by Beth Sullivan
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Multi-flora rose offers some protection
for nesters and berries for food, but can
take over a field in no time. |
Over the last years I have written about invasive species,
plant, animal and insect.
It is a
challenge to actually define the term as there are many species that have been
brought to our habitats that are not truly native or were not here before
European contact.
Many species of
animals have been domesticated such as cows, sheep, horses, pets. Most don’t
become an invasive problem but could, like feral cats. Some species, like the
Eastern Cottontail, have been introduced
purposefully and now have taken over a niche
that was occupied by their native relative the New England Cottontail.
They have become naturalized, a nuisance, but
not many people would refer to them as invasive.
Invasive insects have become a bigger problem. As products
from foreign countries come to our shores, they contain plant material or
insects and their eggs associated with the wood or packing material. Once these insects are released into a new
environment, they do not have native predators to control them. Often, they find sources of abundant food and
appropriate habitat. Then they go to
town, unimpeded and often leave a path of destruction. We have witnessed this
most recently with gypsy moths, hemlock woolly adelgid, emerald ash borer,
Asian long-horned beetles and now spotted lanternfly. As climate warms, many of these pests are not
affected by winter temperatures anymore, so they survive. In most cases there
are few, if any, natural insect controls. I don’t think many of our native
birds are fully adapted to eat invasive insects, but we know cuckoos eat gypsy
moths and woodpeckers will go into wood for various beetle larvae. As a result of invasive insects, we are
losing our hemlocks, ash trees and many of our oak trees.
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Porcelain berry, a beauty of a beast
that will cover and smother entire
trees and walls. |
Invasive plants form another real threat.
People have been intrigued by plants and
their uses, probably forever!
Moving
plants around for food, medicine and decoration is an ongoing activity.
Centuries ago, people, and plants, didn’t
move quite as far or as quickly as they can now.
Settlers introduced grasses for their
livestock that have become integrated into farm fields. Food plants were
introduced to give us all greater variety.
But most of these kinds of plants have “better manners”.
Most don’t spread widely or
aggressively.
In the last century,
ecologists have noted new plants becoming monocultures in some areas, taking
over habitats, killing native species with various methods, and ultimately
enticing native wildlife to make use of them and spread their seeds far and
wide.
Some of these plants are
beautiful,
and the uninformed are also
responsible for their spread.
Some
plants were deemed useful in landscaping and no one really knew how
aggressively they would spread beyond their intended use.
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Oriental bittersweet twist
their way up and then
strangle the supporting tree. |
So, here we are, as stewards for Avalonia, hoping to
maintain habitats that are appropriate for all kinds of wildlife and reflect,
as closely as possible, native species in their natural habitats. Sadly, as we
look closely and learn more, it is hard to see the native forest…for all the
invasive trees and shrubs and vines in the way!
There are several places where I feel the landscape would be completely
barren, if we were able to remove all the invasive plants.
On some preserves, we have worked tirelessly
to remove invasive shrubs such as multiflora rose and autumn olive and bush
honeysuckle. However the minute the area is opened to sun, new invasives take
their place.
We got bittersweet, reed
canary grass and porcelain berry. When those were tackled, swallowwort,
bindweed and stilt grass have began their destructive march.
A habitat overrun by invasives may offer some minimal
shelter for wildlife, but the food value is often very poor. In some cases,
nothing eats an invasive plant. In the worst case, our native and endangered
Monarchs are fooled into laying their eggs on black swallowwort but when the
caterpillars emerge, they cannot eat that plant, and they die.
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Stilt grass has taken over the banks
of the Pequotsepos Brook and will
spread downstream. |
Stilt grass is relatively new here. However, in the more
southern/mid Atlantic states, the grass has spread so rapidly, and
destructively, that it carpets entire forests and parks, preventing any native
plants, flowers, or tree seedlings, from germinating.
The seeds originally came in packing material
that protected Japanese ceramics.
It is
now wreaking havoc in our area.
Avalonia stewards are determined to learn the best way to
control this grass, and other invasive species. We are conducting workshops, and
compiling data/fact sheets for our stewards to use. These, we hope will soon be
available on our website. Right now,
Japanese stilt grass is being tracked into preserves by hikers and bikers. It has spread along the roadsides and
vehicles carry seeds to parking lots and other preserves. Landscape equipment
can carry and spread seed. This is the
time to identify it and begin to wage war.
As an annual grass, it relies on self-seeding, so removal now, before
the seeds are set, is imperative. It is easy to pull. If seeds are present, already, it should be
bagged and not put into compost. It can
even be “weedwhacked” down close to the
ground at this time of year, to inhibit the seeds. The plants will die. But sadly, seeds from previous years are already
in the seed bank and can last up to five years.
Too bad we didn’t start, didn’t know, years ago!
There is a lot to learn. Identification is the first
step. Then learning about the best ways
to manage or treat infestations will take time and thought. We, as an organization are working on finding
the right balance.
This is a great resource: Good luck in your own home areas.
Connecticut
Invasive Plant Working Group:
https://cipwg.uconn.edu
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If you find swallowwort, at least remove the
pods to prevent seeding. |
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Autumn Olive berries make great jam, but there
are just too many of them! |
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Stilt grass is not too hard to identify,
once you know it.
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