Video Reviews

1
Video Reviews

• Wolves of Yellowstone
• Stoneflies
• Invasive species
• Wildlife corridors
• Flying foxes
• Dung beetles
• Sea Otters
• Sea lamprey
• Ants and acacia tree

2
Community Ecology

• AP Environmental Science
• Milton High School

3
Habitat fragmentation causes significant decline
in species diversity

• Reduce species richness
• Reduce amount of functional habitat
• Cause isolation of a species
• Possibility of genetic drift or inbreeding

4
(No Transcript)
5
Edge Effects Associated with Habitat
Fragmentation Can Reduce Biodiversity

• Makes many species vulnerable to stresses such as
  predators and fires
• Creates barriers that can prevent some species
  from colonizing new areas and finding food and
  mates

6
Edge effect
7
Conservation Biologists Protect Biodiversity

• Preserving large areas of habitat
• Using migration corridors to link smaller habitat
  patches

8
Bridges over roads
Tunnels under roads
9
Who benefits from wildlife corridors?
10
Species diversity

• Species richness number of different species
• Species evenness abundance of individuals
  within each of those species

11
The Most Species-rich Environments

• Tropical forests
• Coral reefs
• Deep sea
• Large tropical lakes

12
Three Major Factors Affect Species Diversity

• Latitude (distance from equator)
• Depth (aquatic systems)
• Pollution (aquatic systems)

13
Number of Species Found on an Island Determined
by a Balance Between

• Rate at which new species immigrate to the island
• The rate at which species become extinct on the
  island

14
Two features of an island which affects its
immigration and extinction rate

• Islands size
• Islands distance from the mainland

15
Canary Archipelago
What can you predict about how each island was
colonized by wild species?
16
General principles of island colonization

• The closer the island is to another land mass,
  the higher the probability of colonization.
• 2) The older the island, the more likely it will
  be colonized.
• 3) The larger the island, the more species are
  likely to be established.
• 4) The geographic isolation reduces gene flow
  between populations.
• 5) Over time, colonial populations become
  genetically divergent from their parent
  population due to natural selection, mutation,
  and/or genetic drift

17
Island Biogeography
Explain Robert MacArthur and E.O. Wilsons Theory
of Island Biogeography? How is this theory
applied to the management of National Parks?
18
Critical Roles of Keystone Species

• Pollination of flowering plant species
• Dispersion of seeds by fruit-eating animals
• Habitat modification (Gopher tortoise)
• Predation by top carnivores to control
  populations of various species
• Improving the ability of plant species to obtain
  soil minerals and water
• Efficient recycling of animal wastes

19
Sea Otter A keystone species
20
Sea otters feed on the sea urchin which eats the
base of the kelp plants (killing the kelp plants)
21
(No Transcript)
22
The Dodo bird inhabited the island of Mauritius
in the Indian Ocean
23
In 1505, the Portuguese became the 1st humans to
set foot on Mauritius

• Dodo bird source of food for the sailors
• Dutch used the island as a penal colony and
  brought pigs and monkeys which ate the eggs of
  the dodo bird

24
A combination of human exploitation and
introduced species significantly reduced the dodo
population
The last dodo bird was killed in 1681
25
Scientists discovered a certain species of tree
was becoming quite rare on Mauritius. All of the
remaining trees of their species were about 300
years old and no new trees had germinated since
the late 1600s.
26
Was it coincidence that the tree had stopped
reproducing 300 years ago and that the dodo bird
had become extinct 300 years ago?
27
The dodo ate the fruit of the tree and the seed
only became active and could grow after passing
through the digestive tract of the dodo bird.
Scientists discovered the turkeys digestive
tract accomplishes the same task and they are now
using turkeys to begin a new generation of the
tree - Tambalacoque
28
Biological indicator species are unique
environmental indicators as they offer a signal
of the biological condition of a particular
habitat
Using bioindicators as an early warning of
pollution or degradation in an ecosystem can help
sustain critical resources
29
Fish are an excellent indicator of watershed
health because

• Live in water all of their life
• Differ in their tolerance levels to amount and
  types of pollution
• Are easy to collect
• Live for several years
• Are easy to identify

30
Benthic macroinvertebrates are good indicators
because

• Live in water for all or most of their life
• Stay in areas suitable for their survival
• Are easy to collect
• Differ in their tolerance to amount and types of
  pollution
• Are easy to identify
• Often live for more than one year
• Have limited mobility
• Are integrators of environmental condition

31
Possible Causes of Amphibian Declines

• Loss of habitat
• Prolonged drought
• Pollution (pesticides, nitrates, pH)
• Increases in ultraviolet radiation
• Increase parasitism
• Overhunting
• Epidemic diseases
• Immigration or introduction of alien predators
  and competitors

32
(No Transcript)
33
What is the disadvantage?
34
Five Basic Types of Interactions Between Species

• Interspecific competition
• Intraspecific competition
• Predation
• Parasitism
• Mutualism
• commensalism

35
sucking disc does not harm shark
Remora
Commensalism
36
Bacteria in your intestines
37
Significant Niche Overlap one of the competing
species must

• Migrate to another area
• Shift its feeding habits or behavior through
  natural selection or evolution
• Suffer a sharp population decline
• Become extinct in that area

38
How Species Avoid Predators

• Run, swim, fly fast
• Highly developed sense of smell or sight
• Protective shells
• Thick bark
• Spines
• camouflage

• Parts that break off
• Chemical warfare
• Warning coloration
• Behavioral strategies
• Puffing up
• Mimicry
• Schooling
• Living in large groups
• Spreading their wings

39
Avoiding predators
40
(No Transcript)
41
(No Transcript)
42
Examples of Primary Succession

• Bare rock exposed by glacial retreat or severe
  soil erosion
• Newly cooled lava
• An abandoned highway or parking lot
• Newly created shallow pond or reservoir

43
Pioneer species start soil formation process by

• Trapping wind-blown soil particles and tiny
  pieces of detritus
• Producing tiny bits of organic matter
• Secreting mild acids that slowly fragment and
  break down the rock

Lichen
44
(No Transcript)
45
Examples of Secondary Succession

• Abandoned farmlands
• Burned or cut forests
• Heavily polluted streams
• Land that has been dammed or flooded

46
Three Aspects of Stability

• Persistence resist disturbance
• Constancy keep within limits
• Resilience bounce back

47
The End
48
Role of positive and negative feedback loops in
the stability of an ecosystem

• Negative feedback loops promote stability in a
  dynamic system
• Positive feedback loops usually leads to one or
  more populations being wiped out (local
  extinction)

Positive feedback loop causes a system to
change further in the same direction (positive
refers to the direction of change, rather than
desirability of the outcome) Negative feedback
loop causes a system to change in the opposite
direction
49
Positive feedback loop
A warmer atmosphere will melt ice and this
changes the Earths albedo which further warms
the atmosphere
An increase in temperature will melt the
permafrost in the tundra causing a release of
trapped carbon dioxide and methane (both are
greenhouse gases)
50
Negative feedback loop
Predator-prey relationship The moose population
will rise and fall in response to the wolf
population
51
Positive and negative feedback loops coupled
together

1. The settlers of Easter Island found plenty of
   natural resources
2. The Islanders had many children and the
   population went up
3. The islands tree and soil resources were used
   faster than they could be renewed
4. Without trees Islanders could not build
   traditional seagoing canoes
5. All of the islands natural resources were
   used up
6. Both the population and the civilization
   collapsed

52
Example of negative feedback loop
An example of negative feedback is body
temperature regulation. If blood temperature
rises too high, this is sensed by specialized
neurons in the hypothalamus of the brain. They
signal other nerve centers, which in turn send
signals to the blood vessels of the skin. As
these blood vessels dilate, more blood flows
close to the body surface and excess heat
radiates from the body. If this is not enough to
cool the body back to its set point, the brain
activates sweating. Evaporation of sweat from the
skin has a strong cooling effect, as we feel when
we are sweaty and stand in front of a fan.
Read more Homeostasis - Biology Encyclopedia
- cells, body, examples, function, human,
process, system, organisms, blood
http//www.biologyreference.com/Ho-La/Homeostasis.
htmlixzz11mSI4EzD
53
Example of positive feedback loop
An example of its beneficial effect is seen in
blood clotting. Part of the complex biochemical
pathway of clotting is the production of an
enzyme that forms the matrix of the blood clot,
but also speeds up the production of still more
thrombin. That is, it has a self- catalytic ,
self-accelerating effect, so that once the
clotting process begins, it runs faster and
faster until, ideally, bleeding stops. Thus, this
positive feedback loop is part of a larger
negative feedback loop, one that is activated by
bleeding and ultimately works to stop the
bleeding. Read more Homeostasis - Biology
Encyclopedia - cells, body, examples, function,
human, process, system, organisms, blood
http//www.biologyreference.com/Ho-La/Homeostasis.
htmlixzz11mSpKQyy