Transcript Slide 1
BIODIVERSITY / CONSERVATION
Biodiversity
Variety of life on planet Earth
• Includes the genetic, species, and ecosystem diversity
• About 1.7 – 2 million organisms currently known
• Estimated that there are 3 – 100 million total on Earth
WHY DO ESTIMATES VARY SO MUCH?
Levels of Biodiversity
• Species Diversity- number of species
in an area
• Ecosystem Diversity- number of
ecosystems or habitats in an area
• Genetic Diversity- Different genes or
Traits available in a population
Benefits for all species
• Species depend on each other for
survival
• Keystone species- critical
species that affects the survival of
other species
• Foundation species- primary
producer within an ecosystem
which if eliminated, it will collapse
the system
Benefits of Biodiversity
• Ecosystem: Loss of biodiversity at
any level could lead to ecosystem
instability (ex: keystone species)
• Agriculture: pest resistance,
commercial uses (ex: babassu palm,
gives more oil than coconut and could
be used for cooking, etc.)
• Medicine: cures for diseases (ex:
rosy periwinkle used to treat
Hodgkin’s lymphoma) – 25% of
prescriptions come from plants
• Ecotourism: source of income for
many countries (ex: Costa Rica)
Loss of Biodiversity
• Organisms naturally go extinct if they cannot survive
• Times when extinction rate is much greater (mass
extinctions)
• Currently we could be in the “Sixth Mass Extinction”
Loss of Biodiversity
• Background extinction- Extinction through
natural process.
– Usually a very small number per year
• Mass extinction- abrupt rise in extinction rates
– Usually global
– 25-70% species loss
– 5 mass extinctions have occurred over 500 million
years
– Adaptive radiations- post mass extinction where
diversity increases
• Adaptive radiations- post mass extinction
where diversity increases
Loss of Biodiversity
• ENDANGERED SPECIES Serious risk of
extinction
• THREATENED SPECIES Likely to become
extinct soon
•ENDANGERED SPECIES - A species is likely to
become extinct if not protected
Loss of Biodiversity
• Extirpated- species that have disappeared
from an area where they once lived, but still
exist elsewhere
• Extinct- A species that once occurred but no
longer exists across their original range
PA Endangered Species
BOG TURTLE Draining or
destruction of its habitat are
causing it to go extinct… (very
rare so worth money and illegally
removed at times)
MASSASAUGA RATTLESNAKE
Only found in historic sites due to
dam building, highway construction,
urbanization, forest succession,
mining, and agricultural activity
Causes of Biodiversity Loss
1) Habitat Fragmentation: Division of habitat into smaller
patches (ex: clearing forests, building roads, etc.) 75% of
all extinction is caused by habitat loss
2) Invasive Species: Exotic species move in and spread
(ex: Zebra mussel)
• Exotic species- species introduced to an area that
are not native
3) Pollution: Harmful chemicals find their way into
habitats (ex: metals, oils, fertilizers)
Habitat Fragmentation
Causes of Biodiversity Loss
4) Overharvesting: Catching / hunting too much (ex:
Siberian tiger)
-POACHING Illegal capture or killing of an
organism for $$$
5) Climate Change: Warming temperatures on Earth
Critical Areas of Biodiversity
• HOTSPOTS- areas of the world that are
being destroyed rapidly
– 34 identified spots worldwide
– Endemic Species- species that are native,
and only found in that localized area
Critical Areas of Biodiversity
– Tropical Rain forests- 7% of worlds area,
50% of earth’s species
Critical Areas of Biodiversity
• Coral Reefs- high biodiversity, major damage
is from ecotourism
• worth $375 Billion
Protecting Biodiversity
• Protect biodiversity “hotspots” (lots of organisms)
-ENDEMIC SPECIES: found only in one area
Madagascar Lemurs
Galapagos Tortoise
• Economic approaches (ex: get paid to conserve)
Protecting Biodiversity
• Endangered Species Act 1973 - Law that protects
biodiversity
-Successful with Brown Pelican and Bald Eagle
-Costs can be high (ex: Spotted Owl protection caused many
loggers to lose their jobs)
• Captive Breeding Process of breeding and raising organisms
in controlled conditions (ex: Zoos)
• Convention on International Trade in Endangered Species of
Wild Fauna and Flora (CITES) Treaty to save biodiversity
(bans transport of their body parts)
Legal Protection
• Private groups- most successful- Green Peace, WWF,
and Conservation International
• International Union for the Conservation of Nature
and Natural Resources- provides a global list of
endangered and threatened species (Red List). Also
controls and enforces illegal trade of poached animals
or parts.