1. After 100 years of supposed No inhabitance of New York City
What are these changes called?

2. Succession-
a series of changes in a community in which new populations of organisms gradually replace existing ones
What would happen to the road if no one used it?

3. Primary succession-
colonization of new sites by communities of organisms
takes place on bare rock
Sources of bare rock:
1. Volcanic lava flow cools and leaves bare rock
2. Glaciers retreat and expose rock

4. First to colonize: Lichens

5. What comes next??? Mosses Create humus Retain water
Decayed matter that provides nutrients for the soil
Retain water

6. Pioneer Species: the first organisms to colonize a new site
Ex: lichens are the first to colonize lava rocks
Rock

7. Climax community-
a stable, mature community that undergoes little or no succession

8. Secondary succession-
sequence of community changes that takes place when a community is disrupted by natural disaster or human actions – takes place on existing soil

9. Secondary succession-
Ex:
A fire levels portions of a forest
A farmer plows his field

11. Why does Secondary Succession happen faster?
Seeds are already in the soil
Some plants can re-grow from their stumps, roots
Soil still has nutrients & micro organisms in it.

12. Secondary succession-

13. What do you think is happening in the pictures?

14. Pond Succession

16. Start of Pond Succession
1) seeds are flown in by birds and land animals come to inhabit the pond. These are the pond pioneers.
2) As more creatures arrive the debris on the bottom increases.
*Emergent plants have roots under water while part of their bodies resides above the water line.

17. Slowly the vegetation takes over until…..
3) Emergents then appear on the edges of the pond.
Over time, sometimes hundreds of years, as ponds plants grow, die and decompose, layers of debris build up. These layers of decaying matter raise the pond floor over the years.
4) After some time, the pond floor is close enough to the bottom that emergents can grow all the way across the floor.

18. Review
What type of succession is pictured?

19. Higher Level Thinking What happens as succession increases over time?
# of species increases
Total population increases
Total Biomass increases
Organic Matter increases

20. Which pond is the youngest?

22. Ecology of Populations22

23. Population Growth
Populations grow when birth rate exceeds rate of mortality
DEATH 23

24. Population Growth World population now 6.47 billion (Oct 12, 2005)
At the present time the current population of the earth is 6.47 billion (October 12, 2005), having reached six billion on 19-Jun-99 at about 5:56:07 AM GMT. For a current estimate, see the Population Clock web page at:
World population now 6.47 billion (Oct 12, 2005)
Click here for current US and World population estimates ->

25. Demography is the study of factors that affect the growth and decline of populations
Additions occur through birth, and subtractions occur through death.
Demography studies the vital statistics that affect population size.
Less-developed counties represent 80% of the world population, but more than 90% of projected growth
Richer countries tend to have negative growth rates
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

26. Current Birth and Death Rates
Every second: about 4 children are born, while about 2 other people die
Net gain: 2.3 humans added to the world population every second, 72 million added every year
The human population continues to grow rapidly. I am not sure if these statistics put it into perspective, but basically, every second twice as many children are born as people die and the impact of this of this is that 2.3 people are added to the world population every second. There are over 31 million seconds in every year, which means that about 72 million people are added each year.

27. Parameters that effect size or density of a population:
Immigration
Birth
Population (N)
Death
Emigration
Figure 1. The size of a population is determined by a balance between births, immigration, deaths and emigration

28. Age Distribution
Age-Structure Diagram shows growth patterns of populations grouped into categories
Horizontal axis = Number of individuals 28

29. Human Age Distribution
Developed countries
Less-developed countries 29

30. Exponential growth (J-shaped curve)-- Assumes no limitations on resources.

31. S-shaped curve

32. KEY FEATURES OF POPULATIONS, con’t Population size is limited by:
density-dependent factors
Disease
Competition
Predators
Parasites
Food
Crowding
The greater the population, the greater effect these factors have.
Ex. Black plague in the Middle Ages – more deaths in cities
density-independent factors
Volcanic eruptions
Temperature
Storms
Floods
Drought
Chemical pesticides
Major habitat disruption (as in the New Orleans flooding)
Most are abiotic factors

33. Humans are part of the Earth's ecosystem. Human activities
can either deliberately or
inadvertently
alter the balance
of an ecosystem.  

34. How do human activities affect the environment?
What do you Think???
How do human activities affect the environment?

35. Will you change your perspective or will you feel the same way?
With more info…
Will you change your perspective or will you feel the same way?

36. Human impacts on the Environment
Global warming
Use of machinery by humans seems to be increasing CO2 levels in the air. CO2 prevents heat from escaping, causes slight world wide temperature increases
Rising water temperatures causes coral bleaching 36

37. Human impacts on the environment
Deforestation
Caused by demand for wood products,
need for space, farmland, housing,
roads
Deforestation causes
habitat fragmentation
Animals and plants are forced into
confined areas 37

38. Habitat Fragmentation

39. Habitat Fragmentation

40. Human impacts on the Environment
Ozone depletion
Caused by aerosol chemicals called
chlorofluorocarbons (CFCs)
CFC’s
Escape into atmosphere, reacts breaking down the ozone (O3, a protective atmospheric layer)
UV rays penetrate the atmosphere and cause harm to many organisms 40

41. “HOLE” in the ozone (O3)

42. Human impacts on the Environment
Fishing activities
Demand for fish and shellfish
Commercial Fishing be harmful to environment in many ways 42

43. Human impacts on the environment
Invasive species (EXOTIC SPECIES)
introduced by people accidentally or intentionally
Can cause problems if no natural enemies are
present
Cane toad was introduced to Australia to control cane beetles, pest insects that destroy sugar cane crops 43

44. Human impacts on the Environment
Exotic pet trade
Capture and sell wild animals from
exotic locations
Wealthy buyers and collectors desire
obscure animals
Animals removed from their habitat
causes an imbalance in the ecosystem 44

47. Importance of the Environment
Biodiversity = Many different types of organisms
Organisms depend upon one another
Interfering with one
Organism can have a
Ripple effect to many
w/in the habitat 47

48. Importance of the environment
Natural resources:
Non-renewable includes fossil fuels (petroleum, coal)
Renewable includes animals, plants, water, wind, etc.
even renewable resources can run out 48

49. Importance of the Environment
Natural resources
Renewable energy sources include wind power, geothermal energy, ocean currents 49

50. Pollution: Agricultural Homes Industry DDT Fertilizers
Animal wastes (nitrogen)
Homes
Strong cleaning agents
Industry
Toxic gases and wastes
Acid rain

51. Effects of Human Activities on Water Cycle
We alter the water cycle by:
Withdrawing large amounts of freshwater.
Clearing vegetation and eroding soils.
Polluting surface and underground water.
Contributing to climate change.

52. Effects of Human Activities on Carbon Cycle
We alter the carbon cycle by adding excess CO2 to the atmosphere through:
Burning fossil fuels.
Clearing vegetation faster than it is replaced.
Figure 3-28

53. Effects of Human Activities on the Nitrogen Cycle
We alter the nitrogen cycle by:
Adding gases that contribute to acid rain.
Adding nitrous oxide to the atmosphere through farming practices which can warm the atmosphere and deplete ozone.
Contaminating ground water from nitrate ions in inorganic fertilizers.
Releasing nitrogen into the troposphere through deforestation.

54. Toxins in food chains-
While energy decreases as it moves up the food chain, toxins increase in potency.
This is called biological magnification 54

56. What Sustains Life on Earth?
Biogeochemical Cycles
What Sustains Life on Earth?
Solar energy, the cycling of matter, and gravity sustain the earth’s life.
Figure 3-7

57. Two Secrets of Survival: Energy Flow and Matter Recycle
An ecosystem survives by a combination of energy flow and matter recycling.
Figure 3-14

58. Water cycle- 58

59. Carbon Cycle
All living things are made of carbon. Carbon is also a part of the ocean, air, and even rocks.
Plants use carbon dioxide and sunlight to make their own food and grow. The carbon becomes part of the plant.
Plants that die and are buried may turn into fossil fuels made of carbon like coal and oil over millions of years.
When humans burn fossil fuels, most of the carbon quickly enters the atmosphere as carbon dioxide

60. Carbon cycle- 60

61. Nitrogen cycle-
Atmospheric nitrogen (N2) makes up nearly 78%-80% of air.
Organisms can not use it in that form.
Lightning and bacteria convert nitrogen into usable forms.
Only in certain bacteria and industrial technologies can fix nitrogen they are called nitrogen- fixing bacteria- Some live in a symbiotic relationship with plants.
Nitrogen fixation-convert atmospheric nitrogen (N2) into ammonium (NH4+) which can be used to make organic compounds like amino acids. 61

64. Effects of Human Activities on the Nitrogen Cycle
Human activities such as production of fertilizers now fix more nitrogen than all natural sources combined.
Figure 3-30

65. Phosphorous Cycle
Phosphorous is an essential nutrient for plant and animals.
Can be found on earth in water, soil & sediments.
Slowest cycle of them all
Cycles through plants and animals faster than rocks and sediments

66. Effects of Human Activities on the Phosphorous Cycle
We remove large amounts of phosphate from the earth to make fertilizer.
We reduce phosphorous in tropical soils by clearing forests.
We add excess phosphates to aquatic systems from runoff of animal wastes and fertilizers.

67. mining Fertilizer excretion Guano agriculture weathering uptake by
autotrophs
uptake by
autotrophs
leaching, runoff
Marine
Food
Webs
Dissolved
in Ocean
Water
Dissolved
in Soil Water,
Lakes, Rivers
Land
Food
Webs
death,
decomposition
death,
decomposition
Figure 3.31
Natural capital: simplified model of the phosphorus cycle. Phosphorus reservoirs are shown as boxes; processes that change one form of phosphorus to another are shown in unboxed print. QUESTION: What are three ways in which your lifestyle directly or indirectly affects the phosphorus cycle? (From Cecie Starr and Ralph Taggart, Biology: The Unity and Diversity of Life, 9th ed., Belmont, Calif.: Wadsworth © 2001)
weathering
sedimentation
settling out
uplifting over
geologic time
Marine Sediments
Rocks
Fig. 3-31, p. 77

68. Toxins in food chains-
While energy decreases as it moves up the food chain, toxins increase in potency.
This is called biological magnification 68