Transcript Biodiversity - ScienceWithMrShrout

Biodiversity
Biodiversity
• Biological diversity or “Biodiversity” = the sum of the
genetically based variety of all organisms in the biosphere
• Our existence relies on a great variety of other organisms.
• Some branches within biodiversity:
– Ecosystem diversity = variety of habitats,
communities, and ecological processes in the
ecosystem
– Species diversity = number of different species in
the system
– Genetic diversity = total of all the different forms
of genetic information carried by all organisms
present
Species Diversity
Section 6-3
Insects
54.4%
Protists
4.2%
Other Animals
19.7%
Plants
18%
Fungi
3.4%
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Section:
Bacteria
0.3%
Value of Biodiversity
• Biodiversity is one of Earth’s greatest natural
resources providing us with food, industrial
products, and medicines (painkillers, antibiotics,
heart drugs, antidepressants, and anticancer
drugs)
• When biodiversity is lost, potential sources of
material with significant value to the biosphere
and to humankind may be lost.
• Think of biodiversity as a library- lost species are
essentially lost books that can’t be replaced.
Ecosystem services are provided, but it’s
your responsibility to help save the Earth!
Section 6-4
Solar energy
Production of oxygen
Storage and recycling of
nutrients
Regulation of climate
Purification of water and air
Storage and distribution of
fresh water
Food production
Nursery habits for wildlife
Detoxification of human and
industrial waste
Natural pest and disease
control
Management of soil erosion
and runoff
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Section:
Threats to Biodiversity
 Human activities can reduce biodiversity by:
 Habitat alteration
 Hunting species to extinction
 Extinction = occurs when a species disappears from all or
part of its range
 Endangered species = species in danger of extinction with
declining population sizes
 As the population declines, the species loses genetic
diversity, making it more vulnerable to extinction
 Introducing toxic compounds (pollutants) into food
webs
 Introducing foreign species to new environments
Habitat Alteration & Fragmentation
• When land is developed, natural habitats may
be destroyed and the species that live in those
habitats may vanish
• Habitat fragmentation = development of land
that splits ecosystems into pieces resulting in
biological “islands” with fewer species and
smaller populations more vulnerable to
further disturbances or climate changes
– Reduces habitat space
– Restricts movement
– Reduces diversity
Fragmentation
Hunting/Wildlife Products
• In the past, hunting for meat, fur, hides or other body
parts caused the extinction of some species
• Today, endangered species are protected from hunting by
laws in most of the world
• Endangered Species- species in danger of going extinct.
Protected by international and local laws
– Poaching- illegal harvest of wildife is still a major problem
• Bear gall bladders, ivory, shark fins, tiger bones, etc.
Pollution
• Pollution can threaten biodiversity, because toxic
compounds accumulate in tissue of organisms
– Toxic wastes, sedimentation, thermal pollution
• Biological magnification = increasing concentrations
of harmful substances in organisms at higher trophic
levels in a food chain/web
– Entire food web is affected, but top-level carnivores are at
highest risk
Biological Magnification of DDT
Section 6-3
Magnification of
DDT Concentration
Fish-Eating Birds
10,000,000
Large
Fish
Small Fish
100,000
Zooplankton
10,000
Producers
Water
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Section:
1,000,000
1000
1
Thermal Pollution
• Thermal pollution: is the degradation of water
quality by any process that changes ambient water
temperature
– Power plants and industry using local water supplies to
cool during manufacturing.
– The temperature of the discharge water is significantly
warmer than normal
– Warmer water holds less
Oxygen, supports less life
Introducing Foreign Species
 Biodiversity is also threatened by apparently harmless
plants and animals that humans transport around the
world either accidentally or intentionally
 Invasive species = organisms introduced into new habitats
and reproduce rapidly (think exponential) lacking the
parasites and predators that control population size in
their native country
 They can displace native species driving them close to
extinction
 Ex. Zebra Mussels
Invasive species
 Non-native species
 reduce diversity in ecosystem
 examples
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African honeybee (killer bees)
gypsy moth
zebra mussel
purple loosestrife
Phragmites
phragmites
gypsy moth
kudzu
Purple loosestrife
1968
1978
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reduces diversity
loss of food & nesting sites for
animals
Zebra mussel
~2 months
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ecological & economic damage

reduces diversity
loss of food & nesting sites for
animals
economic damage
Brown Tree Snakes, Guam
• This introduced snake has caused the extinction
on Guam of 12 of 14 forest bird species, two of
three bat species, and at least six lizard species.
– Grow up to 8-10 feet long.
– Hatch at 15 inches can grow to 3 feet in one year
Guam Bird Populations
Conserving Biodiversity
• Conservation = wise management of natural resources
– Preservation of habitats and wildlife to protect
Earth’s biodiversity for future generations,
however protected areas may not be enough
• Current conservation efforts focus on protecting individual
species as well as entire ecosystems (to ensure natural
habitats and interactions among different species are
preserved).
• Biodiversity “Hot spots” = places around the world where
everything possible is being done to conserve the ecosystem
and species
World Wide Hotspots