1. ECOLOGICAL PRINCIPLES

2. INTRODUCTION TO ECOLOGY
ORGANIZATION OF LIVING EARTH
POPULATION DYNAMICS
FLOW OF ENERGY
CYCLES IN NATURE
SUCCESSION
INTRODUCED, ENDANGERED AND KEYSTONE SPECIES

3. BIOSPHERE
a thin blanket of life surrounding the earth which arises when atmosphere, land and sea meet
most fragile layer of the earth
10 miles thick (5 miles up into atmosphere, 5 miles down into ocean)
ecosystems exist within the biosphere

4. Arrangement of the Biosphere

5. ? COMPONENTS OF A BIOME Biomes are large geographic areas defined by:
-climate (temp, rainfall…)
-soil type
-type of plants
(plants determine animals) ?

8. Biome terms
Diversity-number of different kinds of living and non-living “things”
Temperate-distinct seasons
Tropical-consistently warm
Deciduous-plants shed leaves
Coniferous-leaves are year round

9. ECOSYSTEM: a place where relationships between biotic and abiotic factors are affected by geology and climate
energy is processed through the biotic components
interrelationships create stability
populations are the basis of ecosystems

10. BIOTIC: living organisms (plants and animals)
ABIOTIC: non-living (water, minerals, soil…)
POPULATION: the number of organisms of the same species
SPECIES: organisms that can interbreed and produce fertile offspring

11. Microclimates ?

12. HABITATS
small subdivisions of an ecosystem where biotic components live and acquire the basic requirements of life
must include essential abiotic components
BASIC REQIREMENTS: food, shelter, water, space, air

13. Habitat is the ADDRESS varies in size
habitats overlap between different species
varieties of habitats increase diversity
BIODIVERSITY: number of different kinds of organisms within the ecosystem

14. DIVERSITY = STABILITY
survival of the ecosystem is dependent on its diversity
the greater the diversity, the more likely an ecosystem could survive a cataclysmic event (like an extinction, volcano…)

15. EDGES ARE VERY STABLE
the edge habitat (place where 2 habitats overlap) has the greatest diversity of plants and animals
edge is usually more stable than either of the 2 habitats it divides
edge shares species from both habitats as well as supporting edge only species

18. POPULATION DYNAMICS
Explains how wild populations control and maintain themselves
Based on the idea that resources are limited (CARRYING CAPACITY)
All species (plants and animals) must have the BASIC REQUIREMENTS OF LIFE
-FOOD, SHELTER, WATER, SPACE, AIR
AND OF COURSE THE RIGHT CLIMATE

19. POPULATIONS Members of the same species
Populations are limited in “range” by habitat, geology, climate and limiting factors within their habitat
Tends to be maintained within the carrying capacity and critical number

20. LIMITING FACTORS
something that maintains population size within the habitats carrying capacity
Food Climate
Competition 8. Disease
Predation
Geology/geography/topography
Human influences
Lack of any requirement of life

21. Squirrels in the Grand Canyon use to be one population
Squirrels in the Grand Canyon use to be one population. But, geological process have separated 2 groups which have evolved into 2 different species—The Kaibab on the north rim and the Aberts on the south rim. They have acquired so many differences that they are now 2 different species.

22. Kaibab Squirrel Aberts Squirrel
Two populations of squirrels, each have their own habitat and niche. Each exist because they fit into the environment with its abiotic factors. Temperture, humidity, and plants have shaped these populations.

23. Carrying Capacity
CARRYING CAPACITY: the number of organisms of a species that a habitat can support (provide basic requirements)
Example: The pond can support 25 frogs. What may limit the number of frogs?

24. Consequences
breaking the carrying capacity will cause collapse of the population
may lead to extinction
may reduce gene pool
may just reduce numbers long enough for the habitat to recover

25. Can Carrying Capacity Change?
Yes
Increases with habitat improvement
Decrease in abusive population
Better weather promoting good food
Decreases with habitat destruction
Increase in populations above carrying capacity
Cataclysmic event (volcano)
Changes in climate (global warming?)

26. Critical Number
The lowest number a species can drop to in an ecosystem and still recover
Set by nature to maintain genetic diversity
Prevents in-breeding and passing on “bad genes”

27. Populations may stabilize
Stable populations will fluctuate between the carrying capacity and the critical number.
Most species with proper limiting factors will function along these lines
This is called DYNAMIC
EQUILIBRIUM
These are called S-Curve populations

28. S-curve Populations Draw your own in your notes!!! NUMBER TIME
Carrying Capacity
NUMBER
Critical Number
TIME

29. causes of stabilization
Emigration
Immigration These are
Death limiting factors!
birth
predator-prey
disease

30. J-curve Populations Are not stable populations
Usually crash after they break carrying capacity
Due to lack of limiting factors or it has a special reproductive strategy
-many young with lack of parental care such as fish
May be an invasive species (gypsy moth)

31. J-curve Populations Draw your own in your notes!!! NUMBER TIME
Carrying Capacity
NUMBER
Recovery
Critical Number
Extinction
TIME

32. FLOW OF ENERGY Energy is processed Feedback
input energy ecosystem output energy
-this allows the ecosystem to maintain an energy balance

33. NICHE = JOB the way an organism makes a living in their habitat
niche describes how the organism gets it energy
producer (autotrophs and herbivores)
consumer (carnivores, scavengers)
decomposers

34. NICHE
WHAT THEY EAT
TYPES OF ORGANISMS
Autotroph
Sunshine—these organisms make their own food
Plants (the green guys)
Herbivore
Plants
Bunnies, deer, bees
Carnivore
other animals-general term
Lions, anteaters, fox, bass
Predator
Hunts, kills, eats other animals
Parasite
Lives on or in living organisms, on their body materials
Ticks, tapeworms, fleas
Omnivore
Both plants and animals
Bears, people, skunks
Scavenger
Dead or dying animals
Vultures, crows, crayfish
Detritivore
Dead plants and leaves
Beetles, fungus
Decomposer
Small particles and dead portions of other organisms
Bacteria, fungus

35. THE SUN IS THE SOURCE OF ENERGY FOR ALL LIVING THINGS (almost)
photosynthesis in autotrophic organisms converts sunlight energy into carbohydrates (BIOMASS)
they use oxygen to accomplish this
organisms are called photosynthetic autotrophs (plants and algae)

36. ? BIOMASS: the total weight of living matter in an ecosystem
It accumulates in the food chain as processed energy
Energy
can be
“lost” ?

37. exception to the rule CHEMOSYNTHESIS
organisms make carbohydrates out of carbon dioxide, water and inorganic compounds (like sulfur and nitrates)
organisms are called chemosynthetic autotrophs (deep ocean bacteria)

38. Chemosynthetic organisms

39. Deep Ocean Ecosystems

40. FOOD CHAINS
a series of organisms which pass energy from one feeding level to the next
This process coverts one form of biomass to another
these levels are called TROPHIC LEVELS

41. TROPHIC LEVELS Primary Producer Primary Consumer Secondary Consumer
After secondary you can call them “higher consumers” by referring to their trophic level (3rd consumer, 4th consumer…..)

42. Food Chains always contain: sun, primary producer, decomposer
primary producer are autotrophs
the arrow points in the direction the energy is being transferred to
always flows in one direction
reads as “is eaten by”

43. examples sun carrot rabbit bacteria sun acorns squirrel hawk bacteria
sun grass deer bear human bacteria
Primary consumer
energy
Decomposer
Primary producer

44. ? some general rules Large carnivores do not eat large carnivores
herbivores do not eat carnivores
organisms within an ecosystem may compete for food sources
interacting food chains are called FOOD WEBS ?

45. ?
WHATS MISSING?

46. ENERGY PYRAMID or PYRAMID OF BIOMASS

47. 90% used/lost at each level
Energy lost
10% to next level
90% used/lost at each level
-biomass decreases at each step in a food chain
-energy is lost at each step: bones not used, fur, energy expended in eating and metabolism, feces….

48. larger organisms require more energy so there will be fewer at the upper levels
the shorter the food chain, the more organisms you can feed at the upper levels

49. eat lower on the food chain
1 human
300 trout
90, 000 frogs
27, 000,000 grasshoppers
1000 tons of grass
eat lower on the food chain
900 human
27, 000,000 grasshoppers
1000 tons of grass ?

50. ?

51. Species Interact with each other to maintain energy and population balances
Predator-Prey relationships

52. ?
Predators and Prey regulate each others populations

53. Competition -attempt to use the same limited resources
-limits population size between competitors

54. Categories of Competition
Interspecific:
competition between 2 or more species for a single resource
Intraspecific:
competition between members of the same species
-usually for mates or nesting habitat or territory

55. Interspecific competition shows how competition can be avoided by sharing resources (RESOURCE PARTITIONING). This guarantees that all species survive and increase diversity

56. Parasitism -lives on or in a host species -often host specific
-generally causes harm or death of host in extreme situations

57. Mutualism -both organisms will benefit from the arrangement
-symbiosis arises through coevolution

58. Commensalism one member of the relationship benefits
one member of the relationship gains nothing, but is not harmed
example: lichens growing on the tree benefit from the tree, but the tree is not harmed or helped by the lichen

59. DIVERSITY = STABILITY
the more food chains in a food web the higher the diversity
the greater the diversity, the more stable the ecosystem becomes
all ecosystems seek stability

60. IV. MATERIALS CYCLE MATERIALS CYCLE IN ECOSYSTEMS water cycle
carbon cycle
nitrogen cycle

61. WATER CYCLE

62. CARBON CYCLE

63. NITROGEN CYCLE

64. V. ECOSYSTEMS CHANGE SUCCESSION CAUSES CHANGES IN ECOSYSTEMS
ecosystems are never static
ecosystems tend to move from less diverse to more diverse systems

65. low species high species
diversity diversity
more energy less energy
available available
less biomass more biomass

66. Primary Succession occurs where no ecosystem has occurred before
uses pioneer species (lichens, moss) to form soils
begins on rock
often accompanies a cataclysmic event

67. Pioneer Species small plant organisms like lichens and mosses
their “roots” will gradually break off small chips of rocks
as they grow and die, the organic material mixes with the chips of rocks
soils begin to form (200 years = 1 inch of top soil)

68. Secondary Succession
occurs in areas of disturbance of existing ecosystems
species who are opportunistic will begin process
opportunistic species are generally fast growing and have a high reproductive rate

70. There are natural patterns of succession.
-fields become forests
-ponds become fields
-forests will change types of vegetation until maturity

71. Maturity ecosystems will become more complex
complexity slows rates of change
the higher the maturity, the longer the ecosystem will stay in that state
in general--fields become shrub lands
-- shrub lands become forests
-- ponds will become grasslands
as the ecosystem changes, the species composition changes

72. Fire Maintained Ecosystems
tends to halt/slow succession
maintains a particular successional state
some species require fire for reproduction
fire is used as a management tool to maintain ecosystems

74. Climax Communities
all ecosystems tend to move toward an idealistic end state called a climax community
arguments occur about its existence
climax allows for very little change

75. Introduced, Endangered, and Keystone Species
Introduced: a species that did not evolve in the habitat, it was released on purpose or by accident
Endangered: a species which are so close to the critical number that it may become extinct in the near future
Keystone: a species which is critical to the survival of an ecosystem-they are tied to many other species

76. Introduced Species
Gypsy Moths introduced into this country in 1869 have devastated much of the eastern oak forests. Non-native species do not have limiting factors to control their populations. This causes elimination of native species.

77. Rabbits introduced into Australia have devastated the native grasslands and endangered kangaroos and other native wildlife.

78. California Condor
The largest bird of North America was brought to the brink of extinction due to:
-over hunting
-habitat destruction
-egg collecting
-DDT (pesticide)

79. In 1987, the last wild condor was removed and placed with the remaining population in captivity-there were 26
A captive breeding program is in effect and as of 2005 there were 146 birds
Scientists question if they had reached the critical number as all 27 of the first breeding population had originated from 14 birds

80. KEYSTONE SPECIES- organisms which are important in shaping the total ecology of an ecosystem
Cray fish and Beaver are both keystone species in Pennsylvania. It is because they form habitats (like beaver) or are a major food source for many organisms. Either way they have major influence over their ecosystems. Loss of these species would result in ecosystem collapse.