bicarbonate, carbonate Terrestrial
photosynthesis
TERRESTRIAL ROCKS
volcanic action
weathering
diffusion
Atmosphere
Bicarbonate, carbonate
Terrestrial
Rocks
Land Food Webs
Marine food
webs
Soil Water
Peat, Fossil Fuels
Marine Sediments

10. Carbon in the Oceans
Most carbon in the ocean is dissolved carbonate and bicarbonate
Ocean currents carry dissolved carbon

11. Carbon in Atmosphere Atmospheric carbon is mainly carbon dioxide
Carbon dioxide is added to atmosphere
Aerobic respiration, volcanic action, burning fossil fuels, decomposition of organic materials
Removed by photosynthesis

12. Nitrogen Cycle
Nitrogen is used in amino acids and nucleic acids (all living organism need nitrogen to make proteins)
Main reservoir is nitrogen gas in the atmosphere
Decomposers are vital to convert ammonia into:
usable nitrites & nitrates for plants (nitrogen fixation)
nitrogen gas (denitrification = puts it back into the atmosphere)

15. Phosphorus Cycle
Phosphorus is part of phospholipids and all nucleotides
What are these? The basis of all DNA and cell membranes
It is the most prevalent limiting factor in ecosystems
Main reservoir is Earth’s crust; no gaseous phase (it never enters the atmosphere – like carbon and nitrogen)

16. Phosphorus Cycle mining FERTILIZER excretion GUANO agriculture
weathering
uptake by autotrophs
uptake by autotrophs
MARINE FOOD WEBS
DISSOLVED IN OCEAN WATER
weathering
DISSOLVED IN SOILWATER, LAKES, RIVERS
LAND FOOD WEBS
death, decomposition
death, decomposition
sedimentation
setting out
leaching, runoff
uplifting over geolgic time
MARINE SEDIMENTS
ROCKS

18. Chapter 3 – Communities & Biomes
Vocabulary to Know:
Limiting Factor
Succession
Primary
Secondary
Climax Community

19. Community All the populations that live together in a habitat
Habitat is the type of place where individuals of a species typically live
Type of habitat shapes a community’s structure

20. Biogeography
The study of the distribution of organisms and the processes that underlie distribution patterns

21. Factors that Affect Distribution
Geologic history
Topography
Climate
Species interactions

22. Climate Average weather condition in a region Affected by:
amount of incoming solar radiation
prevailing winds
elevation

23. Rotation and Wind Direction
Earth rotates faster under the air at the equator than it does at the poles
Deflection east and west

24. Seasonal Variation
Northern end of Earth’s axis tilts toward sun in June and away in December
Difference in tilt causes differences in sunlight intensity and day length
The greater the distance from the equator, the more pronounced the seasonal changes

25. Ocean Currents
Upper waters move in currents that distribute nutrients and affect regional climates

26. Rain Shadow
Air rises on the windward side, loses moisture before passing over the mountain

27. Biomes
Regions of land characterized by habitat conditions and community structure
Distinctive biomes prevail at certain latitudes and elevations

28. Biomes

29. Population Size Factors that affect: Natality Mortality/Fatality
Immigration
Emigration
                                                    

30. Population Density

31. Environmental Limits on populations
Density-dependent
Disease
Food
Parasitism
Predation
Competition
Intraspecific
Interspecific
Density-independent
Temperature
Storms
Floods
Drought
Habitat Disruption

32. Organism Interactions Limit Populations
Predation
Competition
Both types
Parasitism
Crowding/stress

33. Chapter 5: Diversity & Conservation
Importance to nature
Importance to people
Oxygen
Diet
Medicines

34. Loss of Diversity Threatened Species Endangered Species
Extinction of Species

35. Threats to Biodiversity
Habitat Loss
Habitat Fragmentation
Biotic Issues
Abiotic Issues
Habitat Degradation
Air Pollution
Water Pollution
Land Pollution

36. Exotic Species Example: Page 124
Non-native organisms that “move-in” to a particular area
There can be a lack of competitors = exponential growth
Can take over the niches of native species

37. Conservation Sustainable use:
Use what you need, but don’t damage the ecosystem
Is this a good example of sustainable use?

38. Humans & The Environment
Ozone (O3) Depletion
O3 forms a “good layer” around the Earth
CFC release is breaking down the protective ozone layer
UV rays increase skin cancers & other cell mutations to plants & animals!

39. How is Acidity Measured?
When we observe acid rain, acidity is measured in units called pH.
The pH scale is from 0 to 14
pH 7 indicates neutral
higher pH numbers = alkalinity (base)
smaller numbers = acid
We’ll do more on pH in the “Biochemistry” chapter

40. Natural Acid Precipitation
CO2 combines with water to form a weak acid H2CO3 (carbonic acid)
But we are adding to the problem…
by adding nitric and sulfuric acids
Look at the “clean rain” – it’s already slightly acidic???

41. Effects of Acid Precipitation
In Japan, rain which registers pH 5.6 or less is considered acid rain; some 80-90% of the rain that falls in Japan in a year is acid rain.
In Japan, acid rain with acidity equal to lemon juice has been observed at Mount Tsukuba in 1984 (pH 2.5) and at Kagoshima in 1987 (pH 2.45). The problem is even more serious in North America and Europe. In those regions, forests are withering and lakes becoming uninhabitable to fish, and stone structures such as buildings and bronze statues are being damaged by corrosion.
1970
1985

43. Humans & The Environment
Global Warming
“The Greenhouse Effect”
Fossil fuels give off lots of CO2
This builds a blanket around the earth
It is predicted that the Earth temp. will increase ~50C before 2050 = Ice age????

44. Carbon Dioxide Increase
Carbon dioxide levels fluctuate seasonally
The average level is steadily increasing
Burning of fossil fuels & deforestation are contributing to the increase

45. Greenhouse Effect
Greenhouse gases impede the escape of heat from Earth’s surface

47. Global Warming
Long-term increase in the temperature of Earth’s lower atmosphere

48. Other Greenhouse Gases
CFCs - synthetic gases used in plastics and in refrigeration
Methane - produced by termites and bacteria
Nitrous oxide - released by bacteria, fertilizers, and animal wastes