Evaluating Biodiversity and Vulnerability Topic 4.2
Slide 2
4.2.1 Identify factors that lead to loss of diversity. You will
be allocated a factor from the list on the next few pages.describe
and explain (using real life examples) how biodiversity is affected
by your factor:
Slide 3
How do Natural Disasters effect Biodiversity? By Kieran Harris,
Fausti Preysler, and Anil Daryanani
Slide 4
The visible path of a meteoroid that enters the Earths
atmosphere. Meteors are otherwise known as shooting stars or
falling stars Destroys the land that each meteor strikes
Meteors:
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Cretaceous Period Meteor wiped out all dinosaurs Burned down
50% of forests Caused excessive amounts of carbon to enter the
atmosphere killing most life species on earth Aqua life much
further down in the seas survived as they were unaffected Turtles
survived as well due to their slow metabolisms and aquatic
lifestyles No land animal larger than 23 kg survived Meteors:
Slide 6
Drought: A long period of no rain Causes extreme heat and
dryness Effects on biodiversity Dries everything up, kills it all
Plants dry up and die, leaving no shelter for other living
organisms like bugs, birds, etc.
Slide 7
Drought: Example: Dust Bowl Caused by severe drought in the
American and Canadian prairie land in the 1930s Caused by severe
drought, plus decades of extensive farming without things such as
crop rotation Nothing to keep soil in place, dried up, turned into
dust and blew away into many cities
Slide 8
Volcanoes and Animals: When volcanoes erupt they release huge
amount of ash into the atmosphere, it also spews out molten lava.
The lava destroys the habitats of the animals that are surrounding
the volcano, the animals that also live near the volcano would die
as well due to this.
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Volcanos and Environments: The trees and forests around the
volcanos will be destroyed from the magma that seeps down the
mountain side onto the ground and they also release a great deal of
soot into the air which pollutes the atmosphere. Volcanos can also
effect the people surrounding the volcano by destroying homes,
crops, and there livelihood.
Ecosystem degradation Look back at your work on deforestation,
desertification, leaching and salinization. (topic 3.4)
Slide 13
Fragmentation definition: The term habitat fragmentation
includes five discrete phenomena: 1.Reduction in the total area of
the habitat 2.Decrease of the interior : edge ratio 3.Isolation of
one habitat fragment from other areas of habitat 4.Breaking up of
one patch of habitat into several smaller patches 5.Decrease in the
average size of each patch of habitat
http://en.wikipedia.org/wiki/Habitat_fragmentation
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Ecosystem Fragmentation Habitat fragmentation as the name
implies, describes the emergence of discontinuities (fragmentation)
in an organism's preferred environment (habitat), causing
population fragmentation. Habitat fragmentation can be caused by
geological processes that slowly alter the layout of the physical
environment (suspected of being one of the major causes of
speciation), or by human activity such as land conversion, which
can alter the environment much faster and causes extinctions of
many species. Fragmentation and destruction of Great Ape habitat in
Central Africa, from the GLOBIO and GRASP projects
http://en.wikipedia.org/wiki/Habitat_fragmentation
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Natural causes and effects Evidence of habitat destruction
through natural processes such as volcanism, fire, and climate
change is found in the fossil record. [1] For example, habitat
fragmentation of tropical rainforests in Euramerica 300 million
years ago led to a great loss of amphibian diversity, but
simultaneously the drier climate spurred on a burst of diversity
among reptiles. [1] [1]
http://en.wikipedia.org/wiki/Habitat_fragmentation
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Human causes Habitat fragmentation is frequently caused by
humans when native vegetation is cleared for human activities such
as agriculture, rural development, urbanization and the creation of
hydroelectric dams.
http://en.wikipedia.org/wiki/Habitat_fragmentation
Slide 17
Habitats which were once continuous become divided into
separate fragments. After intensive clearing, the separate
fragments tend to be very small islands isolated from each other by
cropland, pasture, pavement, or even barren land. The latter is
often the result of slash and burn farming in tropical forests
slash and burn
http://en.wikipedia.org/wiki/Habitat_fragmentation
Slide 18
In the wheat belt of central western New South Wales,
Australia, 90% of the native vegetation has been cleared and over
99% of the tall grass prairie of North America has been cleared,
resulting in extreme habitat fragmentation.
http://en.wikipedia.org/wiki/Habitat_fragmentation
Slide 19
Implications One of the major ways that habitat fragmentation
affects biodiversity is by reduction in the amount of available
habitat (such as rainforests, boreal forests, oceans, marshlands,
etc.) for all organisms in an ecological niche. biodiversity
Habitat fragmentation invariably involves some amount of habitat
destruction. Plants and other non- moving or slow moving organisms
in these areas are usually directly destroyed. Mobile animals
(especially birds and mammals) retreat into remnant patches of
habitat. This can lead to crowding effects and increased
competition.habitat destruction The remaining habitat fragments are
smaller than the original habitat. Species that can move between
fragments may use more than one fragment. Species which cannot move
between fragments must make do with what is available in the single
fragment in which they ended up. Since one of the major causes of
habitat destruction is agricultural development, habitat fragments
are rarely representative samples of the initial landscape.
http://en.wikipedia.org/wiki/Habitat_fragmentation
Monoculture Monoculture is the practice of producing one single
crop over a wide area Monocultures often kill off all the
biodiversity because the crops are not used to having to share soil
with other plants and often kill of the competition
Slide 22
Pesticide Use Pesticides can be spread through the air and
water into areas which they were not originally intended, harming
many other organisms than pests Some of these chemicals are toxic
or lethal to the organisms they make contact with But some of the
chemicals would also not be considered directly toxic or lethal,
with effects sufficiently impairing populations in these ways:
Inability to recover from infectious disease due to
immunosuppression Inability to obtain sufficient food, effectively
avoid predators, or apply proper parenting instincts due to
neurotoxicological effects Development of abnormal sexual anatomy
or behavior due to hormone disruption
Slide 23
Genetically Modified Organisms Genetically modified organisms
can compromise biodiversity in these ways: Out-crossing: If GM
plants pass their traits onto their wild relatives, then those
relatives could be changed in a way that could change their
ecological role, which would potentially enable them to out-compete
other species
Slide 24
GMOs (continued) New traits agreed upon by genetic engineering
could offer advantages that could lead to widespread use of only a
few crop varieties, but this means a loss of cultivar biodiversity.
(Cultivar is a term used in plant breeding for the differentiation
of breeding lines) Reducing the diversity of the cultivars found in
agriculture could lead to problems such as raised susceptibility to
widespread outbreaks of plant diseases and pests Using GMOs doesnt
necessarily mean reducing the diversity of cultivars, but it is
still a good idea to keep a close eye on this
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Sites to look at: Monoculture: HERE :DHERE :D & AND HEREAND
HERE Pesticides: HELLOHELLO & HOW ARE YOU?HOW ARE YOU? GMOs:
BYE
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Invasive species Cane-toad and rabbit, cats and goats
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Invasive species affect on biodiversity There are two ways for
the invasive species to affect biodiversity, out-competing and
hybridizing native species. The invasive species is one that
lessens that diversity by throwing off the natural balance Damage
life forms effecting the ecosystem Habitat destruction, such as
forest clearing The more invasive species invading certain levels
of ecosystems, the biodiversity would be more threatened
Slide 28
Australia - Rabbits Rabbits are an invasive species in
Australia brought by Europeans. Since rabbits reproduce very
quickly, the population of rabbits quickly increased. Native
species of animals, such as the Rabbit-eared Bandicoot or Bilby
needs a constant supply of carbohydrate-rich seeds and roots. The
rabbits graze or degrade vegetation that provides food and shelter
for them and other native animals. Rabbits grazing on vegetation
also cause erosion and removal topsoil, and thus endangers some
native vegetation. If rabbits destroy or eat the native vegetation,
the Bilby and other native species are placed under greater
pressure, and thus the native species become endangered.
Slide 29
Australia - Rabbits Rabbits are an invasive species in
Australia brought by Europeans. Since rabbits reproduce very
quickly, the population of rabbits quickly increased.
Slide 30
Australia - Rabbits Native species of animals, such as the
Rabbit- eared Bandicoot or Bilby needs a constant supply of
carbohydrate-rich seeds and roots. The rabbits graze or degrade
vegetation that provides food and shelter for them and other native
animals. Rabbits grazing on vegetation also cause erosion and
removal topsoil, and thus endangers some native vegetation. If
rabbits destroy or eat the native vegetation, the Bilby and other
native species are placed under greater pressure, and thus the
native species become endangered.
Biodiversity Decreasing The IUCN has reported that about 5,200
species of animals currently are threatened with extinction,
including: * Close to 1,100 species of mammals, one-quarter of the
total number of mammals. Over 1,100 birds, 11% of the 9,600 known
species of birds. Over 2,000 species of freshwater fish, 20% of the
total number identified. 253 species of reptiles, 20% of the total
number surveyed. An estimated 124 species of amphibians, 25% of the
total number surveyed Plant species are not faring well, either. Of
the 270,000 known species of higher plants, 34,000 are endangered.
In the US nearly 30% of the 16,000 known plant species are at risk
of extinction. View these statistics here:
https://online.uas.alaska.edu/online/portfolio/CJOHNSON9/Courses/Fall-
2008/Introduction/Pollution__Life?behavior=UAS;https://online.uas.alaska.edu/online/portfolio/CJOHNSON9/Courses/Fall-
2008/Introduction/Pollution__Life?behavior=UAS
Slide 34
Pollution Increasing Since the industrial revolution in the
1800s, weve been relying on environmentally detrimental methods of
creating materials and products. Factories and waste help our
industrial development but hinder our biodiversity
development.
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How does one affect the other? WATER Toxic discharges This
includes metals, organic chemicals, and suspended sediments usually
found in industrial and municipal effluents that are discharged
directly into waterbodies. Toxic discharges can inversely impact
the biota (living organisms) in an ecosystem by killing them,
weakening them, or affecting their ability to carry out essential
biological functions (feeding, reproducing, etc.). Bacterial
contamination For example, fecal coliforms that come from human
waste are found in municipal effluent discharges. Potable water is
treated to destroy fecal coliforms which can make people ill if
ingested.
Slide 36
How does one affect the other? LAND Area Pollution Area
pollution prevents a specific region from having nutrient buildup,
which is ultimately an disadvantage to species such as lichen. But
it helps stimulate rapid growth of algae and aquatic plants.
Slide 37
How does one affect the other? AIR Acid Rain Acid precipitation
is the air pollutant that has the most significant impact on
biodiversity in Canada. Despite legislation aimed at reducing acid
rain and acid loading, it is predicted that we will lose fish,
mollusk and amphibian populations in thousands of lakes because
they will not be able to survive in acidified conditions. This is
of particular concern in the Canadian Shield region of Quebec,
whose countless lakes are sensitive to acidification because their
drainage basins cannot neutralize acid inputs the way they can in
more southern Quebec regions. These information is mostly based on
the St. Lawrence watershed in the southwest and northeast of North
America and Canada. Read more at:
http://redpath-museum.mcgill.ca/Qbp/3.Conservation/impacts.htmhttp://redpath-museum.mcgill.ca/Qbp/3.Conservation/impacts.htm
Slide 38
Researchers say that pollution affects plant diversity more
than animal diversity Air pollution affects lower life forms more
than higher life forms. Plants are generally more affected than
animals on land. Plants constantly take up atmospheric gases i.e.
air everyday to sustain their biological processes. Vegetation
growing under optimum conditions is most susceptible to air
pollution. As air pollution is for the most part man-made, we are
the main source of this phenomenon. Pollution can be derived from
two kinds of sources namely, stationary and multiple point sources.
Multiple point sources are usually mobile and include automobiles
and other vehicles. The vehicles are the most important source of
atmospheric pollutants as they release carbon monoxide. This is
followed by industrials sources which release sulphur oxides, steam
and electric power plants, space heating and lastly refuse burning.
Agricultural chemicals also form part of air pollution. The uptake
of pollutants depends on the concentration gradient between the
ambient air and the absorptive sites within the leaf. It also
depends on the conductance of the stomata. The toxic effect of a
pollutant may thus be almost directly related to the functioning of
the stomata. Because of the higher susceptibility of dying off as a
result of pollution in plants, their biodiversity is at a greater
threat. But sometimes, the biodiversity of plants can affect the
biodiversity of animals as youll see in the next slide.. Read more
at:
http://bcb705.blogspot.com/2007/03/air-pollution-lethal-injection.htmlhttp://bcb705.blogspot.com/2007/03/air-pollution-lethal-injection.html
Slide 39
Example: The Pollination Crisis Since 2006, honeybee colonies
in the United States have been suffering from a widespread
phenomenon known as colony collapse disorder (CCD), in which adult
worker bees abandon an otherwise-healthy hive. Air pollution
interferes with the ability of bees and other insects to follow the
scent of flowers to their source, undermining the essential process
of pollination, a study by three University of Virginia researchers
suggests. Their findings may help unlock part of the mystery
surrounding the current pollination crisis that is affecting a wide
variety of crops. Scientists already knew that scent-bearing
hydrocarbon molecules released by flowers can be destroyed when
they come into contact with ozone and other pollutants. Most bees
have poor eyesight, which makes scent particularly important, the
researchers wrote. This phenomenon triggers a cycle, the authors
noted, in which the pollinators have trouble finding sufficient
food, and as a result their populations decline. That, in turn,
translates into decreased pollination and keeps flowering plants,
including many fruits and vegetables, from proliferating. "We know
that ozone levels continue to be high and go well beyond EPA
standards for public health," Tear said. "What's been pretty
consistent is the more we look at air pollution's impacts on
natural resources, the more we find those impacts to be. Tear and
his colleagues have recently completed a survey of how atmospheric
pollution is affecting biodiversity in the Eastern United States
and concluded that high levels of ozone can decrease forest growth
by as much as 30 percent. Read more at:
http://www.washingtonpost.com/wp-dyn/content/article/2008/05/04/AR2008050401737.htmlhttp://www.washingtonpost.com/wp-dyn/content/article/2008/05/04/AR2008050401737.html
Slide 40
Hunting, collecting and Harvesting
Slide 41
Hunting Most extinction over the past several hundred years are
mainly due to over-harvesting for food, fashion, and profit
Commercial hunting, both legal and illegal (poaching), is the
principal threat. For Example Rhino Horns for $40,000 to $100,000
per horn The pet and decorative-plant trade falls within this
commercial hunting category, and includes a mix of legal and
illegal activities. The annual trade is estimated to be at least US
$5 billion, with perhaps one-quarter to one-third of it
illegal.
Slide 42
Hunting (continued) Sport or recreational hunting causes no
endangerment of species where it is well regulated, and may help to
bring back a species from the edge of extinction. Many wildlife
managers view sport hunting as the principal basis for protection
of wildlife. http://www.fathom.com/course/21701785/se ssion2.html
http://www.fathom.com/course/21701785/se ssion2.html
Slide 43
Harvesting/Collecting Conversion of Forests into agriculture
for harvesting Lessens habitat, which in turn lessens species
diversity. Harvesting removes certain foods or areas of nutrition
for animals Overharvesting any area is a direct threat to a
biodiversity Habitat loss and overharvesting often occur
simultaneously The problem with biological resource extraction is
when the rate of increase in demand for the resource far outstrips
the reproductive rate of the population - demand outstrips supply
http://redpath-museum.mcgill.ca/Qbp/3.Conservation/impacts.htm
Slide 44
The recent expansion of road networks into previously remote
tropical forests enables the bush meat trade resulting in what some
conservationist describe as empty forests as more and more wild
animals are shot for food. Link to a table which shows the affects
of overharvesting in comparison with the other factors. Link to a
table which shows the affects of overharvesting in comparison with
the other factors.
http://www.fathom.com/course/21701785/session2.html
Harvesting/Collecting (continued)
Slide 45
Overharvesting (3 points) The unsustainability of biological
resource extraction has, at its root, three main problems a) too
many people want the resources, b) the short-term profit goals of
extractors c) Lack of information about the ecology and about the
life-histories of the populations being harvested.
http://redpath-museum.mcgill.ca/Qbp/3.Conservation/impacts.htm