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
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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.
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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
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
• Today the Endangered Species Act:– prohibits killing of listed species– prohibits sale, import/export of whole
animal/plant or any part– protects habitat from destruction