5Why care about sea otters? EthicsKeystone species (Eat sea Urchins)Tourism dollars
6Science Focus: Why Should We Care about Kelp Forests? Kelp forests: one of the most biologically diverse marine habitatOne blade of kelp can grow 2 feet in a single dayMajor threats to kelp forestsSea urchinsPollution from water run-offGlobal warming (changing of the water’s temp)
105-1 How Do Species Interact? Concept 5-1 Five types of species interactions—competition, predation, parasitism, mutualism, and commensalism—affect the resource use and population sizes of the species in an ecosystem.
11Species Interact in Five Major Ways Interspecific Competition: over same resourcesPredationParasitism:one gains, one loses (not always death)Mutualism: both gainCommensalism: one gains, the other gets no benefits
13Most Species Compete with One Another for Certain Resources Competition for same limited resources (food, shelter, space)Competitive exclusion principle: no 2 species can occupy exactly the same ecological niche for very long
14Most Consumer Species Feed on Live Organisms of Other Species (1) Predators may capture prey byWalkingSwimmingFlyingPursuit and ambushCamouflageChemical warfare
15Most Consumer Species Feed on Live Organisms of Other Species (2) Prey may avoid capture byCamouflageChemical warfareWarning colorationMimicryDeceptive looksDeceptive behavior
16Some Ways Prey Species Avoid Their Predators (a) Span worm(b) Wandering leaf insectSome Ways Prey Species Avoid Their Predators(c) Bombardier beetle(d) Foul-tasting monarch butterfly(e) Poison dart frog(f) Viceroy butterfly mimicsmonarch butterflyFigure 5.2Some ways in which prey species avoid their predators: (a, b) camouflage, (c–e) chemical warfare, (d, e) warning coloration, (f) mimicry, (g) deceptive looks, and (h) deceptive behavior.(g) Hind wings of Io mothresemble eyes of a muchlarger animal.(h) When touched,snake caterpillar changesshape to look like head of snake.Stepped ArtFig. 5-2, p. 103
22Some Species Feed off Other Species by Living on or in Them ParasitismParasite-host interaction may lead to coevolutionHost’s point of view: parasites badPopulation level POV: promote biodiversity, keep populations in check
23Parasitism: Tree with Parasitic Mistletoe, Trout with Blood-Sucking Sea Lampreys
25In Some Interactions, Both Species Benefit MutualismNutrition and protection relationshipGut inhabitant mutualism: vast armies of bacteria, break down foodHow is a Cow like a termite?Cooperation between species?
29In Some Interactions, One Species Benefits and the Other Is Not Harmed CommensalismEpiphytesBirds nesting in treesArmy ants and silverfish
30Commensalism: Bromiliad Roots on Tree Trunk Without Harming Tree
31Chapter 5, section 1Q1: What are the 5 different ways that species interact with each other? Give an example of each. Describe what is unique about each interaction type.Q2: Describe a trait possessed by the southern sea otter that helps it a) catch prey and b) avoid being preyed uponQ3: Compare Competitive exclusion principle with coevolution
32Q5: Why would detritus feeders and decomposers not considered predators? Q6: What methods/ways help predators catch their prey?Q7: What ways have the prey developed to avoid being caught?Q9: Why can coevolution be described like an arms race?Q10: Explain how each of the species interactions can affect the population sizes of species in ecosystems.
335-2 How Can Natural Selection Reduce Competition between Species? Concept 5-2 Some species develop adaptations that allow them to reduce or avoid competition with other species for resources.
34QuestionDo species want to compete for niche space?
35Some Species Evolve Ways to Share Resources Resource partitioningReduce niche overlap, increase species diversityUse shared resources at differentTimesPlacesWays
36Competing Species Can Evolve to Reduce Niche Overlap
37Sharing the Wealth: Resource Partitioning Blackburnian WarblerBlack-throated Green WarblerCape May WarblerBay-breasted WarblerYellow-rumped WarblerFigure 5.8Sharing the wealth: resource partitioning of five species of insect-eating warblers in the spruce forests of the U.S. state of Maine. Each species minimizes competition for food with the others by spending at least half its feeding time in a distinct portion (shaded areas) of the spruce trees, and by consuming different insect species. (After R. H. MacArthur, “Population Ecology of Some Warblers in Northeastern Coniferous Forests,” Ecology 36 (1958): 533–536.)Stepped ArtFig. 5-8, p. 107
38Insect and nectar eaters Fruit and seed eatersInsect and nectar eatersGreater Koa-finchKuai AkialaoaSpecialist Species of HoneycreepersAmakihiKona GrosbeakCrested HoneycreeperAkiapolaauFigure 5.9Specialist species of honeycreepers. Evolutionary divergence of honeycreepers into species with specialized ecological niches has reduced competition between these species. Each species has evolved a beak specialized to take advantage of certain types of food resources.Maui ParrotbillApapaneUnkown finch ancestorFig. 5-9, p. 108
39Honey creepers on Hawaii Evolved into different species, each concentrating on different food resourcesEvolutionary divergence-speciation
40Chapter 5, section 2 questions Q11: How does resource partitioning increase species diversity? Q12: How did the warblers reduce competition when eating insects on spruce trees? Q13: How is the evolutionary progress of honey creepers an example of evolutionary divergence?
41QuestionHow many humans can live on the Earth?How many cockroaches?
425-3 What Limits the Growth of Populations? Concept 5-3 No population can continue to grow indefinitely due to:limitations on resourcescompetition among species for those resources.
43What information can be used to describe the differences between 2 different populations of the same creature?
44Populations Have Certain Characteristics (1) Populations differ inDistributionNumbersAge structureThese values are Population dynamics
45Populations Characteristics can change due to:Temperature changePresence of disease, organisms or harmful chemicalsResource availabilityArrival or disappearance of competing species
47Most Populations Live Together in Clumps or Patches (1) Different types of population distribution:ClumpingUniform dispersion (what would cause this?)Random dispersion (what would cause this?)
48Most Populations Live Together in Clumps or Patches (2) Why clumping?Species tend to cluster where resources are availableGroups have a better chance of finding clumped resourcesHerds protect some animals from predatorsPacks allow some predators to get preyTemporary groups for mating and caring for young
49Why does the population of the US continues to increase, despite the birthrate falling below 2.0 kids per mother?
50Populations Can Grow, Shrink, or Remain Stable (1) Population size governed byBirthsDeathsImmigrationEmigrationPopulation change =(births + immigration) – (deaths + emigration)
51Populations Can Grow, Shrink, or Remain Stable (2) Age structurePre-reproductive ageReproductive age (if greatest %, greatest growth)Post-reproductive ageExcluding emigration/immigration, a population that has an even distribution amongst the groups will remain stable.
52How would you describe the US population, in terms of age? Pre-reproductiveReproductivePost-reproductive
53Population Growth Rates Biotic potential: capacity for pop growthLow (elephants, whales)High (insects and bacteria)Intrinsic rate of increase (r)Steepness of curveIndividuals in populations with high rReproduce early in lifeHave short generation times (adaptable)Can reproduce many timesHave many offspring each time they reproduce
54Better than roaches and bunnies A species of bacteria could carpet the entire surface of the earth 1 foot deep in 36 hours, if there was nothing to control its population numbers.What stops it from doing so?
55Environmental resistance Combo of all factors which limit growthSize of populations limited byLightWaterSpaceNutrientsExposure to too many competitors, predators or infectious diseases
56No Population Can Grow Indefinitely: J-Curves and S-Curves (3) Carrying capacity (K)Max population sustained indefinitelyExponential growth (j-curve)(even 1-2% growth is exponential)Logistic growth (s-curve)Rapid growth followed by leveling off
57The first part of any population graph should be a J As population nears carrying capacity, graph should change into an s-curve
58No Population Can Continue to Increase in Size Indefinitely
59Logistic Growth of a Sheep Population on the island of Tasmania, 1800–1925
60When a Population Exceeds Its Habitat’s Carrying Capacity, Its Population Can Crash Carrying capacity: not fixed, dependent on environmental factors (food, conditions)Reproductive time lag may lead to overshootDieback (crash)Overshoot Damage may reduce area’s carrying capacity
61Science Focus: Why Are Protected Sea Otters Making a Slow Comeback? Low biotic potentialPrey for orcasCat parasites (from kitty liter flushed)Thorny-headed worms (seabirds)Toxic algae blooms (urea, fertilizer)PCBs and other toxinsOil spills
62Population Size of Southern Sea Otters Off the Coast of So Population Size of Southern Sea Otters Off the Coast of So. California (U.S.)
63Exponential Growth, Overshoot, and Population Crash of a Reindeer
64Story of the Reindeer 26 introduced to island in Bering Sea No predators, pop soaredFood is slow growth lichens and mossesPop starved, crashed to 8 in 1950
65Species Have Different Reproductive Patterns r-Selected species, opportunistsCapacity for high rate of pop increaseLittle or no care of offspringLarge populationsK-selected species, competitorsReproduce later in lifeLong life spansSmall number of offspring, careSmall Populations
66Positions of r- and K-Selected Species on the S-Shaped Population Growth Curve
67Genetic Diversity Can Affect the size, success of Small Populations Founder effect: few individuals start new colonyDemographic bottleneck: few individuals survive catastropheGenetic drift: random changes to gene frequencies in pop that lead to unequal reproductive successInbreeding: increase of defective genes in small popUse above to estimate minimum viable population size
68Population Density and Population Size Density independent pop controlsMostly abiotic like weather, forest fires…Density-dependent population controlsPredationParasitismInfectious diseaseCompetition for resources
69Several Different Types of Population Change Occur in Nature StableIrruptive:external conditions (temp…)Cyclic fluctuations, boom-and-bust cycles (more than once, internal)Top-down population regulation (bunnies-lynx)Bottom-up population regulation (lemmings)Irregular (no drastic increases)
70Population Cycles for the Snowshoe Hare and Canada Lynx (notice general delay in lynx crashes)
71Humans Are Not Exempt from Nature’s Population Controls IrelandPotato crop in 1845Bubonic plagueFourteenth centuryAIDSGlobal epidemic
72Questions on 5.3 Q15: Why do populations tend to live in clumps? Q17: What are the 3 age group categories in a population’s age structureQ21: Which group grasshoppers or elephants have a high biotic potential? Why?Q25: Use the concepts of carrying capacity to explain why there are always limits to population growth in natureQ30: Distinguish between r-selected species and k-selected species and give an example of each type. Which are humans?
74Case Study: Exploding White-Tailed Deer Population in the U.S. 1900: deer habitat destruction and uncontrolled hunting1920s–1930s: laws to protect the deerResults of current population explosion for deerLyme diseaseDeer-vehicle accidentsEating garden plants and shrubsWays to control the deer population
75Solutions to the consequences of the exploding deer population List at least 3 different solutions that would result in a sustainable deer population. (several in textbook or come up with your ownFor each solution, describe:The economic and environmental costChanges in the population dynamics over timeMain causes for change in the carrying capacity for deer
785-4 How Do Communities and Ecosystems Respond to Changing Environmental Conditions? Concept 5-4 The structure and species composition of communities and ecosystems change in response to changing environmental conditions through a process called ecological succession.
82Communities and Ecosystems Change over Time: Ecological Succession Natural ecological restorationPrimary successionStarts from bare rockSecondary successionDoes not start from bare rockNew home construction (why?)
83Some Ecosystems Start from Scratch: Primary Succession No soil in a terrestrial systemNo bottom sediment in an aquatic systemEarly successional plant species, pioneerMidsuccessional plant speciesLate successional plant species
84Primary Ecological Succession Figure 5.16Primary ecological succession. Over almost a thousand years, plant communities developed, starting on bare rock exposed by a retreating glacier on Isle Royal, Michigan (USA) in northern Lake Superior. The details of this process vary from one site to another. Question: What are two ways in which lichens, mosses, and plants might get started growing on bare rock?Balsam fir,paper birch, andwhite spruceforest communityJack pine,black spruce,and aspenHeath matSmall herbsand shrubsLichens andmossesExposedrocksTimeFig. 5-16, p. 116
86Some Ecosystems Do Not Have to Start from Scratch: Secondary Succession (1) Some soil remains in a terrestrial systemSome bottom sediment remains in an aquatic systemEcosystem has beenDisturbedRemovedDestroyed
87Natural Ecological Restoration of Disturbed Land (secondary) Figure 5.17Natural ecological restoration of disturbed land. Secondary ecological succession of plant communities on an abandoned farm field in the U.S. state of North Carolina. It took 150–200 years after the farmland was abandoned for the area to become covered with a mature oak and hickory forest. A new disturbance, such as deforestation or fire, would create conditions favoring pioneer species such as annual weeds. In the absence of new disturbances, secondary succession would recur over time, but not necessarily in the same sequence shown here. Questions: Do you think the annual weeds (left) would continue to thrive in the mature forest (right)? Why or why not? See an animation based on this figure at CengageNOW.Mature oak and hickory forestYoung pine forestwith developing understory of oak and hickory treesShrubs andsmall pineseedlingsPerennialweeds andgrassesAnnualweedsTimeFig. 5-17, p. 117
88Some Ecosystems Do Not Have to Start from Scratch: Secondary Succession (2) Primary and secondary successionTend to increase biodiversityIncrease species richness and interactions among speciesPrimary and secondary succession can be interrupted byFiresHurricanesClear-cutting of forestsPlowing of grasslandsInvasion by nonnative species
89Factors that affect the rate of succession Facilitation:one set of species makes area makes area suitable for following species, less for themselves (mosses/lichens and grasses)Inhibition:hinder establishment and growth of species ex: pine treesTolerance:unaffected by plants in earlier stages (mature trees vs shade plants)
90Succession Doesn’t Follow a Predictable Path Traditional viewBalance of nature and a climax communityAchieves equilibriumCurrent viewSuccession Doesn’t follow a predictable pathEver-changing mosaic of patches of vegetationMature late-successional ecosystemsState of continual disturbance and change, not permanent equilibrium
91Living Systems Are Sustained through Constant Change Inertia, persistenceAbility of a living system to survive moderate disturbancesResilienceAbility of a living system to be restored through secondary succession after a moderate disturbanceTipping point
92Tropical Rain ForestEcosystem is persistent but is not resilant
94UN project QuestionsGive 2 examples of r-selected and k-selected species that live in your countryObtain a picture of a park or wilderness area of your country. Where in terms of ecological succession (early, mid, late, climax) does your picture represent? State evidence to support your choiceIndicate specific examples from your country for the following, (avoid examples that could show up globally):a) Interspecific competitionb) Predator and Preyc) Parasite and hostd) Mutualisme) Commensalismf) For each example given describe the population distribution pattern