1. Conservation Biology and Restoration Ecology
Chapter 56
Conservation Biology and Restoration Ecology

2. Overview: The Biodiversity Crisis
Conservation biology integrates the following fields to conserve biological diversity at all levels
Ecology
Evolutionary biology
Physiology
Molecular biology
Genetics
Behavioral ecology

3. Restoration ecology applies ecological principles
In an effort to return degraded ecosystems to conditions as similar as possible to their natural state

4. Losing Tropical Forests
Contain some of the greatest concentrations of species
Are being destroyed at an alarming rate
Figure 55.1

5. The HUMAN Impact
Throughout the biosphere, human activities are altering ecosystem processes on which we and other species depend!
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 ecosystem degradation by humans
Humans are threatening Earth’s biodiversity

6. 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

7. Levels of Biodiversity
Genetic diversity comprises
The genetic variation within a population
The genetic variation between populations
Species diversity
Is the variety of species in an ecosystem or throughout the biosphere
Ecosystem diversity
Identifies the variety of ecosystems in the biosphere
Is being affected by human activity

8. Conservation biologists are concerned about species loss
Species Diversity
An endangered species
Is one that is in danger of becoming extinct throughout its range
Threatened species
Are those that are considered likely to become endangered in the foreseeable future
Conservation biologists are concerned about species loss
Because of a number of alarming statistics regarding extinction and biodiversity

9. Biodiversity and Human Welfare
Human biophilia
Allows us to recognize the value of biodiversity for its own sake
Species diversity
Brings humans many practical benefits

10. Benefits of Species and Genetic Diversity
Many pharmaceuticals
Contain substances originally derived from plants
The loss of species
Also means the loss of genes and genetic diversity
The enormous genetic diversity of organisms on Earth
Has the potential for great human benefit

11. Ecosystem services include
Ecosystem services encompass all the processes through which natural ecosystems and the species they contain help sustain human life on Earth
Ecosystem services include
Purification of air and water
Detoxification and decomposition of wastes
Cycling of nutrients
Moderation of weather extremes
And many others

12. Four Major Threats to Biodiversity
Most species loss can be traced to four major threats
Habitat destruction
Introduced species
Overexploitation
Disruption of “interaction networks”

13. Human alteration of habitat
Habitat Destruction
Human alteration of habitat
Is the single greatest threat to biodiversity throughout the biosphere
Massive destruction of habitat
Has been brought about by many types of human activity
In almost all cases
Habitat fragmentation and destruction leads to loss of biodiversity

14. (b) Introduced kudzu thriving in South Carolina
Introduced Species
Introduced species
Are those that humans move from the species’ native locations to new geographic regions
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

15. 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
The fishing industry
Has caused significant reduction in populations of certain game fish

16. Disruption of Interaction Networks
The extermination of keystone species by humans
Can lead to major changes in the structure of communities
Figure 55.8

17. Conservation biologists who adopt the small-population approach
Conservation Effort
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
Conservation biologists who adopt the small-population approach
Study the processes that can cause very small populations finally to become extinct

18. A small population is prone to positive-feedback loops
The Extinction Vortex
A small population is prone to positive-feedback loops
That draw the population down an extinction vortex
Small
population
Inbreeding
Genetic
drift
Lower reproduction
Higher mortality
Loss of
genetic
variability
Reduction in
individual
fitness and
adaptability
Smaller
Figure 55.9

19. The key factor driving the extinction vortex
Is the loss of the genetic variation necessary to enable evolutionary responses to environmental change

20. Minimum Viable Population Size
The minimum viable population (MVP)
Is the minimum population size at which a species is able to sustain its numbers and survive
A population viability analysis (PVA)
Predicts a population’s chances for survival over a particular time
Factors in the MVP of a population
A meaningful estimate of MVP
Requires a researcher to determine the effective population size, which is based on the breeding size of a population

21. Declining-Population Approach
The declining-population approach
Focuses on threatened and endangered populations that show a downward trend, regardless of population size
Emphasizes the environmental factors that caused a population to decline in the first place
The declining-population approach requires that population declines be evaluated on a case-by-case basis
Involves a step-by-step proactive conservation strategy

22. Case Study: Decline of the Red-Cockaded Woodpecker
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 55.13a–c

23. Case Study: Decline of the Red-Cockaded Woodpecker
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 to rebound

24. Weighing Conflicting Demands
Conserving species often requires resolving conflicts
Between the habitat needs of endangered species and human demands

25. Regional Conservation
Landscape and regional conservation aim to sustain entire areas of biodiversity
In recent years, conservation biology has attempted to sustain the biodiversity of entire communities, ecosystems, and landscapes
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

26. Fragmentation and Edges
The structure of a landscape can strongly influence biodiversity
The boundaries, or edges, between ecosystems are defining features of landscapes
As habitat fragmentation increases and edges become more extensive, biodiversity tends to decrease
(a) Natural edges. Grasslands give way to forest ecosystems in Yellowstone National Park.
(b) Edges created by human activity. Pronounced edges (roads) surround clear-cuts in this photograph of a heavily logged rain forest in Malaysia.
Figure 55.14a, b

27. Much of the focus on establishing protected areas
Biological Hot Spots
Much of the focus on establishing protected areas
Has been on hot spots of biological diversity
Biodiversity hot spots are obviously good choices for nature reserves
But identifying them is not always easy

28. Finding Biodiversity Hot Spots
A biodiversity hot spot is a relatively small area
With an exceptional concentration of endemic species and a large number of endangered and threatened species
Terrestrial biodiversity hot spots
Equator
Figure 55.17

29. Philosophy of Nature Reserves
Nature reserves are biodiversity islands
In a sea of habitat degraded to varying degrees by human activity
One argument for extensive reserves
Is that large, far-ranging animals with low-density populations require extensive habitats

30. Restoration Ecology
Restoration ecology attempts to restore degraded ecosystems to a more natural state
The larger the area disturbed
The longer the time that is required for recovery
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

31. Bioremediation & Biological Augmentation
Is the use of living organisms to detoxify ecosystems
Biological augmentation
Uses organisms to add essential materials to a degraded ecosystem

32. Exploring Restoration
The newness and complexity of restoration ecology
Require scientists to consider alternative solutions and adjust approaches based on experience

33. Facing increasing loss and fragmentation of habitats
Sustainable Use
Sustainable development seeks to improve the human condition while conserving biodiversity
Facing increasing loss and fragmentation of habitats
How can we best manage Earth’s resources?

34. Sustainable Biosphere Initiative
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 Earth’s resources

35. Biophilia and the Future of the Biosphere
Our modern lives
Are very different from those of early humans who hunted and gathered and painted on cave walls
(a) Detail of animals in a Paleolithic mural, Lascaux, France
Figure 55.24a

36. Biophilia and the Future of the Biosphere
But our behavior
Reflects remnants of our ancestral attachment to nature and the diversity of life, the concept of biophilia
(b) Biologist Carlos Rivera Gonzales examining a tiny tree frog in Peru
Figure 55.24b

37. Biophilia and the Future of the Biosphere
Our innate sense of connection to nature
May eventually motivate a realignment of our environmental priorities