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

2. Biodiversity
The current rate of species extinction is high and is largely a result of ecosystem degradation by humans
Humans are a huge threat to Earth’s biodiversity

3. 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

4. Diversity Genetic diversity comprises Species diversity
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

5. Endangered species Threatened 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

6. (a) Philippine eagle
(b) Chinese river dolphin
(c) Javan rhinoceros
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

7. Biodiversity (affect on Human Welfare)
Biophilia: Our sense of connection to nature and to other life forms
Allows us to recognize the value of biodiversity for its own sake
The loss of species means the loss of genes and genetic diversity
The enormous genetic diversity of organisms on Earth has the potential for great human benefit

8. Benefits of Species and Genetic Diversity
Many pharmaceuticals contain substances originally derived from plants
Rosy periwinkle is a source of anti-cancer drugs

9. Ecosystem Services
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
Pollination of crops
Moderation of weather extremes
Etc., etc., etc.

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

11. Habitat Destruction
Human alteration of habitat is the single greatest threat to biodiversity throughout the biosphere

12. Madagascar Deforestation
Movie

13. Many natural landscapes have been broken up
Fragmenting habitat into small patches
Habitat fragmentation and destruction leads to loss of biodiversity
Fragmented forest habitat in Mount Hood National Forset

14. Habitat fragmentation in the foothills of Los Angeles

15. Introduced Species
Introduced species-Are those that humans move from the species’ native locations to new geographic regions

16. (b) Introduced kudzu thriving in South Carolina
Introduced species that gain a foothold in a new habitat usually disrupt their adopted community
Kudzu: Native to Japan and China, kudzu was introduced into the US as an ornamental and for erosion control.
It can grow as much as a foot-a-day.
(a) Brown tree snake, intro duced to Guam in cargo
(b) Introduced kudzu thriving in South Carolina

17. The Vine That Ate the South
Kudzu

18. 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

19. The fishing industry
Has caused significant reduction in populations of certain game fish
Bluefin tuna auction in Japan fish market
(seafood guide)

20. Disruption of Interaction Networks
The extermination of keystone species by humans can lead to major changes in the structure of communities
Pollinating flying fox
Urchin munching sea otter

21. Population Conservation
Population conservation focuses on
population size
genetic diversity
critical habitat
Biologists focusing on conservation at the population and species levels follow two main approaches
Small-population model approach
Declining population approach

22. Small-Population Approach
Conservation biologists who adopt the small-population approach
Study the processes that can cause very small populations finally to become extinct

23. 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

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

25. Case Study: The Greater Prairie Chicken and the Extinction Vortex
Populations of the greater prairie chicken were fragmented by agriculture and later found to exhibit decreased fertility
As a test of the extinction vortex hypothesis scientists imported genetic variation by transplanting birds from larger populations

26. (a) Population dynamics
The declining population rebounded
Confirming that it had been on its way down an extinction vortex
EXPRIMENT
Researchers 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 DNA from 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.
RESULTS
After translocation (blue arrow), the viability of eggs rapidly improved, and the population rebounded.
CONCLUSION
The researchers concluded that lack of genetic variation had started the Jasper County population of prairie chickens down the extinction vortex.
Number of male birds
(a) Population dynamics
(b) Hatching rate
200
150
100 50
1970
1975
1980
1985
1990
1995
2000
Year
Eggs hatched (%) 90 80 70 60 40 30
Years

27. 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
Effective population size
Based on number of males and females that successfully breed…so smaller than the actual total population count.
Effective population size is used to estimate MVP

28. Case Study: Analysis of Grizzly Bear Populations
One of the first population viability analyses was conducted as part of a long-term study of grizzly bears in Yellowstone National Park

29. The study has shown that the grizzly bear population has grown substantially in the past 20 years.
There are currently about 400 grizzly in the Yellowstone area. Enough for a viable population, but low genetic diversity is a concern
Number of individuals
150
100 50
1973
1982
1991
2000
Females with cubs
Cubs
Year

30. 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

31. Steps for Analysis and Intervention
The declining-population approach
Requires that population declines be evaluated on a case-by-case basis
Involves a step-by-step proactive conservation strategy. (A do-something-before-it’s-too-late philosophy)

32. Case Study: Decline of the Red-Cockaded Woodpecker
Red-cockaded woodpeckers
Require specific habitat factors for survival (they like habitat with minimal undergrowth and a good supply of optimal nesting trees)
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.

33. On the basis of this experiment
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

34. Landscape Structure and Biodiversity
The structure of a landscape can strongly influence biodiversity

35. Fragmentation and Edges
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.

36. Habitat fragmentation effects

37. Fragmented Forest

38. Sprawl
Sprawl fragments wildlife habitat, increasing the amount of development-associated species (e.g., white-tailed deer, Canada goose), at the expense of the more rare development-sensitive species (e.g., eastern bluebird, box turtle).

39. Size: Population Stability Populations are typically more stable and sustainable and less susceptible to local extinction in large patches than small patches.

40. Connectivity Species movement among habitat patches can be facilitated through the protection of discrete spatial features such as stepping stones and linkages .

41. Connectivity:   Isolation Small patches that are connected to other patches generally are more ecologically viable than isolated patches. Species within an isolated habitat patch are highly susceptible to disturbance and degradation from surrounding land uses because species movement (to and from the patch) is limited.

42. Connectivity:   Interconnectedness Interconnectedness is an important feature of networks, as it facilitates species movement among patches. Small interconnected patches provide cover, resting, and foraging habitats for animals en route to larger habitat patches. But, a network that is designed for connectivity but ignores other principles may have too much linear habitat and edge.

43. Corridors That Connect Habitat Fragments
A movement corridor
Is a narrow strip of quality habitat connecting otherwise isolated patches
They promote dispersal and help sustain populations

44. In areas of heavy human use
Artificial corridors are sometimes constructed
Wildlife bridge in Banff

45. Establishing Protected Areas
Protected areas are established to slow the loss of biodiversity
A lot of the focus on establishing protected areas has been on hot spots of biological diversity

46. Biodiversity Hot Spots
A biodiversity hot spot is a relatively small area with an exceptional concentration of endemic species (specific confined to a certain geographic area) and a large number of endangered and threatened species
Terrestrial biodiversity hot spots
Equator

47. Rain Forest

48. 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

49. Often the size of reserves is smaller than the actual area needed to sustain a population
Biotic boundary for
short-term survival;
MVP is 50 individuals.
long-term survival;
MVP is 500 individuals.
Grand Teton
National Park
Wyoming
Idaho
43
42
41
40 50
100
Kilometers
Snake R.
Yellowstone
National
Park
Shoshone R.
Montana
Madison R.
Gallatin R.
Yellowstone R.

50. Yellowstone-to-Yukon initiative

51. WWF “Heart of Borneo” initiative

52. World’s longest insect
Only lungless frog

53. Restoration Ecology
Restoration ecology attempts to restore degraded ecosystems to a more natural state
One of the basic assumptions of restoration ecology is that most environmental damage is reversible

54. Tall-grass Prairie restoration/preserve
Movie

55. Two key strategies in restoration ecology
Are bioremediation and augmentation of ecosystem processes
Bioremediation
Is the use of living organisms to detoxify ecosystems
Biological augmentation
Uses organisms to add essential materials to a degraded ecosystem

56. Sustainable Development
Sustainable development seeks to improve the human condition while conserving biodiversity
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

57. The field of sustainable development can be conceptually broken into three constituent parts: environmental sustainability, economic sustainability, social-political sustainability