Download Invasive Species

Invasive Species
Review

Native Species - A species which has evolved to adapt to

Exotic Species - Species that have moved into a particular

Invasive Species - An exotic or a native species that causes
specific conditions in a particular region
region that they are not native to
harm to some aspect of the pre-existing ecosystem
Review

Methods of Introduction
Passive
Intentional
Passive Introduction

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These species, the Japanese Stilt Grass and the
Zebra Mussel, were NOT introduced intentionally
Examples of passive introduction:
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
Seeds that are stuck on clothing can be carried to a new
region where they may fall off
A species can be transported accidentally by attaching to a
boat, plane or car and falling off in another area
Japanese Stilt Grass
Microstegium vimineum (Trin.)
Camus

Native to China, Japan, Korea, Malaysia, and
India
How did it get here?
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
In the early 1900’s,
Japanese Stilt Grass was
used to pack porcelain for
shipment. It is believed
that this is how stilt grass
made its way to the U.S.
It was first seen growing
in the wild in Tennessee in
1919 and has slowly
worked its way to
Pennsylvania
Effects

Out competes native shade dwelling vegetation

Crowds out native forest and wetland vegetation
Control

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The most effective method of controlling Japanese
Stilt Grass is to prevent disturbing vegetation and
soils which helps to prevent further infestation by
increasing seed dispersal
Small isolated populations can be controlled by
hand-pulling and cutting
Zebra Mussel
Dreissena polymorpha


Native to the Balkans, Poland and the former Soviet
Union
The first identified populations were found in the
Caspian Sea and Ural River in 1769
How did it get here?


Introduced through the release of ballast water
from one water body into another
Can be transported to new waters by attaching to
boats; both commercial and recreational
Effects



Known for their biofouling
capabilities, by colonizing
in water supply pipes for
power plants and water
supply plants and in
discharge pipes
Remove large quantities of
plankton from the water
when feeding
After death, the zebra
mussel washes up on to
the shore where it decays
leaving its shell
Control



Manual removal
 High pressure
washing
 Hand scraping
Thermal
 Steam injection
Creation of
conditions leading
to Anoxia/ Hypoxia
Intentional Introduction


Introduced
purposefully in order to
serve a function
Examples:
 Introduced for
agricultural reasons
 Used to combat another
environmental problem
 Introduced for economic
reasons
Gypsy Moth
Lymantria dispar


Originated in Europe, Asia and North Africa
Survives in climates ranging in temperature from
the frigid Russian Steppes to the subtropical shores
of the Mediterranean
Why was it introduced?


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The gypsy moth was
introduced intentionally by
Professor Trovoulet from
Massachusetts while he was
attempting to breed a hardy
silkworm
The species escaped by
accident when a specimen
jar containing gypsy moths
fell out of Trovoulet’s
window
The gypsy moth has
flourished and is slowly
expanding its range
Effects


Defoliates hundreds of
plant species in North
America, but prefers
Oak and Aspen trees
Severely weakens the
tree, often leading to
its death and can also
reduce nut production
reducing food for some
animal species
Control


Removal of any egg
masses that may be
on cars, firewood,
picnic tables or
outdoor furniture
before they are
moved to a new
area
Burlap Wrap
Multiflora Rose
Rosa multiflora


Native Range: Japan, Korea and Eastern
China
Thorny perennial shrub introduced to the
East Coast of the U.S. from Japan
Why was it introduced?


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1866- Used as rootstock for ornamental roses
1930- Used for erosion control and as “living
fences” to confine livestock such as cows
Also used for wildlife cover for pheasants and the
cottontail rabbit. It has also been planted in
highway medians as a crash barrier and to reduce
headlight glare
Effects


Creates dense thickets
that prevent other
native plant species
from growing
Invades open
woodlands, forest
edges, fields, pastures,
prairies and savannahs
that have had land
disturbances
Control


For small populations, the entire plant and root
system can be removed with a shovel
Mowing or cutting is used for large populations
– In some extreme cases, herbicides are used in
conjunction with this process
Additional examples of
Invasive species

Intentionally Introduced Species
▪ Purple Loosestrife, Japan Knot Weed, Garlic
Mustard, European Starling ,Tree of Heaven,
Tartarian Honeysuckle, Mile-a-minute

Accidentally Introduced Species
▪ Ruffe, Round Goby, White Perch, Sea
Lamprey