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Last edited January 14, 2003
By Hubert Ling
As explained in the movie "Jurassic Park",
contained within the coils of DNA is one
of the mightiest powers on earth. Coded
with a simple alphabet of A, T, G, and
C is the power to kill billions of organisms,
change the gas concentration of the atmosphere,
and yes even destroy the whole earth with
a nuclear Winter.
By carelessly shifting around organisms,
with their awesome genetic potential,
we have caused major ecological disasters.
Gone is the most important tree in the
Northeast, the American Chestnut, our
premier landscaping tree, the American
Elm, and gone are huge tracts of productive
fresh water marsh. Now these marshes contain
only monocultures (only one species present)
of purple loosestrife.
Cornell ecologist David Pimentel has
estimated that alien species annually
cause $138 billion dollars of damage to
our US economy; an estimated 50,000 alien
species of insects, plants and other pests
now crowd our shores. The US government
spent $37 million in 2000 to attempt to
alleviate some of the harmful effects
of invasives but that amount has done
little to control the problem.
The basic problem is that all organisms
have been programmed with a reproductive
capacity that can easily outstrip all
available resources. This humungous genetic
potential is generally held in check by
competition with dozens if not hundreds
of other organisms, which also have the
similar genetic potentials. With so much
competition, no one organism takes it
all; generally each organism takes only
a small share of the total resources of
land, water, minerals, light etc.
In addition to direct or indirect competition
for resources, disease agents control
population growth of any one species.
If any one organism grows very well, very
large populations develop of that one
species. These large populations are very
susceptible to attack by disease agents,
which include fungi, viruses, and bacteria.
Disease agents spread rapidly when their
hosts grow close together.
Thus, in any community a dynamic balance
is maintained, where populations often
ebb and surge but monocultures are rare
and populations whose numbers have dwindled
are under less stress and eventually recover.
Native plants in any given area have adapted
to all the other organisms in a given
area and genetically diverse ecosystems
are generally maintained.
A different scenario takes place when
an alien species is transported to a new
area. Although direct competition with
similar species is still a problem, the
new kid in the block may have no natural
pests and diseases. Thus, large stands
of monocultures can occur. It is generally
accepted that one plant species will support
10 species of animals. If one species
takes over 99% of a given habitat dozens
if not hundreds of species are lost from
that area and some populations are stressed
enough that extinction is possible.
Humans are responsible for almost all
of the invasive plant and animal problems.
Many of our problem invasives were (and
often still are) planted as landscape
plants in New Jersey. These include: Norway
Maple, Japanese Barberry, Asian Bittersweet,
English Ivy, Mimosa, Wisteria, Japanese
Honeysuckle, Bugleweed, Bamboo, Day Lily,
Purple Loosestrife, Tansy, and Dame's
Rocket.
Only a relatively few commercially important
plants such as teasel, which was used
in colonial days to raise the knap on
woolen garments and spearmint, show much
of a tendency to persist and multiply
in the wild. We should probably include
in this short list the important pasture
clovers: White Sweet, White, and Red as
plants thath have become so common most
people would think that they have been
here forever.
Other plants have escaped local and federal
projects: Multiflora Rose (previously
used as crash barriers along highways,
Crown Vetch (still used to stabilize steep
hillsides, and Russian and Autumn Olive
(used for wildlife habitat support).
We will probably never know how most
of the alien plants arrived here. Many
may have arrived as contaminating weed
seeds along with seed stocks. It is very
probable that the following list of plants
arrived by that route: Common Mullein,
Moth Mullein, Buttercups, Spotted Knapweed,
Ox-eye Daisy, Queen Ann's Lace etc.
What can you do to help? Plant only native
plants. How would you feel if you started
a several billion-dollar problem such
as Purple Loosestrife? Definitely avoid
plants in categories 1 and 2 and support
legislation to restrict these plants.
Join the Native
Plant Society or other conservation
groups. Other sources of information include
the New Jersey Department of Agriculture
Invasive Weed Council, Invasivespecies.gov
, and The Nature
Conservancy.
Listed below are the scientific and common
names for problem invasive plants for
NJ. These lists are not complete and we
would like additions, modifications and
suggestions.
Category 1, Strongly
Invasive and Widespread
Herbaceous Dicots:
Achillea millefolium, Yarrow
Alliaria petiolata, Garlic Mustard
Artemisia vulgaris, Mugwort
Cichorium intybus, Chickory
Coronilla varia, Crown Vetch
Daucus carota, Wild Carrot
Glechoma hederacea, Gill-Over-The -Ground
Hesperis matronalis, Dane's Rocket
Lythrum salicaria, Purple Loosestrife
Malva moschata, Musk Mallow
Meliotus alba, White Sweet Clover
Plantago lanceolata, English Plantain
Polygonium cuspidatam, Japanese Knotweed
Rumex crispus, Curly Dock
Trifolium pratense, Red Clover
T. repens, White Clover
Monocots:
Allium vineale, Field Garlic
Arundinaria, Bambusa, Any Hardy Bamboo
Dendrocalamus, Bamboo
Cynodon dactylon, Bermuda Grass
Dactylis glomerata, Orchard Grass
Digitaria sanguinalis, Crab Grass
Echinochloa crusgalli, Barnyard Grass
Hemercallus fulva, Day Lily
Microstegium vimineum, Japanese Stilt
Grass
Phragmites australis, Common Reed
Vines and Woody Plants
Acer platanoides, Norway Maple
Alianthus altissima, Tree of Heaven
Berberis thunbergii, Japanese Barberry
Celastrus orbiculatus, Asian Bittersweet
Elaeaghus angustifolia, Russian Olive
E. umbellata, Autumn Olive
Hedera helix, English Ivy
Lonicera japonic, Japanese Honeysuckle
Rhamnus cartharticus, Buckthorn
R. frangula, Alder Buckthorn
Rosa multiflora, Multiflora Rose
Category 2, Invasive
But Not As Widespread (Yet)
Herbaceous Dicots:
Ajuga reptans, Common Bugleweed
Centaurea maculosa, Spotted Knapweed
Chelidonium majus, Celandine
Chrysanthemum leucanthemum, Ox-Eye Daisy
Dianthus armeria, Depford Pink
Galinsoga ciliata, Galinsoga
Lamium purpureum, Purple Dead Nettle
Linaria vulgaris, Butter-and-Eggs
Lysimachia nummularia, Moneywort
Matricaria matricariodes, Pineapple Weed
Mentha spicata, Spearment
Polygonum persicaria, Lady's-Thumb
Portulaca oleracea, Purslane
Ranunculus acris, Common Buttercup
R. bulbosus, Bulbous Buttercup
R. ficaria, Lesser Celandine
R. repens, Creeping Buttercup
Rumex acetosella, Sheep's Sorrel
Rumex obtusifolius, Broad Dock
Verbascum thapsus, Common Mullein
V. blattaria, Moth Mullein
Monocots:
Commelina communis, Day Flower
Vines and Woody Plants:
Albizia julibrissin, Mimosa
Prunus avium, Crab Cherry
Wisteria frutescens, Wisteria
W. floribunda, Wisteri
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