1. Ch. 3- The Biosphere
ECOLOGY!

2. 3.1 Levels of Organization

3. What is Ecology? Study of interactions among organisms and
between organisms and their environment

4. Biosphere All portions of planet in which life exists atmosphere land
Air
Water
atmosphere
land
water

5. Interactions Interactions w/in biosphere
Web of interdependence between organisms and the environment
Ever changing biosphere

6. Levels of Organization
Individual: living thing of a single species

7. Levels of Organization
Population: group of organisms of same species

8. Levels of Organization
Community: Populations that live together

9. Levels of Organization
Ecosystem: community & nonliving surroundings

10. Levels of Organization
Biome: group of ecosystems with same climate
and similar dominant communities

11. Levels of Organization
Biosphere: contains ALL ecosystems & biomes

12. Ecosystem Processes

13. Thinking Question:
While browsing through the drinks offered at a convenience store, you notice a new soft drink advertised as a “low-calorie energy drink.” Write out your definition of “energy,” and then decide if this drink label is accurate or a case of false advertising.

14. Energy Energy is defined as the ability to do work.
Energy is NOT a material. Energy is a phenomenon.
Energy can be transformed (i.e. mechanical to heat) and transferred, but is not recycled.

15. Energy flows Energy for most ecosystems on earth comes from the sun.
Light energy is converted to chemical energy by producers to power their own metabolism.
Energy is lost from the earth as heat.

17. Photosynthesis
Energy is converted and nutrients are fixed by the process of photosynthesis.
Producers use the sun’s energy to convert inorganic carbon dioxide into organic molecules, such as sugars.

18. Biomass (g/m2)

19. Thinking question discussion
So what about that “low-calorie energy drink?”

20. Energy Flows

21. Thinking Question:
One reason that some people become vegetarians is to reduce their impact on the environment. List as many positive ecological effects of vegetarianism as you can think of. Then list as many negative effects.

22. Food Chain Concept
Chemical energy is passed through the ecosystem as organisms consume other organisms.
Organisms occupy one or more trophic levels (“feeding” levels) depending on what they are eating.

23. Trophic Levels
Producers: Use light energy to manufacture organic molecules.
Primary consumers: eat producers
Secondary consumers: eat primary consumers
Tertiary consumers: eat secondary consumers.

27. Food Webs A food web is a model of energy flow in a community.
Arrows indicate the direction in which energy flows from one organism to the next. (Note that this is NOT a cycle.)
A single organism will be involved in many food chains, and some will occupy several trophic levels.

29. “Death Eaters”
Decomposers: Bacteria and fungi, which use external digestion to break organic matter down into inorganic substances.
Detritivores: Animals that feed on dead plant material.
Scavengers: Animals that feed on dead animal flesh.

30. Energy Loss
At each step in a food chain or food web, energy is lost as heat. Each organism takes in energy to meet its own needs, so most of the energy taken in is converted to motion and heat.
10% or less of the energy consumed will be available to the next consumer.

32. Energy Pyramid
Because 90% or more of consumed energy is used by the organism, and only a small amount can be passed on, the entire system is inefficient.
The higher an organism is on the food chain, the greater amount of biomass is required to support that organism.

33. It’s all about ENERGY! Arrows show direction of ENERGY flow:
NOT direction of eating:
Grass
Cow
Cow
Grass

34. Energy Energy is defined as the ability to do work.
Energy is NOT a material. Energy is a phenomenon.
Energy can be transformed (i.e. mechanical to heat) and transferred, but is not recycled.

35. Thinking Question:
One reason that some people become vegetarians is to reduce their impact on the environment. List as many positive ecological effects of vegetarianism as you can think of. Then list as many negative effects.

37. Energy Pyramid Relative energy amounts at each trophic level
Only 10% energy passed on from one level to the next

38. Biomass pyramid

39. Thinking question discussion
What are possible positive and negative effects of “going veggie?”
How can your everyday food choices have an impact on the environment?

41. Bioaccumulation/ Biomagnification
Buildup of chemicals inside organisms.
Organisms can’t break down (metabolize) the chemicals OR
Chemicals are taken up faster than they are broken down

42. Big Problem Mercury, pesticides (DDT) buildup in fish
Once a pollutant is in the soil, it can easily enter the waterways and thus, food chains

43. At lower trophic levels (producer), the contaminant may not cause much harm, but as you move higher into the food chain, the levels increase. This phenomenon is referred to as BIOMAGNIFICA TION!

44. Human Food Chain
Humans are omnivores, capable of eating a wide variety of foods.
We can create a human food chain by looking at our meat sources.

45. Grass-fed Food Chain
A cow can convert grass, which we cannot eat, into meat, which we can.
We obtain 8-10% of the energy that a pasture-fed cow consumes.

46. Industrial Food Chain
Corn, which could be fed to humans, is fed to feedlot cattle. Because of overproduction, corn is cheap.
Cheap burgers come at a high ecological cost. The industrial food chain is about 1/3 as efficient as the grass food chain.
A cow’s digestive system is not adapted to eating corn. The cattle are often sick, and much of the energy is wasted.

47. Nutrients Cycle

48. Thinking Question:
Global climate change has everyone’s attention these days. One action that some people take in response is to plant trees. What does planting trees have to do with alleviating global climate change?

49. Nutrients
“Nutrient” in an ecological sense refers to the inorganic materials taken in by producers and converted into organic molecules.
Nutrients include carbon (as carbon dioxide), nitrogen, phosphorous, oxygen, and other building blocks of biological molecules.

50. Nutrients Cycle
Because nutrients ARE materials, they cycle in the earth’s ecosystems. Carbon from carbon dioxide may become carbon in a sugar made by a plant.
Decomposers break down organic molecules and release inorganic nutrients to the ecosystem.

51. Material Cycles
Material cycling follows the law of conservation of matter.
Elements used by living organisms are taken up and used by producers, used passed down the food chain by consumers, and are released back to the environment by decomposers.

52. Carbon Cycle Carbon forms the backbone of all organic molecules.
Carbon from the atmosphere is “fixed” by producers, which manufacture organic molecules using the sun’s energy.
Breakdown of these molecules releases carbon dioxide back to the atmosphere.

53. Carbon Cycles Biological
Photosynthesis, respiration, and decomposition (take up and release CO2)
Geochemical
Erosion, volcanic activity (release CO2)

54. Carbon Cycle

55. 2 Biggest Biological Carbon Movers:
Photosynthesis and respiration

56. The Carbon Cycle
CO2 in
Atmosphere
CO2 in Ocean

57. Nitrogen Cycle
The earth’s atmosphere is 78% nitrogen, but in this form it cannot be used by producers.
Nitrogen-fixing bacteria convert nitrogen gas into nitrogen compounds that plants can absorb and use in making amino acids to build proteins.

58. The Nitrogen Cycle Nitrogen is required for amino acids
Most of the atmosphere is made of nitrogen (78%)
Most decaying matter (detritus) produces ammonia (NH3), Nitrate ions (NO3-), and others
Bacteria convert nitrogen into plants (nitrogen fixation)
Some bacteria convert nitrates into N gas which is called “denitrification”

59. Nitrogen Cycle

60. The Nitrogen Cycle
N2 in Atmosphere
NO3-
and NO2-
NH3

61. Phosphorous Cycle
Unlike other nutrients, phosphorous does not exist as an atmospheric gas.
Rock phosphates dissolve in rain as rock weathers, carrying phosphates into streams and soil.
Phosphates settle out on the bottoms of ponds, and may consolidate back into phosphate-rich rock.

62. Phosphorus Cycle Used to make DNA and RNA (Ph backbone)
Not very common in the biosphere
Does not enter the atmosphere
Usually in rock and soil minerals
Dissolves in water

63. Phosphorous Cycle

64. Water Cycle Weather patterns form part of the water cycle.
Water remains chemically unchanged during the water cycle. It is evaporated as water vapor, condensed into rain clouds, and finally falls as precipitation.
Water may collect in rocks as groundwater.

65. Water Cycles All living things require water
Water is recycled in the biosphere in the water cycle through
Evaporation - water to gas (vapor)
Transpiration – evaporation from plants
Condensation – vapor water droplets that form clouds
Precipitation – rain, snow, hail, and sleet

66. Water Cycle

67. The Carbon Cycle Carbon is the key element in living tissue
Carbon dioxide, Glucose, Calcium carbon (bones) and more include carbon!
Carbon is moved throughout the environment in the carbon cycle

68. Global “Warming”
“Global Warming” — better termed “Global Climate Change” — has been strongly linked to levels of carbon dioxide in the atmosphere.
The warming of the Earth’s temperature (surfac eand air)
While natural events add carbon dioxide to the atmosphere, humans activity also contributes to carbon levels.

69. Fossil Fuels
Fossil fuels are the remains of ancient swamps. Plants fixed carbon as carbon-rich organic compounds. Carbon compounds accumulated in swamps over hundreds of millions of years.
In less than 200 years, humans have burned nearly half of the world’s fossil fuels.

70. Greenhouse Gases
Earth’s atmosphere has many different gases, inc. water vapor and CO2.
These GREENHOUSE GASES help maintain Earth’s constant temperature
No greenhouse gases = very COLD atomosphere)
Too many greenhouse gases = EXCESSIVE HEAT

71. Greenhouse Effect

72. Impacts of Human Domination of Cycles
Increased global concentrations of greenhouse gases like nitrous oxide (N2O), carbon dioxide (CO2), which are potent greenhouse gases, in the atmosphere as well as increased regional concentrations of other oxides of nitrogen (including nitric oxide, NO) that drive the formation of smog;
Losses of soil nutrients such as calcium and potassium that are essential for long-term soil fertility;
Substantial acidification of soils and of the waters of streams and lakes in several regions;
Greatly increased transport of nitrogen by rivers into estuaries and coastal waters where it is a major pollutant.
We are also confident that human alterations of the cycles have:
Accelerated losses of biological diversity, especially among plants adapted to low-nitrogen soils, and subsequently, the animals and microbes that depend on these plants;
Caused changes in the plant and animal life and ecological processes of estuarine and nearshore ecosystems, and contributed to long-term declines in coastal marine fisheries.

73. Carbon and Temperature

74. The outcome depends on what happens to the west Antarctic ice shelf.
Future Trends?
The outcome depends on what happens to the west Antarctic ice shelf.

75. Current Effects

77. Photosynthesis
Energy is converted and nutrients are fixed by the process of photosynthesis.
Producers use the sun’s energy to convert inorganic carbon dioxide into organic molecules, such as sugars.

78. Food Chain Concept
Chemical energy is passed through the ecosystem as organisms consume other organisms.
Organisms occupy one or more trophic levels (“feeding” levels) depending on what they are eating.

79. Trophic Levels
Producers: Use light energy to manufacture organic molecules.
Primary consumers: eat producers
Secondary consumers: eat primary consumers
Tertiary consumers: eat secondary consumers.

81. Producers Autotrophs Energy from the sun (photosynthesis)
Energy from chemical bonds (chemosynthesis)
Producers = produce/make their own energy

82. Consumers Heterotrophs Herbivores: only eat plants
Carnivores: only eat animals
Omnivores: eat both plants & animals
Called consumers because they eat or consume food

83. Decomposers Detritus = plant & animal remains/ dead matter
Earthworms, snails
Decomposers – break down organic matter
Bacteria, fungus

84. “Death Eaters”
Decomposers: break down organic matter down into inorganic substances.
Ex. Bacteria, fungi
Detritivores: Animals that feed on dead plant and animal remains/dead matter
Earthworms, snails
Scavengers: Animals that feed on dead animal flesh.

85. Feeding Relationships
Energy flows through ecosystem in one direction
Sun / Inorganic compounds
Producers
Consumers
Arrow = direction of energy flow

86. Food Webs A food web is a model of energy flow in a community.
Arrows indicate the direction in which energy flows from one organism to the next. (Note that this is NOT a cycle.)
A single organism will be involved in many food chains, and some will occupy several trophic levels.

87. Food chain
How far removed is top consumer from producer
Food web: network of complex interaction
Trophic Levels – each step/level in food chain or web

88. Each level in food chain
Trophic Levels –
Each level in food chain
Food chain
How far removed is top consumer from producer
Food web: network of complex interaction
Trophic Levels – each step/level in food chain or web

90. 3.3Cycles of Matter

91. Nutrients
“Nutrient” in an ecological sense refers to the inorganic materials taken in by producers and converted into organic molecules.
Nutrients include carbon (as carbon dioxide), nitrogen, phosphorous, oxygen, and other building blocks of biological molecules.

92. Nutrients Cycle
Because nutrients ARE materials, they cycle in the earth’s ecosystems. Carbon from carbon dioxide may become carbon in a sugar made by a plant.
Decomposers break down organic molecules and release inorganic nutrients to the ecosystem.

93. Nutrient Cycles
Nutrients: chemical substances in organisms that are necessary to sustain life
Building blocks
Nutrients are passed between organisms and environment in the biogeochemical cycles

94. Material Cycles
Material cycling follows the law of conservation of matter.
Elements used by living organisms are taken up and used by producers, used passed down the food chain by consumers, and are released back to the environment by decomposers.

95. Recycling
As you know: Energy flows in ecosystems in one way (sunprod.Cons.)
However… elements, compounds, and other forms of matter are passed from one part of an ecosystem to another in a cycle…
Examples are:
The water cycle
The nutrient cycles
Carbon, nitrogen, and phosphorus

96. Nitrogen Cycle
The earth’s atmosphere is 78% nitrogen, but in this form it cannot be used by producers.
Nitrogen-fixing bacteria convert nitrogen gas into nitrogen compounds that plants can absorb and use in making amino acids to build proteins.