1. Equilibrium in the Biosphere
Biology 20
Equilibrium in the Biosphere

2. Ecology
explain the one-way flow of energy through the biosphere and how stored biological energy in the biosphere is eventually “lost” as thermal energy
explain how biological energy in the biosphere can be perceived as a balance between both photosynthetic and chemosynthetic, and cellular respiratory activities

3. Ecology
Study of the interactions between organisms and their physical environment and with each other.
includes aspects of both the living (biotic) and non-living (abiotic) components of the physical environment.

4. Biosphere
Biosphere
the part of the earth that is inhabited by organisms.
3 parts:
Lithosphere
Land
Hydrosphere
water
Atmosphere
The gasses that surround the Earth.

5. Living vs. Non-living
There are two factors which make up the biosphere.
Biotic Factors
Living components of the biosphere
plants and animals…
Abiotic Factors
Non-living components
of the biosphere
minerals, water, weather...

6. Interactions Within the Biosphere
Abiotic vs Biotic
When a non-living factor affects a living factor.
i.e. The weather affecting a living organism
Biotic vs. Biotic
When a living factor affects another living factor.
i.e. Two organisms fighting for the same food.
Biotic vs. Abiotic
Abiotic vs. Abiotic

7. Levels of Organization

8. Levels of organization
Cell
Tissue
Organ
System
Organism
Population
Community
Ecosystem
Biome
Biosphere

9. Levels of Organization

10. Hierarchical Levels within the Biosphere
Biosphere Ecosystem Community Population Organism
World Lake or River Lots of different species of organisms Lots of same species of fish Fish

11. Important Definitions
Population: group of individuals of the same: species, place & time
Community: populations of all species in an area
Ecosystem: community and its biotic and abiotic factors
interactions
Biome: large scale ecosystems
Can be found around the world  tundra, grassland

13. Food Chain
a linear illustration that represents the step sequence of who eats whom in the biosphere.
used to show:
energy transfers
cycling of matter through the biosphere
Two types:
Grazer: plant, herbivore, carnivore
Detritus: organic waste
Waste – scavengers – decomposers

14. Assignment 1.1 Use your text book and define the following Terms
Biodiversity
Producer
Consumer
Read pages 8-10 (new text only)
Do Questions 1-7 section 1.1 page 10

15. Equilibrium Unbalanced

16. Autotrophs “self feeders” Require energy from sun – photosynthesis
Convert energy from sun into a form of energy that other living things can use
Provides O2 – required by all living things
Provide basic molecules for life
Carbohydrates, proteins, fats, and nucleic acids
PRODUCERS!

17. Heterotrophs
Require a source of chemical energy and basic organic molecules
NO photosynthesis
Feed on plants OR other heterotrophs
CONSUMERS!
A primary consumer eats a producer
A secondary consumer eats a primary consumer
A tertiary consumer eats a secondary consumer…

19. General Terms Herbivore Carnivore Omnivore
An organism that only eats plants.
Rabbit, squirrel
Carnivore
An organism that only eats animals.
Wolf, Lion, Tyrannosaurus Rex
Omnivore
An organism that eats both plants and animals.
Bear, Human

20. More General Terms Scavenger Decomposer
An organism that feeds on dead organisms or the wastes of organisms.
Vulture, Seagull,
Decomposer
An organism that breaks down organic wastes and the remains of dead organisms into simpler compounds such as:
carbon dioxide
ammonia
Water

21. Species At-Risk
Species At-Risk

22. Species At-Risk
Indicator Species – A species sensitive to small changes in environmental conditions

23. Frogs live in two different ecosystems
Describe why frogs and other amphibians are important indicator species:
Frogs live in two different ecosystems
Water as a tadpole
In forest and grassland as adults
Any hazards in either ecosystem will have an effect on the frogs.
Also frogs occupy two different food chains.

24. Why Are Frogs Disappearing?
The worldwide disappearance of frogs is puzzling scientists around the globe.
- Loss of Habitat
Frogs need wetlands, ponds, or lakes with clean water to breed and lay their eggs.
They need a place where they can catch insects such as forest and fields.

25. - Climate Change - Air and Water Quality
Frogs can breath through their skin, pollutants can also pass through their skin.
Acid of water also has an ability to reproduce.
- Climate Change
Climate change can cause important changes in local ecosystems.
If the climate becomes drier frogs populations will decline.

26. 4. Ultraviolet Radiation
The thin skin of the frog is susceptible to ultraviolet radiation.
The amount to UV radiation reaching Earth's surface is increasing because of damage to the protective ozone layer surrounding Earth.

27. Ecology Energy and Matter Exchange
Biology 20
Ecology
Energy and Matter Exchange

28. General Terms Ecosystem Autotrophs –Producers Heterotrophs - Consumers
A community of organisms interacting with each other and with their nonliving surroundings.
Autotrophs –Producers
Heterotrophs - Consumers

30. Biogeochemical Cycles
Input energy
Ecosystems are OPEN SYSTEMS. Energy and matter can flow in and out of system
Biogeochemical
Cycles
Energy Lost

31. Ecosystem Models
Explain the structure of ecosystem trophic levels, using models such as food chains and food webs

32. Food chains Food Chain energy transfers Characteristics:
step sequence of who eats whom in the biosphere.
used to show:
energy transfers
Characteristics:
Energy is transferred from organism to organism
Each time energy is transferred about 90% is lost as heat or used for life processes

33. Food Chain Note that: the arrow points at the eater
the arrows separate trophic (eating) levels

34. Trophic Levels
Trophic level: how far an organism is from the original energy source
Plants – first trophic level
Original energy is from the sun
When an organism is ingested by another, energy is transferred
Plant – mouse – owl
Producer – primary consumer – secondary consumer (top carnivore)
T1 – T2 – T3

36. Food Webs What would happen if we relied on deer for our food?
In reality, a consumer relies on more than one food source
If one source is scarce, consumer can eat more of something else
Food web:
a series of interlocking food chains
more accurately represents energy pathways
who eats whom… really

37. Food Web ABCD represent different trophic levels.
Level D represents the decomposers

41. Laws of Thermodynamics
Biosphere requires a constant flow of energy
Energy flows one way through the biosphere following basic scientific principles called the laws of thermodynamics

42. Laws of Thermodynamics
First Law
Energy can be changed in form,
but not created or destroyed.
(Law of conservation of energy)
Energy input = Energy Output

43. Energy input  desired energy + waste energy
Second Law
Any energy change results in loss of energy as heat
Energy input  desired energy + waste energy

44. Energy Flow
About 10% of the energy is transferred from one trophic level to the next.

45. During any change, some of the energy is lost as waste energy or heat.
Applied to an ecosystem, as energy flows through the community there is energy loss at each trophic level.
Much of this loss is in the form of heat which is lost when food molecules are broken down in the cells.
There would be less energy loss in the community if only herbivores fed on the producers

47. Energy Flow in the Ecosystem
explain quantitatively, energy exchange in ecosystems, using models such as pyramids of energy , biomass, and numbers
explain the interrelationship of energy, matter and ecosystem productivity (biomass production)

48. Ecological Pyramids
Ecological pyramids illustrate the energy loss through the trophic levels
Solar radiation transformed in plants
Plants create chemical energy
Plant eaten by consumer
Energy lost at each transformation
Higher trophic level = less energy available
Number of trophic levels limited b/c of loss of energy

49. Ecological Pyramids In ecological pyramids,
Base -the producer populations
Next Level - the primary consumers
Higher levels and above -the secondary, tertiary etc.

51. Ecological Pyramids Three types:
Numbers: total number of organisms in each trophic levels
Biomass: mass of dry tissue of organisms at each trophic level
shows how mass decreases as you move up the food chain
Energy: based on energy produced at each trophic level

52. Ecological Pyramids

53. Pyramid of Numbers

56. Pyramid of Biomass

57. Human Interference in the Ecosystem
Fire
Hunting and fishing
Monoculture
Pesticide usage and biological amplification (magnification)

58. Fire Before the Europeans settlement, wildfires swept across the land.
Fire destroys vegetation, returning nutrients to the soil
Fire usually only destroys vegetation above ground. Allowing new growth.
Fire prevents the over growth of aspen parkland into the grassland ecosystem

59. Fire European settlement Impact upon grasslands.
Fire control (More Aspen Parkland)
Introduction of many new species of plants
(Mustard, pepperfrass, Russian thistle, pigweed, and stinkweed)

60. Hunting and fishing
New technology has improved ways of finding animals. Which has resulted in:
Over hunting and fishing
Reducing the number of animals.

61. Monocultures Monoculture: Huge diversity of species on earth
growing a single species of plant, excluding others
Huge diversity of species on earth
million
Ecological change = species extinction
Humans = biggest change maker

62. Monoculture Effects Impact? Humans rely on a small variety of species
Other species being decimated
At what cost?
Loss of diversity
Loss of possible cures
Rainforests: soil not suited to human needs
loses productivity in a few years

63. Pesticides Pesticides used to kill pests mosquitoes - malaria
pesticides in food chain accumulate
causes loss of diversity.

64. Example DDT: dichloro diphenyl trichloroethane
developed as a biological weapon in WWII
1950’s - used as a pesticide for insects

66. DDT also affects human pops
found in breast milk
came from sprayed crops
animals that ate crops
Banned in Canada and US in 1970’s
Not banned in other areas - Mexico, Central America
Continues to be produced as a cheap pesticide in poorer nations

67. Biological amplification
Pesticides accumulate at the top level of the pyramid
toxins accumulate in fatty tissue
not released in wastes
accumulates each time you move up
higher trophic level - higher concentration

70. Biogeochemical cycles
explain and summarize the cycling of carbon, oxygen, nitrogen, and phosphorus and relate it to the reuse of all matter in the biosphere
explain water’s role in the matter cycles, using its chemical and physical properties
explain how the equilibrium between gas exchanges in photosynthesis and cellular respiration influences atmospheric conditions