Three
components: Image
species diversity - within a community
genetic diversity - within a population or species
ecosystem diversity - variety of habitats
Species
diversity - Image
species richness
relative abundance of species
How many
species are described in the literature? About 1.5 million are known to science
How many are thought to exist on earth? Maybe 30 million. Estimates range from
10-100 million
Geographical patterns of species richness
Human
activities affecting species - Fig 40.6
Reasons
for preserving species
Agricultural importance -
1.
biocontrol agents
2. soil microorganisms
3. pollinators
4. genes for plant breeding
and genetic engineering
5. new food crops
Medicines
About
80% of people in LDC's rely primarily on traditional medicines, mostly from
plants
1. quinine
2. taxol
3. digitoxin from Digitalis
Soil stabilization
Aesthetics
Because its the right thing to do
Characters
of extinction-prone
species
often K-selected species
low reproductive rate
feed at high trophic level
large size
very specialized feeding habits
limited distribution
prey on livestock
migratory species map
plane
behavioral patterns
desirable to humans
Genetic
problems faced by small populations
loss of genetic diversity - little to fall
back on in times of environmental change
increase in harmful homozygous recessives
Extinction vortex - Image
Captive
propagation: The peregrine
falcon (Falco peregrinus)
Northern Aplomado Falcon
(Falco femoralis septentrionalis) program
Attwaters
prairie chicken program
Sustaining
genetic diversity: The black rhino Fig. 40.21
Preserving
keystone species: flying foxes (a type of bat) Fig 40.22
Landscape
Ecology
Restoration
Ecology - Image and Fig. 40.20
