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Invasive Species Corner

Invasive species are a major threat to our environment because they can change an entire habitat, place ecosystems at risk, crowd out or replace native species and damage human enterprise - costing the economy millions of dollars.

Native ecosystems are in a state of balance. When nonnative plants enter, they upset this balance, sometimes producing such deleterious effects as creating toxins lethal to some animals, and altering hydrological patterns, fire regimes and soil chemistry. (www.epa.gov/reg3esd1/garden/invas.htm) Further, nonnative plants occupy the habitats of native plants, replacing the native plants that people enjoy. In the extreme, invasive plants might contribute to extinction of native species, with uncertain long-term results.

The Sierra Club is constantly targeting newly discovered and stubbornly surviving invasive plant species to remove- and we need your help! 

Click HERE to get involved! 

What kinds of plants are problems?

It's a plant, and the more plants we have the better, right?

Why can't we just use herbicides and be done with it?  Or why can't we bring over something that eats it?

Doesn't the ecosystem adapt?

What can I do about removing invasive plants?

What can I expect on an invasive removal?

What kinds of plants are problems?

The short answer to this question would be a list of names:  Japanese stilt grass, wavyleaf basketgrass, English ivy, Japanese honeysuckle, multiflora rose, wineberry, barberry, and kudzu just to name a few.  Click here to see Sierra Club's in depth look look at wavyleaf basketgrass.

The longer answer is any plant that is non-native and its reproductive strategy goes unchallenged in our native ecosystem.  In their own environments, these plants have controls like an insect or blight.  In North American ecosystem, there are no such controls on the populations. 

It's a plant, and the more plants we have the better, right?

Not necessarily!  Just because something is lush and green does not mean that its presence is good for the surrounding ecosystem.  As a matter of fact, population studies show that a lush green carpet of a single pervading species lowers the biodiversity, exactly opposite of what a healthy ecosystem does.  To clarify the question, the more different kinds of native plants, the better.  A healthy ecosystem may have fewer numbers in the populations, but it will have more different populations.

Why can't we just use herbicides and be done with it?  Or why can't we bring over something that eats it?

Herbicide has been a powerful tool and it is used to control the spread of non-native invasive plants; however, it does have its drawbacks.  Responsible herbicide use means  that the herbicide can only be used on monocultures where the only living plant in an area is the target species.  Herbicide can't tell the difference between a native plant struggling underneath the overgrowth of an invasive and the invasive itself.  The herbicide would end up killing the pioneer native plants as well, killing the potential parents for reseeding a population of natives.

Biological controls such as insects or fungi are another powerful tool, but the consequences of using such a tool have ended in disaster before.  For example, bringing over an insect that lives off of an invasive plant species could in fact eradicate the invasive plant, or it could move to decimating our native flora or onto food crops.  Scientists are now required to research thoroughly and provide irrefutable evidence that a potential biological control will not harm anything else but the target species.  You can read more about it here.

Doesn't the ecosystem adapt?

Not as fast as the invasive species spreads.  Historically, a new non-native species, plant or otherwise, may be introduced every century or so.  Now with modern travel, people and the seeds and spores on their clothes and shoes bring non-native species virtually all the time.  Invasive species also have a more difficult time taking over a very healthy, undisturbed ecosystem where the high biodiversity has a fighting chance of overcoming the invasive pressure.  Due to constant development, pollution, the construction of roads, and general impact of Homo sapiens, more ecosystems are disturbed than not.  Consequently, invasive plants can get a foothold and begin their spread.

What can I do about removing invasive plants?

Sierra Club is working with many other organizations around Maryland who share a common concern for the impact of invasive species.  After all, we all share the same planet.  Click here to see Sierra Club's listing of Stewardship Outings.

What can I expect on an invasive removal?

A leader will meet you at a designated place and demonstrate the targeted plant and how to remove it.  Getting in contact with your leader for crucial information about equipment or any last minute changes helps build a more enjoyable experience, so please RSVP to the contact person before the event.

Going on an invasive removal is just like any other outdoor event:  dress for dirt!  Wearing older clothes and sturdy shoes will make your outing all the more enjoyable.  Many outings will take a break for a snack, so bring something to eat when you come.  Lastly and most importantly, stay hydrated by bringing along a water bottle.  If there are any other additional needs, the contact will be able to provide you with information.

Click here to see Sierra Club's listing of Stewardship Outings.