Chapter 5 Biodiversity, Species Interactions, and Population Control
description
Transcript of Chapter 5 Biodiversity, Species Interactions, and Population Control
![Page 1: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/1.jpg)
LIVING IN THE ENVIRONMENT 17THMILLER/SPOOLMAN
Chapter 5Biodiversity, Species Interactions, and Population Control
![Page 2: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/2.jpg)
Core Case Study: Southern Sea Otters: Are They Back from the Brink of Extinction?• Habitat
• Hunted: early 1900s
• Partial recovery
• Why care about sea otters?• Ethics• Tourism dollars• Keystone species
![Page 3: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/3.jpg)
Southern Sea Otter
Fig. 5-1a, p. 104
Figure 5.1: An endangered southern sea otter in Monterey Bay, California (USA), uses a stone to crack the shell of a clam (left). It lives in a giant kelp bed (right). Scientific studies indicate that the otters act as a keystone species in a kelp forest system by helping to control the populations of sea urchins and other kelp-eating species.
![Page 4: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/4.jpg)
5-1 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.
![Page 5: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/5.jpg)
Species Interact in Five Major Ways• Interspecific Competition
• Predation
• Parasitism
• Mutualism
• Commensalism
![Page 6: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/6.jpg)
Most Species Compete with One Another for Certain Resources
• For limited resources
• Ecological niche for exploiting resources
• Some niches overlap
![Page 7: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/7.jpg)
Some Species Evolve Ways to Share Resources
• Resource partitioning• Using only parts of resource
• Using at different times
• Using in different ways
![Page 8: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/8.jpg)
Resource Partitioning Among Warblers
Fig. 5-2, p. 106
Figure 5.2: Sharing the wealth: This diagram illustrates resource partitioning among five species of insect-eating warblers in the spruce forests of the U.S. state of Maine. Each species minimizes competition with the others for food by spending at least half its feeding time in a distinct portion (yellow highlighted areas) of the spruce trees, and by consuming somewhat different insect species. (After R. H. MacArthur, “Population Ecology of Some Warblers in Northeastern Coniferous Forests,” Ecology 36 (1958): 533–536.)
![Page 9: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/9.jpg)
Specialist Species of Honeycreepers
Fig. 5-3, p. 107
Figure 5.3: Specialist species of honeycreepers: Through natural selection, different species of honeycreepers developed specialized ecological niches that reduced competition between these species. Each species has evolved a specialized beak to take advantage of certain types of food resources.
![Page 10: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/10.jpg)
Most Consumer Species Feed on Live Organisms of Other Species (1)
• Predators may capture prey by1. Walking2. Swimming3. Flying4. Pursuit and ambush5. Camouflage6. Chemical warfare
![Page 11: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/11.jpg)
Predator-Prey Relationships
Fig. 5-4, p. 107
![Page 12: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/12.jpg)
Most Consumer Species Feed on Live Organisms of Other Species (2)
• Prey may avoid capture by1. Run, swim, fly2. Protection: shells, bark, thorns3. Camouflage4. Chemical warfare5. Warning coloration6. Mimicry7. Deceptive looks8. Deceptive behavior
![Page 13: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/13.jpg)
Some Ways Prey Species Avoid Their Predators
Fig. 5-5, p. 109
Figure 5.5: These prey species have developed specialized ways to avoid their predators: (a, b) camouflage, (c–e) chemical warfare, (d, e) warning coloration, (f) mimicry, (g) deceptive looks, and (h) deceptive behavior.
![Page 14: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/14.jpg)
Fig. 5-5a, p. 109
(a) Span worm
camouflage
![Page 15: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/15.jpg)
Fig. 5-5b, p. 109
(b) Wandering leaf insect
camouflage
![Page 16: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/16.jpg)
Fig. 5-5c, p. 109
(c) Bombardier beetle
chemical warfare
![Page 17: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/17.jpg)
Fig. 5-5d, p. 109
(d) Foul-tasting monarch butterfly
chemical warfare
![Page 18: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/18.jpg)
Fig. 5-5e, p. 109
(e) Poison dart frog
warning coloration
![Page 19: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/19.jpg)
Fig. 5-5f, p. 109
(f) Viceroy butterfly mimics monarch butterfly
warning coloration
![Page 20: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/20.jpg)
Fig. 5-5g, p. 109
(g) Hind wings of Io moth resemble eyes of a much larger animal.
mimicry
![Page 21: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/21.jpg)
Fig. 5-5h, p. 109
(h) When touched, snake caterpillar changes shape to look like head of snake.
mimicry
![Page 22: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/22.jpg)
(d) Foul-tasting monarch butterfly
(e) Poison dart frog
Stepped Art
(h) When touched,snake caterpillar changesshape to look like head of snake.
(a) Span worm (b) Wandering leaf insect
(c) Bombardier beetle
(f) Viceroy butterfly mimicsmonarch butterfly
(g) Hind wings of Io mothresemble eyes of a muchlarger animal.
Fig. 5-5, p. 109
![Page 23: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/23.jpg)
Science Focus: Threats to Kelp Forests• Kelp forests: biologically diverse marine habitat
• Major threats to kelp forests1. Sea urchins2. Pollution from water run-off3. Global warming
![Page 24: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/24.jpg)
Purple Sea Urchin
Fig. 5-A, p. 108
![Page 25: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/25.jpg)
Predator and Prey Interactions Can Drive Each Other’s Evolution
• Intense natural selection pressures between predator and prey populations
• Coevolution• Interact over a long period of time• Bats and moths: echolocation of bats and sensitive
hearing of moths
![Page 26: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/26.jpg)
Coevolution: A Langohrfledermaus Bat Hunting a Moth
Fig. 5-6, p. 110
![Page 27: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/27.jpg)
Some Species Feed off Other Species by Living on or in Them
• Parasitism
• Parasite is usually much smaller than the host
• Parasite rarely kills the host
• Parasite-host interaction may lead to coevolution
![Page 28: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/28.jpg)
Parasitism: Trout with Blood-Sucking Sea Lamprey
Fig. 5-7, p. 110
![Page 29: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/29.jpg)
In Some Interactions, Both Species Benefit
• Mutualism
• Nutrition and protection relationship
• Gut inhabitant mutualism
• Not cooperation: it’s mutual exploitation
![Page 30: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/30.jpg)
Fig. 5-8, p. 110
Mutualism: Hummingbird and Flower
Figure 5.8: Mutualism: This hummingbird benefits by feeding on nectar in this flower, and it benefits the flower by pollinating it.
![Page 31: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/31.jpg)
Mutualism: Oxpeckers Clean Rhinoceros; Anemones Protect and Feed Clownfish
Fig. 5-9, p. 111
Figure 5.9: Examples of mutualism: (a) Oxpeckers (or tickbirds) feed on parasitic ticks that infest large, thick-skinned animals such as the endangered black rhinoceros. (b) A clownfish gains protection and food by living among deadly, stinging sea anemones and helps to protect the anemones from some of their predators.
![Page 32: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/32.jpg)
In Some Interactions, One Species Benefits and the Other Is Not Harmed
• Commensalism
• Epiphytes
• Birds nesting in trees
![Page 33: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/33.jpg)
5-2 What Limits the Growth of Populations?
• Concept 5-2 No population can continue to grow indefinitely because of limitations on resources and because of competition among species for those resources.
![Page 34: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/34.jpg)
Most Populations Live Together in Clumps or Patches (1)
• Population: group of interbreeding individuals of the same species
• Population distribution 1. Clumping2. Uniform dispersion3. Random dispersion
![Page 35: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/35.jpg)
Most Populations Live Together in Clumps or Patches (2)
• Why clumping?1. Species tend to cluster where resources are
available2. Groups have a better chance of finding clumped
resources3. Protects some animals from predators4. Packs allow some to get prey
![Page 36: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/36.jpg)
Population of Snow Geese
Fig. 5-11, p. 112
![Page 37: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/37.jpg)
Generalized Dispersion Patterns
Fig. 5-12, p. 112
Figure 5.12: This diagram illustrates three general dispersion patterns for populations. Clumps (a) are the most common dispersion pattern, mostly because resources such as grass and water are usually found in patches. Where such resources are scarce, uniform dispersion (b) is more common. Where they are plentiful, a random dispersion (c) is more likely. Question: Why do you think elephants live in clumps or groups?
![Page 38: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/38.jpg)
Populations Can Grow, Shrink, or Remain Stable (1)
• Population size governed by• Births• Deaths• Immigration• Emigration
• Population change = (births + immigration) – (deaths + emigration)
![Page 39: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/39.jpg)
Populations Can Grow, Shrink, or Remain Stable (2)
• Age structure• Pre-reproductive age• Reproductive age• Post-reproductive age
![Page 40: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/40.jpg)
Some Factors Can Limit Population Size
• Range of tolerance• Variations in physical and chemical environment
• Limiting factor principle• Too much or too little of any physical or chemical
factor can limit or prevent growth of a population, even if all other factors are at or near the optimal range of tolerance
• Precipitation• Nutrients • Sunlight, etc
![Page 41: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/41.jpg)
Trout Tolerance of Temperature
Fig. 5-13, p. 113
Figure 5.13: This diagram illustrates the range of tolerance for a population of organisms, such as trout, to a physical environmental factor—in this case, water temperature. Range of tolerance restrictions prevent particular species from taking over an ecosystem by keeping their population size in check. Question: For humans, what is an example of a range of tolerance for a physical environmental factor?
![Page 42: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/42.jpg)
No Population Can Grow Indefinitely: J-Curves and S-Curves (1)
• Size of populations controlled by limiting factors:• Light• Water• Space• Nutrients• Exposure to too many competitors, predators or
infectious diseases
![Page 43: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/43.jpg)
No Population Can Grow Indefinitely: J-Curves and S-Curves (2)
• Environmental resistance • All factors that act to limit the growth of a population
• Carrying capacity (K)• Maximum population a given habitat can sustain
![Page 44: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/44.jpg)
No Population Can Grow Indefinitely: J-Curves and S-Curves (3)
• Exponential growth• Starts slowly, then accelerates to carrying capacity
when meets environmental resistance
• Logistic growth• Decreased population growth rate as population size
reaches carrying capacity
![Page 45: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/45.jpg)
Logistic Growth of Sheep in Tasmania
Fig. 5-15, p. 115
Figure 5.15: This graph tracks the logistic growth of a sheep population on the island of Tasmania between 1800 and 1925. After sheep were introduced in 1800, their population grew exponentially, thanks to an ample food supply and few predators. By 1855, they had overshot the land’s carrying capacity. Their numbers then stabilized and fluctuated around a carrying capacity of about 1.6 million sheep.
![Page 46: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/46.jpg)
Science Focus: Why Do California’s Sea Otters Face an Uncertain Future?
• Low biotic potential
• Prey for orcas
• Cat parasites
• Thorny-headed worms
• Toxic algae blooms
• PCBs and other toxins
• Oil spills
![Page 47: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/47.jpg)
Population Size of Southern Sea Otters Off the Coast of So. California (U.S.)
Fig. 5-B, p. 114
Figure 5.B: This graph tracks the population size of southern sea otters off the coast of the U.S. state of California, 1983–2009. According to the U.S. Geological Survey, the California southern sea otter population would have to reach at least 3,090 animals for 3 years in a row before it could be considered for removal from the endangered species list. (Data from U.S. Geological Survey)
![Page 48: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/48.jpg)
Case Study: Exploding White-Tailed Deer Population in the U.S.
• 1900: deer habitat destruction and uncontrolled hunting
• 1920s–1930s: laws to protect the deer
• Current population explosion for deer• Spread Lyme disease• Deer-vehicle accidents• Eating garden plants and shrubs
• Ways to control the deer population
![Page 49: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/49.jpg)
Mature Male White-Tailed Deer
Fig. 5-16, p. 115
![Page 50: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/50.jpg)
When a Population Exceeds Its Habitat’s Carrying Capacity, Its Population Can Crash• A population exceeds the area’s carrying capacity
• Reproductive time lag may lead to overshoot• Population crash
• Damage may reduce area’s carrying capacity
![Page 51: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/51.jpg)
Exponential Growth, Overshoot, and Population Crash of a Reindeer
Fig. 5-17, p. 116
Figure 5.17: This graph tracks the exponential growth, overshoot, and population crash of reindeer introduced onto the small Bering Sea island of St. Paul. When 26 reindeer (24 of them female) were introduced in 1910, lichens, mosses, and other food sources were plentiful. By 1935, the herd size had soared to 2,000, overshooting the island’s carrying capacity. This led to a population crash, when the herd size plummeted to only 8 reindeer by 1950. Question: Why do you think the sizes of some populations level off while others such as the reindeer in this example exceed their carrying capacities and crash?
![Page 52: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/52.jpg)
Species Have Different Reproductive Patterns (1)
• Some species
• Many, usually small, offspring• Little or no parental care• Massive deaths of offspring• Insects, bacteria, algae
![Page 53: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/53.jpg)
Species Have Different Reproductive Patterns (2)
• Other species• Reproduce later in life• Small number of offspring with long life spans• Young offspring grow inside mother• Long time to maturity• Protected by parents, and potentially groups• Humans• Elephants
![Page 54: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/54.jpg)
Under Some Circumstances Population Density Affects Population Size
• Density-dependent population controls• Predation• Parasitism• Infectious disease• Competition for resources
![Page 55: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/55.jpg)
Several Different Types of Population Change Occur in Nature
• Stable
• Irruptive• Population surge, followed by crash
• Cyclic fluctuations, boom-and-bust cycles• Top-down population regulation• Bottom-up population regulation
• Irregular
![Page 56: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/56.jpg)
Population Cycles for the Snowshoe Hare and Canada Lynx
Fig. 5-18, p. 118
Figure 5.18: This graph represents the population cycles for the snowshoe hare and the Canadian lynx. At one time, scientists believed these curves provided evidence that these predator and prey populations regulated one another. More recent research suggests that the periodic swings in the hare population are caused by a combination of top-down population control—through predation by lynx and other predators—and bottom-up population control, in which changes in the availability of the food supply for hares help to determine their population size, which in turn helps to determine the lynx population size. (Data from D. A. MacLulich)
![Page 57: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/57.jpg)
Humans Are Not Exempt from Nature’s Population Controls
• Ireland• Potato crop in 1845
• Bubonic plague• Fourteenth century
• AIDS• Global epidemic
![Page 58: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/58.jpg)
5-3 How Do Communities and Ecosystems Respond to Changing Environmental
Conditions?• Concept 5-3 The structure and species composition
of communities and ecosystems change in response to changing environmental conditions through a process called ecological succession.
![Page 59: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/59.jpg)
Communities and Ecosystems Change over Time: Ecological Succession
• Natural ecological restoration• Primary succession• Secondary succession
![Page 60: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/60.jpg)
Some Ecosystems Start from Scratch: Primary Succession
• No soil in a terrestrial system
• No bottom sediment in an aquatic system
• Takes hundreds to thousands of years
• Need to build up soils/sediments to provide necessary nutrients
![Page 61: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/61.jpg)
Primary Ecological Succession
Fig. 5-19, p. 119
Figure 5.19: Primary ecological succession: Over almost a thousand years, these 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?
![Page 62: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/62.jpg)
Some Ecosystems Do Not Have to Start from Scratch: Secondary Succession (1)
• Some soil remains in a terrestrial system
• Some bottom sediment remains in an aquatic system
• Ecosystem has been• Disturbed• Removed• Destroyed
![Page 63: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/63.jpg)
Natural Ecological Restoration of Disturbed Land
Fig. 5-20, p. 120
Figure 5.20: Natural ecological restoration of disturbed land: This diagram shows the undisturbed 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. See an animation based on this figure at CengageNOW. Questions: Do you think the annual weeds (left) would continue to thrive in the mature forest (right)? Why or why not?
![Page 64: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/64.jpg)
Secondary Ecological Succession in Yellowstone Following the 1998 Fire
Fig. 5-21, p. 120
Figure 5.21: These young lodgepole pines growing around standing dead trees after a 1998 forest fire in Yellowstone National Park are an example of secondary ecological succession.
![Page 65: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/65.jpg)
Some Ecosystems Do Not Have to Start from Scratch: Secondary Succession (2)
• Primary and secondary succession• Tend to increase biodiversity• Increase species richness and interactions among species
• Primary and secondary succession can be interrupted by• Fires• Hurricanes• Clear-cutting of forests• Plowing of grasslands• Invasion by nonnative species
![Page 66: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/66.jpg)
Science Focus: How Do Species Replace One Another in Ecological Succession?
• Facilitation
• Inhibition
• Tolerance
![Page 67: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/67.jpg)
Succession Doesn’t Follow a Predictable Path
• Traditional view • Balance of nature and a climax community
• Current view • Ever-changing mosaic of patches of vegetation• Mature late-successional ecosystems • State of continual disturbance and change
![Page 68: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/68.jpg)
Living Systems Are Sustained through Constant Change
• Inertia, persistence• Ability of a living system to survive moderate
disturbances
• Resilience • Ability of a living system to be restored through
secondary succession after a moderate disturbance
• Some systems have one property, but not the other: tropical rainforests
![Page 69: Chapter 5 Biodiversity, Species Interactions, and Population Control](https://reader037.fdocuments.in/reader037/viewer/2022103100/5681334e550346895d9a5356/html5/thumbnails/69.jpg)
Three Big Ideas
1. Certain interactions among species affect their use of resources and their population sizes.
2. There are always limits to population growth in nature.
3. Changes in environmental conditions cause communities and ecosystems to gradually alter their species composition and population sizes (ecological succession).