© 2012 Pearson Education, Inc. Lecture by Edward J. Zalisko
PowerPoint Lectures forCampbell Biology: Concepts & Connections, Seventh EditionReece, Taylor, Simon, and Dickey
Chapter 38 Conservation Biology
Introduction
▪ Over the past century, wild tiger populations have been reduced from about 100,000 to 3,200.
▪ Tigers are threatened by– declining habitat,
– poaching, and
– human populations encroaching into their habitat.
Figure 38.0_1
Chapter 38: Big Ideas
The Loss of Biodiversity
Conservation Biologyand Restoration
Ecology
▪ Biodiversity has three levels:1. ecosystem diversity,
2. species diversity, and
3. genetic diversity.
38.1 Loss of biodiversity includes the loss of ecosystems, species, and genes
▪ As natural ecosystems are lost, so are essential services, including– productivity of natural environments for human food
supplies and
– the purification of water used by cities.
38.1 Loss of biodiversity includes the loss of ecosystems, species, and genes
38.1 Loss of biodiversity includes the loss of ecosystems, species, and genes
▪ At present, scientists have described and formally named about 1.8 million species.– It is difficult to estimate species loss.
– Species loss may be 1,000 times higher than at any time in the past 100,000 years.
– Extirpation is the loss of a single population of a species.
– Extinction is the irreversible loss of all populations of a species.
Figure 38.1B
0%Birds Amph
ibiansFreshwaterfishes
Reptiles(N =
1,429)(N = 2,689)
(N = 4,688)
(N = 9,933)
(N = 4,653)
20%
40%
60%
80%
100%
Lowest risk Nearthreatened
Threatened Extinct
Perc
enta
ge o
f spe
cies
ass
esse
d
Mammals
▪ Because of the network of community interactions among populations of different species within an ecosystem,– the loss of one species
– can negatively affect the species richness of an ecosystem.
38.1 Loss of biodiversity includes the loss of ecosystems, species, and genes
▪ Genetic diversity of a species is reduced if– local populations are lost and
– the total number of individuals declines.
38.1 Loss of biodiversity includes the loss of ecosystems, species, and genes
38.2 CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are
major threats to biodiversity
▪ Human alteration of habitats poses the greatest threat to biodiversity.
▪ Habitation alteration is caused by– agriculture,
– urban development,
– forestry,
– mining, and
– environmental pollution.
▪ Invasive species rank second behind habitat destruction as a threat to biodiversity.
▪ Invasive species– compete with native species,
– prey on native species, and
– parasitize native species.
38.2 CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are
major threats to biodiversity
▪ Overexploitation is the third major threat to biodiversity. Overharvesting has threatened– rare trees,
– reduced populations of tigers, Galápagos tortoises, whales, and rhinoceroses, and
– depleted wild populations of game fish.
38.2 CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are
major threats to biodiversity
38.2 CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are major threats to biodiversity
▪ Human activities produce diverse pollutants that may affect ecosystems far from their source.
– The water cycle transfers pollutants from terrestrial to aquatic ecosystems.
– The release of chemicals into the atmosphere promoted the thinning of the ozone layer.
▪ Biological magnification concentrates synthetic toxins that cannot be degraded by microorganisms.
Figure 38.2EConcentration
of PCBs
Herringgull eggs124 ppm
Lake trout4.83 ppm
Smelt1.04 ppm
Phytoplankton0.025 ppm
Zooplankton0.123 ppm
38.3 CONNECTION: Rapid warming is changing the global climate
▪ The scientific debate about global warming is over.
▪ Increased global temperatures caused by rising concentrations of greenhouse gases are changing climate patterns with grave consequences.– Global temperature has risen 0.8°C in the last 100 years.
– 0.6°C of that increase occurred in the last three decades.
– 2 to 4.5°C increases are likely by the end of the 21st century.
– Temperature increases are not distributed evenly.
– Precipitation patterns are changing too.
38.4 CONNECTION: Human activities are responsible for rising concentrations of greenhouse gases
▪ Much of the rapid warming is the result of burning fossil fuels.– Atmospheric CO2 did not exceed 300 ppm for 650,000
years.
– The preindustrial concentration was below 300 ppm.
– Atmospheric CO2 is approximately 385 ppm today.
– High levels of methane and nitrous oxide also trap heat.
Figure 38.4A
400
350
300
2500 50
01000 1500 2000
600
Year
800
1,000
1,200
1,400
1,600
1,800
2,000
CH
4 (pa
rts
per b
illio
n)
Carbon Dioxide (CO2)Nitrous Oxide (N2O)Methane (CH4)
CO
2 (pp
m),
N2O
(par
ts
per b
illio
n)
38.5 Global climate change affects biomes, ecosystems, communities, and populations
▪ Climate change in western North America has spawned catastrophic wildfires.
38.5 Global climate change affects biomes, ecosystems, communities, and populations
▪ The greatest impact of global climate change is affecting organisms that live at– high latitudes and
– high elevations.
38.5 Global climate change affects biomes, ecosystems, communities, and populations
▪ Warming oceans threaten coral reef communities.
▪ Earlier arrival of warm temperatures in the spring is disturbing ecological communities.– Birds and frogs have begun their breeding periods earlier.
– Migratory birds may experience mismatches, arriving after peak food availability has already passed.
38.5 Global climate change affects biomes, ecosystems, communities, and populations
▪ Climate change has also– increased the range of disease-carrying mosquitoes and
– enabled bark beetles to reproduce faster, promoting the destruction of millions of acres of conifers in western North America.
38.6 EVOLUTION CONNECTION: Climate change is an agent of natural selection
▪ Phenotypic plasticity– has minimized the impact of global climate change on
some species, and
– cases of microevolutionary changes have been observed.
– The rapidity of the environmental changes makes it unlikely that evolutionary processes will save many species from extinction.
▪ In Europe, the great tit bird– has shifted its breeding season earlier, in an example of
directional selection,
– favoring individuals that lay their eggs sooner, and
– better matching the earlier emergence of caterpillars.
38.6 EVOLUTION CONNECTION: Climate change is an agent of natural selection
▪ In the Yukon Territory of Canada,– where the spring temperatures have increased by
about 2°C,
– red squirrels have begun breeding earlier in the spring.
38.6 EVOLUTION CONNECTION: Climate change is an agent of natural selection
38.7 Protecting endangered populations is one goal of conservation biology
▪ Conservation biology is a goal-driven science that seeks to– understand and
– counter the rapid loss of biodiversity.
▪ Some conservation biologists direct their efforts at– protecting populations and
– increasing endangered populations.
– Threats posed by human activities are also assessed.
38.7 Protecting endangered populations is one goal of conservation biology
▪ The black-footed ferret in the United States– is one of three ferret species worldwide and the only ferret
found in North America,
– was reduced to just 18 individuals,
– has been bred in captivity, and
– was reintroduced into the wild.
38.7 Protecting endangered populations is one goal of conservation biology
▪ In Hawaii, the silversword plants once abundant on the cinder cone of the volcano Mauna Kea– were bred in greenhouses and
– reintroduced to reestablish wild populations.
38.8 Sustaining ecosystems and landscapes is a conservation priority
▪ Conservation efforts are increasingly aimed at sustaining– ecosystems and
– landscapes, a regional assemblage of interacting ecosystems.
▪ Landscape ecology is the application of ecological principles to the study of the structure and dynamics of a collection of ecosystems.
38.8 Sustaining ecosystems and landscapes is a conservation priority
▪ Edges between ecosystems have distinct sets of features and species.
▪ The increased frequency and abruptness of edges caused by human activities can increase species loss.
▪ Movement corridors connecting isolated habitats may be helpful to fragmented populations.
38.9 Establishing protected areas slows the loss of biodiversity
▪ To establish parks, wilderness areas, and other legally protected reserves, conservation biologists are applying their understanding of– population,
– ecosystem, and
– landscape dynamics.
38.9 Establishing protected areas slows the loss of biodiversity
▪ Choosing locations for protection often focuses on biodiversity hot spots, relatively small areas with– a large number of endangered and threatened species,
and
– an exceptional concentration of endemic species, those that are found nowhere else.
▪ Migratory species pose a special problem for conservationists.– Monarch butterflies occupy many areas.
– Sea turtles travel great distances.
38.9 Establishing protected areas slows the loss of biodiversity
38.10 Zoned reserves are an attempt to reverse ecosystem disruption
▪ Zoned reserves are undisturbed wildlands surrounded by buffer zones of compatible economic development.
▪ Costa Rica has established many zoned reserves.
▪ Ecotourism– is travel to natural areas for tourism and recreation and
– has become an important source of revenue for conservation efforts.
38.11 CONNECTION: The Yellowstone to Yukon Conservation Initiative seeks to preserve biodiversity by connecting protected areas
▪ The Yellowstone to Yukon Conservation Initiative – created a string of parks and reserves in a 3,200-km
wildlife corridor,
– extends from Alaska south across Canada to northern Wyoming,
– included the reintroduction of wolf populations, considered a keystone species in this region, and
– sparked angry protests from some ranchers.
Figure 38.11A
YUKONTERRITORY
Whitehorse
MACKENZIE
MOUNTAINS
NORTHWEST TERRITORIES
ALBERTA
ROCKY
MOUNTAI
NS
BRITISHCOLUMBIA
WASHINGTON
OREGON
MONTANA
Calgary
Bozeman
Spokane
Vancouver
COLUMBI
AMOUNTAI
NS
PACIFICOCEAN
Jackson
IDAHO WYOMING
Figure 38.11A_1
YUKONTERRITORY
Whitehorse
MACKENZIE
MOUNTAINS
NORTHWEST TERRITORIES
ALBERTA
ROCKY MOUNTAINS
Figure 38.11A_2
ROCKY MOUNTAINS
BRITISHCOLUMBIA
WASHINGTON
OREGON
MONTANA
Calgary
Bozeman
Spokane
Vancouver
COLUMBIA
MOUNTAINS
PACIFICOCEAN
JacksonIDAHO WYOMING
38.12 CONNECTION: The study of how to restore degraded habitats is a developing science
▪ Restoration ecology uses ecological principles to restore degraded areas to their natural state, a process that may include– detoxifying polluted ecosystems,
– replanting native vegetation, and
– returning waterways to their natural course.
38.12 CONNECTION: The study of how to restore degraded habitats is a developing science
▪ Large-scale restoration projects attempt to restore damaged landscapes.
▪ The Kissimmee River Restoration Project in Florida is– restoring river flow and wetlands and
– improving wildlife habitat.
Figure 38.12A
Widenedcanal
Water controlstructure remaining
Water controlstructure removedRiver channelrestored
Phase 1completed
Water controlstructure tobe removed inPhase 2
Miles
KissimmeeRiver
Floodplain
Canal backfilled
FLORIDA 0 1
0
Ksi sim
Rmee
iver
38.13 Sustainable development is an ultimate goal
▪ Sustainable development– seeks to improve the human condition while conserving
biodiversity,
– depends on increasing and applying ecological knowledge, and
– values our linkages to the biosphere.
38.13 Sustainable development is an ultimate goal
▪ We are most likely to– save what we appreciate and
– appreciate what we understand.
▪ Now is the time to– aggressively pursue more knowledge about life and
– work toward long-term sustainability.
Figure 38.UN02
Conservationbiology
seeks to conserve may involve
ecosystems and
landscapes
(c)
(a)
attemptto restore
naturereserve
s
may be
restorationprojects
which uses
to
detoxify orreplenish degraded
ecosystems
FLORIDA
ATLANTICOCEAN
(d)
sustainable
development
which support
GULF OFMEXICO
may beprotected in