55 conservation text
Post on 30-May-2018
214 Views
Preview:
TRANSCRIPT
-
8/14/2019 55 Conservation Text
1/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
PowerPoint Lectures for
Biology, Seventh Edition
Neil Campbell and Jane Reece
Lectures by Chris Romero
Chapter 55
Conservation Biology and
Restoration Ecology
-
8/14/2019 55 Conservation Text
2/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Overview: The Biodiversity Crisis
Conservation biology integrates the following fieldsto conserve biological diversity at all levels
Ecology
Evolutionary biology
Physiology
Molecular biology
Genetics
Behavioral ecology
-
8/14/2019 55 Conservation Text
3/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Restoration ecology applies ecological
principles In an effort to return degraded ecosystems to
conditions as similar as possible to their
natural state
-
8/14/2019 55 Conservation Text
4/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Tropical forests
Contain some of the greatest concentrations ofspecies
Are being destroyed at an alarming rate
Figure 55.1
-
8/14/2019 55 Conservation Text
5/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Throughout the biosphere, human activities
Are altering ecosystem processes on which weand other species depend
-
8/14/2019 55 Conservation Text
6/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Concept 55.1: Human activities threaten
Earths biodiversity Rates of species extinction
Are difficult to determine under natural
conditions
The current rate of species extinction is high
And is largely a result of ecosystemdegradation by humans
Humans are threatening Earths biodiversity
-
8/14/2019 55 Conservation Text
7/77Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The Three Levels of Biodiversity
Biodiversity has three main components
Genetic diversity
Species diversity
Ecosystem diversity
Genetic diversity in a vole population
Species diversity in a coastal redwood ecosystem
Community and ecosystem diversity
across the landscape of an entire region
Figure 55.2
-
8/14/2019 55 Conservation Text
8/77Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Genetic Diversity
Genetic diversity comprises
The genetic variation within a population
The genetic variation between populations
-
8/14/2019 55 Conservation Text
9/77Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Species Diversity
Species diversity
Is the variety of species in an ecosystem orthroughout the biosphere
-
8/14/2019 55 Conservation Text
10/77Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
An endangered species
Is one that is in danger of becoming extinctthroughout its range
Threatened species
Are those that are considered likely to become
endangered in the foreseeable future
-
8/14/2019 55 Conservation Text
11/77Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Conservation biologists are concerned about
species loss Because of a number of alarming statistics
regarding extinction and biodiversity
-
8/14/2019 55 Conservation Text
12/77Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Harvard biologist E. O. Wilson has identified
the Hundred Heartbeat Club Species that number fewer than 100
individuals and are only that many heartbeats
from extinction(a) Philippine eagle
(b) Chinese riverdolphin
(c) Javan
rhinocerosFigure 55.3ac
-
8/14/2019 55 Conservation Text
13/77Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Ecosystem Diversity
Ecosystem diversity
Identifies the variety of ecosystems in thebiosphere
Is being affected by human activity
-
8/14/2019 55 Conservation Text
14/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Biodiversity and Human Welfare
Human biophilia
Allows us to recognize the value of biodiversityfor its own sake
Species diversity
Brings humans many practical benefits
-
8/14/2019 55 Conservation Text
15/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Benefits of Species and Genetic Diversity
Many pharmaceuticals
Contain substances originally derived fromplants
Figure 55.4
-
8/14/2019 55 Conservation Text
16/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The loss of species
Also means the loss of genes and geneticdiversity
The enormous genetic diversity of organisms
on Earth
Has the potential for great human benefit
-
8/14/2019 55 Conservation Text
17/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Ecosystem Services
Ecosystem services encompass all the
processes Through which natural ecosystems and the
species they contain help sustain human life
on Earth
-
8/14/2019 55 Conservation Text
18/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Ecosystem services include
Purification of air and water
Detoxification and decomposition of wastes
Cycling of nutrients
Moderation of weather extremes
And many others
-
8/14/2019 55 Conservation Text
19/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Four Major Threats to Biodiversity
Most species loss can be traced to four major
threats Habitat destruction
Introduced species
Overexploitation
Disruption of interaction networks
-
8/14/2019 55 Conservation Text
20/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Habitat Destruction
Human alteration of habitat
Is the single greatest threat to biodiversitythroughout the biosphere
Massive destruction of habitat
Has been brought about by many types of
human activity
-
8/14/2019 55 Conservation Text
21/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Many natural landscapes have been broken up
Fragmenting habitat into small patches
Figure 55.5
-
8/14/2019 55 Conservation Text
22/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
In almost all cases
Habitat fragmentation and destruction leads toloss of biodiversity
-
8/14/2019 55 Conservation Text
23/77
-
8/14/2019 55 Conservation Text
24/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Introduced species that gain a foothold in a
new habitat Usually disrupt their adopted community
(a) Brown tree
snake, intro-
duced to Guam
in cargo
(b) Introduced kudzu thriving in South Carolina
Figure 55.6a, b
-
8/14/2019 55 Conservation Text
25/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Overexploitation
Overexploitation refers generally to the human
harvesting of wild plants or animals
At rates exceeding the ability of populations of
those species to rebound
-
8/14/2019 55 Conservation Text
26/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The fishing industry
Has caused significant reduction in populationsof certain game fish
Figure 55.7
Di i f I i N k
-
8/14/2019 55 Conservation Text
27/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Disruption of Interaction Networks
The extermination of keystone species by
humans
Can lead to major changes in the structure of
communities
Figure 55.8
-
8/14/2019 55 Conservation Text
28/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Concept 55.2: Population conservation focuses
on population size, genetic diversity, and
critical habitat
Biologists focusing on conservation at the
population and species levels Follow two main approaches
S ll P l ti A h
-
8/14/2019 55 Conservation Text
29/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Small-Population Approach
Conservation biologists who adopt the small-
population approach
Study the processes that can cause very small
populations finally to become extinct
Th E i i V
-
8/14/2019 55 Conservation Text
30/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The Extinction Vortex
A small population is prone to positive-
feedback loops
That draw the population down an extinction
vortexSmall
population
InbreedingGenetic
drift
Lower
reproduction
Higher
mortality Loss of
genetic
variabilityReduction in
individual
fitness and
population
adaptability
Smaller
population
Figure 55.9
-
8/14/2019 55 Conservation Text
31/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The key factor driving the extinction vortex
Is the loss of the genetic variation necessary toenable evolutionary responses to
environmental change
C St d Th G t P i i Chi k d th
-
8/14/2019 55 Conservation Text
32/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Case Study: The Greater Prairie Chicken and theExtinction Vortex
Populations of the greater prairie chicken Were fragmented by agriculture and later
found to exhibit decreased fertility
-
8/14/2019 55 Conservation Text
33/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
As a test of the extinction vortex hypothesis
Scientists imported genetic variation bytransplanting birds from larger populations
-
8/14/2019 55 Conservation Text
34/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The declining population rebounded
Confirming that it had been on its way down anextinction vortex
EXPRIMENTResearchers observed that the population
collapse of the greater prairie chicken was mirrored in a reduction in
fertility, as measured by the hatching rate of eggs. Comparison of
DNA samples from the Jasper County, Illinois, population with DNAfrom feathers in museum specimens showed that genetic variation
had declined in the study population. In 1992, researchers began
experimental translocations of prairie chickens from Minnesota,
Kansas, and Nebraska in an attempt to increase genetic variation.
RESULTSAfter translocation (blue arrow), the viability of
eggs rapidly improved, and the population rebounded.
CONCLUSIONThe researchers concluded that lack of genetic
variation had started the Jasper County population of prairie
chickens down the extinction vortex.
Numberofmalebirds
(a) Population dynamics
(b) Hatching rate
200
150
100
50
0
1970 1975 1980 1985 1990 1995 2000
Year
Eggshatched(%)
100
90
80
70
60
50
40
30
1970-74 1975-79 1980-84 1985-89 1990 1993-97
Years
Figure 55.10
Mi i Vi bl P l ti Si
-
8/14/2019 55 Conservation Text
35/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Minimum Viable Population Size
The minimum viable population (MVP)
Is the minimum population size at which aspecies is able to sustain its numbers and
survive
-
8/14/2019 55 Conservation Text
36/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
A population viability analysis (PVA)
Predicts a populations chances for survivalover a particular time
Factors in the MVP of a population
Effective Population Size
-
8/14/2019 55 Conservation Text
37/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Effective Population Size
A meaningful estimate of MVP
Requires a researcher to determine theeffective population size, which is based on the
breeding size of a population
Case Study: Analysis of Grizzly Bear Populations
-
8/14/2019 55 Conservation Text
38/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Case Study: Analysis of Grizzly Bear Populations
One of the first population viability analyses
Was conducted as part of a long-term study ofgrizzly bears in Yellowstone National Park
Figure 55.11
-
8/14/2019 55 Conservation Text
39/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
This study has shown that the grizzly bear
population
Has grown substantially in the past 20 years
Num
berofindividuals
150
100
50
01973 1982 1991 2000
Females with cubs
Cubs
Year
Figure 55.12
Declining Population Approach
-
8/14/2019 55 Conservation Text
40/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Declining-Population Approach
The declining-population approach
Focuses on threatened and endangeredpopulations that show a downward trend,
regardless of population size
Emphasizes the environmental factors thatcaused a population to decline in the first place
Steps for Analysis and Intervention
-
8/14/2019 55 Conservation Text
41/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Steps for Analysis and Intervention
The declining-population approach
Requires that population declines be evaluatedon a case-by-case basis
Involves a step-by-step proactive conservation
strategy
Case Study: Decline of the Red Cockaded
-
8/14/2019 55 Conservation Text
42/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Case Study: Decline of the Red-CockadedWoodpecker
Red-cockaded woodpeckers Require specific habitat factors for survival
Had been forced into decline by habitat
destruction
(a) A red-cockaded woodpecker perches at the
entrance to its nest site in a longleaf pine.
(b) Forest that can
sustain red-cockaded
woodpeckers has
low undergrowth.
(c) Forest that cannot sustain red-cockaded
woodpeckers has high, dense undergrowth that
impacts the woodpeckers access to feeding grounds.Figure 55.13ac
-
8/14/2019 55 Conservation Text
43/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
In a study where breeding cavities were
constructed
New breeding groups formed only in these
sites
On the basis of this experiment
A combination of habitat maintenance and
excavation of new breeding cavities has
enabled a once-endangered species torebound
Weighing Conflicting Demands
-
8/14/2019 55 Conservation Text
44/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Weighing Conflicting Demands
Conserving species often requires resolving
conflicts
Between the habitat needs of endangered
species and human demands
-
8/14/2019 55 Conservation Text
45/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Concept 55.3: Landscape and regional
conservation aim to sustain entire biotas
In recent years, conservation biology
Has attempted to sustain the biodiversity of
entire communities, ecosystems, andlandscapes
-
8/14/2019 55 Conservation Text
46/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
One goal of landscape ecology, of which
ecosystem management is part
Is to understand past, present, and future
patterns of landscape use and to make
biodiversity conservation part of land-use
planning
Landscape Structure and Biodiversity
-
8/14/2019 55 Conservation Text
47/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Landscape Structure and Biodiversity
The structure of a landscape
Can strongly influence biodiversity
-
8/14/2019 55 Conservation Text
48/77
-
8/14/2019 55 Conservation Text
49/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
As habitat fragmentation increases
And edges become more extensive,biodiversity tends to decrease
-
8/14/2019 55 Conservation Text
50/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Research on fragmented forests has led to the
discovery of two groups of species
Those that live in forest edge habitats and
those that live in the forest interior
Figure 55.15
Corridors That Connect Habitat Fragments
-
8/14/2019 55 Conservation Text
51/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Corridors That Connect Habitat Fragments
A movement corridor
Is a narrow strip of quality habitat connectingotherwise isolated patches
-
8/14/2019 55 Conservation Text
52/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
In areas of heavy human use
Artificial corridors are sometimes constructed
Figure 55.16
-
8/14/2019 55 Conservation Text
53/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Movement corridors
Promote dispersal and help sustainpopulations
Establishing Protected Areas
-
8/14/2019 55 Conservation Text
54/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Establishing Protected Areas
Conservation biologists are applying their
understanding of ecological dynamics
In establishing protected areas to slow the loss
of biodiversity
-
8/14/2019 55 Conservation Text
55/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Much of the focus on establishing protected
areas
Has been on hot spots of biological diversity
Finding Biodiversity Hot Spots
-
8/14/2019 55 Conservation Text
56/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
i di g iodive sity ot Spots
A biodiversity hot spot is a relatively small area
With an exceptional concentration of endemicspecies and a large number of endangered
and threatened species
Terrestrial
biodiversity
hot spots
Equator
Figure 55.17
-
8/14/2019 55 Conservation Text
57/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Biodiversity hot spots are obviously good
choices for nature reserves
But identifying them is not always easy
Philosophy of Nature Reserves
-
8/14/2019 55 Conservation Text
58/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
p y f
Nature reserves are biodiversity islands
In a sea of habitat degraded to varyingdegrees by human activity
One argument for extensive reserves
Is that large, far-ranging animals with low-
density populations require extensive habitats
-
8/14/2019 55 Conservation Text
59/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
In some cases
The size of reserves is smaller than the actualarea needed to sustain a population
Biotic boundary for
short-term survival;
MVP is 50 individuals.
Biotic boundary for
long-term survival;
MVP is 500 individuals.
Grand Teton
National Park
Wyoming
Idaho
43
42
41
40
0 50 100
Kilometers
SnakeR
.
Yellowstone
NationalPark
Shoshone R.
Montana
Wyoming
Montana
Idaho
MadisonR.
GallatinR.
YellowstoneR.
Figure 55.18
-
8/14/2019 55 Conservation Text
60/77
-
8/14/2019 55 Conservation Text
61/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Zoned reserves
Are often established as conservation areas
(a) Boundaries of the zoned reserves are indicated by black outlines.
(b) Local schoolchildren marvel at the diversity of life in one of
Costa Ricas reserves.
Nicaragua
Costa
Rica
Panam
aNational park land
Buffer zone
PACIFIC OCEAN
CARIBBEAN SEA
Figure 55.19a, b
-
8/14/2019 55 Conservation Text
62/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Some zoned reserves in the Fiji islands are
closed to fishing
Which actually helps to improve fishing
success in nearby areas
Figure 55.20
-
8/14/2019 55 Conservation Text
63/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Concept 55.4: Restoration ecology attempts to
restore degraded ecosystems to a more natural
state
The larger the area disturbed
The longer the time that is required forrecovery
-
8/14/2019 55 Conservation Text
64/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Whether a disturbance is natural or caused by
humans
Seems to make little difference in this size-
time relationship
Recoverytime(years)
(logscale)
104
1,000
100
10
1
103 102 101 1 10 100 1,000 104
Natural disasters
Human-caused disasters
Natural OR human-
caused disastersMeteor
strike
Groundwater
exploitationIndustrial
pollution
Urbanization Salination
Modern
agriculture FloodVolcanic
eruptionAcidrain
Forest
fire
Nuclear
bomb
Tsunami
Oilspill
Slash& burn
Land-slide
Tree
fallLightning
strike
Spatial scale (km2)(log scale)
Figure 55.21
-
8/14/2019 55 Conservation Text
65/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
One of the basic assumptions of restoration
ecology
Is that most environmental damage is
reversible
Two key strategies in restoration ecology
Are bioremediation and augmentation of
ecosystem processes
Bioremediation
-
8/14/2019 55 Conservation Text
66/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Bioremediation
Is the use of living organisms to detoxifyecosystems
Biological Augmentation
-
8/14/2019 55 Conservation Text
67/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Biological augmentation
Uses organisms to add essential materials to adegraded ecosystem
Exploring Restoration
-
8/14/2019 55 Conservation Text
68/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The newness and complexity of restoration
ecology
Require scientists to consider alternative
solutions and adjust approaches based on
experience
-
8/14/2019 55 Conservation Text
69/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Exploring restoration worldwide
Truckee River, Nevada. Kissimmee River, Florida.
Equator
Figure 55.22
-
8/14/2019 55 Conservation Text
70/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Tropical dry forest, Costa Rica. Succulent Karoo, South Africa.
Rhine River, Europe. Coastal Japan.Figure 55.22
-
8/14/2019 55 Conservation Text
71/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Concept 55.5: Sustainable development seeks
to improve the human condition while
conserving biodiversity
Facing increasing loss and fragmentation of
habitats
How can we best manage Earths resources?
Sustainable Biosphere Initiative
-
8/14/2019 55 Conservation Text
72/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The goal of this initiative is to define and
acquire the basic ecological information
necessary
For the intelligent and responsible
development, management, and conservation
of Earths resources
Case Study: Sustainable Development in Costa
-
8/14/2019 55 Conservation Text
73/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Rica
Costa Ricas success in conserving tropical
biodiversity
Has involved partnerships between the
government, other organizations, and private
citizens
-
8/14/2019 55 Conservation Text
74/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Human living conditions in Costa Rica
Have improved along with ecologicalconservation
Infantm
ortality(per1,000livebirths)
200
150
100
50
0
1900 1950 2000
80
70
60
50
40
30
Year
Life expectancy
Infant mortality
Lifeexpectancy(years)
Figure 55.23
Biophilia and the Future of the Biosphere
-
8/14/2019 55 Conservation Text
75/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Our modern lives
Are very different from those of early humanswho hunted and gathered and painted on cave
walls
(a) Detail of animals in a Paleolithic mural, Lascaux, FranceFigure 55.24a
-
8/14/2019 55 Conservation Text
76/77
Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings
But our behavior
Reflects remnants of our ancestral attachmentto nature and the diversity of life, the concept
of biophilia
(b) Biologist Carlos Rivera Gonzales examining a tiny tree frog in
PeruFigure 55.24b
-
8/14/2019 55 Conservation Text
77/77
Our innate sense of connection to nature
May eventually motivate a realignment of ourenvironmental priorities
top related