Transcript Alpha diversity

For a landscape of many ecosystems to perpetuate over
time, there must be a diversity of species within each
ecosystem, a diversity of ecosystems, and a diversity of
successional stages within each ecosystem type
Alpha diversity: many different species within an
ecosystem type
Beta diversity: the difference in species composition
among ecosystems
Gamma diversity: the total diversity of organisms
over a landscape of ecosystems
BIODIVERSITY = biological diversity
Congress: "..refers to the variety and variability
among living organisms and the eco-logical
complexes in which they occur."
The Wildlife Society: "..the variety of life and
processes that link plants, animals, soil, air, and water
into ecological systems."
Types of Biodiversity: (a matter of scale)
Genetic - each individual organism is unique; a varied
genetic base provides a hedge against an unknown
future; allows species to adapt through natural
selection
Species - each is an important link in the web of life;
enhances our survival and adds to stability of
individual ecosystems.
Ecosystem - a marsh, a stream, an bottomland forest,
an upland forest within a limited geographic area
Landscape - grassland, forest, desert, scattered over a
large geographic area
Protecting Biodiversity - what difference does it make?
The field of Conservation Biology deals with this question
and ways of preserving diversity
Ecosystem integrity = completeness
Biodiversity = foundation of ecosystems
Eliminating a species damages an ecosystem in
ways we probably do not understand.
What is the earths species diversity?
About 2 million species identified:
- 1.5 million insects
- 0.5 million plants
- only a few thousand birds and mammals
How many not yet identified?
- 5 million? 50 million?
By preserving ECOSYSTEMS, we can preserve species
diversity without knowing what species are present!
Although most species
yet to be discovered are
bugs, some are not!
New genus of rat found
in the Andes Mountains
in 2000
One-half of world's prescription and non-prescription drugs
have active ingredients extracted from wild organisms.
One-fourth of these are from tropical forest plants.
Drug industry is billions of $$ in economy
penicillin = from fungus / tetracycline = from bacteria
anti-biotic from the African Clawed Frog
• new birth-control pill from Mexican
wild yam
• Endangered species of primrose has
chemical that may help treat multiple
sclerosis
• many others known or yet to be
discovered
Extinction: a natural process in evolution where certain
kinds of animals die out and other better-adapted species
take their place
How many species have become extinct?
99% of all species that ever existed are now extinct!
Fact: all species will eventually become extinct!
What is a SPECIES?
all organisms of the same kind
organisms that freely interbreed
(for sexually-reproducing species)
What is a subspecies??
What is a population??
Can look at DNA to find level of similarity
Diversity is the most important point, not whether it
deserves a special name from man
Extinct species - species that no longer exists (due to
inability to adapt to changes in its environment)
e.g., dinosaurs (why?)
e.g., passenger pigeon (why?)
logging, disease, 1 egg/female, persecution, last
one in 1914
Endangered Species - insufficient #'s left to assure
perpetuation of the species (will decline to extinction unless
something is changed)
Threatened Species - expect to be endangered
Who decides what species are endangered?
May be international, national or state government, or
private organization:
IUCN - International Union for Conservation of Nature:
lists about 5,000 species in "Red book"
CITES - Convention on International Trade of
Endangered Species (1975): now 120 nations list and
protect through treaties endangered (675), threatened, or
species of special concern (27,000, mostly plants) due to
trade of plants, animals, or their parts.
USDI - U.S. Department of Interior lists over 1,000
species, of which about half are U.S. species
Endangered Species – who decides, cont.
States - many individual U.S. states list species that may
be of more-local concern (these species may or may not
be on the federal list); Kentucky, no official state list
Private organizations - e.g., over 3,000 plant species in
U.S. have been identified as endangered; < 200 are
federally protected.
U.S. Laws on Endangered Species
1966 - Endangered Species Preservation Act
First legislation; called for keeping list, research, and
acquisition of habitat
1969 - Expanded to include some invertebrates
1973 - Expanded to include all kinds of plants and animals
except insect pests
includes "subspecies" (e.g., eastern Mt. lion, N.
spotted owl, southern bald eagle)
1978 - Amended to protect critical habitat
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Today the Endangered Species Act:
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prohibits killing of listed species
prohibits sale, import/export of whole
animal/plant or any part
protects habitat from destruction
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No public money can be used to destroy habitat
Exempt:
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Little Tennessee River (Tellico) Dam)
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snail darter
Also Exempt:
Logging in Pacific Northwest
N. spotted owl, marbled murrelet
CAUSES OF EXTINCTION:
1. Restricted range or habitat (narrow niche)
Kirtland’s warbler
- only exist in an 85X100 mi. Area in Michigan and
other isolated sites
- “pine barren” habitat of 6-15 year-old trees (5-20 ft.
Tall)
- about 500 left in the world
2. Slow population growth rate (low reproduction)
California condor
S 1 egg every 2 years so only about a dozen eggs
produced per year in entire world
S researcher dropped an egg ;
3. Interbreeding with more successful species
red wolf/coyote or black duck/mallard
S “swamping of genes
4. Non-adaptive behavior
Carolina parakeet
S extinct in 1914
S flock around dying bird
5. Specialized diet (narrow niche)
Koala
S eats eucalyptus leaves only
S hunted for fur; can’t hide in eucalyptus forest
S now only in a few protected forests
6. Pet trade
Puerto Rican Parrot, etc.
S now bred in captivity
7. Introduction of exotic species
Rats introduced to islands
S kill off many species of birds
S mongoose introduced to kill rats in Puerto Rico (
S rats nocturnal, mongoose diurnal ;
8. Open trade
Elephant (ivory)
Alligator (skin)
Tortoise (shell)
Spotted cats (fur)
various birds (plumes)
9. Pesticides
Peregrine falcon - DDT
Osprey - DDT
Bald eagle - DDT