Community Ecology, Community Ecology, Population Ecology, and Population Ecology, and
SustainabilitySustainability
Chapter 5 (New Book – 14Chapter 5 (New Book – 14thth Ed) Ed)
(Chapter 6 – Old Book – 13(Chapter 6 – Old Book – 13thth Ed) Ed)
Why Should We Care about the Why Should We Care about the American Alligator?American Alligator?
OverhuntedOverhunted
NichesNiches
Ecosystem servicesEcosystem services
Keystone speciesKeystone species
Endangered and threatened speciesEndangered and threatened species
Alligator farmsAlligator farms
New pp. 74-75
Key ConceptsKey Concepts
Factors determining number of species in a Factors determining number of species in a communitycommunity
Roles of speciesRoles of species Species interactionsSpecies interactions Responses to changes in environmental Responses to changes in environmental
conditionsconditions Reproductive patternsReproductive patterns Major impacts from humansMajor impacts from humans Sustainable livingSustainable living
Community Structure and Community Structure and Species DiversitySpecies Diversity
Physical appearancePhysical appearance
Edge effectsEdge effects
Species diversity or richnessSpecies diversity or richness
Species abundance or evennessSpecies abundance or evenness
Niche structureNiche structure
OLD Fig. 6-2, p. 110
Natural Capital: Types, Sizes, and Natural Capital: Types, Sizes, and Stratification of Terrestrial PlantsStratification of Terrestrial Plants
Tropical rain forest
Coniferous forest
Deciduous forest
Thorn forest
Thorn scrub
Tall-grass prairie
Short-grass prairie
Desert scrub
Species Diversity and Ecological Species Diversity and Ecological StabilityStability
Many different species provide ecological stabilityMany different species provide ecological stability
Some exceptionsSome exceptions
Minimum threshold of species diversityMinimum threshold of species diversity
Many unknownsMany unknowns
Net primary productivity (NPP)Net primary productivity (NPP)
Essential and nonessential speciesEssential and nonessential species
Types of SpeciesTypes of Species
NativeNative
Nonnative (invasive or alien)Nonnative (invasive or alien)
IndicatorIndicator
KeystoneKeystone
FoundationFoundation
Indicator SpeciesIndicator Species
Provide early warningsProvide early warnings
Indicator of water qualityIndicator of water quality
Birds as environmental indicatorsBirds as environmental indicators
ButterfliesButterflies
AmphibiansAmphibians
New p. 73
Amphibians as Indicator SpeciesAmphibians as Indicator Species
Environmentally sensitive life cycleEnvironmentally sensitive life cycle
Vulnerable eggs and skinVulnerable eggs and skin
Declining populationsDeclining populations
New p. 73
sperm
Eggs
Sexualreproduction
Fertilized eggdevelopment Organ formation
Egg hatches
Tadpole
Tadpole develops into frog
Young frogAdult frog(3 years)
OLD Fig. 6-3, p. 112
Life Cycle of a FrogLife Cycle of a Frog
Possible Causes of Declining Possible Causes of Declining Amphibian PopulationsAmphibian Populations
Habitat loss and fragmentationHabitat loss and fragmentation
Prolonged droughtProlonged drought
PollutionPollution
Increases in ultraviolet radiationIncreases in ultraviolet radiation
ParasitesParasites
OverhuntingOverhunting
DiseaseDisease
Nonnative speciesNonnative species
Why Should We Care about Why Should We Care about Vanishing Amphibians?Vanishing Amphibians?
Indicator of environmental healthIndicator of environmental health
Important ecological roles of amphibiansImportant ecological roles of amphibians
Genetic storehouse for pharmaceuticalsGenetic storehouse for pharmaceuticals
Keystone SpeciesKeystone Species
What is a keystone?What is a keystone?
Keystone species play critical ecological rolesKeystone species play critical ecological roles
PollinationPollination
Top predatorsTop predators
Dung beetlesDung beetles
SharksSharksNew p. 74
Why are Sharks Important?Why are Sharks Important? Ecological roles of sharksEcological roles of sharks
Shark misconceptionsShark misconceptions
Human deaths and injuriesHuman deaths and injuries
Lightning is more dangerous than sharksLightning is more dangerous than sharks
Shark hunting and shark finsShark hunting and shark fins
Mercury contaminationMercury contamination
Medical researchMedical research
Declining populationsDeclining populations
Hunting bans: effective?Hunting bans: effective?New p. 61
Foundation SpeciesFoundation Species
Relationship to keystones speciesRelationship to keystones species
Play important roles in shaping communitiesPlay important roles in shaping communities
ElephantsElephants
Contributions of bats and birdsContributions of bats and birds
Species Interactions Species Interactions
Interspecific competitionInterspecific competition
PredationPredation
ParasitismParasitism
MutualismMutualism
CommensalismCommensalism
Fig. 6-4, p. 114
Nu
mb
er o
f in
div
idu
als
Nu
mb
er o
f in
div
idu
als
Resource use
Resource use
Species 1 Species 2
Regionof
niche overlap
Species 1 Species 2
Resource Partitioning and Niche Resource Partitioning and Niche SpecializationSpecialization
OLD
OLD Fig. 6-5, p. 115
Resource Partitioning of Warbler Resource Partitioning of Warbler SpeciesSpecies
New Fig. 5-2, p. 81
Predator and Prey InteractionsPredator and Prey Interactions
Carnivores and herbivoresCarnivores and herbivores
PredatorsPredators
PreyPrey
Natural selection and prey populationsNatural selection and prey populations
New pp. 81-83
How Do Predators Increase Their How Do Predators Increase Their Chances of Getting a Meal?Chances of Getting a Meal?
SpeedSpeed
SensesSenses
Camouflage and ambushCamouflage and ambush
Chemical warfare (venom)Chemical warfare (venom)
New pp. 81-83
Avoiding and Defending Against Avoiding and Defending Against PredatorsPredators
EscapeEscape SensesSenses ArmorArmor CamouflageCamouflage Chemical warfareChemical warfare Warning colorationWarning coloration MimicryMimicry Behavior strategiesBehavior strategies Safety in numbersSafety in numbers
New pp. 81-83
Span worm Bombardier beetle
Viceroy butterfly mimicsmonarch butterfly
Foul-tasting monarch butterfly
Poison dart frog When touched, the snake caterpillar changes shape to look like the head of a snake
Wandering leaf insect
Hind wings of io mothresemble eyes of a much larger animal
OLDFig. 6-6, p. 116
How Species Avoid PredatorsHow Species Avoid Predators
New Fig. 5-3, p. 82
ParasitesParasites
ParasitismParasitism
HostsHosts
Inside or outside of hostsInside or outside of hosts
Harmful effects on hostsHarmful effects on hosts
Important ecological roles of parasitesImportant ecological roles of parasitesNew pp. 83-84
MutualismMutualism
Both species benefitBoth species benefit
PollinationPollination
Benefits include nutrition and protectionBenefits include nutrition and protection
MycorrhizaeMycorrhizae
Gut inhabitant mutualismGut inhabitant mutualismNew p. 84
Oxpeckers and black rhinoceros Clown fish and sea anemone
Lack of mycorrhizae fungi on juniper seedlings in sterilized soil Fig. 6-7, p. 117
Examples of MutualismExamples of Mutualism
© 2006 Brooks/Cole - Thomson
Mycorrhizae fungi on juniper seedlings in normal soil
New Fig. 5-5. p. 84
OLD
CommensalismCommensalism
Species interaction that benefits one Species interaction that benefits one and has little or no effect on the otherand has little or no effect on the other
Example: Small plants growing in Example: Small plants growing in shade of larger plantsshade of larger plants
EpiphytesEpiphytes
New pp. 84-85
Bromeliad CommensalismBromeliad Commensalism
Fig. 6-8, p. 118OLD
New Fig. 5-6, p. 85
Ecological Succession: Ecological Succession: Communities in TransitionCommunities in Transition
What is ecological succession?What is ecological succession?
Primary successionPrimary succession
Secondary successionSecondary succession
New pp. 88-89
New Fig.5-9,p.89 OLD Fig. 6-9, p. 119
Time
Small herbsand shrubs
Heath mat
Jack pine,black spruce,
and aspen
Balsam fir, paper birch, and white spruce climax
community
Exposedrocks
Lichensand mosses
Primary Ecological SuccessionPrimary Ecological Succession
Ne
NewNewwmmmmmmm
New
New
New Fig.5-10,p.90 OLD Fig. 6-10, p. 120
Annualweeds
Perennialweeds and
grasses
Shrubs and pine seedlings
Young pine forest with developing understory
of oak and hickory trees
Mature oak-hickory forest
Secondary Ecological SuccessionSecondary Ecological Succession
Time
How Predictable is Succession?How Predictable is Succession?
Climax community conceptClimax community concept
““Balance of nature”Balance of nature”
New views of equilibrium in natureNew views of equilibrium in nature
Unpredictable successionUnpredictable succession
Natural strugglesNatural strugglesNew pp. 88-89
Population Dynamics: Factors Population Dynamics: Factors Affecting Population SizeAffecting Population Size
Population change = (births + immigration) Population change = (births + immigration) – (deaths + emigration)– (deaths + emigration)
Age structure (stages)Age structure (stages)
Age and population stabilityAge and population stability
New p. 85
Limits on Population GrowthLimits on Population Growth
Biotic potentialBiotic potential
Intrinsic rate of increase (Intrinsic rate of increase (rr) )
No indefinite population growthNo indefinite population growth
Environmental resistanceEnvironmental resistance
Carrying capacity (Carrying capacity (KK))New pp. 86-87
Exponential and Logistic Exponential and Logistic Population GrowthPopulation Growth
Resources control population growthResources control population growth
Exponential growthExponential growth
Logistic growthLogistic growth
New pp. 86-87
OLD Fig. 6-11, p. 121
Carrying capacity (K)
Environmentalresistance
Bioticpotential
Exponentialgrowth
Population Growth CurvesPopulation Growth Curves
Time (t)
Po
pu
lati
on
siz
e (N
)
New Fig. 5-7, p. 86
OLD Fig. 6-12, p. 121
Logistic Growth of Sheep PopulationLogistic Growth of Sheep Population
Overshoot Carrying Capacity
Year
Nu
mb
er o
f sh
eep
(m
illi
on
s)2.0
1.5
1.0
.5
1800 1825 1850 1875 1900 1925
When Population Size Exceeds When Population Size Exceeds Carrying CapacityCarrying Capacity
Switch to new resources, move or dieSwitch to new resources, move or die
OvershootsOvershoots
Reproductive time lagReproductive time lag
Population dieback or crashPopulation dieback or crash
Famines among humansFamines among humans
Factors controlling human carrying capacityFactors controlling human carrying capacityNew pp. 87-88
Exponential Growth, Overshoot and Exponential Growth, Overshoot and Population Crash of ReindeerPopulation Crash of Reindeer
OLD Fig. 6-13, p. 122
PopulationOvershootsCarrying Capacity
Populationcrashes
Carrying capacity
Year
Nu
mb
er o
f sh
eep
(m
illi
on
s) 2,000
1,500
1,000
500
01910 1920 1930 1940 1950
New Fig. 5-8, p. 87
Reproductive PatternsReproductive Patterns
r-selected speciesr-selected species
Opportunists (mostly r-selected)Opportunists (mostly r-selected)
Environmental impacts on opportunistsEnvironmental impacts on opportunists
K-selected species (competitors)K-selected species (competitors)
Intermediate and variable reproductive patternsIntermediate and variable reproductive patterns
Carrying capacity
K species;experienceK selection
r species;experiencer selection
K
OLD Fig. 6-14, p. 122
Positions of r-selected and K-selected Positions of r-selected and K-selected Species on Population Growth CurveSpecies on Population Growth Curve
Number of individuals
Time
Nu
mb
er o
f in
div
idu
als
OLD Fig. 6-15, p. 123
r-selected Opportunists and K-selected Speciesr-selected Opportunists and K-selected Species
r-Selected Species
CockroachDandelion
Many small offspring
Little or no parental care and protection of offspring
Early reproductive age
Most offspring die before reaching reproductive age
Small adults
Adapted to unstable climate and environmental conditions
High population growth rate (r)
Population size fluctuates wildly above and below carrying capacity (K)
Generalist niche
Low ability to compete
Early successional species
OLD Fig. 6-15a, p. 123
r-selected r-selected Opportunists Opportunists
and K-selected and K-selected SpeciesSpecies
Fewer, larger offspring
High parental care and protection of offspring
Later reproductive age
Most offspring survive to reproductive age
Larger adults
Adapted to stable climate and environmental conditions
Lower population growth rate (r)
Population size fairly stable and usually close to carrying capacity (K)
Specialist niche
High ability to compete
Late successional species
ElephantSaguaro
K-Selected Species
OLD Fig. 6-15b, p. 123
r-selected r-selected Opportunists Opportunists
and K-selected and K-selected SpeciesSpecies
OLD Fig. 6-16, p. 124
Property Natural Systems Human-DominatedSystems
Complexity
Energy source
Waste production
Nutrients
Net primaryproductivity
Biologically diverse
Renewable solarenergy
Little, if any
Recycled
Shared among manyspecies
Biologicallysimplified
Mostly nonrenewablefossil fuel energy
High
Often lost of wasted
Used, destroyed, ordegraded to supporthuman activities
Characteristics of Natural and Characteristics of Natural and Human-Dominated SystemsHuman-Dominated Systems
OLD Fig. 6-17, p. 125
Reduction of biodiversity
Increasing use of the earth'snet primary productivity
Increasing genetic resistanceof pest species and diseasecausing bacteria
Elimination of many naturalpredators
Deliberate or accidentalintroduction of potentiallyharmful species intocommunities
Using some renewableresources faster than they canbe replenished
Interfering with the earth'schemical cycling and energyflow processes
Relying mostly on pollutingfossil fuels
Human Impacts on EcosystemsHuman Impacts on EcosystemsNatural Capital Degradation
Altering Nature to Meet Our Needs
OLD Fig. 6-18, p. 126
Four Principles of SustainabilityFour Principles of Sustainability
PRINCIPLESOF
SUSTAINABILITY
Solar
Energy
Population
Control
Nutrient
Recycling Biodiv
ersi
ty
Runs on renewable solar energy.
Recycles nutrients and wastes. There is little waste in nature.
Uses biodiversity to maintain itself and adapt to new environmental conditions.
Controls a species' population size and resource use by interactionswith its environment and other species.
Rely mostly on renewable solarenergy.
Prevent and reducepollution and recycleand reuse resources.
Preserve biodiversity by protecting ecosystemservices and preventing premature extinction of species.
Reduce births and wasteful resource use to prevent environmental overload and depletion and degradation of resources.
OLD Fig. 6-19, p. 126
Solutions:Implicationsof the Principlesof Sustainability
Solutions
Principles of Sustainability
How Nature Works Lessons for Us
Lessons from NatureLessons from Nature We are dependent on the Earth and SunWe are dependent on the Earth and Sun
Everything is interdependent with everything elseEverything is interdependent with everything else
We can never do just one thingWe can never do just one thing
Earth’s natural capital must be sustainedEarth’s natural capital must be sustained
Precautionary PrinciplePrecautionary Principle
Prevention is better than curePrevention is better than cure
Risks must be takenRisks must be taken