| In eco-lingo (the talk of ecologists, conservationists, and
the like), the word "invasive" is usually linked with "alien". That's so
because, generally, it's things from outside the ecosystem that run riot,
given half a chance, destroying bio-diversity.
There are, however, some native species that are as much a problem, from
humans' perspective, as the worst invasive alien. These are problems of our
own making, such as a yard full of Canadian geese guano. The eco-lingo is
"enhanced", meaning a species that flourishes around humans. Good examples
are the cockroach and the house cat.
Two notorious North American noxious weeds for which we only have
ourselves to blame are ragweed and poison ivy. Both flourish where humans
have replaced the native forest and meadows with fencerows and roadsides,
and have left patches of raw earth.
How it happens: the birds find the white poison ivy berries good eating.
As a result, the non-digestible seeds end up, nicely fertilized with bird
droppings, under the birds' roosting places. This works for the birds and
the poison ivy. In the deep shade of the forest, poison ivy seedlings
don't crowd out other plants, which works for the eco-system. However, give
too many seedlings a (human-made) place in the sun, and they'll take over.
This works for the birds and the poison ivy but not for the rest of us.
When I was a kid, humans balanced out their poison-ivy-enhancing behavior
by pulling the plant up anywhere it was found. However, today, I see poison
ivy all over suburbia. If you have trouble identifying it in the summer,
wait until mid fall and look for the brilliant red leaves, often smothering
trees. Some conservationists who would gladly eradicate the alien invasive
vines such as porcelain vine (issue 31, 10/27/02), Indian bitter sweet
(issue 40,12/29/02), and rosa multiflora (issue 44, 01/26/03), think we
ought to leave the poison ivy because it's native and the birds eat it.
That doesn't do it for me. I hear that poison ivy got so far out of hand
on Fire Island, for example, that some of the wild area have been abandoned
by all but some (very fat) birds. Remember that poison ivy is very
dangerous to humans. The only way to give rid of an acre-size patch is to
bring bulldozers and workers in "moon suits". But then what would you do
with the dead stuff that still contains the deadly oils? You can't even
burn it except under controlled conditions because the smoke carries the oil
and is very harmful to touch or breathe.
The best thing to do for poison ivy is pull it up when it's small. Do
as the "pooper -scoopers" do: use a couple of layers of plastic shopping bag
as an oversized glove to protect your hand while pulling up the plant. Then
reverse the bag to cover the plant; tie and drop in the garbage. Cut large
vines at the root, dig up and destroy the root (place in sealed black garage
bag in the sun for a few months). Consider leaving the vine to die in
place; don't try to pull down a large vine without protection, particularly
for the face and eyes.
BTW: don't think you're immunity to poison ivy just because it hasn't
bothered you in the past. Only too many people have ended up in the
hospital this way. And don't think it's just a minor skin rash. A big does
of poison ivy can lead to serious, long-term health problems.
Further information on poison ivy and its kin poison oak and poison
sumac:
http://poisonivy.aesir.com/view/welcome.html |
