Biodiversity -What is Biodiversity -Why do we care? -Measuring Biodiversity -Global Decline in Genetic/ Species Diversity -Causes of the decline in biodiversity -Sustaining Biodiversity
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Biodiversity-What is Biodiversity
-Why do we care?
-Measuring Biodiversity
-Global Decline in Genetic/ Species Diversity
-Causes of the decline in biodiversity
-Sustaining Biodiversity
What is Biodiversity?
• Biodiversity is the diversity of life forms in an environment
– Exists on 3 scales:
• Genetic
• Species
• Ecosystem
Biodiversity
• Genetic diversity measures the genetic variation among individuals in a population– The higher the genetic diversity the more adaptable the
population
• Species diversity indicates the number of species in a region or particular habitat– Approx 2 million species on Earth identified– Estimates of the total number of species range between 5
– 10 million– Higher species diversity the more resilient and productive
the ecosystem
• Ecosystem diversity is a measure of diversity within an ecosystem– The greater number of healthy ecosystems means a
healthier environment
Why Do We Care?• Why should we care?
– Instrumental Value: For the usefulness in terms of economic and ecological services.• Stability- relationship between people and environment
• Genetic diversity- increases susceptibility to disease
• Medicinal
• Agricultural
• Scientific- new technology
• Ethical- what should we do about the environment
– Intrinsic Value: existence, aesthetics, bequest for future generations. Value for its own sake, no benefit elsewhere• Aesthetic- ecotourism
• Religious
• Homo sapiens are arguably the only species this involve
Measuring Biodiversity
• Species Richness- the # of species in a given area– Used to give an approximate sense of the
biodiversity in the area
• Species Evenness- the proportion of individuals within the different species– Determines which species is numerically dominate
– High species evenness is when all species groups within an area have a similar amount of members
Measuring Biodiversity• Scientists use species richness and evenness to
determine how diverse an area is
• The more species in an ecosystem that have a high evenness the more diverse
Measuring Biodiversity• Species richness is influenced by:
– Latitude- the further from the equator, the species diversity declines
– Time- the longer a habitat exists the more chances for speciation = more diversity
– Habitat size and distance:
• Theory of island biogeography
Measuring Biodiversity
• Theory of Island Biogeography– Demonstrates the dual importance of habitat size and
distance in determining species richness
• Larger habitats typically contain more species– Dispersing species are more likely to discover larger
habitats/islands than smaller ones
– Larger habitats can support more species and less prone to extinction
– Large habitats contain a wider range of environmental conditions which provides more niches to support a richer diversity
Measuring Biodiversity
• The distance between a habitat and a source of colonizing species affects species richness on an island
– Oceanic islands have fewer species than islands that are closer to continents
– If two islands are the same size, the one closest to a continent should accumulate more species because of a higher rate of immigration
Global Decline of Biodiversity
• Scientists estimate that ~50,000 species go extinct per year (about 0.5% of the worlds species per year)
• The rate of species decline has been 100-1,000 times faster during the past 50 years than at any other time in human history
– Most likely caused by humans
Biodiversity Hot Spots
• Biodiversity is not distributed evenly on Earth• Conservation International recognize 25
biodiversity hot spots– Biologically diverse and ecologically distinct regions
under the greatest threat of destruction– Cover only 1.4% of the land area– Identified on the basis of the number of species
present, the amount of endemism and the extent to which the species are threatened
– Over 1/3rd of known terrestrial plant and animal species are found in hotspots
Biodiversity Hotspots– Found near dense human habitation
– Areas with rapid human population growth
– Most are located in the tropics within forests
Case Study: The U.S. Endangered Species Act
• Biodiversity hotspots in relation to the largest concentrations of rare and potentially endangered species in the U.S.
Figure 11-18
Decline of Genetic Diversity
• Species with low genetic diversity are not well suited to surviving environmental change
• Populations with low genetic diversity are prone to inbreeding depression
– Typically relatives (similar genotypes) breed with each other and produce offspring that have an impaired ability to survive and reproduce
• When two copies of harmful mutations from the parents get passed on to their offspring
Decline of Genetic Diversity
• Species can be considered:
– Rare- noticeable decline in population, uncommonly seen
– Threatened/Vulnerable- a species that in the near future will become endangered
– Endangered- species is present in such small numbers it is on the verge of extinction
– Extinct- gone from this planet forever
Decline in Genetic Diversity
• Species can become extinct:
– Locally: A species is no longer found in an area it once inhabited but is still found elsewhere in the world.
– Ecologically: Occurs when so few members of a species are left they no longer play its ecological role.
– Globally (biologically): Species is no longer found on the earth.
Decline in Genetic Diversity• Some species have become extinct prematurely due
to human activities
• The Great Auk became extinct in 1844 from overhunting because of its willingness to march up the boardwalks to ships
• What are some common attributes of birds that put them at risk for extinction?
Case Study: The Passenger Pigeon• 1813 John James Audubon saw a single flock of
passenger pigeons that took 3 days to fly past him and were so dense that it darkened the skies
• On March 24th 1900, a young boy in Ohio shot the last known wild passenger pigeon.
• In 1914 the last passenger pigeon, Martha, died in the Cincinnati Zoo
• How could something so abundant disappear in a short span of time?
Case Study: The Passenger Pigeon
The decline-
• Uncontrolled commercial hunting
• Habitat loss- forests were cleared for farms and cities
• “Stool Pigeon”– Food
– Feathers used for pillows
– Bones used for fertilizer
– In 1858, hunting these birds became a business• In 1878 one man killed 3 million birds and made $60,000
Decline in Genetic Diversity
• Some species have characteristics that make them vulnerable to extinction
• Feeding habits:
– Generalist: feeds on a wide variety of items
• Gulls feed on material that may be dead, living, aquatic, terrestrial, plant or animal
– Specialist- feeds on very specific things
• European oyster-catchers and wading shorebirds often feed on a very specific species of shellfish
• Which is more prone to extinction?
Decline in Genetic Diversity
• Reproductive rates:
– K selected/strategist- has fewer offspring over time but provides longer parental care
• K for kangaroo
– R selected/strategist- has many, many offspring at once and little to no parental care
• R for roaches
• Which is more prone to extinction?
• Other characteristics
• Need to know these
Require
• Scientists use measurements and models to estimate extinction rates.
– The International Union for the Conservation of Nature and Natural Resources (IUCN) publishes an annual Red List, listing the world’s threatened species.
• Global figures for 2011.1 IUCN Red List of Threatened Species:
TOTAL SPECIES ASSESSED = 59,508
Extinct = 797Extinct in the Wild = 64
Critically Endangered = 3,801Endangered = 5,566Vulnerable = 9,898
Near Threatened = 4,273Lower Risk/conservation dependent = 260 (this is an old category that is
gradually being phased out of the Red List)Data Deficient = 8,996
Least Concern = 25,853
Endangered Species- examples
Grizzly bear Kirkland’s warbler
Knowlton cactus
Florida manatee
African elephant
Utah prairie dog Swallowtail butterfly
Humpback chub
Golden lion tamarin
Siberian tiger
Endangered Species Examples
Hawksbill sea turtle
Giant panda Black-footed ferret
Whooping crane
Northern spotted owl
Blue whale
Mountain gorilla Florida panther
California condor
Black rhinoceros
Fig. 11-8a, p. 230
Range 100 years ago
Indian Tiger
Range today(about 2,300 left)
Fig. 11-8b, p. 230
Range in 1700
Black Rhino
Range today(about 3,600 left)
Fig. 11-8c, p. 230
Probable range 1600
African Elephant
Range today
Fig. 11-8d, p. 230
Range today(34,000–54,000 left)
Asian or Indian Elephant
Former range
Causes of Biodiversity Decrease
• We have depleted and degraded some of the earth’s biodiversity and these threats are expected to increase.
Biodiversity
Biodiversity decline-
Conservation biologists summarize the most important causes of premature extinction as “HIPPO”:
– Habitat destruction, degradation, and fragmentation**
– Invasive species
– Population growth
– Pollution
– Overharvest or Commercial harvest (sold for a profit, exploiting exotic species)
• “C” recently added…
– CHIPPO? HIPPCO? CHOPPI?
Habitat Loss
• Habitat Loss: poses the greatest threat of extinction
– Fragmented habitat:
• Conversion: old growth forestfarmland
• Fragmentation: highway dividing a forest
• Simplification: removing dead logs from an ecosystem
CASE STUDY: TROPICAL DEFORESTATION
• At least half of the world’s terrestrial plant and animal species live in tropical rain forests.
• Large areas of tropical forest are burned to make way for cattle ranches and crops.
Figure 10-17
CASE STUDY: TROPICAL DEFORESTATION
• Large areas of ecologically and economically important tropical forests are being cleared and degraded at a fast rate.
Figure 10-16
Satellite images of Amazon deforestation in Brazil between 1975 and 2001
Why Should We Care about the Loss of Tropical Forests?
• About 2,100 of the 3,000 plants identified by the National Cancer Institute as sources of cancer-fighting chemicals come from tropical forests.
Figure 10-18
Animal Potential Medical Uses Extinction Rates
Amphibians -Antibiotics, alkaloids for pain killers, chemicals for treating heart disease and High BP-Natural adhesives for treating tissue damage-Some Newts and Salamanders can regenerate organs and tissues-Contain “antifreeze” compounds that allow them to survive freezing
30% of all species are threatenedwith extinction
Bears -An acid from bears’ gall bladder treats gallstones and liver disease and prevents bile buildup during pregnancy-Build up bone mass during hibernation- could be used to treat osteoporosis and hip fractures-Hibernating bears do not excrete waste- could be used to treat renal disease
9 species are at risk for extinction
Cone snails -Compounds found in these snails include one that may prevent the death of brain cells from head injuries and strokes as well as a pain killer 1,000x more potent than morphine
Most live in coral reefs, which are threatened ecosystems
Sharks -Squalamine from the liver could lead to novel antibiotics, appetite suppressant, tumor shrinking and vision loss drugs-Study of salt glands helping address kidney disease
Most populationsreduced, some now at risk
Horseshoe Crabs
-Antibiotic development-Contains a compound that may treat AIDS as well as treat arthritis and cancer- Cells from blood can help detect cerebral meningitis in people
Overfishing is sharply diminishing populations
Invasive Species
• Alien or Non indigenous Species (NIS)
• Spreads widely and rapidly and becomes dominant in and community and interferes with the communities normal functions
• Many nonnative species provide us with food, medicine, and other benefits but a few can wipe out native species, disrupt ecosystems, and cause large economic
Fig. 11-13, p. 236
• Climate similar to habitat of invader
• Absence of predators on invading species
• Early successionalsystems
• Low diversity of native species
• Absence of fire
• Disturbed by human activities
Characteristics ofSuccessful
Invader Species
• High reproductive rate,short generation time(r-selected species)
• Pioneer species
• Long lived
• High dispersal rate
• Release growth-inhibitingchemicals into soil
• Generalists
• High genetic variability
Characteristics ofEcosystems Vulnerable
to Invader Species
Invasive Species• Professor E.O. Wilson
was first to discover the invasion of fire ants while he in HS studying entomology in Alabama
• The Argentina fire ant was introduced to Mobile, Alabama in 1932 from South America.– Most probably from the
ballast of ships.– No natural predators.
Invasive Species
• Many invasive species have been introduced intentionally.
Figure 11-11
INVASIVE SPECIES
• Many invasive species have been introduced unintentionally.
Figure 11-11
Invasive Species• Kudzu vine was introduced in 1930 to the
southeastern U.S. to control erosion.
• It is highly adaptable and fast growing
• It has taken over native species habitats.
Invasive Species• The Zebra Mussel is native to the
Caspian Sea and Black Sea in Asia
• Cargo ships traveling from Asia carry the mussels in their sea-water filled ballast which is typically emptied when they dock
• Zebra mussels are filter feeders so they can filter out some pollutants and algae
• However, they can physically overcrowd the ecosystem causing millions of $$ of damage
Zebra Mussel
Limnoperna (Golden Mussel)
Worst Case Scenarios: Potential Economic Losses From 15 Selected Nonindigenous Species Through 1991
Group Species Studied Cumulative Losses
Plants Melaleuca, Purple Lossestrife, Witchweed,
$4,588,000,000
Insects African Honeybee, Asian Gypsy Moth, Boll Weevil, Mediterranean Fruit Fly, Spruce Bark Beetles
$73,739,000,000
Aquatic Invertebrates
Zebra Mussel $3,372,000,000
Plant Pathogens
Annosus Root Disease, Larch Canker, Soybean Rust Fungus
$26,924,000,000
Other Foot and Mouth Disease, Pine Wood Nematodes
$25,617,000,000
TOTAL 15 SPECIES $134,240,000,000
Fig. 11-14, p. 236
• Do not allow wild animals to escape.
• Do not spread wild plants to other areas.
• Do not dump the contents of an aquarium into waterways, wetlands, or storm drains.
• When camping use wood near your campsite instead of bringing firewood from somewhere else.
• Do not dump unused bait into the water.
• After dogs visit woods or the water brush them before taking them home.
• After each use clean your vehicle, mountain bike, surfboard, kayaks, canoes, boats, tent, hiking boots, and other gear before heading for home.
• Empty all water from canoes, kayaks, dive gear, and other outdoor equipment before heading home.
• Plant a variety of trees, shrubs, and other plants in your yard to reduce losses from invasive species.
• Do not buy plants from overseas or swap them with others using the Internet.
What Can You Do?
Invasive Species
Population and Pollution
• The two P’s of “HIPPO” will be discussed more in depth later this year
• Exciting, I know!
Overexploitation/Over Use/Overharvesting
• When a species is removed from the ecosystem faster than the population can replace it
• Passenger Pigeon
• The Dodo bird had no innate fear of humans therefore were easily hunted
• In the late 1800s and early 1900s wild animals were slaughtered to sell their parts– American Bison were once abundant with 60-75
million individuals by the 1900s there were less than 1,000
• Photograph from the mid-1870s of a pile of American bison skulls waiting to be ground for fertilizer.
Overexploitation
• Some protected species are killed for their valuable parts or are sold live to collectors.
• Killing predators and pests that bother us or cause economic losses threatens some species with premature extinction.
• Legal and illegal trade in wildlife species used as pets or for decorative purposes threatens some species with extinction.
WARNING
The following slides may be disturbing to some viewers
Viewer Discretion is Advised
Case Study: Rising Demand for Bushmeat in Africa
• Bushmeat hunting has caused the local extinction of many animals in West Africa.
• Some regard gorilla meat as a source of status and power
• Can spread disease such as HIV/AIDS and ebola virus.
Figure 11-17
• Because of scarcity of inspectors, probably no more than 1/10th of the illegal wildlife trade in the U.S. is discovered.
Figure 11-19
Climate Change
• Costa Rica’s Golden Toad- first animal to go extinct largely due to climate change
• Lives in the well protected MonteverdeCloud Forest Reserve
• Went extinct in 1989
Climate Change
• Much of the moisture that supported the rain forest habitat came in the form of moisture laden clouds blowing in from the Caribbean Sea
• Warmer air from global climate change caused the clouds to rise
• The Golden Toad, and many others, habitats dried up
• Global climate change has also contributed to the extinction of five other toad and frog species in the jungles of Costa Rica
• More on climate change later!
Sustaining Biodiversity
• How do we sustain biodiversity?
• Scientists can protect animals by means of in situ conservation or ex situ conservation
• In situ methods focus on ecological restoration and legislation– Long term process
– Leaving animals where they are but protecting them
– Ex. Elephants- make laws that prevent poach AND have people to enforce it
– Marine turtles- escape nets must be used on all fishing nets so turtles can get out and not drown
Advantages of in-situconservation
Disadvantages of in-situconservation
-Species have access to their natural resources and breeding sites
-Species will continue to develop and evolve in their natural environment without human influence, thus conserving their natural behavior
-Able to protect more species at once and allow them greater space than those in captivity
-Protects larger breeding populations
-Less expensive and requires fewer specialized facilities
-Difficult to control illegal exploitation on in-situ populations
-Habitats that shelter in-situ populations may need extensive restoration, including pest eradication and ongoing control
-Populations may continue to decline during restoration
Sustaining Biodiversity• Ex situ- operate away from the natural environment
and are particularly useful where species are critically endangered– Taking an animal out of the habitat to protect it
• Ex- Zoos, aquariums, botanical gardens• Egg pulling- collecting wild eggs laid by critically
endangered bird species and then hatching them in zoos or research centers
• Captive Breeding- wild individuals of a critically endangered species are captured for breeding in captivity, with the aim of reintroducing the offspring into the wild.
• Seed banks- preserve genetic diversity of plant species
Advantages of ex situ conservation
Disadvantages of ex situ conservation
-Provides the possibility of saving a species from extinction
- Provides more control of the circumstances concerning the species than in situ
-Able to educate the public of a species endangered/threatened –creates public interest
-Not all organisms can thrive in captivity
-Not all habitats can be 100% replicated
-Genetic diversity may be lost
-Some animals breed in captivity might not thrive when/if released back into the wilderness
-Can be expensive- the facilities as well as any assistance in breeding (in vitro)
What Can We Do?
Eight priorities for protecting biodiversity:1. Take immediate action to preserve world’s biological hot
spots.2. Keep intact remaining old growth.3. Complete mapping of world’s biodiversity for inventory
and decision making.4. Determine world’s marine hot spots.5. Concentrate on protecting and restoring lake and river
systems (most threatened ecosystems).6. Ensure that the full range of the earths ecosystems are
included in global conservation strategy.7. Make conservation profitable.8. Initiate ecological restoration products to heal some of the
damage done and increase share of earth’s land and water allotted to the rest of nature.
Help Sustain Biodiversity• Preservation- Setting aside or protecting
undisturbed natural areas from harmful human activities.
• Remediation/Restoration: trying to return to a condition as similar as possible to original state.
• Rehabilitation: attempting to turn a degraded ecosystem back to being functional.
• Replacement: replacing a degraded ecosystem with another type of ecosystem.
• Creating artificial ecosystems: such as artificial wetlands for flood reduction and sewage treatment.
ECOLOGICAL RESTORATION
• Five basic science-based principles for ecological restoration:– Identify cause.
– Stop abuse by eliminating or sharply reducing factors.
– Reintroduce species if necessary.
– Protect area form further degradation.
– Use adaptive management to monitor efforts, assess successes, and modify strategies.
When planning to protect biodiversity Scientists must consider the Mitigation Costs-
• The costs of offsetting damages.
• For example, how much would it cost to protect a forest from cutting, move an endangered species to a new habitat, or restore a statue damaged by air pollution?
Issues with Restoration
• There is some concern that ecological restoration could promote further environmental destruction and degradation.
– Suggesting that any ecological harm can be undone.
• “If you mess it up, don’t worry- it can be fixed!”
– Preventing ecosystem damage is far cheaper than ecological restoration.
Laws to Protect Biodiversity
• We will learn more about these later but the following laws involve protecting biodiversity:
– Endangered Species Act (ESA)
– CITES or CITIES
– Lacey Act
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