Maybe a dumb question?

Is this a proper - if there is one - definition of Invasive plant?

Invasive, meaning that there are few or no naturally occurring measures such as insects or competitors to control them and can spread rapidly and smother or out-compete preferred vegetation.

I've wanted to find a brief description for some time now and wonder if this fits the bill. Thank you.

Dea

Tough question. There was a conference a few years ago in St Louis that brought together those who were at opposite ends of the spectrum. I think you might find it rather interesting-
http://www.centerforplantconservation.org/invasives/home.html

Came up as no page displayed.

Guess I'm just really searching for our own definition - that is me and Michael's (DH). The above sentence is kind of a compilation of our thoughts.

It's hard to put it down in just a sentence, but for us right now, this is what works. Just curious if others had a one or two sentence description. Again, thanks :)

Dea

Here are some to consider: http://davesgarden.com/terms/go/500.html

No its not a dumb question.

In order for a species to be considered invasive, it needs to have the capability to cause harm to the economy, the environment or human health. (per the US government definition)

***sigh*** I'd completely forgotten about Garden Terms Terry - thanks :)

Dea


This message was edited Feb 9, 2006 5:38 PM

Now that this is answered, is there any way to mark this question as "solved" like in Identification ? Thanks :)

Dea

The link repeatedly fails. Sorry about that, I don't know what I am doing wrong that is breaking the link.

If you are interested, please go to google and enter into your search engine the following-

Linking Ecology & Horticulture to Prevent Plant Invasions St Louis declaration
the first few links that come in the search engine get you to where I was trying to get you.

Here is a rather fascinating recap of a survey taken a few years ago-
http://www.brown.edu/Research/EnvStudies_Theses/full9900/mhall/IPlants/Results.html

Here is the definition of invasive species according to our government-
http://www.invasivespeciesinfo.gov/

I tried the above address (www.centerforplantconservatio n.org) with the space before "...n.org" removed and it took me to the site, I think. Try removing the space and see if it works for you, i.e. (www.centerforplantconservation.org). Is this it?

Paula

Funny, my post preview showed the changed link to be without the space, but when it posted, the space is back in the address, and it won't let me edit the space out. At any rate, removing the space seemed to work. (A computer whiz I'm not) :~)

You know, it perplexed me too and I certainly am not that great with computers. I had to edit the post and edit the post and finally I went back and gave up on trying to fix the hyperlink because it just flat out wasn't working so I cleaned up my post with all the edits so people could make sense of it. Glad it's not just me.

It's a good site when you finally get to it, Equilibrium. Thanks.

Paula

How about this:

http://www.centerforplantconservation.org/invasives/

This will get you where you want to be. Here's a list of who participated:

http://www.centerforplantconservation.org/invasives/mbgN.html#appF




This message was edited Feb 11, 2006 12:30 PM

John, The URL is not valid and cannot be loaded..........

And John, where oh where is my sambucus, oh where oh where can it be???

For whatever reason, the URL looks right in the preview page, and then loads up here with a space between the "o" and the "n" in address. I don't know how to change that, but if you click on the hyperlink, after it loads up to nowhere go into the address line and delete the extra stuff (on my PC I get an extra %20 in the address) and you'll get there.

It really is a good link.

Maybe an Admin can step in and fix this for us?

Wild Raisin! You're still out there in the snowy tundra? The Sambucus canadensis is safe and sound in soil. It'll be later, probably March, before it can be lifted. You wouldn't ask a poor fellow recovering from knee surgery to get out and satisfy your every whim, would you? Don't answer that...

I will probably probe around next month and dislodge some root pieces and whack off some of the tall stems (8' plus). This is a plant that can be propagated in each of those ways, as well as by division and transplantation. Soon, you'll be in a sylvan Sambucus canadensis shelterbelt.

OK, back on topic, and it looks like the links have been corrected above. Taking a gander at that site should be revelatory to those who haven't considered that precision in terminology can be important.

Give your working definition of invasive plants; here's mine is kind of how this thread started. I've read down through it all. I have also observed the inflammatory nature of statements when the term is mentioned on other forums at DG and elsewhere.

It's one thing to get fired up because you just don't want anybody putting limits on you. That's fine, even if I don't agree.

It's another thing to get fired up because someone is using terms that don't mean what you think they mean. So, here we are.

The term is not subjective: behavior of plants may vary from place to place, and one's opinion of this behavior may be at variance with others, but the term invasive means what it means despite how different people choose to use it (note the wide-ranging list at Garden Terms). A range of terms to mean the other things that species do in gardens or elsewhere are necessary if civil discussion can continue, but one cannot use the same word to describe them all! I would liken this to a Botanary term, or the scientific name of a plant, or a color.

Something like: dioecious, from Latin for two houses, meaning that male and female reproductive parts occur on separate plants (I hope that's right). Definite term, not a debatable point. This should be the same for the concept or term invasive. Then adults can have the knock-down drag-out over whether Johnsongrass or cogongrass or English ivy qualify as such, or where.

I believe that the scientific terminology or basis for invasive species is not related to garden-worthiness or weediness. The links and quotes above are representational of this position. EQ, Darwin, and Terry hit closest to the mark but each leave out some key pieces. A weedy plant may also be invasive, but its movement around a garden situation does not rise to the impact of what invasive means. A colonizer (like Rhus, Aralia, or even Equisetum) is not invasive per se either, though they are quite annoying when they continue to spread into zones you don't want them!

An invasive species changes the system that it invades. I haven't read anyone posting that yet. Some of these ways of change:

Soil chemistry
Hydrology
Fire behavior
Allelopathy

I'm running dry right now and am probably leaving some points out. These changes to the system, along with the diminution of indigenous plant populations, economic harm, and lack of normal pathogenic balancing elements against the invasive species, are the reason the term invasive should not be used or considered interchangeable with concepts like weediness or aggressive spreader (in garden terminology).

Whew! I've probably bored to sleep most readers by now. I hope these thoughts are useful, and that the premise behind meaning creeps into how things are said/written here and elsewhere.

John,

What snow?? I don't have any. So, I have to wait for the sambucus? You're paying me a visit in March, are ya? And ye...oh wait, you said not to answer :o)

Terry

Well, here's a monkey wrench for you. I knew the late Dr. Larry W. Mitich, who was a Professor Emeritus at the University of California Davis and an expert on weeds/invasive plants. I asked him one day what his definition was of a weed, and he said, "It's a plant that's in the wrong place. Every plant is a weed somewhere in the world." Boy, does that definition open up possibilities!

Marilyn

A plant out of place is the definition of a weed used by lots of people. And I think the point of this thread is not to confuse the terms weed and aggressive with the term invasive.

I have used this before: corn is a weed in a kbg lawn, kbg is a weed in a corn field. But neither of those plants are considered invasive.

I've been reading the Final Report of the New York State Invasive Species Task Force this morning and here is the definition they put forth (be aware that this task force covers ALL invasives, not just plants)

"Invasive species are non-native species that can cause harm to the environment or to human health. Terminology frequently confuses discussions of invasive species because most terms used to describe invasive species are not rigrously defined scientific terms, so no set of definitions is universally recognized. For example, the terms 'nonn-native', 'alien' and 'exotic' generally refer to organisms that come from other political jurisdictions, usually other nations. 'Nonindigenous' has more scientific roots and refers to organisms that come from other environments or ecosystems but not necessarily from other nations ore even states. In fact, many species 'indigenous' to some parts of New York state are 'nonindigenous' elsewhere within our borders. 'Introduced' clearly connotes human intervention. Whereas some organisms may expand their ranges, even to new continents, in response to natural forces, 'introductions' happen only when humans play a role, usually purposefully."

It goes on to say that they, as a task force, have adopted the definiton containes in the fedreal Executive Order 13112 , signed in 1999, which boils down to: "1) non-native to the ecosystem under consideration, and 2) whose introduction causes or is likely to cause economic or environmental harm or harm to human health."

(just a side note, this does point out the problem with "Indigenous Plants")

There is a paragraph further on that discusses the problem and begins with the sentence: "Invasive species are a form of biological pollution."

Kathleen, adopting the definition of the Federal Executive Order is what many organizations have done. I believe all would agree on the definition of weed being a plant in the wrong place. Per chance would you be able to share NY State Invasive Species Task Force definition of noxious? You are correct, misinterpretating/misrepresenting/twisting/contorting/subverting or manipulation of definitions by the masses does point out the problem with Indigenous Plants.

They use 'nuisance' and noxious' synonymously and state that these terms often apply to indigenous as well as nonindigenous species. "...'nuisance' plants are deemed either 'noxious' or simply weeds."

all of these definitions are on page 17 of the report at this link:

http://www.dec.state.ny.us/website/dfwmr/habitat/istf/istfreport1105.pdf

The Invasive Plant Council of NYS uses this:

"The term "invasive plant" is used to describe plants that aggressively compete with, and displace, locally adapted native plant communities."

I haven't yet done a lot of reading at their website, but the link is
http://www.ipcnys.org/

Thanks Kathleen, I liked their summation of the problem.

Ragweed (Ambrosia spp.) is a great example of a plant that is not deemed invasive but identified by many local governments as being noxious. Ragweed is a species native to North America. One that comes to mind for me as being a nuisance/noxious species that is also introduced would be Hemp (Cannabis sativa). Cannabis sativa is additionally listed as invasive. Plants can be noxious as well as invasive.

I always think of invasive as being a relative term...aside from strict gov't definitions, I consider invasive as something you planted and can't get RID of it !!!! For me, the three worst invasive plants are: ANY mint...unless in a container..., violets, and Four O'Clocks !!! I had mint grow under the house and come up through the foundation vents on the opposite side! Violets that come up through any tiny crack of anything and four o'clocks with tubers that look like mutant yams !!!

My, my my......... mutant yams.......... that is very good. I'm very careful about gifts after the amount of Forget-me-not volunteers I 've pulled over the last few years. I've forgiven the chicken manure for all the chick-weed as it could easily be some other seed blown in I suppose. I was really brave when I started here in 1979...... planted Crownvetch on a steep slope......... it worked, looked good in 5 years, but now 'it's coming to take me away'! The driveway bed is being invaded from below! My worst weed remains common buttercups.... and I have a contact allergy to boot. I still battle them,,,,,, hate it when they get in a peony! I discovered and accidentally spread goutweed - now I spray the first sign of a leaf of it! (I heard a blowtorch worked in the U.K.) There are some bad nettles I discovered in poor soil areas of Portugal Cove..... but NIMBY. My candidate for the worst around here is Polygonum cuspidatum - needs a bomb and a backhoe to get it all out; there are those who love this 'September Mist'...... Another possible mistake on my part was to plant perennial ivy ... to combat the buttercups - no clear winner yet! I did have some black violets self-seed......... and I finally said 'heck' and pulled the whole lot..... just too messy. There isn't much mint in my patch of the landscape......... but I have seen it here, wild and invasive...... and typically you would have to cogitate a while about replacements a/c habitat. FYI, cattails are a fairly recent addition to Newfoundland flora - it will do well in wet areas which do not have 'wind and waves' - there are a lot of ponds/lakes here cum WIND.
Bill in Portugal Cove-St. Philip's, NL Canada zone 5a

Cattails.......we can't kill them. They are taking over the resacas. We chop them, spray them, dig them out with backhoes, cut them off.......they still multiply.