Download (Introduced) species

The Benefits of Healthy Ecosystems
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Ecosystem services are the benefits people obtain from ecosystems. Many of
the services listed here are interlinked.
Provisioning Services. These are the products obtained from ecosystems,
including:
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Food. This includes the vast range of food products derived from plants, animals, and
microbes.
Fibre. Materials such as wood, jute, cotton, hemp, silk, and wool.
Fuel. Wood and other biological materials serve as sources of energy.
Genetic resources. This includes the genes and genetic information used for animal
and plant breeding and biotechnology.
Biochemicals, natural medicines, and pharmaceuticals. Many medicines and food
additives such as alginates, and biological materials are derived from ecosystems.
Ornamental resources. Animal and plant products, such as skins, shells and flowers
are used as ornaments and whole plants are used for landscaping and ornaments.
Freshwater. Freshwater in rivers is also a source of energy. Because water is required
for other life to exist, it could also be considered a supporting service.
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The Benefits of Healthy Ecosystems
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Regulating Services. These are the benefits obtained from the regulation of
ecosystem processes, including:
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Air quality regulation. Ecosystems both contribute chemicals to and extract chemicals
from the atmosphere, influencing many aspects of air quality;
Climate regulation. Ecosystems influence climate both locally and globally. Changes
in land cover can affect both temperature and precipitation.
Water regulation. The timing and amount of runoff, flooding, and aquifer recharge can
be strongly influenced by changes in land cover.
Erosion regulation. Vegetation plays an important role in soil retention and the
prevention of landslides.
Water purification and waste treatment. Ecosystems can help to filter out and
decompose organic wastes introduced into inland waters and coastal ecosystems.
Disease regulation. Changes in ecosystems can directly change the abundance of
human disease.
Pest regulation. Ecosystem changes affect the frequency of crop and livestock pests
and diseases.
Pollination. Ecosystem changes affect the distribution, abundance, and effectiveness
of pollinators.
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The Benefits of Healthy Ecosystems
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Cultural Services. These are the non-material benefits people obtain from
ecosystems through spiritual enrichment, reflection, recreation, and aesthetic
experiences, including:
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Cultural diversity. The diversity of ecosystems is one factor influencing the diversity of
cultures.
Spiritual and religious values. Many religions attach spiritual and religious values to
ecosystems or their components.
Knowledge systems (traditional and formal). Ecosystems influence the types of
knowledge systems developed by different cultures.
Educational values. Ecosystems and their components and processes provide the
basis for both formal and informal education in many societies.
Inspiration. Ecosystems provide a rich source of inspiration for art, national symbols,
architecture, and advertising.
Aesthetic values. Many people find beauty or aesthetic value in ecosystems, as reflected
in the support for parks, scenic drives, and the selection of housing locations.
Social relations. Ecosystems influence the types of social relations that are established
in particular cultures.
Sense of place. Many people value the "sense of place" that is associated with
recognized features of their environment.
Cultural heritage values. Many societies place high value on the maintenance of either
historically important landscapes ("cultural landscapes") or culturally significant species.
Recreation and ecotourism. People often choose where to spend their leisure time
based in part on the characteristics of the natural or cultivated landscapes in a particular
area.
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The Benefits of Healthy Ecosystems
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Supporting Services. Supporting services are those that are
necessary for the production of all other ecosystem services. They
differ from provisioning, regulating, and cultural services in that their
impacts on people are often indirect or occur over a very long time.
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Soil Formation. Because many provisioning services depend on soil fertility,
the rate of soil formation influences human well-being in many ways.
Photosynthesis. Photosynthesis produces oxygen necessary for most living
organisms.
Primary Production. The assimilation or accumulation of energy and
nutrients by organisms.
Nutrient cycling. Approximately 20 nutrients essential for life, including
nitrogen and phosphorus, cycle through ecosystems and are maintained at
different concentrations in different parts of ecosystems.
Water cycling. Water cycles through ecosystems and is essential for living
organisms.
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Ecosystem Service
Ecosystem Functions
Examples
Gas regulation
Regulation of atmospheric
chemical composition
CO2/O2 balance, O3 for UVB
protection, SOx levels.
Climate regulation
Regulation of global
temperature, precipitation and
other climatic processes
Greenhouse gas regulation.
Disturbance regulation
Storage, damping and other
responses to environmental
fluctuations
Storm protection, flood control,
drought recovery and other
habitat responses, mainly
controlled by vegetation
structure and landforms.
Water regulation
Regulation of hydrological flows.
Water for agriculture, industry,
transportation or power
generation.
Water supply
Storage and retention of water
Storage of water in watersheds,
reservoirs and aquifers.
Erosion control and sediment
retention
Retention of soil within an
ecosystem.
Prevention of soil loss by wind,
runoff or other processes,
storage of silt in lakes and
wetlands.
Soil formation
Soil formation processes.
Weathering of rock and the
accumulation of organic
material.
Nutrient cycling
Storage, internal cycling,
processing and acquisition of
nutrients.
Nitrogen Fixation, N, P and other
elemental or nutrient cycles.
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Ecosystem Service
Ecosystem Functions
Examples
Waste treatment
Recovery of nutrients and
removal or breakdown of excess
nutrients and compounds.
Waste treatment, pollution
control, detoxification.
Pollination
Fertilization of flowers.
Providing pollinators for the
reproduction of plant
populations.
Biological control
Population regulation.
Predator control; reduction of
herbivory.
Refugio
Habitat for resident and
transient populations.
Nurseries, migration habitat,
over wintering grounds.
Food production
Production useable as food.
Fish, game, crops, nuts and
fruits.
Raw materials
Production useable as raw
materials.
Lumber, fuel, fodder.
Genetic resources
Sources of unique biological
materials and products.
Medicine, products for materials
science, resistant genes/strains,
ornamental species.
Recreation
Opportunities for recreational
activities.
Eco-tourism, sport fishing,
hunting, hiking, camping.
Cultural
Non-commercial uses.
Aesthetic, artistic, educational,
spiritual, scientific.
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Threats to biodiversity
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In part because the value of biodiversity and the resulting ecosystem services
are poorly understood by a lot of people, nature's “cogs and wheels” are going
missing at an alarming rate — on the order of 100 to 1000 times the background
rate, estimated from fossil records to be from one to ten species/year (Pimm, et
al., 1995 and others). Some estimates of current rates are much higher. There
have been five mass extinctions in the past 500 million years, the most recent
about 65 million years ago (Raup and Sepkoski, 1982). We appear to be in the
sixth, with the major difference being that for this one, the cause appears to be
not a major physical catastrophe such as severe volcanism or a meteor strike,
but a single species: us.
The Millennium Ecosystem Assessment (2005) reports that there has been a
substantial and largely irreversible loss in the earth's biodiversity, with some 1030% of mammal, bird and amphibian species currently threatened with
extinction, and 15 of 24 ecosystem services being degraded. Fortunately, it
comes at a time when the earth probably contains more species than ever
before (Rhode and Muller, 2005), and there's some redundancy built into the
system. We can lose some species — some — before things start to really
unravel.
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Threats to biodiversity
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The causes of these losses
are varied and can be
encompassed in the term
HIPPOC:
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Habitat loss: Habitat loss,
alteration and fragmentation
directly affect the species
that rely on the habitat that
is being changed.
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Threats to Biodiversity – Habitat Destruction
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Habitat destruction – single greatest threat to
biodiversity
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Deforestation of tropical forests
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Deforestation Closer to Home
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Threats to Biodiversity – Habitat Destruction
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Fragmentation of a forest ecosystem
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Threats to Biodiversity
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The history of habitat reduction and fragmentation in a Wisconsin
forest
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Threats to Biodiversity – Habitat Destruction
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Tropical forests house between 50 and 90 percent of species live
on earth. About 17 million hectares of tropical forests – an area
four times the size of Switzerland – are now being cleared
annually, and scientists estimate that at these rates roughly 5 to
10 percent of tropical forest species may face extinction within
the next 30 years.
Rates of tropic forest loss are accelerating, and some particularly
species-rich forests are likely to be largely destroyed in our
lifetime. Some scientists believe that about 60,000 of the world's
240,000 plant species, and perhaps even higher proportions of
vertebrata and insect species, could lose their lease on life over
the next three decades unless deforestation is slowed
immediately.
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Threats to Biodiversity – Habitat Destruction
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Tropical forests are by no means the only sites with endangered
biodiversity. Worldwide, nearly as much temperate rainforest – once
covering an area nearly the size of Malaysia – has also been lost.
Although the total extent of forest in the northern temperate and boreal
regions has not changed much in recent years, in many areas the
species-rich, old-growth forests have been steadily replaced by secondgrowth forests and plantations. Evidence of accelerating clearance of
temperate forests is also appearing: between 1977 and 1987, 1.6
million hectares of forest was lost in the United States alone.
In several spots in Europe, fungal species diversity has dropped by 50
percent or more over the past 60 years. In such "Mediterranean"
climates as California, South Africa, central Chile, and Southwest
Australia, at least 10 percent of all plant and animal species are
imperiled. The largest number of recent extinctions has been on
oceanic islands: some 60 percent of plant species endemic to the
Galapagos Islands are endangered, as are 42 percent of the Azores'
endemic species and 75 percent of the endemic plant species of the
Canary Islands.
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Threats to biodiversity
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The causes of these losses are varied
and can be encompassed in the term
HIPPO(C):
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Invasive (Introduced) species:
Invasive species are harmful nonnative species whose introduction or
spread threatens the environment, the
economy and society, including human
health. Invasive species originate from
other continents, adjacent countries or
from other ecosystems within Canada.
Free from predation and competition
that would normally limit their
distribution and abundance in their
natural habitats, many invasive species
reproduce rapidly and damage,
displace or destroy native species in
our forests (e.g., emerald ash
borer), agricultural areas (e.g., plum
pox virus), wetlands (e.g., purple
loosestrife) and lakes and rivers (e.g.,
zebra mussel). The zebra mussel
disrupts ecosystem composition and
structure, clogs water intake pipes, and
affects public beaches.
2008 Fall Lecture 5
emerald ash borer
plum pox virus
SCIE 103 Life Sciences
zebra mussel
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Threats to Biodiversity – Introduced Species
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Introduced Species
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Ranking second to habitat loss as a cause of biodiversity crisis
Species that humans move from the species’ native locations to
new geographic regions.
Of all 1,880 imperiled species in the United States, 49% are
endangered because of introduced species alone or because of
their impact combined with other forces.
Introduced species are a greater threat to native biodiversity than
pollution, harvest, and disease combined.
Through damage to agriculture, forestry, fisheries, and other
human enterprises, introduced species inflict an enormous
economic cost, estimated at $137 billion per year to the U.S.
economy alone.
Some introduced species (such as most of our food crops and
pets) are beneficial. However, others are very damaging.
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Threats to Biodiversity – Introduced Species
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The Asian chestnut blight fungus
virtually eliminated American chestnut
from over 180 million acres of eastern
United States forests in the first half of
the 20th century. It was a disaster for
many animals that were highly
adapted to live in forests dominated by
this tree species. For example, ten
moth species that could live only on
chestnut trees became extinct.
The Australian paperbark tree has
replaced native plants, such as
sawgrass, over 400,000 acres of south
Florida, because it has a combination
of traits (for example, spongy outer
bark and flammable leaves and litter)
that increase fire frequency and
intensity. Many birds and mammals
adapted to the native plant community
declined in abundance as paperbark
spread.
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Threats to Biodiversity – Introduced Species
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Pump house and water control
structure for green-tree
impoundment at Montezuma
National Wildlife Refuge in central
New York. Waterfowl broods
produced in adjacent flooded forest
found excellent foraging conditions
among floating and emergent
aquatic plants in the foreground, 18
June 1968.
Ten years later, purple loosestrife
had displaced native food and cover
plants in the waterway surrounding
the green-tree impoundment at the
Montezuma Refuge. Biologist
holding stadia rod in middle
foreground is obscured by mature
plants. Note the abundance of
Lythrum salicaria seedlings along
the water line, 16 August 1978.
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Threats to Biodiversity – Introduced Species
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Zebra mussels (Dreissena polymorpha) are
small, fingernail-sized mussels native to the
Caspian Sea region of Asia. They are
believed to have been transported to the
Great Lakes via ballast water from a
transoceanic vessel. The ballast water,
taken on in a freshwater European port was
subsequently discharged into Lake St. Clair,
near Detroit, where the mussel was
discovered in 1988. Since that time, they
have spread rapidly to all of the Great Lakes
and waterways in many states, as well as
Ontario and Quebec.
Diving ducks and freshwater drum eat zebra
mussels, but will not significantly control
them.
Likely means of spread: Microscopic larvae
may be carried in livewells or bilgewater.
Adults can attach to boats or boating
equipment that is in the water.
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Threats to Biodiversity – Introduced Species
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Nile perch (Lates niloticus),
a voracious predator
introduced to Lake Victoria
as a food fish, has already
extinguished over one
hundred species of native
cichlid fish there.
The introduction of Nile
perch into Australia was
considered after a reduction
in Queensland barramundi
stocks, but this was decided
against due to the
devestation they caused in
several African lakes.
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Threats to Biodiversity – Introduced Species
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A parasite can be
similarly devastating.
The sea lamprey
reached the Great
Lakes through a series
of canals and, in
combination with
overfishing, led to the
extinction of three
endemic fishes.
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Threats to Biodiversity – Introduced Species
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Scientific name: Boiga irregularis
Common name: Brown tree snake
Native To: Australia
Date of U.S. Introduction: First
detected in Guam in the 1950s,
introduced in cargo from the Admiralty
Islands.
Means of Introduction: Arrived in
Guam accidentally in imported cargo
Impact: Preys on native lizards and
birds, has eliminated ten of the eleven
native bird species from the forests of
Guam; causes frequent power outages
by climbing on electrical wires
Current U.S. Distribution: Guam
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Threats to Biodiversity – Introduced Species
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The first Argentine ants set foot on U.S. soils in
the late 1890's, as coffee ships from Brazil
unloaded their cargo in New Orleans. Being
prolific breeders and constantly on the go, they
moved across the southern half of the United
States. A single colony may contain 10,000
female workers, and there may be hundreds of
colonies around your home; the total number of
ants could easily reach a million. Although they
cannot sting, they can bite; however, they are
only about 3 mm long and there tiny mandibles
are too small to hurt humans. But, in the world
of insects, these ants are truly a living terror.
They are very aggressive and readily overtake
other ant species, even ants that are much
larger and with powerful stings. Argentine ants
are relentless and simply outnumber their
adversaries until the enemy colony is destroyed.
They even attack paper wasp nests under the
eaves of a house, forcing the huge wasps to
flee their nests in terror. Even nests of large
carpenter bees are no match for these
relentless ants. A "killer bee" nest probably
could not withstand an invasion of Argentine
ants. They also will attack bird nests, driving off
the mother bird and killing the helpless young.
One possible redeeming quality about these
little warriors is that they may attack dry-wood
(aerial) termite colonies in your home.
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Threats to Biodiversity – Introduced Species
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Beauty can be a trap, and
despite the appeal of the
Caulerpa taxifolia with its
lovely green flowers, this
invasive species represents
a great danger for neritic
Mediterranean habitats.
These algae preferentially
invade posidonia prairies,
impoverishing the already
threatened marine flora and
fauna.
Caulerpa taxifolia
Posidonia
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Threats to Biodiversity – Introduced Species
Some impacts of invaders are subtle but nonetheless
destructive to native species:
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North American gray squirrels are driving native red squirrels to
extinction in Great Britain and Italy by foraging for nuts more
efficiently than the native species. Such competition for
resources is not easy to observe, but the end result is the loss of
a native species.
Hybridization, or cross-breeding, of introduced species with
natives is an even subtler impact (no lineage goes extinct), but it
is insidious because it leads gradually to the extinction of many
native species, as their gene pools inevitably evolve to become
those of the invader. Introduced mallards, for instance, are
driving the native Hawaiian duck to a sort of genetic extinction by
breeding with them.
Of 26 animal species that have gone extinct since being listed
under the Endangered Species Act, at least three were wholly or
partly lost because of hybridization with invaders. One was a fish
native to Texas, eliminated by hybridization with introduced
mosquito fish.
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Threats to Biodiversity – Introduced Species
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Rainbow trout introduced widely in
the United States as game fish are
hybridizing with five species listed
under the Endangered Species Act,
such as the Gila trout and Apache
trout.
The endangered, endemic Hawaiian
duck is being lost to hybridization
with North American mallards
introduced for hunting.
The rarest European duck (the
white-headed duck) is threatened by
hybridization with the North
American ruddy duck, which was
originally kept as an amenity in a
British game park. The ruddy duck
escaped, crossed the English
Channel
2008 Fall Lecture 5
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white-headed duck
ruddy duck
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Threats to Biodiversity – Introduced Species
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Often invaders interact with one another to generate a problem
where either species alone would be harmless. For example,
ornamental fig trees in the Miami area for over a century stayed
where planted, in people's yards, because they were sterile.
Each fig species requires a particular wasp to pollinate it, and the
wasps were absent. About fifteen years ago, the pollinating
wasps for three fig species arrived independently in the region,
and now these fig species are reproducing. At least one has
become invasive, with seedlings and saplings being found many
miles from any planted figs. More cases of this phenomenon,
termed "invasion meltdown," are likely to arise as more species
are introduced and have the opportunity to interact with each
other.
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Threats to biodiversity
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The causes of these losses are varied and can be encompassed in the term
HIPPO(C):
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Pollution: Pollution is emitted in many different forms, including atmospheric pollution, soil and
water pollution, pesticides, particulate matter, and heavy metals. There are thousands of
pollutants circulating through the Earth's ecosystems, and many of these materials have
significant, large-scale impacts on forests and aquatic ecosystems. Acid precipitation, for
example, has had a significant impact on Ontario's maple forests and industrial pollutants such
as DDT is known to have caused significant declines in populations of many bird species
including Peregrine Falcon and Bald Eagles. Pollution can also disrupt ecological processes.
For example, scientists are now linking light pollution to declines in migratory songbirds.
Population growth: Human population growth adds to the impact of all the other causes
because more people require more space and more resources. There are now about 6 billion
people on Earth, more than twice as many as in 1950. While the rate of increase is slowing, it
still adds more than 90 million people each year. Habitats, even healthy ones, can support just
so many of anything, including people.
Over-consumption or unsustainable use: Over-consumption is the harvest of species at a
rate higher than can be sustained by the natural reproduction of the population. In Ontario, for
example, wild American ginseng has been over-harvested from its natural rich woodland habitat
to the point of being Endangered.
Climate Change and other Cumulative impacts: People have added carbon dioxide, nitrous
oxide, methane and other greenhouse gases to the atmosphere by extracting and burning fossil
fuels such as coal, oil and natural gas. The effect of these gases has been to trap heat and
accelerate the rate of global warming and climate change. Climate change is a major threat to
the world's biodiversity. The cumulative impacts of pollution, habitat modification, the global
redistribution of species and over-harvesting place many ecosystems at risk. These cumulative
impacts cause alteration, reduction and loss of ecosystem function, populations and species,
degradation, loss and fragmentation of habitat. They also damage human health.
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Threats to Biodiversity - Overconsumption
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Refers generally to the human harvesting of
wild plants and animals at rates exceeding
the ability of the populations of those species
to regenerate.
Logging, hunting and fishing
Especially susceptible are large species with
low intrinsic reproductive rates.
Eg. Elephants, whales, rhinoceroses, and
species on small islands.
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Threats to Biodiversity - Overconsumption
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A new global study concludes that
90 percent of all large fishes have
disappeared from the world's
oceans in the past half century,
the devastating result of industrial
fishing.
The study, which took 10 years to
complete and was published in the
international journal Nature, paints
a grim picture of the Earth's
current populations of such
species as sharks, swordfish, tuna
and marlin.
The authors used data going back
47 years from nine oceanic and
four continental shelf systems,
ranging from the tropics to the
Antarctic. Whether off the coast of
Newfoundland, Canada, or in the
Gulf of Thailand, the findings were
dire, according to the authors.
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Threats to Biodiversity - Overconsumption
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Threats to Biodiversity - Overconsumption
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Reducing the threats to biodiversity
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The global response to HIPPOC has been the promotion of sustainable
development, defined by the OBS as “development that meets the needs of the
present without compromising the ability of future generations to meet their own
needs.”
But what does that mean, in a practical sense? One way is to link biodiversity to
sustainable development through the concept of “sustainable use: the use of
components of biodiversity in a way and at a rate that does not lead to their
long-term decline, thereby maintaining the potential for future generations to
meet their needs and aspirations” (OBS, 2005). We don't want to lose species
because it will eventually degrade our natural capital, and any reduction in
ecological services is a sure sign that biodiversity is eroding.
The loss of a single species is not “the end of the world as we know it,” but
cumulatively it may be. Losing species destabilizes ecosystems and weakens
their ability to deal with natural disasters such as floods, droughts and fire and
with human-caused stresses such as pollution and climate change. The
precautionary principle states, when in doubt do no harm. In this case, stopping
all species loss where possible is probably the best rule of thumb.
Blue-Ringed Dancer (Argia sedula)
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What can you do to help?
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Learn more. Knowledge is power. The more we know about the causes, consequences
and how to prevention of biodiversity loss, the more power we will have to act. Also, our
actions will be more efficient and focused.
Tell others. As we learn more about biodiversity, we need to let others know as well that
biodiversity conservation is worth pursuing. We can discuss it among groups we belong to.
We can write letters or emails to editors and others of influence.
Help monitor biodiversity. Citizen science, the monitoring of species and ecosystems by
individuals and groups, is growing across the world. It's a good way to involve people who
already have an interest and perhaps knowledge of nature. Learn more and make a
difference!
Get organized. Work is ongoing on many of the Action Items. If you belong to
organizations that should be involved, contact that group, encourage involvement and offer
to help.
Reduce our Ecological Footprints. We all do things every day which directly or indirectly
affect biodiversity by putting pressure on our natural systems. Reduce such pressure by:
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Being aware of Species at Risk and taking action to protect their populations or habitat.
Being knowledgeable of Invasive Species, and acting to limit their spread.
Creating habitat for wild things on your property - planting butterfly or wildflower gardens with
native plants and trees, maintaining brush piles, or participating in a local habitat restoration
project.
Avoiding pesticides, herbicides and chemical fertilizers.
Buying locally grown food whenever possible.
Reducing energy use in homes, businesses and institutions and vehicles.
Influence politicians. Let politicians at all levels know that biodiversity conservation is a
critical issue that the government needs to do more about.
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What is a "Species at Risk?"
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A species at risk is any native plant or animal that is at risk of
extinction or of disappearing from its natural environment.
“Endangered species” – one that is in danger of extinction
throughout all or a significant portion of its range.
“Threatened species” – those that are likely to become endangered
in the foreseeable future throughout all or a significant portion of
their range.
http://www.iucnredlist.org/info/tables/table5
Region
Mammals
Birds
Reptiles
Amphibians
Fishes
Mollusks
Other Inverts
Plants
Total
Turkey
18
15
13
9
54
0
12
3
124
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Threats to Biodiversity
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The Great Auk is an extinct flightless bird that has become a symbol of
destruction of the Earth and its life forms. The last authenticated sighting of
this species was from Fire Island off the coast of Cape Reykjanes, Iceland,
on June 3, 1844. At that time a pair of adult Great Auks were caught and
killed by collectors. The adults had laid an egg and were incubating. That
was probably the last egg ever laid of this species. Great Auk specimens
soon came to rest in major collections and museums in Europe and North
America. This was largely due to bequests of private collections, integration
of collections into one facility and purchases of collections from estates.
One of Canada's few specimens, at the Royal Ontario Museum, arrived
there from such a purchase.
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Threats to Biodiversity

Greater mouse-eared
bat (Myotis myotis)


The greater mouse-eared bat
is one of the larger European
bats and has become extinct in
England. Its fur is a mediumbrown colour on the upper
body, and greyish-white
underneath. It has large ears
with a very prominent tragus,
the organ which is part of the
bat’s echolocation system.
Status: Classified as Extinct
in the UK. Listed under
Appendix II of the Bonn
Convention, Annex II of the
Berne Convention, Annex II &
IV of the EC Habitats Directive
and Schedule 5 of the Wildlife
and Countryside Act (as
amended).
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A hundred beats from extinction: Most
Endangered Species of 2007

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The western lowland gorilla (Gorilla
gorilla gorilla) is one of many new
additions to the World Conservation
Union (IUCN)'s 2007 Red List of
Threatened Species, which was made
public today. Since 2006, the annual
assessment of the planet's imperiled
wildlife has grown by more than a
thousand species and now totals 41,415.
Many great apes end up on the list, as
their habitat is continually under threat
from human activities.
Western lowland gorilla populations in
central Africa have collapsed due to the
commercial bush meat trade and the
Ebola virus. And in Indonesia,
orangutans are critically endangered
because of forest logging and clearing
land for palm oil plantations. (National
Geographic Sept. 12, 2007)
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A hundred beats from extinction: Most
Endangered Species of 2007
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
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The baiji (Lipotes vexillifer), or Chinese
river dolphin— deemed "functionally
extinct" by a team of scientists in
December—was downgraded from
"endangered" to "critically endangered
(possibly extinct)" on the IUCN's 2007
Red List.
Populations of the light blue-gray animal,
which lives in China's polluted Yangtze
River, have plummeted over the last 30
years.
A possible sighting in August 2007 is
currently being investigated by Chinese
scientists, but even if one or two dolphins
are found, the baiji is almost certainly
doomed.
“Freshwater dolphins are very
vulnerable, because rivers tend to be
heavily used by humans and there is
nowhere else for the dolphins to go,”
Caroline Pollock, a Red List program
officer, told National Geographic News.
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A hundred beats from extinction: Most
Endangered Species of 2007



The Egyptian vulture, a new
addition to IUCN's 2007 Red List,
has declined along with many
other vulture species. Five species
of vulture, including the Egyptian,
have been reclassified to a higher
threat level since 2006. Asian
vultures have declined rapidly
over the last eight years due to the
use of a livestock drug called
diclofenac.
African vultures are struggling due
to habitat loss, a lack of food, and
collisions with power lines.
The scavengers are also being
killed by insecticide-laden
carcasses, which have been
deliberately baited to poison
livestock predators such as
hyenas.
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A hundred beats from extinction: Most
Endangered Species of 2007
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Mexico’s Santa Catalina Island
rattlesnake has been classified as
critically endangered on the 2007
IUCN Red List. The snake, found on
just one island, sports highly desirable
patterned skin that has made it a
collector's item for hunters.
New reptile surveys are revealing the
fragile nature of many reptile
populations.
For instance, a major survey of North
American reptiles has bumped up the
region's Red List reptile species to a
total of 738.
The main culprit behind their decline is
habitat loss due to expanding cities,
Caroline Pollock, a Red List program
officer, told National Geographic
News.
“Unlike birds and mammals, we
haven't assessed all the reptiles on the
planet,” Pollock added.
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A hundred beats from extinction: Most
Endangered Species of 2007

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The Banggai cardinal fish's popularity as
a pet for the home aquarium has landed
it on the 2007 IUCN Red List. In the
wild, the striped fish is only found in the
Banggai Archipelago off Indonesia.
Human pressures such as the aquarium
trade are the main reason for the fish's
decline, with habitat loss and climate
change also posing major threats.
Fish stocks are in free-fall all over the
world, both from overfishing and the
aquarium trade. Scientists estimate
current extinction rates are at least a
hundred to a thousand times higher
than natural rates.
“We need to protect the world's
biodiversity in order to ensure a
sustainable future for all of us,” Caroline
Pollock, a Red List program officer, told
National Geographic News.
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A hundred beats from extinction: Most
Endangered Species of 2007



Reptiles such as the gharial
are becoming more prominent
on the IUCN's Red List each
year. Despite its fearsome
appearance and lengths of up
to 19 feet (6 meters), the
Indian gharial is not a maneater and prefers to eat fish.
Its long, thin snout, which
makes it easily distinguishable
from a crocodile, also allows it
to quickly capture fish.
Habitat loss and poaching is
driving the animal toward
extinction.
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A hundred beats from extinction: Most
Endangered Species of 2007
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For the first time, corals were added to
the 2007 Red List. A recent scientific
survey on the Galápagos Archipelago
has added ten corals to the list, including
the Floreana coral.
In the 1980s, frequent El Niño weather
patterns—which made ocean
temperatures fluctuate—likely led to the
poor state of the Galápagos corals.
Some scientists worry that global
warming may make El Niño events more
regular and prevent corals from
recovering.
Until recently, scientists had not properly
assessed the health of the world's
tropical corals. Scientists estimate that
human activities—such as pollution,
global warming, and sedimentation—
could kill 30 percent of reefs in the next
three decades.
Coral reefs in the Indian and Pacific
Ocean, for example, are vanishing faster
than rain forests.
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A hundred beats from extinction: Most
Endangered Species of 2006


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
Polar bears and hippos for the first
time join more than 16,000 species
threatened with extinction, according
to the World Conservation Union.
The Switzerland-based nonprofit,
known as IUCN, released its 2006 Red
List of Threatened Species on May 2.
The list shows a significant increase in
the number of species on the brink
since the last list was released in
2004.
The Red List now marks polar bears
as vulnerable, largely because of
habitat loss linked to global warming.
Due to decreasing sea ice in the
Arctic, "polar bears are predicted to
suffer more than a 30% population
decline in the next 45 years," the
group wrote in a press release.
The following images highlight other
Red List species, from pink pigeons to
blue poison frogs.
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A hundred beats from extinction: Most
Endangered Species of 2006

Manta rays, familiar
denizens of tropical and
subtropical ocean-shelf
waters, are classified
as near threatened on
the 2006 IUCN Red
List. Of the 547 shark
and ray species
assessed, the group
says, 20 percent are in
danger of extinction.
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A hundred beats from extinction: Most
Endangered Species of 2006

Native to the Indian Ocean
island of Mauritius, the pink
pigeon has been suffering
from decades of habitat loss
and introduction of invasive
predators. The population
dropped to a mere 12
known birds by 1986,
according to the nonprofit
Mauritian Wildlife
Foundation. The bird is now
listed as endangered on the
IUCN Red List.
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A hundred beats from extinction: Most
Endangered Species of 2006

In addition to land and
marine animals, the
IUCN Red List includes
a number of plants and
fungi, such as the
Italian funcia di
basiliscu. This fungus,
which grows on the
island of Sicily, is listed
as critically
endangered.
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A hundred beats from extinction: Most
Endangered Species of 2006

Amphibian populations in
Central and South America
have been declining rapidly,
a trend that many experts
link to environmental
factors. The blue poison
frog of Suriname, which
grows up to one and three
quarters of an inch (four
and a half centimeters)
long, is given "vulnerable"
status on the 2006 IUCN
Red List.
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A hundred beats from extinction


Factors leading to
mammals' extinction
continue with "ever
increasing intensity"
Siberian tigers may
vanish within three
decades.
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A hundred beats from extinction



Lion populations have fallen by
almost 90% in the past 20
years, leaving the animal close
to extinction in Africa. There
are now only 23,000 left,
compared to an estimated
200,000 two decades ago.
The problem will get worse as
Kenya's human population
doubled in the next 12 years.
The wild dog population has
fallen to between 3,500 and
5,000 and there are now fewer
than 15,000 cheetahs.
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A hundred beats from extinction

Orangutans once ranged
throughout Southeast Asia.
Today they can be found
only on the Indonesian
islands of Borneo and
Sumatra. Scientists
estimate that in the last 10
years their numbers have
been reduced by up to 50
percent, to perhaps as few
as 13,000 living in the wild.
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A hundred beats from extinction

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Mutisia magnifica: An Ecuadorian
species threatened by charcoal
production
The species most at risk live only in
small geographic ranges in specific
habitats.
The official estimate by the World
Conservation Union - the IUCN suggests that 13% of the world's
plant species are under threat, but
the two US botanists say it is at
least 22% and could be as many as
47%.
They say the IUCN has reliable
data for plants in Europe, North
America, South Africa and
Australia, but there are no reliable
figures for tropical, developing
countries, where most of the world's
plants grow.
2008 Fall Lecture 5
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Passiflora loxensis
Mutisia magnifica
54
Threats to Biodiversity


The dramatic losses of species and ecosystems obscure equally large
and important threats to genetic diversity. Worldwide, some 492
genetically distinct populations of tree species (including some full
species) are endangered. In the northwestern United States, 159
genetically distinct populations of ocean-migrating fish are at high or
moderate risk of extinction, if they have not already slipped into
oblivion.
Loss of genetic diversity could imperil agriculture. How much the
genetic base has already eroded is hard to say, but since the 1950s,
the spread of modern "Green Revolution" varieties of corn, wheat, rice,
and other crops has rapidly squeezed out native landraces. Modern
varieties were adopted on 40 percent of Asia's rice farms within 15
years of their release, and in the Philippines, Indonesia, and some other
countries, more than 80 percent of all farmers now plant the new
varieties. In Indonesia, 1500 local rice varieties have become extinct in
the last 15 years. A recent survey of sites in Kenya with wild coffee
relatives found that the coffee plants in two of the sites had
disappeared, three sites were highly threatened, and six were possibly
threatened. Only two were secure.
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Threats to Biodiversity


The impact of losses of genetic
diversity often registers swiftly. In
1991, the genetic similarity of Brazil's
orange trees opened the way for the
worst outbreak of citrus canker
recorded in the country. In 1970, U.S.
farmers lost $1 billion to a disease
that swept through uniformly
susceptible corn varieties.
Similarly, the Irish potato famine in
1846, the loss of a large portion of
the Soviet wheat crop in 1972, and
the citrus canker outbreak in Florida
in 1984 all stemmed from reductions
in genetic diversity. In such countries
as Bangladesh, where some 62
percent of rice varieties come from a
single maternal plant, Indonesia (74
percent), and Sri Lanka (75 percent),
such outbreaks could occur at
anytime.
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Threats to Biodiversity
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The loss of genetic, species, and ecosystem diversity both stems
from and invites the loss of cultural diversity. Diverse cultures
have bred and sustained numerous varieties of crops, livestock,
and habitats. By the same token, the loss of certain crops, the
replacement of traditional crops with export crops, the extinction
of species embedded in religion, mythology, or folklore, and the
degradation or conversion of homelands are cultural as well as
biological losses. Since 1900, experts say, about one Indian tribe
has disappeared from Brazil each year. Almost one half of the
world's 6000 languages may die out in the next 100 years. Of the
3000 languages expected to survive for a century, nearly half will
probably not last much longer.
Ubık ( Ubykh): Northwestern Caucasian Language. Last spoken
person Tevfik Esenç died on October 1992.
http://encyclopedia.thefreedictionary.com/Dead+language
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Tevfik Esenç

Tevfik Esenç (1904 – October 7, 1992) was a Circassian exile in
Turkey and the last known speaker of the Ubykh language.
Esenç was raised by his Ubykh-speaking grandparents for a time in the
village of Hacı Osman köyü in Turkey, and he served a term as the
muhtar (mayor) of that village, before receiving a post in the civil
service of Istanbul. There, he was able to do a great deal of work with
the French linguist Georges Dumézil to help record his language.
Blessed with an excellent memory, and understanding quickly the goals
of Dumézil and the other linguists who came to visit him, he was the
primary source of not only the Ubykh language, but also of the
mythology, culture and customs of the Ubykh people. He spoke not only
Ubykh but Turkish and the Hakuchi dialect of Adyghe, allowing some
comparative work to be done between the two languages. He was a
purist, and his idiolect of Ubykh is considered by some as the closest
thing to a standard "literary" Ubykh language that existed.
Esenç died in 1992 at the age of 88. The inscription that he wanted on
his gravestone read as follows:
This is the grave of Tevfik Esenç. He was the last person able to speak
the language they called Ubykh.
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Gaining Biodiversity

Mutation
Mutations increase genetic diversity by altering the
genetic material (almost always DNA) of organisms.
Once mutations arise, they are passed on to the
mutated organism's offspring, and in time may either
disappear if the line dies out. Depending upon the
specific mutation, the result can range from no effect
whatsoever to the creation of an entirely new
species. Although this gives rise to differences in
organisms, it is an extremely slow process
compared to the other ways in which local diversity
increases. Ultimately, though, this is the only way in
which diversity is truly created.
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Gaining Biodiversity

Speciation
The creation of a new species is known as speciation. Species
are typically defined as a group of related organisms that share a
more or less distinctive form and are capable of interbreeding
and producing fertile offsprings. The origin of new species
naturally has the largest immediate effect on species-level
diversity; the immediate changes to genetic and ecosystem
diversity are usually minimal, though the effects will grow in time.
Speciation can occur through several different means, including
geographical isolation, competition, and polyploidy.

Geographical Isolation: Geographical isolation, such as new
mountain chains or a lake whose level lowers enough that it splits
into two separate lakes, can divide a population into two separate
populations. The two isolated populations continue to evolve
separately from one another. Eventually they can diverge to a great
enough degree, either through adaptation to their differing
environments or through random mutations, that they are no longer
able to interbreed and are considered to be different species.
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Gaining Biodiversity

Speciation
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
Competition: If a new resource, such as a new food source, becomes
available to a population, some part of the population may become
specialized in obtaining that resource. Being specialized in obtaining either
the new resource or the original resource may be better than trying to obtain
both. If so, then the specialists would be better off mating with the other
specialists on the same resource, as mating with someone who uses the
other resources will result in offspring that aren't specialized for either
resource and at a disadvantage. In time, there is a chance that the
population will split into two species, each specialized on one of the two
resources. This can happen, but it is probably a fairly rare event.
Polyploidy: Speciation through polyploidy happens far more often in plants
than in animals, as animals are much more sensitive to large changes in
their genetic structure. Most species are diploid, meaning they have two
copies of each chromosome (large packages of DNA), one from each of their
parents. An individual in a normally diploid species may have more copies of
these chromosomes, being polyploid ("poly" meaning many), through errors
at the cellular level. The additional copies of the chromosomes render them
unable to produce functional offspring with normal members of their species.
Plants often fertilize themselves to at least some extent, so polyploid species
can arise from a single individual. This method of speciation is almost
instantaneous, happening in a single generation, and is more common in
plants than animals.
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Galapagos Finches
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Galapagos Finches
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Gaining Biodiversity

Immigration
 Immigration increases diversity as new individuals and perhaps
even new species enter an area, increasing its diversity. The rate
at which immigration happens depends on the size of the area in
question, how many species are there already, and how close the
area in question is to the source of immigration. Even if a species
is unable to survive in an area, a constant flow of immigrants to
the area can keep the species present indefinitely. Island
biogeography is the classic theory on the topic of how these
factors affect immigration and more, and is explained above.
 Most species that immigrate to a new ecosystem have only minor
effects on their new system, though some drastically change it.
Zebra mussels, native to the Caspian Sea and Ural river, were
first recognized in the Great Lakes in 1988. It is most likely that
they were brought over in ballast water. Since then they have
spread throughout the Great Lakes and beyond, killing native
mussel populations and fouling all manner of pipes and intakes.
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Gaining Biodiversity

Succession
Succession is the process through which an area gains species as successive
communities of organisms replace one another until an endpoint is reached. This
endpoint, or climax community, is commonly a forest. Succession may begin on
bare rock, an abandoned field, the burned remnants of a forest, or any stage before
the endpoint. A hypothetical bare field isn't bare for long before annual plants appear.
They are replaced within a few years by perennial plants and shrubs, who in turn are
replaced by pine trees. Eventually, hardwood trees invade and replace the pines,
forming the hardwood climax community.
Different regions have varying climax communities. One usually refers to the different
stages of succession in terms of the plants rather than the animals because the
plants precede the animals and provide the structure and environment that the
animals live in. One exception to this is aquatic communities, where sponges, corals,
bivalves and other animals are responsible for much of the three-dimensional
structure of the community.
The climax community is typically the most diverse stage of succession, and each
stage of succession is more diverse than the one preceding it. This pattern depends
on the group being looked at; plant diversity actually decreases at the final stage,
while animal diversity increases to the end. Species that were common in the early
stages of succession will not be common in the later stages, but may still be found if
small disturbances in the area effectively set the disturbed area back to an earlier
successional stage.
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Does Diversity lead to Stability?
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
Although it is a key question, the relationship between diversity and stability is still being resolved. As
with many topics in biodiversity, there are different ways of expressing stability. One way is to define it
as the ability of a system to return to its original state after being disturbed, so how quickly it can return
and how large a disturbance it can return from are key variables. Another definition is how resistant to
change the system is in the first place. No matter what the definition used, however, there are definite
trends that appear.
Current consensus is that greater diversity does lead to greater stability, for three general reasons:





Insurance Effect: Different species do better under different conditions. As the number of species increases, the
range of conditions that at least some species do well in also increases. When perturbations do occur, it's more
likely that some of the species present will be able to do well, and these species will protect the community as a
whole.
Averaging Effect: Stability is measured as variability relative to community abundance. As diversity increases, the
value of the variability will naturally decrease. One problem with this is that the impact of additional species can be
confused with the effect of larger numbers of individuals (see Doak et al. 1998 and Tilman et al. 1998 for examples
of this debate).
Negative Covariance Effect: Since species are competing for resources such as space and food, any gains that
one species makes will be to some extent at the expense of the other. This means that as a species does more
poorly its competitors will do better. The result is that disturbances aren't as detrimental to the entire system as they
could be, as the losses in one species are offset by the gains of another.
The structure of a food web also affects the stability of the system. Food webs describe the flow of
energy through the system, basically who eats whom and how often. Different levels exist, such as
producers (usually plants), primary consumers (herbivores i.e. who eat plants), secondary consumers
(who eat herbivores), and so on. The food web used to be called the food chain, but the amount of
cross-links makes the whole thing more properly resemble a web than a simple linear chain.
Most of the links in the food web are weak, meaning that the consumer doesn't depend excessively on
what it consumes. As long as the links are weak, no species will be greatly affected by a predator or
prey whose population changes. Strong links means that species are greatly affected by changes in the
populations of species they're linked to; if there are many strong links in the system, drastic changes in
one species spread through the system along the strong links, destabilizing it.
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