Transcript Conservation Ecology

Maintaining Nature’s Balance
What is Conservation?
 Conservation biology is the science of analyzing
and protecting Earth's biological diversity
 addresses population dynamics issues associated with
the small population sizes of rare species
 studies the phenomena that affect the maintenance,
loss, and restoration of biological diversity
Biodiversity
 An abbreviation of ‘biological diversity’, coined in
1986
 Encompasses three levels of complexity
 Diversity of ecosystems on Earth
 Diversity of species within ecosystems
 Genetic diversity within populations
 The primary goal of conservation is to maintain
biodiversity at all three levels
Reasons for Conservation of
Biodiversity
1.
2.
3.
4.
Economic
Ecological
Ethical
Esthetic
From your own experience give an example of each.
Economic Reasons
 New commodities may be found in the wild
 Ex. Medicines
 New crop plants or farm animals can be developed
from wild species
 Ecotourism can provide considerable income
Ecological Reasons
 Native species are well-adapted to local conditions,
introduced species are less likely to prosper
 Consider drought tolerant native species vs. exotics with high water
demands
 Communities are interdependent, removal of one species
will have affect on others
 Recall the idea of keystone species
 Damage to ecosystems may result in soil erosion, silting up
of rivers, and flooding
 Deforestation removes roots and loosens soil
Ethical Reasons
 Every species has the right to life, whether it is
useful to humans or not
 Wildlife can have cultural importance to local
human populations
 Consider America without the bald eagle
 It would be wrong to deprive future generations
from the rich experiences provided by earth’s
natural biodiversity
 Think, no tigers!
Esthetic Reasons
 Natural ecosystems
are beautiful and give
us great enjoyment
 Painters, writers, and
composers have been
inspired by nature
around them.
Loss of Biodiversity – Extinction!
 Extinction, the loss of a species from an ecosystem, can
be local or global
 Local extinction, such as the wolves in the US, can be
reversed with effort
 Global extinction is forever
Passenger Pigeon
(Ectopistes migratorius)
 It is estimated that there were
as many as five billion
passenger pigeons in the
United States at the time
Europeans colonized North
America. They lived in
enormous flocks, and during
migration, it was possible to see
flocks of them a mile (1.6 km)
wide and 300 miles (500 km)
long, taking several days to pass
and containing up to a billion
birds
Passenger Pigeon
(Ectopistes migratorius)
 The primary reduction
factor emerged when
pigeon meat was
commercialized as a
cheap food for slaves
and the poor in the
19th century, resulting
in hunting on a
massive scale.
Mass Extinction
 The current extinction rate is estimated to be similar
to the K-T extinction which saw an end to the
dinosaurs 65 million years ago.
 The list of endangered species is still growing
Monitoring Environmental Change
 Assessing the health of an ecosystem can be
accomplished using a variety of methods
 Biodiversity Index
 Measurement of abiotic factors
 Using indicator species
Simpson’s Biodiversity Index
1.
2.
3.
N = total number of organisms
n = number of individuals of
each species
Values range from 0 to 1
Closer to 1, higher biodiversity
4.
Use a random sampling
technique to search for
organisms in an
ecosystem
Identify each of the
organisms found
Count the total number
of individuals of each
species
Calculate the index (D)
Indicator Species
 A species that requires a specific set of environmental
conditions to survive
 Presence or absence of such a species indicates
conditions of environment
 Often used to assess pollution levels in aquatic
ecosystems
Indicator Species
 Lichens are indicators of
air quality. They are
particularly sensitive to
sulphur dioxide, a gas
emitted from exhaust and
industrial fumes, and so
are rarely found in large
cities and towns or by
roads
Conservation Methods
A variety of methods are used, some are designed and
implemented by scientists, others are a compromise
between politicians stressed by economic and social
forces
 In situ conservation
 Ex situ conservation
In Situ conservation
 Philosophy:
 The best place to preserve a species is in its own habitat
 Method:
 create nature reserves that limit human interaction
 Results:
 Very effective if reserve is large and laws obeyed
Management of Nature Reserves
 Alien species must be eliminated, especially predator and
invasive plants
 Ares that have been degraded by human activities must be
restored
 Special measures may be needed
 Supplementary feeding
 Clearing vegetation
 Exploitation by humans must be controlled
In Situ conservation
 Advantages
 Species remain adapted to their habitat
 Greater genetic diversity can be conserved
 Animals maintain natural behavior patterns
 Species interact, helping to maintain balance of whole
ecosystem
Can you think of other advantages?
In Situ conservation
 Disadvantages
 Some species are so rare that it is not safe to leave them
unprotected in the wild
 Sometimes destruction of a natural habitat makes it
essential to remove threatened species from it
Write down an example of each
Ex Situ conservation
 Philosophy:
 If a species can’t make it, we must help
 Method:
 Captive breeding
 Botanic garden
 Seed banks
 Results:
 As we learn more about the needs of different species success has
been increasing
Captive Breeding
 Some or all members of a species are caught and
brought to a zoo, where they are encouraged to
breed.
 When numbers are high enough some are
returned to the wild to re-establish a natural
population
 Ex., American Condor
California Condor Recovery
Program
 “In the early years of the reintroduction effort some
problems occurred, including five condor mortalities due to
collisions with power lines. Experts made several changes in
the rearing methods used. Among the most successful
changes was the initiation of a power pole aversion training
program for all releasable condors. This training involves the
use of a mock power pole placed inside the flight pen where
the young condors are kept until transferred to a release site.
The power pole emits a small electrical charge whenever a
condor attempts to land on it. The young birds quickly learn
to avoid perching on these and will, instead, opt to use
appropriate natural perches available inside the flight pen.
This program has greatly reduced condor mortalities from
power line collisions.”
California
Condor
Botanic Garden
 Sites where many
different species of
plants are cultivated,
either in greenhouse
or out in the open
 Royal Botanical
Garden of Kew has
50,000 of known
250,000 species
Seed Bank
 Seeds are kept in cold storage at -10ºC to 20ºC.
 Seeds of most species remain viable for more than
a hundred years.
 Other species can be germinated and grown to
produce replacement seed before viability is lost
Svalbard Global Seed Vault