|
Why are Noxious Weeds
So Bad?
|
|
|
|
|
Weeds are considered "Noxious" because
of six main reasons.
Spreading Designated noxious weeds will take over and area so quickly and with such aggression,
that untreated areas could easily be populated exclusively by the noxious, non-native species. For example: One knapweed plant
generally produces 1,000 seeds per plant. These seeds remain viable in the soil for 8 years. Given their growth rate, that
one knapweed plant will produce over 4.7 billion (to be exact, 4,771,469,407) plants and over 5.1 trillion (to be exact, 5,190,972,273,123)
seeds over a ten-year period - an amount that would cover 36,513 acres! The reason these species spread so fast is because
there are not native predators keep plant populations in check.
Habitat for Animals
Non-Native species (noxious weeds) reduce native habitat for area animals by taking away optimal forage
and changing the way animals use areas. Animals may choose to leave areas infested and move to different locations where optimal
forage is available.
This in turn over populates the new habitat over time and thus over grazes native species
making the new area more susceptible to invading weeds.
For example, in Montana, spotted knapweed has taken over
vast acreages of wildlife habitat resulting in a decline in elk and elk licenses each year.
Riparian impacts
Noxious Weeds find residence in riparian areas due to their ease of travel through water or water vehicles. Invading species
take over these areas, causing erosion due to poor root structures, as well as diminishing prime fish reproduction sites.
Furthermore, in times when water is a limited resource, noxious weeds, for example Saltceder (Tamarisk), which is beginning
to encroach onto the Snake River islands and banks, consumes up to 200 gallons of water per day.
Effects on Pastures/Hay Fields
As noxious weeds establish themselves in hay Fields and or pasture lands, valuable forage is reduced as well as weeds are
provided another mode of transportation within horses, or cattle to be deposited at another site.
Equally frightening
is the toxicity of some weeds on animals. An example of this toxicity is the poisonous nature of plants like Hounds Tongue,
and Common Tansy towards the liver of horses.
Biodiversity
The most noticeable effect of non-native species is the reduction of native plants
with the replacement with noxious weeds. This replacement causes more than just replaces one plant with another, but has an
effect on the biodiversity of an area. With reduction of native plants, weeds alter the soil structure, soil moisture and
organic matter, which in turn will decrease the land's ability to produce and contribute to the ecosystem.
Economic Impacts
Noxious weeds impact more than just the environment. Non-native species can dramatically reduce land values by up to ten
percent. Furthermore, weeds cost the Wyoming taxpayer as well. Annually, Wyoming spends more than $1.5 million on the treatment
of noxious weeds on public lands. |
|
How do I Control Noxious Weeds?
|
|
| Ox-eye Daisy |
|
|
Control Options
To properly reduce or eliminate noxious weed infestations, there are different methods to be used dependent on the
stage and severity.
Mechanical Control
Mechanical control is the removal of weeds by cutting of the plant of tilling of the soil. Mechanical control is most
effective if the plants are too far along in their yearly stage to spray (seeded out), and or an annual or biannual plant.
Some perennials, such as Toadflax or Canada thistle can actually be promoted to grow by cutting of the roots.
Chemical Control
Chemical control is the most
widely used and shows the most dramatic effects of control. When controlling chemically, an herbicide is used in a small quantity
and mixed with water. Usually this solution is then sprayed with a backpack, or applied with an ATV using a spray gun or boom
sprayer.
Biological Control
Biological control is put into action mostly when an area is either too large, or too remote for chemical or mechanical
control to be cost effective. Biological control uses root boring or seed eating insects that, with time, reproduce enough
to noticeable control an infestation. For the most part, these remote and heavily infested areas are a top priority for local
government agencies, thus overseen by them.
|
|
|
|
