Transcript Document

Species Diversity and Preservation II
Terminology
Alien species - refers to a species that is transported or
established outside of its native range. This transport
may or may not be intentional.
Introduced species - is an alien species that was
transported intentionally.
Invasive species - is an alien species that disrupts the
normal functioning and/or structure of an ecosystem.
A naturalized species is one that has become established
and is self-sustaining in a new area.
Invasive Species - USA
The current environmental, economic, and health costs of
invasive species could exceed $138 billion per year,
more than all other natural disasters combined.
West Nile virus and Purple loosestrife (northeast)
Kudzu, water hyacinth, nutria, and fire ants (southeast)
Zebra mussels and leafy spurge, (Midwest)
Salt cedar, Russian olive, and Africanized bees (southwest)
Yellow star thistle, Asian clams, and sudden oak death
(California)
Cheatgrass, knapweeds and thistles (Great Basin)
Whirling disease of salmonids (northwest)
Hundreds of species (microbes to mammals) (Hawaii)
Brown tree snake (Guam)
Factors that Contribute to
Community Vulnerability to Invasion
Vacant niches
Escape from biotic constraints
Community species richness
Disturbance before or upon immigration
Exotic Species Introductions (Biotic
Pollution)
Other than habitat loss (and possibly exploitative
hunting/fishing practices), the introduction of exotic
species has caused the greatest threat to biodiversity.
Introduced competitors and predators have a greater
negative effect on local organisms than do native
competitors or predators because exotic species have not
coevolved with those native species. Therefore, the native
species have no adaptations to the introduced species.
Islands (e.g., Hawaii, Australia) are particularly susceptible
to introductions because predators are often rare on islands.
Introduced Species in Hawaii
With the arrival of Captain James Cook in 1778, the
environment of Hawaii began to change dramatically. These
first European settlers brought a number of new species
including; pigs, goats, sheep, and many ornamental and
horticultural plants.
It is now estimated that an
average of 20-50 new species
arrive annually in Hawaii.
The subsequent loss of native
species has decreased the
diversity and produced
economic problems.
Introduced
Species in the
Continental USA
Kudzu: Introduced in the
southeastern U.S. in the
1930s as a control for
erosion. Has overgrown
everything in its path,
causing millions of dollars
in damage annually.
Introduced
Species in the
Continental USA
Purple loosestrife:
Cultivated for its beautiful
purple flowers, this wetland
plant escaped into New
England marshes a century
ago.
It now fills the wetlands
across much of the northern
U.S. and southern Canada,
reducing wetland
biodiversity.
Introduced
Species in the
Continental USA
Japanese honeysuckle:
This aggressive vine
seriously alters or destroys
the understory and
herbaceous layers of
communities it invades,
including prairies, glades,
floodplains, and upland
forests.
Cane toads: Bufo
marinus is the
most introduced
amphibian in the
world. It
outcompetes native
amphibians and
also causes
predator declines
because they have
no natural
immunity to the
bufotoxin it
secretes.
Introduced
Species in the
Continental USA
Great Lakes
Introduction
of Species
Zebra Mussels
Introduced from the ballast water of cargo ships from the
Caspian Sea. They glue themselves to any solid surface.
These mussels clog
intake pipes, cover the
bottom of lakes, and
invaded the Hudson
and Mississippi
Rivers. They cost
$400 million/year in
removal costs, and
exclude other, native
mussels.
Zebra Mussels
The estimated cost to industry,
shipping and sport fishing was
$5 billion in the Great Lake
region alone by the year 2000.
Each female can produce one million
eggs a year. Being colonial, as many as
500 000 mussels may be attached as a
solid mass on each square meter of
substance, encrusting and clogging
various utilities like the intake ducts
and pipes of power stations and
industries, drains, etc.
Lampreys
Lampreys
The impact of lamprey on commercial fishing in the
Great Lakes.
Protecting Species
Habitat Protection:
Placement of habitats into Preserves, Reserves, and
National Monuments, can protect both endangered
species, as well as provide ecosystem stability.
Risks:
Multiple use (recreation, timber extraction, grazing use,
mineral extraction) can often conflict with preservation of
a habitat.
“Paper” parks are often logged, farmed, mined, or
poached. Poaching is a common practice, even in U.S.
protected areas.
Protecting Species
Sometimes the
protection of a
specific habitat
(e.g., freshwater
river) involves
monitoring of
other
ecosystems
(e.g., riparian
environment).
Protecting Species
Debt for Nature Swaps:
The purchase of debt by organizations at a much lower
rate (10 cents on the dollar), and then forgiveness of that
debt in return for that countries efforts to make reserves
in certain areas.
The largest of the “debt for nature swap” organization is
the World Wildlife Fund (WWF). Since its inception in
1961, WWF has invested in over 13,100 projects in 157
countries. The annual budget is about $20 million,
almost all from private donations.
Examples of Non-governmental
Organizations (NGOs) Involved in
Defending Species and Habitats
Nature Conservancy
Conservation International
World Wildlife Fund
Environmental Defense Fund
Sierra Club
Greenpeace.
Protecting Species by Laws
Hunting and Fishing Laws - Limit number of animals that
can be ‘harvested’ on a yearly basis.
Usually animal populations are monitored so that hunting
pressures do not limit the populations.
For some animals, such as deer, management practices
favor them, so they may be even more abundant than
prior to settlement of the U.S.
In these cases, the species can be more of a problem for
habitat integrity than a species that needs protection.
Zoos, Botanical Gardens, Captive
Breeding Programs
Breeding of endangered animals
(Cheetahs, other big cats, rhinos,
other large game animals),
conservation of plant species
(sometimes through the storage
of seeds in banks), may provide
a haven from which to
reestablish very endangered
species.
Costs are prohibitive.
Restoration Ecology
Restoration Ecology means to bring back a habitat to a
former condition. When overexploited, ecosystems
degenerate and services decline. Ultimately we need
the capture of renewable resources while sustaining the
global ecosystems that convert sunlight into ecosystem
services.
Principles and Goals:
Need to consider several levels - genes, populations,
ecosystems at the same time. Ongoing research to
collect data on the restored site to monitor changes.
Curtis Prairie in
Wisconsin:
In 1934, seeds were
collected from
remnants along
railroad right-ofways and in pioneer
cemeteries and
cultivated in an old
field. Periodic fires
helped to establish
the prairie; it now
serves as a seed
source for other
prairies.
Restoration Ecology
Restoration
Ecology
Guanacaste National Park (Tropical dry forest):
In an attempt to restore a tropical dry forest in Costa
Rica, used existing livestock to germinate seeds, fire
control to help establish forests, and intensive labor to
eliminate weedy plants.
Restoration
Ecology
Rivers - The Army Corp of Engineers straightened and
drained naturally occurring meanders in rivers. Now,
after realizing the value of wetlands along rivers as a
flood control (and for groundwater recharge), they are
trying to restore wetlands.
Endangered Species Act of 1973.
Regulate activities involving endangered species,
including taking, selling, or transporting any endangered
animal. Protecting these species often involves
preserving habitats that are also endangered, as well as
the other unidentified species using that habitat.
Recovery Plans: Several success stories,
1.
American Alligator, which was overhunted for
meat and skin
2.
Eagles, hawks, and falcons which were
decimated by DDT.
Definitions Resulting from
Endangered Species Act
Federal Endangered - animal or plant species,
subspecies or varieties in danger of extinction
throughout all or a significant portion of their range.
These are considered "Federally-listed" or "listed"
because a final rule was published in the Federal
Register.
Federal Threatened - species, subspecies or varieties
likely to become endangered within the foreseeable
future throughout all or a significant portion of their
range.
Population:
Policy Responses
Governments can help to
create the conditions
where having fewer
children will make sense,
and where people have
the means to reach their
desired fertility.
And if fertility can be reduced, there will usually be
environmental benefits.
Policy Responses
Consumption:
Realistic approach is to divert
consumption into channels with lower
environmental costs, while ensuring
that people still enjoy the end products
or services they need for dignity and
comfort.
The balance of taxes and subsidies can be shifted so as to
make environmental "bads" like excessive car or fossil-fuel
use less attractive to consumers, and environmental "goods"
such as energy-saving technology more attractive.
Policy Responses
Technology:
The heaviest burden will fall on the
technology element of the equation.
If, as is quite likely, the scale of the
world economy triples by 2050,
then technological changes will
have to reduce the environmental
impact of our activities by two
thirds - just to prevent the present
rate of damage from increasing.