1. Chapter 55 ~ Conservation Biology

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. Tropical forests –Contain some of the greatest concentrations of species –Are being destroyed at an alarming rate Figure 55.1

5. 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 The Three Levels of Biodiversity  Biodiversity has three main components –Genetic diversity –Species diversity –Ecosystem diversity

6. Genetic Diversity  Genetic diversity comprises –The genetic variation within a population –The genetic variation between populations

7. Species Diversity  Species diversity –Is the variety of species in an ecosystem or throughout the biosphere

8.  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

10. (a) Philippine eagle (b) Chinese river dolphin (c) Javan rhinoceros Figure 55.3a–c Conservation biologists, such as E.O. Wilson, are concerned about species loss the Hundred Heartbeat Club –Species that number fewer than 100 individuals and are only that many heartbeats from extinction

11. Ecosystem Diversity  Ecosystem diversity –Identifies the variety of ecosystems in the biosphere –Is being affected by human activity

12. Biodiversity and Human Welfare  Species diversity –Brings humans many practical benefits

13. Benefits of Species and Genetic Diversity  Many pharmaceuticals –Contain substances originally derived from plants Figure 55.4

14.  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

15. Ecosystem Services  Our welfare is directly linked to biotic components of ecosystems –Nutrient cycling –Detoxification of waste waters –Purifying air –Preserve fertile sol –Need I go on!!

16. Four Major Threats to Biodiversity –Habitat destruction—NUMERO UNO! –Introduced species –Overexploitation –Disruption of “interaction networks”

17. 1. 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

18.  Many natural landscapes have been broken up –Fragmenting habitat into small patches Figure 55.5

19.  In almost all cases –Habitat fragmentation and destruction leads to loss of biodiversity

20. 2. Introduced Species  Introduced species/invasive/exotic /nonnative –May be  Intentional  Nonintentional  ( you all should remember this— remember the Kudzu; Zebra mussels?)

21.  Introduced species that gain a foothold in a new habitat –Usually disrupt their adopted community –No natural predators –Outcompete native organisms (a) Brown tree snake, intro- duced to Guam in cargo (b) Introduced kudzu thriving in South Carolina Figure 55.6a, b

22. 3. 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

23. The fishing industry Tuna at risk!! Swordfish too! Salmon!! This impacts other as well—Dolphins caught in tuna nets! Figure 55.7

24. 4. Disruption of Interaction Networks  The extermination of keystone species by humans –Can lead to major changes in the structure of communities –Keystone species  Not necessarily abundant  But,exerts string control on community structure due to its ecological niche  More info at  http://www.bagheera.com/in thewild/spot_spkey.htm Figure 55.8

25.  Elephants  Sea otters

26.  Biologists focusing on conservation at the population and species levels –Follow two main approaches

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

28. 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 population adaptability Smaller population Figure 55.9

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

30. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 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

31.  As a test of the extinction vortex hypothesis –Scientists imported genetic variation by transplanting birds from larger populations

32.  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 0 1970197519801985199019952000 Year Eggs hatched (%) 100 90 80 70 60 50 40 30 1970-741975-79 1980-841985-8919901993-97 Years Figure 55.10

33. Case Study: Analysis of Grizzly Bear Populations population viability analyses –Was conducted as part of a long-term study of grizzly bears in Yellowstone National Park Figure 55.11

34.  This study has shown that the grizzly bear population –Has grown substantially in the past 20 years Number of individuals 150 100 50 0 1973 1982 1991 2000 Females with cubs Cubs Year Figure 55.12

35. 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

36. 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

37. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 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

38.  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

39. Fragmentation and Edges  The boundaries, or edges, between ecosystems –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

40.  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

41. Corridors:Connect Habitat Fragments  A movement corridor –Is a narrow strip of quality habitat connecting otherwise isolated patches

42. In areas of heavy human use Artificial corridors are sometimes constructed Figure 55.16

43.  15th panther killed on Florida roadways this year, breaking previous records  September 2007 (www.wildlifeextra.com )

44. Establishing Protected Areas  Conservation biologists are applying their understanding of ecological dynamics –In establishing protected areas to slow the loss of biodiversity

45.  Much of the focus on establishing protected areas –Has been on hot spots of biological diversity

46. Biological Hot Spots  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

47. 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

48.  In some cases –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. Biotic boundary for long-term survival; MVP is 500 individuals. Grand Teton National Park Wyoming Idaho 43  42  41  40  0 50 100 Kilometers Snake R. Yellowstone National Park Shoshone R. Montana Wyoming Montana Idaho Madison R. Gallatin R. Yellowstone R. Figure 55.18

49. Zoned Reserves  The zoned reserve model recognizes that conservation efforts –Often involve working in landscapes that are largely human dominated

50.  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 Rica’s reserves. Nicaragua Costa Rica Panama National park land Buffer zone PACIFIC OCEAN CARIBBEAN SEA Figure 55.19a, b

51.  Some zoned reserves in the Fiji islands are closed to fishing –Which actually helps to improve fishing success in nearby areas Figure 55.20

52.  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 for recovery

53.  Whether a disturbance is natural or caused by humans –Seems to make little difference in this size- time relationship Recovery time (years) (log scale) 10 4 1,000 100 10 1 10  3 10  2 10  1 1 10 1001,00010 4 Natural disasters Human-caused disasters Natural OR human- caused disasters Meteor strike Groundwater exploitation Industrial pollution Urbanization Salination Modern agriculture Flood Volcanic eruption Acid rain Forest fire Nuclear bomb Tsunami Oil spill Slash & burn Land- slide Tree fall Lightning strike Spatial scale (km 2 ) (log scale) Figure 55.21

54.  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

55. Bioremediation  Bioremediation –Is the use of living organisms to detoxify ecosystems

56. Biological Augmentation  Biological augmentation –Uses organisms to add essential materials to a degraded ecosystem

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

58.  Exploring restoration worldwide Truckee River, Nevada.Kissimmee River, Florida. Equator Figure 55.22

59. Tropical dry forest, Costa Rica. Succulent Karoo, South Africa. Rhine River, Europe. Coastal Japan. Figure 55.22

60.  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 Earth’s resources?

61. 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

62. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Case Study: Sustainable Development in Costa Rica Costa Rica’s success in conserving tropical biodiversity – Has involved partnerships between the government, other organizations, and private citizens

63.  Human living conditions in Costa Rica –Have improved along with ecological conservation Infant mortality (per 1,000 live births) 200 150 100 50 0 190019502000 80 70 60 50 40 30 Year Life expectancy Infant mortality Life expectancy (years) Figure 55.23

64. 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

65.  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

66.  Our innate sense of connection to nature –May eventually motivate a realignment of our environmental priorities