Transcript Biodiversity- Ash and Leah

biodiversity and
hawaii
a case study examination
what is biodiversity?
• at ecosystem level: the number of
biomes in a given region
• at organism level: the number of
species in a given area
• in terms of genetics: number of alleles
in a population
• can also be thought of in terms of
evenness.
is biodiversity in
danger?
•
•
biodiversity is threatened by the disruptions to
the natural ecosystem that limit the resources
needed by an organism (light, food, water, space)
or alter how that organism interacts with other
organisms (predation, competition.)
Disruptions of this sort are caused by two things:
•
•
1. establishment of exotic, or introduced species.
2. habitat fragmentation
•
is biodiversity in
danger?
introduced species
•
•
species brought to an area either intentionally or by accident that are not
naturally part of the ecosystem
most fail to survive, however, some...
•
•
•
•
•
•
thrive and out-compete native species
prey on native species
transmit exotic diseases
facilitate the spread of native diseases
hybridize with natives
alter habitats
is biodiversity in
danger?
•
habitat fragmentation
•
•
when people alter natural
areas through actions, like
agricultural or urban sprawl,
the habitats needed to sustain
native species are often
eliminated, and he remaining
natural areas are left isolated.
extremely concerning to
conservation biologists; habitat
fragmentation does not only
result in a loss of habitat, but
also genetic exchange
amongst the broken up
populations
• How do you measure biodiversity?
Indicator species and biotic
indices (G.4.1)
•
•
•
Indicator species are extremely sensitive to
environmental changes, and their
populations fluctuate greatly depending on
environmental changes; these prove to be
good indicators of change. Frog
populations are quite vulnerable to pollution
and other forms of change, while sludge
worms are good indicators of low oxygen
concentration in waterways.
Biotic indices are calculated via the number
of tolerant and intolerant species at a time.
The numbers of these organisms in the
indicator species populations are monitored
over time directly so it is easy to keep track
of them.
• Often times, new species are
introduced to different areas for
agricultural use (cows, goats, etc) , and
it is not uncommon for these
domesticated animals to become feral.
Because of this, what role do humans
play in the threat to biodiversity?
What leads to extinction?
(G.4.2)
•
DODO BIRD (Origin: Mauritius)
•
•
•
•
Eaten by Dutch sailors who first
discovered them (1600s)
Destruction of forest by settlers
(loss of food supply)
Dodo nests destroyed by sailor’s
animals, including: rats, cats, and
pigs
• What are humans doing to conserve
biodiversity?
Biogeographical features promote
conservation (G.4.3)
•
Large nature reserves usually promote conservation of biodiversity more
effectively than small ones. The ecology of the edges of ecosystems is
different from the central areas due to edge effects and its increase for the
risk of predation. An example of an edge effect is the egg-laying habits of
the cowbird of the western United States. It feeds in open areas, but it lays
its eggs in the nests of other birds near the edges of forests. Fragmentation
of forests has led to a considerable increase in cowbird populations because
of the increase in forest edge. Wildlife corridors allow organisms to move
between different parts of a fragmented habitat, for example, tunnels under
busy roads.
Active Management Techniques
in Conservation (G.4.4)
•
Active Management Techniques:
•
•
•
•
Adaptive Management: A system used by large organizations to manage geographically and/or habitat
diverse conservation projects. Includes digitization of records and the tracking of changes in human,
animal, plant and weather activities and update central databases. The intention of adaptive management is
to create conservation policies that have the largest impact on a multitude of issues by utilizing the most
current data.
Ecosystem Management: A conservation practice that lets conservations within a particular field compare
and argue their conservation plans. Ideas are discussed in a forum-like setting; not all ecosystem will come
to a consensus. The United States Forest Service has adopted ecosystem management practices as its
official policy for managing national forests.
Agroecosystems Analysis: Requires sustainable solutions that can merge with the conservation efforts of
sustainable environmental, socio-economic, and urban development systems. This type of analysis attempts
to classify agricultural activities by region and resource needs. Example: determining how a large farm and
an urban center in close proximity can work together to conserve water and minimize their collective
environmental impact.
Soft Systems Analysis: A method of conservation that uses words, diagrams and images to explain complex
conservation ideas and techniques across disciplines. This gives the multiple groups working together
(government/private agencies) a common language in which management activities and goals can be
discussed. Multiple perspectives are valued in this type of analysis since the more comprehensive and
inclusive communication is, the more effective are the outcomes.
In situ Conservation
•
•
•
In situ conservation: the conservation of species where they are found
naturally.
ie: Nature reserves and/or national parks
Advantages include: Access to all of its familiar resources (will not
have to adapt to new diet or fake environments), species will continue
to evolve in their natural environment, more space, bigger breeding
populations can be kept in situ, and it costs less to keep an organism in
situ.
Disadvantages: Difficult to control illegal exploitation and environment
may need to be restored
Ex situ Conservation
•Ex situ: animals maintained in zoos or wild life parks, especially when not
in original geographic zone.
•Captive Breeding of animals:
•captive breeding of endangered animals is a last resort; it is only used if a
species has no chance of recovering in the wild.
•Works well for species that are bred easily in captivity, like geese and
deer; however, more specialized species are difficult to maintain.
•Animals isolated in captivity do not evolve with their environment
•Small gene pool: inbreeding, invitro fertilization utilized.
•Possible to restore a population in captivity, however, it may have
disappeared in the wild.
Ex situ Conservation
•Botanical Gardens:
•Limited range of species
•Distribution of botanical gardens reflects the distribution of colonial powers;
Most found in Europe and North America. Plant diversity is greatest in the
tropics.
•Seed Banks:
•Seeds can be maintained for decades or centuries in controlled conditions
•Seeds need to be germinated regularly in order to renew stock; otherwise,
seeds will lose viability
•Seed banks are at risk from power failure, natural disasters, and war.
•Duplicate stocks can be maintained
•Seeds that are kept in seed banks do not evolve with environment changes.
Sources
•
•
•
http://www.pbs.org/wnet/nature/episodes/ki
lauea-mountain-of-fire/hawaiis-vulnerablebiodiversity/4838/
http://www.amnh.org/exhibitions/expedition
s/treasure_fossil/Treasures/Dodo/dodo.ht
ml?dinos
http://www.ehow.com/list_6861965_activemanagement-techniquesconservation.html