Key Concepts Ecology and populations Human effects on
biodiversity Importance of biodiversity How human activities affect
wildlife Management of wildlife
Slide 3
Ecology Study of how organisms interact with one another and
with their nonliving environment Sustainable ecosystems have a
balance and resilience in these relationships between the organisms
and the environment in a way that perpetuates the system without
depleting the resources
Slide 4
Setting up the hierarchy Cell organism (prokaryote, eukaryotic,
species, asexual, sexual) Population- all individuals of a species
in an area genetic diversity: size age distrib density genetic
composition Habitat-location, address Niche-function or role in
ecosystem community-populations interacting in area
ecosystem-community of diff species interacting w one another &
with their nonliving env of matter & energy biome
biosphere
Slide 5
Population dynamics respond to Environmental stress Changes in
environmental conditions
Slide 6
ecosystems mosaic of vegetation patches 1-can lead to edges or
boundaries 2-ecotones
Slide 7
Fig. 9.2, p. 199 Clumped (elephants) Uniform (creosote bush)
Random (dandelions) Dispersion: spatial pattern
Slide 8
Biotic potential Capacity for growth If a population is at
biotic potential, it is probably colonizing new areas Intrinsic
rate of increase (r ) is the rate of growth, reproductive rate, if
there were unlimited resources
Slide 9
Growth factors Favorable environmental conditions High
fecundity Generalized niche Adequate food supply Suitable habitat
Ability to compete for resources Ability to protect from predation
and diseases or parasites Able to migrate Able to adapt to
environmental change
Slide 10
Environmental resistances Unfavorable abiotic factors Low
reproductive rate Specialized niche Inadequate food supply Poor or
unsuitable habitat Too much competition Unable to protect against
predation and disease Unable to live in other habitats Inability to
adapt to environmental change
Slide 11
Major Characteristics of a population Size: N number of
individuals Density: number of individuals per unit space
Dispersion: spatial pattern Age distribution
Slide 12
Environmental resistances Unfavorable abiotic factors Low
reproductive rate Specialized niche Inadequate food supply Poor or
unsuitable habitat Too much competition Unable to protect against
predation and disease Unable to live in other habitats Inability to
adapt to environmental change
Slide 13
Carrying capacity No population can grow indefinitely
Environmental resistances limit population growth Carrying capacity
(K) of a population is the result of environmental resistances on
biotic potential or the population size that can be sustained
indefinitely in a given area
Slide 14
Opportunistic vs. Equilibrium Species R selected species small
bodied Mature rapidly Highly fecund Numerous offspring No parental
care Short lived opportunistic K selected species Larger Slow
maturation (yrs) Low fecundity Few offspring Require parental care
Live long equilibrium
Slide 15
Carrying Capacity dN = rN and dN= rN(K-N) dT dT K
Slide 16
Exponential growth If there are few resource limitations, then
exponential growth could occur A small population doubles slowly
and then as the numbers increase the doubling rate decreases
resulting in a J shaped curve
Slide 17
Logistic growth Exponential population growth is decreased with
the population encounters environmental resistance (no food, no
suitable habitat, competition and so on) After a sharp increase,
the growth decreases resulting in an S shaped curve
Slide 18
Fig. 9.4, p. 201 Time (t) Population size (N) K Exponential
GrowthLogistic Growth Exponential and Logistic growth
Slide 19
Fig. 9.5, p. 201 2.0 1.5 1.0.5 Number of sheep (millions)
180018251850187519001925 Year Logistic growth
Slide 20
Density Independent Factors on population growth Affect
populations size regardless of population density Floods Fires
Hurricanes Unseasonable weather Habitat destruction pesticides
Slide 21
Density dependent Factors on population growth Competition for
resources Predation Parasitism disease
Slide 22
Fig. 9.6, p. 201 2,000 1,500 Number of reindeer
19101920193019401950 Year 1,000 500 Exponential growth followed by
population crash
Slide 23
Types of population fluctuations Stable Irruptive (explosive)
Irregular (no known pattern or etiology) Cyclic (boom and
bust)
Slide 24
Fig. 9.7, p. 202 Number of individuals Time Irruptive Stable
Cyclic Irregular Types of population fluctuations
Slide 25
Biodiversity encompasses several levels Humans are reducing
Earths diversity of life Biodiversity sum total of all organisms in
an area Split into three specific levels: Species diversity Genetic
diversity Ecosystem diversity
Slide 26
Species diversity Species Diversity = the number or variety of
species in the world or in a particular region Richness = the
number of species Evenness or relative abundance = extent to which
numbers of individuals of different species are equal or skewed
Speciation generates new species and adds to species richness
Extinction reduces species richness
Slide 27
Genetic diversity Encompasses the differences in DNA among
individuals within species and populations The raw material for
adaptation to local conditions Populations with higher genetic
diversity can survive They can cope with environmental change
Populations with low genetic diversity are vulnerable To
environmental change Disease Inbreeding depression = genetically
similar parents mate and produce inferior offspring
Slide 28
Ecosystem diversity Ecosystem diversity = the number and
variety of ecosystems Also encompasses differing communities and
habitats Rapid vegetation change and varying landscapes within an
ecosystem promote higher levels of biodiversity
Slide 29
Some groups contain more species than others Species are not
evenly distributed among taxonomic groups Insects predominate over
all other life-forms 40% of all insects are beetles Groups
accumulate species by Adaptive radiation Allopatric speciation Low
rates of extinction
Slide 30
Insects outnumber all other species
Slide 31
Measuring biodiversity is not easy Out of the estimated 3 - 100
million species on Earth, only 1.7 - 2 million species have been
successfully catalogued Very difficult to identify species Many
remote spots on Earth remain unexplored Small organisms are easily
overlooked Many species look identical until thoroughly examined
Entomologist Terry Erwin found 163 beetle species specialized on
one tree species
Slide 32
Biodiversity is unevenly distributed Living things are
distributed unevenly across Earth Latitudinal gradient = species
richness increases towards the equator Canada has 30 - 100 species
of breeding birds, while Costa Rica has more than 600 species
Slide 33
Latitudinal gradient has many causes Climate stability, high
plant productivity, and no glaciation Tropical biomes support more
species and show more species evenness Diverse habitats increase
species diversity Human disturbance can increase habitat diversity
But only at the local level
Slide 34
Biodiversity losses and species extinction Extinction = occurs
when the last member of a species dies and the species ceases to
exist Extirpation = the disappearance of a particular population
from a given area, but not the entire species globally Can lead to
extinction
Slide 35
Extinction is a natural process Paleontologists estimate 99% of
all species that ever lived are now extinct Background rate of
extinction = natural extinctions for a variety of reasons 1
extinction per 1 to 10 million species for mammals and marine
species 1 species out of 1,000 mammal and marine species would go
extinct every 1,000 to 10,000 years
Slide 36
Earth has experienced five mass extinctions In the past 440
million years, mass extinctions have eliminated at least 50% of all
species After every mass extinction the biodiversity returned to or
exceeded its original state
Slide 37
The current mass extinction is human caused During this
Quaternary period, we may lose more than half of all species
Hundreds of human-induced species extinctions, and multitudes of
others, teeter on the brink of extinction The current global
extinction rate is 100 to 1,000 times greater than the background
rate This rate will increase tenfold in future decades due to human
population growth and resource consumption
Slide 38
People have hunted species to extinction for millennia
Extinctions followed human arrival on islands and continents
Slide 39
Current extinction rates are higher than normal The Red List =
an updated list of species facing high risks of extinctions 23% of
mammal species 12% of bird species 31 - 86% of all other species
Since 1970, 58 fish species, 9 bird species, and 1 mammal species
has gone extinct In the U.S., in the last 500 years, 236 animal and
17 plant species are confirmed extinct Actual numbers are
undoubtedly higher
Slide 40
Biodiversity loss is more than extinction Decreasing numbers
are accompanied by smaller species geographic ranges Genetic,
ecosystem, and species diversity are being lost. The Living Planet
Index summarizes trends in populations Between 1970 and 2003, the
Index fell by 30%
Slide 41
Biodiversity loss has many causes Reasons for biodiversity
losses are multifaceted, complex, and hard to determine Factors may
interact synergistically Four primary causes of population decline
are: Habitat alteration Invasive species Pollution Overharvesting
Global climate change now is the fifth cause
Slide 42
Habitat alteration causes biodiversity loss The greatest cause
of biodiversity loss Farming simplifies communities Grazing
modifies the grassland structure and species composition Clearing
forests removes resources organisms need Hydroelectric dams turn
rivers into reservoirs upstream Urbanization and suburban sprawl
reduce natural communities A few species (i.e., pigeons, rats)
benefit from changing habitats
Slide 43
Habitat alteration has occurred in every biome Particularly in
tropical rainforests, savannas, and tropical dry forests
Slide 44
Invasive species cause biodiversity loss Introduction of
non-native species to new environments Accidental: zebra mussels
Deliberate: food crops Island species are especially vulnerable
Invaders have no natural predators, competitors, or parasites Cost
billions of dollars in economic damage
Slide 45
Pollution causes biodiversity loss Harms organisms in many ways
Air pollution degrades forest ecosystems Water pollution adversely
affects fish and amphibians Agricultural runoff harms terrestrial
and aquatic species The effects of oil and chemical spills on
wildlife are dramatic and well known The damage to wildlife and
ecosystems caused by pollution can be severe But it tends to be
less than the damage caused by habitat alteration or invasive
species
Slide 46
Overharvesting causes biodiversity loss Vulnerable species are
large, few in number, long-lived, and have few young (K-selected
species) The Siberian tiger is hunted without rules and regulations
The early 1990s saw increased poaching because of powerful economic
incentives Many other species affected: Atlantic gray whale,
sharks, gorillas Today the oceans contain only 10% of the large
animals they once did
Slide 47
Climate change causes biodiversity loss Emissions of greenhouse
gases warms temperatures Modifies global weather patterns and
increases the frequency of extreme weather events Increases stress
on populations and forces organisms to shift their geographic
ranges Most animals and plants will not be able to cope
Slide 48
Warming has been the greatest in the Arctic The polar bear is
being considered for the endangered species list
Slide 49
Biodiversity loss has a variety of causes
Slide 50
Biodiversity provides free ecosystem services Provides food,
shelter, fuel Purifies air and water, and detoxifies wastes
Stabilizes climate, moderates floods, droughts, wind, temperature
Generates and renews soil fertility and cycles nutrients Pollinates
plants and controls pests and disease Maintains genetic resources
Provides cultural and aesthetic benefits Allows us to adapt to
change The annual value of just 17 ecosystem services = $16 - 54
trillion per year
Slide 51
Biodiversity helps maintain ecosystem function Biodiversity
increases the stability and resilience of communities and
ecosystems Decreased biodiversity reduces a natural systems ability
to function and provide services to our society The loss of a
species affects ecosystems differently If the species can be
functionally replaced by others, it may make little difference
Extinction of a keystone species may cause other species to decline
or disappear To keep every cog and wheel is the first precaution of
intelligent tinkering (Aldo Leopold)
Slide 52
Biodiversity enhances food security Genetic diversity within
crops is enormously valuable Turkeys wheat crops received $50
billion worth of disease resistance from wild wheat Wild strains
provide disease resistance and have the ability to grow back year
after year without being replanted New potential food crops are
waiting to be used Serendipity berry produces a sweetener 3,000
times sweeter than sugar
Slide 53
Some potential new food sources
Slide 54
Organisms provide drugs and medicines Each year pharmaceutical
products owing their origin to wild species generate up to $150
billion in sales The rosy periwinkle produces compounds that treat
Hodgkin's disease and leukemia
Slide 55
Biodiversity generates economic benefits People like to
experience protected natural areas, creating economic opportunities
for residents, particularly in developing countries Costa Rica:
rainforests Australia: Great Barrier Reef Belize: reefs, caves, and
rainforests A powerful incentive to preserve natural areas and
reduce impacts on the landscape and on native species But, too many
visitors to natural areas can degrade the outdoor experience and
disturb wildlife
Slide 56
People value and seek out nature Biophilia = connections that
humans subconsciously seek with life Our affinity for parks and
wildlife Keeping of pets High value of real estate with views of
natural lands Nature deficit disorder = alienation from the natural
environment May be behind the emotional and physical problems of
the young
Slide 57
Do we have ethical obligations to other species? Humans are
part of nature and need resources to survive But, we also have
conscious reasoning ability and can control our actions Our ethics
have developed from our intelligence and our ability to make
choices Many people feel that other organisms have intrinsic value
and an inherent right to exist
Slide 58
Conservation biology responds to biodiversity loss Conservation
biology = devoted to understanding the factors that influence the
loss, protection, and restoration of biodiversity Arose as
scientists became alarmed at the degradation of natural systems An
applied and goal- oriented science
Slide 59
Conservation scientists work at multiple levels Conservation
biologists integrate evolution and extinction with ecology and
environmental systems Design, test, and implement ways to mitigate
human impacts Conservation geneticists = study genetic attributes
of organisms to infer the status of their population Minimum viable
population = how small a population can become before it runs into
problems Metapopulations = a network of subpopulations Small
populations are most vulnerable to extinction and need special
attention
Slide 60
Island biogeography Equilibrium theory of island biogeography =
explains how species come to be distributed among oceanic islands
Also applies to habitat islands patches of one habitat type
isolated within a sea of others Explains how the number of species
on an island results from an equilibrium between immigration and
extirpation Predicts an islands species richness based on the
islands size and distance from the mainland
Slide 61
Species richness results from island size and distance Fewer
species colonize an island far from the mainland Large islands have
higher immigration rates Large islands have lower extinction
rates
Slide 62
The species-area curve Large islands contain more species than
small islands They are easier to find and have lower extinction
rates They possess more habitats
Slide 63
Small islands of forest rapidly lose species Forests are
fragmented by roads and logging Small forest fragments lose
diversity fastest Starting with large species Fragmentation is one
of the prime threats to biodiversity
Slide 64
Formation of the earths early crust and atmosphere Small
organic molecules form in the seas Large organic molecules
(biopolymers) form in the seas First protocells form in the seas
Single-cell prokaryotes form in the seas Single-cell eukaryotes
form in the seas Variety of multicellular organisms form, first in
the seas and later on land Biological Evolution (3.7 billion years)
Fig. 5.2, p. 103 Chemical Evolution (1 billion years)
Slide 65
What factors contribute to speciation? Why would an organism be
needed? function What could lead to new niches? Structure
Slide 66
cyanobacters May use CO2 from atmosphere or water Can convert
EMS energy to chemical energy Created pollution crisis due to
production of O2 Contributed to the rise of aerobic
prokaryotes
Slide 67
eukaryotes Fossil evidence 1.2 bya some O2 in atmosphere was
converted by solar energy to O3 now protected from UV green plants
near surface water 780 mya first plants fossil evidence on
land
Slide 68
Fossils present but rare Evolution and expansion of life
Fossils become abundant Plants invade the land Age of reptiles Age
of mammals Insects and amphibians invade the land Modern humans
(Homo sapiens) appear about 2 seconds before midnight Recorded
human history begins 1/4 second before midnight Origin of life
(3.63.8 billion years ago)
Slide 69
Adapted to heat through lightweight fur and long ears, legs,
and nose, which give off more heat. Adapted to cold through heavier
fur, short ears, short legs, short nose. White fur matches snow for
camouflage. Gray Fox Arctic Fox Different environmental conditions
lead to different selective pressures and evolution into two
different species. Spreads northward and southward and separates
Southern population Northern population Early fox population Fig.
5.8, p. 113 Allopatric speciation
Slide 70
Sympatric Speciation A new species forms within the same
spatial and temporal location as the original species; There is no
geographic isolation or difference in diurnal or seasonal patterns
Changes in niche availability can lead to sympatric speciation
Co-evolution can lead to sympatric speciation Need for resource
partitioning can lead to sympatric speciation
Slide 71
What is required to maintain a species?
Slide 72
Maintaining reproductive isolation to remain a species
Prezygotic barriers: prevent zygote from forming postzygotic
barriers: prevent new species from occurring
Slide 73
Prezygotic barriers Habitat isolation: live in different
habitats dont encounter others Behavioral isolation:
mating/courtship rituals, songs, other signals Temporal isolation:
different mating times diurnal, seasonal, or annual differences
Mechanical isolation: anatomically incompatible Gametic isolation:
gametes may not meet or cannot fuse
Slide 74
Postzygotic Barriers Reduced hybrid variability: genetic
incompatibility may abort development of zygote Reduced hybrid
fertility: if hybrid offspring is vigorous, hybrid is
sterile-meiosis cant produce gametes Hybrid breakdown: 1 st
generation hybrid viable and fertile, 2 nd generation feeble or
sterile
Slide 75
microevolution dev of genetic variability in population
heritable traits; gene pool alleles 4-mutations: exposure of DNA to
ext agents radioactivity, X rays, natural and hman made chem.
Mutagens random mistakes DNA copied or when reproduces most
mutations harmful few are beneficial bene if: give offspring better
chances for survival under existing env conditions and when
conditions change mutations random and unpredictable, source of
totally new genetic raw material (alleles) and are rare events
Slide 76
selection artificial selection: we choose traits and we
selectively breed (dog types) natural selection some indiv of pop
have genetically based traits that increase their chances of
survival and their ability to produce offspring must be natural
variability in pop trait must be heritable trait must lead to
differential reproduction (leave more offspring) allele becomes
more common in successive pop called adaptation or adaptive
trait
Slide 77
When is selection likely to occur? when change in env
conditions occurs pop can adapt through nat select or migrate if
poss to better conditions or become extinct example: peppered moth
in England soot on tree trunks birds eat if not blend in
Slide 78
3 types of natural selection directional natural selection:
changing env conditions cause allele freq to shift so individual w
traits at end of normal range become more common than midrange
forms stabilizing natural selection : favor indivi in mid curve
average; works best if env changes little and most member of pop
are adapted to env diversifying natural selection : occurs when env
cond favor individuals at extremes of curve ;eliminate
indeterminate traits ; pop may be split into two groups
Slide 79
Directional selection changing env conditions cause allele freq
to shift so individual w traits at end of normal range become more
common than midrange forms eg peppered moths, genetic resistance to
pesticides or to antibiotics
Slide 80
Natural selection New averagePrevious average Number of
individuals Coloration of snails Proportion of light-colored snails
in population increases Number of individuals Snail coloration best
adapted to conditions Average Coloration of snails Average shifts
Directional Natural Selection
Slide 81
stabilizing natural selection favor indivi in mid curve
-average works best if env changes little and most member of pop
are adapted to env
Slide 82
Coloration of snails Light snails eliminated Dark snails
eliminated Number of individuals Coloration of snails Snails with
extreme coloration are eliminated Number of individuals Average
remains the same, but the number of individuals with intermediate
coloration increases Natural selection Stabilizing Natural
Selection
Slide 83
diversifying natural selection occurs when env cond favor
individuals at extremes of curve eliminate indeterminate traits pop
may be split into two groups
Slide 84
Number of individuals with light and dark coloration increases,
and the number with intermediate coloration decreases Coloration of
snails Number of individuals Snails with light and dark colors
dominate Coloration of snails Number of individuals Light
coloration is favored Dark coloration is favored
Intermediate-colored snails are selected against Natural selection
Diversifying Natural Selection
Slide 85
Coevolution interactions between species results in micro evol
of each of pop
Slide 86
ecological niche: function include range of tolerance for
physical and chemical factors types and amts of resources it uses
how interacts w other living and nonliving components role it plays
in energy flow adaptative traits reflect niche traits enable
population to survive and reproduce effectively under given set
environmental conditions
Slide 87
niche significance prevent from becoming prematurely extinct
assess environmental changes we make in terrestrial and aquatic
systems
Slide 88
fundamental niche vs realized niche Fundamental niche is what
it could be in the best of all circumstances Realized niche is what
it is with limitations that are present
Slide 89
what limits adaptation? traits have to be present to start w
even if beneficial heritable trait present the population ability
to adapt can be limited by its reproductive capacity don't just
eliminate rest of population so that trait can show-usually most of
population still around in gene pool
Slide 90
evolution misconceptions fitness is reprod potential not
strongest there is no grand plan for perfection
Slide 91
divergent evolution speciation: geographic isolation -
allopatric speciation no geographic isolation: sympatric speciation
for either next step is reproductive isolation
Slide 92
Why Should We Care About Biodiversity? Instrumental value
Intrinsic value Value of Nature InstrumentalIntrinsic Utilitarian
Nonutilitarian (human centered) (species or ecosystem centered)
Goods Ecological services Information Option Recreation Existence
Aesthetic Bequest
Slide 93
biodiversity: speciation - extinction extinction followed by
period of recovery that are characterized by adaptive radiation new
species evolve to fill new or vacated ecological roles or niches in
changed environments 5 mya years to rebuild biological
diversity
Slide 94
Ordovician: 50% of animal families, including many trilobites
Devonian: 30% of animal families, including agnathan and placoderm
fishes and many trilobites. Permian: 90% of animal families,
including over 95% of marine species; many trees, amphibians, most
bryozoans and brachiopods, all trilobites. Triassic: 35% of animal
families, including many reptiles and marine mollusks. Cretaceous:
up to 80% of ruling reptiles (dinosaurs); many marine species
including many foraminiferans and mollusks. Current extinction
crisis caused by human activities. Many species are expected to
become extinct within the next 50100 years. Species and families
experiencing mass extinction Bar width represents relative number
of living species Extinction Millions of years ago PeriodEra
Paleozoic Mesozoic Cenozoic Quaternary Tertiary Cretaceous Jurassic
Triassic Permian Carboniferous Devonian Silurian Ordovician
Cambrian Today 65 180 250 345 500 Extinction
Slide 95
Human Impacts on Biodiversity Food supply and demand Freshwater
supply and demand Forest product supply and demand Climate change
Biodiversity loss Habitat change Changes in transpiration and
albedo Loss of crop genetic diversity Reduced resistance to change
Loss and fragmentation of habitat CO 2 emission Habitat change and
fragmentation of habitat Changes in precipitation and temperature
Water availability Water use and pollution and soil nutrient loss
CO 2, CH 4, N 2 O emissions Erosion, pollution, and changes in
water flow Loss and fragmentation of habitat Loss and fragmentation
of habitat Deforestation Changes in water supply and temperature
Changes in water supply and temperature Fig. 22.2, p. 551
Slide 96
Increasing Biodiversity Physically diverse habitat Moderate
environmental disturbance Small variations in conditions Middle
stages of ecological succession
Slide 97
Decreasing Biodiversity Environmental stress Large
environmental disturbance Extreme environmental conditions Severe
limiting factors Introduction of alien species Geographic
isolation
Slide 98
US Diversity 67% Secure or apparently secure 1% Other
16%Vulnerable 8%Imperiled 7%Criticallyimperiled 1% Probably
extinct
Slide 99
Strategies for Protecting Biodiversity Species approach
Ecosystem approach The Species Approach The Ecosystem Approach Goal
Protect species from premature extinction Strategies Identify
endangered species Protect their critical habitats Tactics Legally
protect endangered species Manage habitat Propagate endangered
species in captivity Reintroduce species into suitable habitats
Goal Protect populations of species in their natural habitats
Strategy Preserve sufficient areas of habitats in different biomes
and aquatic systems Tactics Protect habitat areas through private
purchase or government action Eliminate or reduce populations of
alien species from protected areas Manage protected areas to
sustain native species Restore degraded ecosystems
Slide 100
Species Extinction Local extinction Ecological extinction
Biological extinction
Slide 101
mass depletion extinction rate higher than normal but not high
enough to consider it mass extinct
Slide 102
Endangered and Threatened Species Endangered species: any
species that is in danger of extinction throughout all or a
significant portion of its range Threatened (vulnerable species)
any species that is likely to become an endangered species within
the foreseeable future throughout all or a significant portion of
its range Rare: a species where the population is declining to
dangerously low numbers but still has enough members to maintain or
increase its population Florida manatee Northern spotted owl
(threatened) Gray wolfFlorida panther Bannerman's turaco
(Africa)
Slide 103
Extinction Risks Factors: population size, habitat, and
genetics Population viability analysis Minimum viable population
Minimum dynamic area Characteristics of extinction-prone
species
Slide 104
Extinction Rates Background (natural) rate of extinction Mass
extinction Adaptive radiations Number of families of marine animals
Geological Periods Millions of years ago Mass extinctions 800 600
400 200 0 570505438360286208144650 Cambrian Ordovician Silurian
Devonian Carboniferous Permian Triassic Jurassic Cretaceous
Tertiary Quaternary ? 4082452 Fig. 22.10, p. 558
Slide 105
Causes of Depletion of Wild Species Human population growth
Failure to value the environment or ecological services Increasing
per capita resource use Increasing use of Earths primary
productivity poverty
Slide 106
Causes of Premature Extinction of Wild Species Habitat
degradation Introduction of non-native species Overfishing
Habitatloss Habitat degradation Introducingnonnativespecies
Commercial hunting and poaching Sale of exotic pets and decorative
plants Predator and pest control Pollution Climate change Basic
Causes Population growthPopulation growth Rising resource useRising
resource use No environmental accountingNo environmental accounting
PovertyPoverty Fig. 22.13, p. 564
Slide 107
Should conservation focus on endangered species? Endangered
Species Act (1973) (ESA) = forbids the government and private
citizens from taking actions that destroy endangered species or
their habitats To prevent extinction Stabilize declining
populations Enable populations to recover As of 2007, the U.S. had
1,312 species listed as endangered or threatened
Slide 108
Despite opposition, the ESA has had successes Peregrine
falcons, brown pelicans, bald eagles, and others have recovered and
are no longer listed Intensive management has stabilized other
species The red-cockaded woodpecker 40% of declining populations
are now stable These successes occur despite underfunding of the
U.S. Fish and Wildlife Service and the National Marine Fisheries
Service In recent years, political forces have attempted to weaken
the ESA
Slide 109
The ESA is controversial Many Americans support protection of
endangered species Opponents feel that the ESA values endangered
organisms more than the livelihood of people Private land use will
be restricted if an endangered species is present Shoot, shovel,
and shut up = landowners conceal the presence of endangered species
on their land But, the ESA has stopped few development projects
Habitat conservation plans and safe harbor agreements = landowners
can harm species if they improve habitat for the species in other
places
Slide 110
Other countries have their own version of the ESA Species at
Risk Act (2002) = Canadas endangered species law Stresses
cooperation between landowners and provincial governments
Criticized as being too weak Other nations laws are not enforced
The Wildlife Conservation Society has to help pay for Russians to
enforce their own anti-poaching laws
Slide 111
Protecting biodiversity Captive breeding individuals are bred
and raised with the intent of reintroducing them into the wild Zoos
and botanical gardens Some reintroductions are controversial
Ranchers opposed the reintroduction of wolves to Yellowstone
National Park Some habitat is so fragmented, a species cannot
survive
Slide 112
Protecting biodiversity Cloning a technique to create more
individuals and save species from extinction Most biologists agree
that these efforts are not adequate to recreate the lost
biodiversity Ample habitat and protection in the wild are needed to
save species
Slide 113
Umbrella species Conservation biologists use particular species
as tools to conserve communities and ecosystems Protecting the
habitat of these umbrella species helps protect less-charismatic
animals that would not have generated public interest Flagship
species large and charismatic species used as spearheads for
biodiversity conservation The World Wildlife Funds panda bear Some
organizations are moving beyond the single species approach to
focus on whole landscapes
Slide 114
International conservation efforts UN Convention on
International Trade in Endangered Species of Wild Fauna and Flora
(1973) (CITES) protects endangered species by banning international
transport of their body parts Convention on Biological Diversity
(1992) Seeks to conserve biodiversity Use biodiversity in a
sustainable manner Ensure the fair distribution of biodiversitys
benefits By 2007, 188 nations had signed on Iraq, Somalia, the
Vatican, and the U.S. did not join
Slide 115
Biodiversity hotspots Biodiversity hotspots prioritizes regions
most important globally for biodiversity Support a great number of
endemic species = species found nowhere else in the world The area
must have at least 1.500 endemic plant species (0.5% of the world
total) It must have lost 70% of its habitat due to human
impact
Slide 116
There are 34 global biodiversity hotspots 2.3% of the planets
land surface contains 50% of the worlds plant species and 42% of
all terrestrial vertebrate species
Slide 117
Community- based conservation Protecting habitats makes good
sense, but this affects people living in and near these areas
Community-based conservation = conservation biologists actively
engage local people in protecting land and wildlife Protecting land
deprives people access to resources But, it can guarantee that
these resources will not be used up or sold to foreign corporations
and can instead be sustainably managed Many projects have succeeded
But, others have not, due mainly to funding problems
Slide 118
Innovative economic strategies Debt-for-nature swap = a
conservation organization pays off a portion of a developing
countrys international debt In exchange for a promise by the
country to set aside reserves Fund environmental education, and
Better manage protected areas Conservation concession =
conservation organizations pay nations to conserve, and not sell,
resources
Slide 119
Solutions: Protecting Wild Species from Depletion and
Extinction Bioinformatics International treaties: CITES National
Laws: Lacey Act Endangered species Act Habitat conservation plans
Wildlife refuges and protected areas Zoos, bontanical gardens, and
gene banks
Slide 120
Conclusion Loss of biodiversity will result in a mass
extinction Primary causes of biodiversity loss are: Habitat
alteration, invasive species, pollution, overharvesting of biotic
resources, and climate change Human society cannot function without
biodiversitys benefits Science can help save species, preserve
habitats, restore populations, and keep natural ecosystems
intact