sign in sign up
<<
Home , Extinction vortex, Overexploitation

Ch. 55 Conservation

1 Conservation ecology is an effort to save loss

Restoration ecology ­ ecological principles to return that have been disturbed by human acitivity to a condition as similar as possible to their original natural state

2 Three levels of biodiversity:

1. individual variation as well as between

2. ­ variety of species in an U.S. Act (1973) a. endangered ­ "in danger of throughout all or a significant portion of its range"

3 b. threatened ­ organisms that are likely to become endangered in the future c. extinction ­ does not exist anymore either locally or globally ex. 1,183 species (13% in world)

4 Endangered species

Philippine Chinese River Dolphin Eagle

5 3. ex. rainforests loss of keystone predator ( star/mussel scenario)

­extinction of one organism has a great impact on other organisms in the excosystem (think webs!)

6 Why do we want to preserve biodiversity?

1. natural for medicines, fibers, crops, etc.

2. to prevent loss of genes which code for useful proteins

3. potential for future development of new medicines, , petroleum substitutes, chemicals

4. aesthetic reasons

5. ethical reasons

7 6. risk our own survival purification of /air nutrient cycling detoxification and of wastes control agricultural pests

rosy periwinkle used for Hodgkin's disease and acute lymphocytic leukemia

8 II in Arizona ­ 1990, 8 people put inside, had many different ecosystems, supposed to be self sufficient ­lasted 15 months

9 What are the threats to biodiversity? 1. loss = greatest threat a. due to agriculture, forestry, , , urban development, reef destruction b. ecosystems that are broken into smaller pieces

10 habitat reduction and fragmentation in a Wisconsin over time

11 2. = non­native or exotic species ­those that humans move from the species' native location to a new geographic location ( accidentally or on purpose)

Ex. zebra mussels, African bees, brown tree snake in Guam, fox in Australia, purple loosestrife, milfoil

12 ­ Zebra mussels appeared in the Great in 1988

­thought to be brought via ballast in ships from Europe

13 Nile Perch Brown Tree Snake

Argentine Ants Seaweed Caulerpa

14 3. ­humans harvesting wild or animals at rates higher than can be replaced reproductively Ex. elephants, whales, rhinoceroses hurts animals native to islands ­ trawling

White rhinoceros ­ killed for its horn

http://www.nwf.org/Wildlife/Wildlife­Conservation/Threats­to­Wildlife/Overexploitation.aspx

the great auk­ found in North Atlantic Ocean islands

15 Population Conservation approaches 1. small population approach ­ study processes that cause very small populations to become extinct ­ (downward spiral) ­ loss of genetic variation

16 minimum viable ­ the minimum population size that species are able to maintain their numbers and survive ­usually computer generated ­used in part of population viability analysis (predicts species survival) ­ effective population size (Ne) ­ based on breeding potential

Ne = 4Nf Nm Nf = number of breeding females Nf + Nm Nm = number of breeding males

17 Populations with low Ne prone to: inbreeding reduced heterozygosity random effects of /bottlenecking

Ex. Prairie chicken fragmented habitat ­ Illinois chicken ­decreased hatching rate­ headed for extinction vortex until humans introduced chickens from Nebraska, then rates went up

18 in 1992 scientists introduced prairie chickens from Minnesota, Kansas, and Nebraska

19 Grizzly Bear in Yellowstone

monitoring males population by tagging the bears with a radio collar to track movements

20 2. Declining­population approach ­ focuses on threatened and endangered species

­emphasizes environmental factors that cause

­evaluated on a case by case basis

21 Steps for decling population approach:

1. confirm species is in decline ­ look at population trends 2. study species natural history to determine environmental requirements 3. determine all possible causes of decline 4. list hypothesis predictions of decline 5. test hypothesis 6. apply results to help manage species

22 Red cockaded woodpecker forest that sustains woodpecker ­low undergrowth

forest that cannot sustain woodpecker ­ high undergrowth

23 Conflicts of

environment vs. demands for jobs in timber, mining environment vs. economics can't save all organisms, which should we save?? look at individual or whole

24 Conservation focus is on communities

Landscape ecology­ application of ecological principles to the study of human use patterns ­organisms can live on edges of two different environments ­edges have different characteristics than either of the environments on either side ­white­tailed deer, ruff grouse live in these edges ­can have positive or negative effect on community biodiversity ­negative = cowbird ­positive = area of

25 natural edges human created edges

26 use of movement corridors = strip of land or a bridge connecting two isolated areas of inhabitable land Ex. Florida panthers ­important for migrating species ­can also spread disease of population

artificial corridor for Florida panthers

27 How do Conservation biologists attempt to maintain biodiversity?

1. National Parks ­ protected

2. protecting biodiversity hot spots­small areas with high concentrations of endemic species and a large # of endangered or threatened species ­contain 1/3 of all species of plants and

28 Biodiversity Hot Spots

29 Actual area needed by an organism may be larger than the actual protected area ­biotic boundary = area needed to sustain a certain population size

­legal boundary = the actual area of protected area

30 biotic boundary for short­term survival of 50 individuals biotic boundary for long­term survival of 500 bears

31 3. Nature reserves­ biodiversity "islands" in an area degraded by human activity

­zoned reserve ­ a large region of land that includes one or more areas undisturbed by humans surrounded by that have been changed by human activity and are used for economic gain ­surrounding land acts as a buffer zone from intrusion

32 Ex. Costa Rica

green = national parks

gold = buffer zones

33 4. ­returning degraded ecosystems to as close to natural conditions as possible

­ assume­ most damage is reversible

­ based on succession principles

­ larger area disturbed, longer it takes to recuperate

34 ­colored= natural white = human caused

35 two strategies for restoration ecology:

1. bioremediation ­ using organisms to detoxify polluted areas ex. plants for uptake of toxic metals from mining Pseudomonas for oil spills

2. augmentation­ use of organisms to add materials to degraded ecosystem

36 Ex. legumes to add nitrogen to

Albizzia procera in nitrogen poor soil and allows indigenous to recolonize

37 Sustainable Biosphere Initiative

­goal: "define and acquire ecological information necessary for the intelligent and responsible development, management and conservation of 's resources"

­Studies: 1. global changes 2. biological diversity 3. methods of natural and artificial ecosystems

38 Future of the biosphere depends on our biophilia biophilia­our innate sense of love of nature and our connection to other organisms

39 Review ­ You should be able to: • Distinguish between conservation biology and restoration biology • List the three major threats to biodiversity and give an example of each • Define and compare the small­population approach and the declining­ population approach • Distinguish between the total population size and the effective population size • Describe the conflicting demands that may accompany species conservation

40 • Define biodiversity hot spots and explain why they are important • Define zoned reserves and explain why they are important • Explain the importance of bioremediation and biological augmentation of ecosystem processes in restoration efforts • Describe the concept of • Explain the goals of the Sustainable Biosphere Initiative

41 42