Transcript Biodiversity - semwalmanish

Biodiversity
Dr. Manish Semwal
GMIS Jakarta
Pangea
• Two hundred million years ago , research
suggests that all the continents where one
large mass which was named Pangea.
• Terrestrial organisms were able to migrate
across all the continents and were only limited
by their biotic potential.
Biodiversity
• As Pangea began to separate into separate
continents 130 Ma, creating physical barriers
such as seas, restricting migration to within
the continents.
• Gene pools of species are separated and as
they are exposed to different physical (i.e.
climate) and biotic (i.e. change in predators)
conditions, each portion of the species adapts
differently and eventually forms new species
on the separated continents.
• This process is known as speciation.
Biodiversity
• Changes in physical and biotic conditions will
also lead to the creation of new species
increasing the diversity of habitats and niches.
• This also provides the space for new species to
evolve into these habitats.
• The end result of the separation of Pangea
into today’s continental configuration is that
plate tectonics has been one of the main
driving forces promoting biodiversity or
organisms.
Biodiversity
• In addition to continents separating, some like India
left south Africa and Antarctica and joined up with
Asia.
• It took with it organisms that were typical to
Antarctica and Australia.
• Over the next 100 Myrs these organisms evolved in
isolation from any other continent until it formed a
land bridge with Asia.
• Since 30 Myrs ago the species on India and Asia have
been re-adapting themselves causing additional
biodiversity.
Biodiversity
• Australia has one of the most unique sets of organisms as it
and Antarctica have been separate from all the other
continents for the last 130 Myrs.
• Australia separated from Antarctica about 50 Myrs ago.
• This extreme isolation over such a long period of time
supports Darwin’s theory of evolution in that this part of the
world has the most unique organisms.
• Australian species have had such limited contact with species
from other continents that they have only needed to adapt to
their particular set of species and climate.
• No re-adaptation to other species from other continents has
occurred until the arrival of the Europeans.
Biodiversity
• The splitting up of Pangea 200 million years
ago had the following effects on species
diversity and distribution.
a) Species gene pools or populations where
split as Pangea separated.
b) New habitats were created due to a
change in biotic and abiotic factors such as
climate (temperature and moisture), changes
in species relationships, and topography.
Biodiversity
c) New niches were made available and filled causing further
adaptation of species to new conditions thus modifying
the local ecosystem.
d) Species relationships change with respect to mutualism,
predation, and competition. Species need to modify food
source, protection, and dependence patterns in the food
web.
e) Speciation: is the creation of a new species when a gene
pool of one species is split, exposed to new conditions to
which each pool adjusts to. Different genetic traits are
passed on to offspring. A new species evolves once the 2
original populations cannot mate.
Biodiversity
• Rejoining of plates such as India and Asia. 30 Ma ago caused
the following.
a) Migration of one species into the territory of another
introduces new forms of competition and predation that
existing species need to adapt.
b) Further speciation is generated and modified as they come
into contact with a variation of the original gene pool.
The Biosphere
• The sum of Earth’s ecosystems, the Biosphere
encompasses all parts of the planet inhabited by
living things.
• In 2002 about 1.7 million species had been
discovered and identified by biologists, although
estimates of the true number of species on earth
range from 3.6 to over 10 million (Wilson 2002).
• For at least 3.8 billion years, a complex web of life
has been evolving here on Earth
Biome
• The term biome refers to a major type of
terrestrial ecosystem that typifies a broad
geographical region.
• Biomes do not stop at a border; for example, the
Sahara, tundra, tropical rainforests.
• Climate and other limiting factors
determine biome type such as tropical
rainforests are found close to the equator where
there is high insolation and rainfall and where
light and temperature are not limiting.
Biodiversity
• Biodiversity is an abundance of different life.
• Biodiversity (biological diversity) is the
variety of all living organisms and their
interactions. Scientists often speak of three
levels of diversity - species, genetic, and
ecosystem diversity.
Earth’s Biodiversity
Insects
Protozoa
281000
69000
5800
Higher plants
Algae
26900
751000
248400
Fungi
Bacteria & viruses
Other animals
30800
• "Biological diversity is the variety and
variability among living organisms and the
ecological complexes in which they occur.
• Genetic diversity is the combination of
different genes found within a population of a
single species, and the pattern of variation
found within different populations of the
same species. Coastal populations of Douglas
fir are genetically different from Sierran
populations
• Species diversity is the variety and abundance
of different types of organisms which inhabit
an area. A ten square mile area of Modoc
County contains different species than does a
similar sized area in San Bernardino County.
• Ecosystem diversity encompasses the variety
of habitats that occur within a region, or the
mosaic of patches found within a landscape. A
familiar example is the variety of habitats and
environmental parameters in an ecosystem
and its grasslands, wetlands, rivers, estuaries,
fresh and salt water."
• Reasons for why human cultures value
biodiversity:
The rich variety of species in biological
communities gives us food, wood, fibers, energy,
raw materials, industrial chemicals, and
medicines, all of which pour hundreds of millions
of dollars into the world economy each year.
Moreover, people have a natural affinity for
nature, a sense of “biophilia,” wherein they
assign a non-utilitarian value to a tree, a forest,
and wild species of all kinds
Importance of Biodiversity
Pollination
For every third bite you take, you can thank a pollinator.
Air and Water Purification
Biodiversity maintains the air we breathe and the water we drink.
Climate Modification
By giving off moisture through their leaves and providing shade, plants
help keep us and other animals cool.
Drought and Flood Control
Plant communities, especially forests and wetlands, help control floods.
Cycling of Nutrients
The elements and compounds that sustain us are cycled endlessly through
living things and through the environment.
Importance
Habitat
Natural ecosystems provide habitat for the world’s species
(forests, wetlands, estuaries, lakes, and rivers – the world’s
nurseries).
Food
All of our food comes from other organisms.
Natural Pest Control Services
Natural predators control potential and disease-carrying
organisms in the world.
Drugs and Medicines
Living organisms provide us with many drugs and medicines.
Factors that lead to loss of
diversity
• natural hazard events
• Invasive Species
• habitat degradation, fragmentation and loss
• agricultural practices (monoculture, use of
pesticides, use of GMS)
• introduction and/or escape of non-native species
• Pollution
• hunting, collecting and harvesting.
Threats: Invasive species
• A species that is not native to a region
• Threaten native species by taking over
resources
Keystone species - a species which is
CRITICAL to the functioning of an
ecosystem
– Many different species are dependent on it
– If lost, the entire ecosystem is destroyed
Zonation
• Zonation is the classification of biomes into zones based on
their circulation or grouping in a habitat as influenced by
environmental factors, such as altitude, latitude, temperature,
other biotic factors
• Supplement
• An example of ecological zonation is the vertical zonation of
the pelagic ocean:
• epipelagic zone – the zone where photosynthetic organisms
(such as planktons) thrive as they require enough light for
photosynthesis
• mesopelagic zone – the zone under epipelagic zone where
nektons are abundant
• bathypelagic zone – the zone near to the deep sea floor
where benthos abound
Succession
• the gradual and orderly process of change in
an ecosystem brought about by the
progressive replacement of one community by
another until a stable climax is established
Examples of Changing Ecosystems
• A forest could have been a shallow lake a
thousand years ago.
• Mosses, shrubs, and small trees cover the
concrete of a demolished building.
Ecological Succession
• Gradual process of change and replacement of
the types of species in a community.
• May take hundreds or thousands of years.
Primary Succession
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M-DCC / PCB 2340C
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• Newer communities
make it harder for the
older ones to survive.
• Example: Younger birch
trees will have a harder
time competing with
taller, older birch trees
for sun, but a shade
loving tree may replace
the smaller birch trees.
Primary Succession
• Type of succession that
occurs where there was
no ecosystem before.
• Occurs on rocks, cliffs,
and sand dunes.
• Primary succession is very slow.
• Begins where there is no soil.
• Takes several hundred years to produce fertile
soil naturally.
• First species to colonize bare rock would be
bacteria and lichens.
Lichens
• Do not require soil.
• Colorful, flaky patches.
• Composed of two species, a fungi and an
algae.
• The algae photosynthesize and the fungi
absorbs nutrients from rocks and holds water.
• Over time, they break down the rock.
• As the rocks breaks apart, water freezes and
thaws on the cracks, which breaks up the
rocks further.
• When the lichens die, they accumulate in the
cracks.
• Then mosses begin to grow and die, leading to
the creation of fertile soil.
• Fertile soil is made up of the broken rocks,
decayed organisms, water, and air.
Mosses on rocks
• Primary succession can
be seen happening on
the sidewalks.
• If left alone, even NYC
would return to a
cement filled woodland.
Secondary Succession
• More common
• Occurs on a surface where an ecosystem has
previously existed.
• Occurs on ecosystems that have been
disturbed or disrupted by humans, animals, or
by natural processes such as storms, floods,
earthquakes, and volcanoes.
Secondary Succession: Mt. St. Helens
• Erupted in 1980.
• 44,460 acres were
burned and flattened.
• After the eruption, plants
began to colonize the
volcanic debris.
• Pioneer species: the first
organism to colonize any
newly available area and
begin the process of
ecological succession.
• Over time, the pioneer species makes the area habitable
by other species.
• Today, Mt. St. Helens in the process of secondary
succession.
• Plants, flowers, new trees and shrubs have started to
grow.
• If this continues, over time they will form a climax
community.
• Climax community: the final and stable
community.
• Climax community will continue to change in
small ways, but left undisturbed, it will remain
the same through time.
Fire and Secondary Succession
• Natural fire caused by lightening are a
necessary part of secondary succession.
• Some species of trees (ex: Jack pine) can only
release their seeds after they have been
exposed to the intense heat of a fire.
• Minor forest fires remove brush and
deadwood.
Fire and Secondary Succession
• Some animals depend on fires because they
feed on the newly sprouted vegetation.
• Foresters allow natural fires to burn unless
they are a threat to human life or property.
Old-field Succession
• Occurs in farmland that
has been abandoned.
• Grasses and weeds
grow quickly, and
produce many seeds
that cover large areas.
• Over time, taller plants grow in the area,
shading the light and keeping the pioneer
species from receiving any light.
• The longer roots of the taller plants deprive
the pioneer species from water.
• The pioneer species die.
• Taller trees begin to
grow and deprive the
taller plants of water
and light.
• Followed by slow
growing trees (oaks,
maples) takeover the
area.
• After about a century,
the land returns to a
climax community.
Opportunists Vs Equilibrium Species
• Equilibrium species:
Opportunists:
• Produce fewer, heavier
• Produce lots of seeds
seeds. Heavy seeds have
the resources to develop in
• These seeds should be tiny
a crowded, equilibrium
and disperse widely, probably
community.
on the wind
• Delayed sexual maturity.
• Form a seed bank: seeds
which survive in the soil until a • Long-lived plants,
new period of disturbance.
reproducing for many
years.
• Set seed early, before the
better competitors arrive.
Opportunists are usually
annuals
Need to Know – How????
• Diversity changes through succession
• Greater habitat diversity leads to greater species
and genetic diversity
• A complex ecosystem, provides
stability
• An ecosystem’s capacity to survive change may
depend on diversity, resilience and inertia
• human activities modify succession and simplify
Ecosystem Such as logging, grazing, burning and
Simplification or Prairies by humans
Measuring Biodiversity
• The simplest measure of biodiversity is the number of
species – called species richness.
– Usually only count resident species, and not accidental or
temporary immigrants
• Another concept of species diversity is heterogeneity:
Community 1 Community 2
Species A
99
50
Species B
1
50
Heterogeneity is higher in a community where there are more
species and when the species are more equally abundant.
Diversity Indices
• A mathematical measure of species diversity
in a community.
• Reveals important information regarding rarity
and commonness of species in a community.
Simpson’s Diversity Index
• Attempts to quantify the diversity (variety) of
an ecosystem.
• There are two components:
Evenness
Richness
Evenness
• Evenness is a measure of the relative
abundance of the different species within an
area.
• When the numbers of each type of species is
even, the value for the Simpson Diversity
Index will be larger.
Species richness
• Richness is a measure of the variety of the
species
• More species is “richer” so the value for the
index will be higher.
The equation
D = N(N - 1)
 n(n -1)
D = diversity index
N = total number of organisms of all species
found
n = number of individuals of a particular species
The Simpson Diversity Index
• A high value of D suggests a stable and ancient
site
• A low value of D could suggest pollution, recent
colonization or agricultural management.
• The value of D indicates the richness and
evenness of the species found within the area
sampled.
Predict the value for D for the
following: (high or low)
• Tropical rainforest
• Desert
• A wheat field
• A polluted river
• A tall grass prairie
How to Calculate D:
D = N(N – 1)
 n(n -1)
1.
2.
3.
4.
Record the numbers of each species
Calculate n-1 for each species
Find the total number of organisms, N
Calculate the Simpson Diversity Index
Values for D
• What is the lowest possible value?
• What does a higher value indicate?
The values for D
• The lowest possible value is 1. When there is
only one kind of species.
• This is a monoculture or an area that has been
disturbed by pollution, a flood, or another big
event
• A high value for D indicates stability,
complexity and an older ecosystem.
Calculate the Simpson’s Diversity Index
for each sample
Comment on the evenness and richness of each sample.
Answers
• Sample One: 2.99
• Sample Two: 1.15
• Both have the same richness as there are
three species in each area.
• Sample One is more diverse because the
species are more even.
Sampling Methods
• Transects and Quadrants
– Plants and Non-motile animals
• Lincoln Index
• Capture –Mark- Recapture
– Small animals
• Aerial observations
– Large trees and animals
Average Size
• Measure all trees in a transect or quadrat.
• Produce a size-frequency histogram to show
the size distribution.
• Can also calculate the average size tree.
Quadrat Sampling
Quadrat
1
1
1
1
1
1
2
2
2
2
2
2
Species
BoxElder
Button Bush
Chinese Tallow
Cottonwood
Maple
Willow
BoxElder
Button Bush
Chinese Tallow
Cottonwood
Maple
Willow
No.
0
2
1
9
0
62
4
0
0
1
2
60
• Randomly select plots and
count all individuals in that
plot.
• Each quadrat = 200m2.
• Can calculate density as
#/m2 then multiply by total
area to estimate the total #
of trees.
• 60,703 m2 = 15 acres
Transect Sample
Transect
1
1
1
1
2
2
2
2
3
3
3
3
Species
BoxElder
Cottonwood
Maple
Willow
BoxElder
Cottonwood
Maple
Willow
BoxElder
Cottonwood
Maple
Willow
No.
1
1
2
27
2
1
0
37
2
4
0
44
• Randomly select a transect
of known area and count
every tree in that transect.
• Each transect = 90m2.
• Can calculate density for
each tree species.
• 60,703 m2 = 15 acres
Sampling along Transects
• Samples taken at fixed intervals
• Set up along an environmental gradient (e.g.
high to low on a mountain)
Line transect method
• A measured line laid across the area in the
direction of the environmental gradient
• All species touching the line are be recorded
along the whole length of the line or at specific
points along the line
• Measures presence or absence of species
Belt transect method
• Transect line is laid out and a quadrant is placed
at each survey interval
• Samples are identified and abundance is
estimated
– Animals are collected
– For plants an percent coverage is estimated
• Data collection should be completed by an
individual as estimates can vary person to
person
Quadrats
• Used to measure coverage and abundance of
plants or animals
• A grid of known size is laid out and all the
organisms within each square are counted.
Lincoln Index
• Capture-Mark-Recapture
– Animals are captured,counted, tagged and released.
– After a period of time another capture occurs.
– Previously tagged animals are counted and unmarked
organisms are marked.
– Abundance is calculated using the following formula:
n 1 x n2
n3
n1=total marked after catch 1
n2=total marked after catch 2
n3=total caught in catch 2 but
marked in catch 1
Measurements
• Sampling methods measure
–
–
–
–
–
Density
Coverage
Frequency
Biomass
Diversity
Conservation of biodiversity
• Can be done through ethical, aesthetic, genetic
resource and commercial point of view but
argumentative.
• Role of United Nations Environment Programm
(UNEP) as an intergovernmental organization and the
World Wide Fund for Nature (WWF) and Greenpeace
as non-governmental organizations. (Evaluate role of
all organization)
• Earth Summits
• Protect Design area management (See Examples)
• Species based approach (strength and weakness and
see examples)
Must see Websites
• For Biodiversity case studies
– http://www.environment.gov.au/biodiversity
Green Peace --http://www.environment.gov.au/biodiversity
WWF - http://www.worldwildlife.org
UNEPhttp://www.unep.org/ecosystemmanagement/
Bibliography (Not MLA- Direct Link for further reading)
• http://www.biology-questions-andanswers.com/ecological-succession.html
• http://www.uzinggo.com/ecologicalsuccession/population-dynamics/life-science
• http://press.princeton.edu/chapters/s3_8879.pdf
• http://gk12calbio.berkeley.edu/lessons/less_mea
sbiodiv.html
• http://www.environment.gov.au/biodiversity
• ESS SUBJECT GUIDE IBO
Thank You