Ch 55 Conservation Biology

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Transcript Ch 55 Conservation Biology

 Chapter
55 ~ Conservation Biology
Three Levels of Biodiversity
Loss of Genetic
diversity:
 Loss of Species
Diversity: endangered
vs. threatened
 Loss of Ecosystem
Diversity

Biodiversity crisis

Extinction ~ natural phenomenon,
however, rate is of concern…..

50% loss of species when 90% of
habitat is lost
Major Threats:

Habitat destruction ~ single greatest

threat; cause of 73% of species
designation as extinct, endangered,
vulnerable, rare; 93% of coral reefs

Competition by exotic (non-native)
species ~ cause of 40% of species
designation as extinct.

Overexploitation ~ commercial
harvest or sport fishing; illegal trade
Biodiversity: Human welfare
25% of all medical
prescriptions
 Genetic variability
 Aesthetic and ethical
reasons
 Species survival

Conservation at the Population and
Species Level


Small Population
Approach: study process
that causes very small
pop. To become extinct.
Extinction Vortex
How small is too small?
– Minimum Viable
Population (MVP)
– Effective Population Size
(Ne) breeding potential
Conservation biology focus

Preservationism: setting aside select
areas as natural and underdeveloped

Resource conservation: public
lands to meet the needs of agriculture and
extractive industries, i.e., ”multiple use”

Evolutionary / ecological view:
natural systems result from millions of
years of evolution and ecosystem
processes are necessary to maintain the
biosphere
Declining Population Approach
Action oriented
 Focuses on threatened and endangered pop.
 Case by Case process
 Steps

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Confirm species is in decline
Study history to determine environmental needs
Determine all possible causes of decline
List prediction of each hypothesis for the decline
Test most likely hypothesis
Apply results of diagnosis
Case Study
Red-Cockaded Woodpecker
•Build nest in Heartwood of •Logging/Agriculture
live pines.
destroyed habitate.
•Center rotten
•Fire prevention
•Space
•Caused
•Resin repels insect and other
pred.
•Overgrowth
of forest undergrowth
•Under-story must be low cover/profile
Ecologist construct cavities in pines at 20 sites.
18 of 20 were occupies
Breeding
pairs w/ helpers
for inhabitating
incubation ofarea
eggsbecause
Woodpeckers
were not
Occupy
nests b/c
takes several years to make nest
ofabandoned
lack of breeding
cavities
Prevents dispersion of species
Population & species level conservation

Biodiversity hot spot: small area
with an exceptional concentration of
species

Endemic species: species found
nowhere else

Endangered species: organism
“in danger of extinction”

Threatened species: likely to
become endangered in the foreseeable
future

Bioremediation: use of living
organisms to detoxify polluted systems
Conservations
Protected
of world’s land is a form of reserve.
 EdgedArea:
and 7%
corridors:
Biodiversity Hotspot: small area w/ high concentration of
natural and created,
endemic species and large # of endangered/threatened species
define an ecosystem
 La
Fin
 El Extremo
 Das Ende
 L’ estremita
 The End