1. Energy Flow & Roles

2. Producers a.k.a. autotrophs Can make their own food
May use energy from the Sun
May use chemical energy (chemosynthesis)
Ex. Plants, algae & some types of bacteria

7. Consumers A.k.a. heterotrophs Include: Herbivores (1st level)
…carnivores (2nd level)
…omnivores (3rd level)
… scavengers (also 3rd level)
…decomposers / detritivores (4th level)

9. Food Chains Must start with a producer –
A producer makes it’s own food!
Continues to include all levels of consumers
Shows WHO eats WHO

10. Food Webs Several food chains together
Shows how every organism is interdependent
Everything depends on producers

16. Energy Pyramid
Made of “Trophic Levels”
Each step of energy transfer ONLY 10%
90% of Energy is lost
as heat or respiration

17. Producers are at the base
Decomposers are at the top
Shows DECREASING ENERGY FLOW!!!

22. Populations

27. Characteristics of Populations
(3 of ‘em!)

28. 1 - Geographic distribution
3 types:

29. 2 - Population Density
Low
High

30. 3 – Growth Rate:
Birthrate
Death-rate
Immigration
Emigration

31. If birth rate , & death rate
Population increases
If birth rate & death rate
Population decreases

32. Types of Growth

33. Has unlimited resources J -shaped
Exponential Growth
Has unlimited resources
J -shaped

35. Logistic Growth
Normal
S – shape
It stops increasing at carrying capacity

37. How many organisms a given area can support Determined by:
Carrying Capacity
How many organisms a given area can support
Determined by:
Space and food

38. Limiting Factors
LIMIT population growth
2 Types:
Density –Dependent &
Density-Independent

39. -1- DD: Competition Food Water Sunlight Space (Valley / mtn./ dam)
Soil type

40. Examples of Competition
Male lions for control of female prides
plants for water, nutrients and light

41. -2- DD: Predation Predators eat prey Prey is eaten
Predators help the ecosystem by reducing the size of prey populations and…..
Allow for BIODIVERSITY

42. -3- DD: Parasitism & Disease

43. -4- DD: Stress & Crowding

44. Density Independent 1. Weather / temperature 2. Natural disaster
3. Seasonal cycles (rainy /drought)
4. Human activities (clear cutting forests, damming rivers)

45. Human Impact on the Environment
Includes:
Soil Erosion (from agriculture)
Runoff & flooding (thru deforestation)
Pollution (untreated sewage)

46. Interrupting nutrient cycles (burning trash; not recyclable)
Population growth (depletes resources)

47. What is the WORST things humans do????
Habitat destruction!!!!
Might be done by invasive species
Causes a loss of biodiversity

50. Succession

51. Succession
The process of how ecosystems form over a long period of time

52. Begins by hardy invaders called the pioneer species
This includes lichens & mosses
Progresses to a stable climax community (endpoint of succession)

53. Two Types

54. 1 -Primary succession no previous growth Requires thousands of years
Requires the creation of soil
Occurs when new land is formed
Ex. after volcanic eruption
After a glacier melts

56. 2 - Secondary succession
develops after existing ecosystem has been disturbed
More rapid – reaches climax within two centuries
Ex: forest fire
Natural disaster
abandoned farm field

58. Biggest difference between primary and secondary is time, due to the presence/ absence of soil. Soil is made by the decomposition of rock; broken down by lichens and mosses (pioneer species).

59. Cycles That Occur in Nature

61. Water cycle
Moves between atmosphere, oceans & land
1 – water evaporates from the ocean
2 – water evaporates from the leaves of plants during transpiration

62. 3 - enters atmosphere as a gas (water vapor)
4 – Vapors condense to form clouds
5 – when large enough, water will fall back to earth as precipitation

63. 6 – Water travels as runoff or seepage

64. 7 – Plants remove water from root uptake
Water is always equal in the cycle
The amount never changes

65. Concerns (due to humans)
Groundwater depletion due to irrigation
Unsafe drinking water due to pollution or animal waste (causes 80% of diseases in undeveloped countries)

67. Carbon cycle

68. Photosynthesis: CO2 is taken in by plants & converted to sugar

69. Cellular Respiration: how energy from sugar is released

70. Erosion & volcanoes: releases CO2 in the air & ocean

71. Decomposition: carbon is released from dead stuff
stored underground as fossil fuels

72. Human Activities: Mining Burning fossil fuels
Cutting / burning down forests
**We ADD to the carbon cycle !!

74. Nitrogen cycle Nitrogen –make up proteins and DNA
Where is most of it stored?
In the atmosphere!! (79%)
Plants and animals cannot take nitrogen from the atmosphere

75. 1. Bacteria converts nitrogen gas (N2) into ammonia in a process called:
Ammonification
2. A different bacteria converts ammonia into nitrates and nitrites needed by plants to make proteins process called
nitrogen fixation

76. 3. Plants take in nitrogen (as nitrates and nitrites)
4. Consumers (including us) get nitrogen by eating producers
5. Organisms die, they return nitrogen to soil as ammonia

77. 6. Some ammonia may be taken up by producers
7. Nitrates are converted into nitrogen gas by bacteria in a process called denitrification
8. Nitrogen gas returns to the atmosphere

79. Human activities can also add Nitrogen:
Use of fertilizers (travel by runoff)
Dumping raw sewage
Burning fossil fuels & wood
Leads to eutrophication (algal blooms)

83. Phosphorus Cycle 1 – stored in rock (land & ocean floor) & soil
2 - Released by weathering & erosion
3 – travels in runoff

84. 4 – enters the ocean & gets used by some marine animals
5 – travels through the food web
6 – returned to soil through waste

85. Why do we need phosphorus?
Along with calcium, you need it to make bones
#1: it is a part of DNA

86. Phosphorous Cycle