1. ES: Community Ecology, Population Ecology, and Sustainability
Chapter 6

2. KEY IDEAS What determines the number of species in a community?
How classify according to roles in community?
How do species interact?
Communities respond to environmental changes?
How do reproductive patterns differ in species? Human Impact?
How do Niches Change?
Sustainability?
Natural Capital?

3. Lets talk Niche

4. NICHE and ADAPTATIONS (4.3) & ( 6.3)
A Niche is an organisms role in the ecosystem. It affects it and others survival and reproductive Fitness(reproduction)
No two organisms occupy the same niche
Habitat: Where it lives

5. Niche: Fundamental and Realized
Realized the actual range available due to competition
Fundamental
Full potential range that can theoretically used
Chthamalus : fundamentally could
live in many zones. Balanus moves
him out.

6. NICHE Fundamental niche Realized Niche
Describes the potential a species has to be completely successful in using its resources to the fullest extent without competition,predation, or pressure from limiting factors.
Describes what a species is actually going to do in terms of using its resources due to pressures from limiting factor s ,predation, or competition

7. Exclusion of an organisms niche
Competitive Exclusion or interspecific exclusion
Intraspecific Exclusion
Competition between two species forms exclusion of each other . They Competitively exclude one another out of a niche .One of the competitors always overcomes the other.
New niche may form or evolutionary shift or extinction
When the same species exclude each other it is Intraspecific Exclusion.
Niches Overlap

8. Competitive exclusion

9. When the same species exclude each other it is Intraspecific Exclusion The woodpecker
Males characteristically forage on small trees or on small branches of large trees
females typically forage on the trunks and larger limbs of large trees.
The niches overlap, but the slight distinction limits competition between the sexes
So long as there are enough resources species can share them.

10. Can lead to adaptations or radiation of the species

11. Radiation of the Species: adaptations form from competition creating speciation – new species

12. Resource Partitioning reduces or avoids competition
Specialized traits evolve that allows them to share resources at different
Times -temporal
Ways- Ways they get food
places - different areas of same resource
One tree many resources

13. Speciation:Formation of a species through competition, limiting factors, and adaptations

14. Resource partitioning summary: forms adaptations that cause specialization and new niches

15. Limiting Factors ?DDLF – DDIF?
Density Dependent Limiting factors (DDLF)
Density Independent Limiting factors(DILF)
Limiting factors that are intensified by the density of populations
Are typically bioitc factors
Competition
Bacterial disease
Symbiosis-species relationships
Limiting factors that are NOT intensified by population numbers
Are typically abiotic factors
Climate
Natural disasters
Viral disease

16. 6.1 Community Structure and Species Diversity
Physical Appearance – Sizes, stratification and distribution of species (pg 110)
Physical Appearance lends to species richness and evenness as physical appearance changes

17. Community Structure is Zoned
Community Structure is Zoned. Zones are Wide and Varied due to many factors
Aquatic Zones affected by temperature, amount of light, salinity,pressure,

18. Some other Factors cause these variances: Sunnier, warmer, drier, lighter, darker,moister, acidic, salinity,biomass abundant…

19. Zoned Life is Patchy…. (directly from your book!)
Community structure also varies around its edges where transitions of communities
take place.

20. Human Impact: Habitat Fragmentation
Increases forest edge or buffers: Makes species more vulnerable to stresses like predators, fire, and creates barriers where species cannot colonize and finding food.

21. Species Diversity and Niche Structure
Species Richness (number of species)
Species Evenness (number of individuals within species) = Species Diversity
Allows community a to differ from b to differ from c………
Typically a community is either rich or even but not both!

22. Species Diversity Types
Species Richness The number of species in an areas of each species present. This is rrsity
How rich are the species in your area?
Species Evenness : how many of each species exists in that areanumber of members How even is the diversity?
IF: Species A = 56 members
Species B = 55 members
Species C = 52
Then: species evenness is good but diversity is low!
Rainforest, coral reef , deep sea, large tropical lakes have high species diversity but low species evenness
(few members in each)

23. DIVERSITY CREATES NICHE STRUCTURE
Highest in tropics and declines as move North and south from equator

25. Are Complex Communities more sustainable than Simple ones?
Typically: Net Primary productivity indicates ecosystem is more resilient with species diversity of (complex) However, not conclusive, and still a hot environmental topic. Some believe simple communities have just enough diversity to survive.
Agree: All communities need producers and decomposers .which producers and which are essential is the question.

26. Species Types 6.2

27. 6.2 Species Types Native:Normally live and thrives in area
Has competitors and
Natural predators
Non-Native,Invasive, Alien Have Migrated or been deliberately or accidentally transferred into an area Some have no effect: corn, chickens

28. Indicator Species Think : Range of Tolerance

29. Indicator Species Biological smoke alarms
Fish, birds, amphibians, butterflies
Indicate ecosystem health: pH, Habitat fragmentation, dissolved oxygen in water communities, pollution, reduction in stratospheric ozone, climate change, over hunting…

30. Amphibians as an Indicator Species
Habitat loss-defragmentation
Prolonged Draught
Pollution – pesticides
UV Radiation
Parasites
Overhunting
Viral/Fungal diseases
Non-native predators/competitors

31. WHY CARE? 1st – environmental health deterioration
2nd – Amphibians eat more pests and feed many others
3rd – They are genetic storehouse of pharmaceuticals
Painkillers, antibiotics, burn treatment
(biopharming)

32. Keystone Species
A wedge shaped stone placed in an archway supporting the entire arch
IF REMOVED: DRAMATIC !!!!
Ecological Services go out all over

33. Keystone Species
Have a huge effect on the species richness and evenness of an ecosystem.
A keystone species disappears can lead to population crashes and extinction.

34. Keystone Niche Pollination Regulation/control population
Remove, Bury, Recycle (dung it anyway!)
Biopharming

35. Foundation Species: Create and enhance habitat in ways that benefit others
Trimming Trees
Rolling over rocks
Tearing trees out by roots
Planting

36. 6.3 Species Interactions
Key Concept: Increase ability to survive through Competition and Symbiotic Relationships

37. Competition Interspecific Competition
Abundant Resources personify fundamental niche
Non abundant causes a more realized niche
Humans deprive species of resources causing more realized niches occupation
Interspecific
Competition

38. Can we Reduce or Avoid Competition? Competition allows for
1.Adaptations through Natural Selection
2.Predator/Prey Relationship Prey on the least fit
3.Keeps populations in check not to exceed resources

39. How do predators increase their chances of catching prey?
Lie in wait
Persue
Camoflage

40. Can Prey Defend Themselves?
Escape
Pretective shells
Camoflage
Mimicry
Chemicals

41. Parasites Sponge Off Each Other
Parasite (sponger)
Host (spongee)

42. Other symbiotic relationships
Mutualistic:
Commensalistic:
Parasitic
Both benefit ++
One benefits other is neither harmed or benefits +0
One benefits the other is harmed +-

43. 6.4 Ecological Succession
Change of Producers mass Over Time
Terrestrial Succession

44. Aquatic Succession

45. Succession
PRIMARY
Gradual establishment of biotic communities on newly exposed rock
No soil, No bottom sediment
Receding ice bergs
New Lava Flows
SECONDARY
On existing soil, or bottom sediment
Reestablishment of any Cleared area due to
Fires, tornados, tsunamis, human impact

46. Is this primary or secondary succession?

48. From Pioneer Species to Intermediate Species, to a Climax Community Primary: initial, does not need much soil or water Intermediate species: need some soil, water, sun Climax community: needs more soil and other factors

49. Can we Predict Succession? Not Always
An ever changing mosaic of vegetation patches
On going struggle by species for resources
Climax Community: Mature community for that climate

50. 6.5 Population Dynamics and Carrying Capacity
Enter: Births, immigration, and decrease in deaths
Exit: Death, emigration

51. © 2004 Brooks/Cole – Thomson Learning
Figure 9-4 Page 193
© 2004 Brooks/Cole – Thomson Learning K
Population size (N)
Population size (N)
Time (t)
Time (t)
Exponential Growth is J shaped: rarely keeps
going
Logistic Growth: levels off is S shaped.
Growth is never just exponential only – it reaches carrying capacity and levels off

52. Overshoot of Carrying Capacity
Occurs when births are greater than deaths
Humans not exempt
Then causes a ‘dieback’ or ‘crash’
Polynesians on Easter Island

53. Carrying Capacity is ecosystems maximum ability to support populations
Carrying Capacity is ecosystems maximum ability to support populations. Directly related to producer biomass and climate

54. Exponential vs. Logistical Growth Curves
Lag Phase—First portion of the curve; slow population growth.
Exponential Growth Phase—More organisms reproducing causing accelerated growth; continues as long as birth rate exceeds death rate.
Stable Equilibrium Phase—Death rate and birth rate equilibrate; population stops growing; achieved in logistical growth curves

55. Population Growth Curve

56. Reproductive Patterns R and K Strategies
Some species have few offspring and take care of them until they care for themselves
K Selected Species
( K = competitor)
Some have many and care-less
R-selected species
(R means Rapid)

57. Reproductive Strategies and Population Fluctuations
Not all species reach a stable carrying capacity.
Species can be broadly lumped into two categories:
K- strategists- competitor species; they do well in competitive situations where population size is close to or at carrying capacity; logistical growth
R-strategists- have a high intrinsic rate (r) of increase; exponential “boom & bust” cycles of growth

58. Reproductive Strategies Which one has a greater Range of Tolerance?
K-selected:
mature slowly
have few offspring at a time
most endangered species are K-selected
population stabilizes near carrying capacity
maintain numbers in stable ecosystems
Do well in competitive conditions
Specialist Niche
Late Succession dwellers
High ability to compete
Livestock
Mammals
r-selected:
mature rapidly
have many offspring - tend to overproduce 
Die before reach maturity 
population not regulated by density
 opportunistic -- invade new areas
Generalist Niche
Early Succession dwellers
low ability to compete
opportunists
Crops
Algael
Bacteria
Depends on the available habitat determines success!

59. 6.6 Human Impact on Ecosystems
Where Natural Systems would allow
re-growth, reuse,recycling, and be renewable…Man doesn’t and is less forgiving ,simplifying biodiversity, Using up non-renewable energy, producing much waste, wastes rather than recycles
and uses, destroys, or degrades Net Productivity
Ie: (doesn’t share with others well)

60. Principles of Sustainability
Follow Nature - Four Ways
Nutrient Cycling -Renewable Resources Especially Energy and waste
Solar Energy
Use Biodiversity to maintain itself and adapt
Control population size and resource use