"It seemed there was some debate if Eastern red cedar Juniperus virginiana, was invasive in Kansas."

Juniperus virginiana is NATIVE to Kansas!!!! Good grief.
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"...which...site is regarded as the most accurate to determine if something one wishes to plant is invasive?"

It really does vary from state to state and, for regional and national information, even from species to species. For most states with an EPPC (exotic pest plant council), that particular state's EPPC site is probably the best reference. Most states have some dedicated group to address the issue, and these groups can usually be identified pretty easily with a couple of google searches. I usually start off by googling 'invasive plants' along with the name of the state. Some states are a little trickier than others, but I think every state has some guidance. I have noticed certain trends regarding which states have the best resources, but I think it best to leave that discussion for another time.

For a nationwide search, Google is your answer, but here are a few resouces:

Alien Plant Invaders of Natural Areas (National Park Service): http://www.nps.gov/plants/alien/factmain.htm

Invasive.org - Center for Invasive Species and Ecosystem Health: http://www.invasive.org/species.cfm

Mid-Atlantic EPPC: http://www.ma-eppc.org/

Southeast EPPC: http://www.se-eppc.org/

There are other sites that I use a lot, but they escape me at the moment.

Here is a link that might be useful:

I would not describe it as "invasive" on grazing land - rather it is probably considered a "pest" because it gets in the way of what they are trying to do with grazing land: hold back the natural process that would have that land be something other than grazing land!

IMO, the term in "invasive" is used by groups officially reporting "invasives" to describe non-native plants that take over native plant habitat. Those that categorize agricultural pest plants are a different group.

Your best resource for determining invasiveness is your state (or sometimes even county) invasive species regulating/monitoring authority - every state has one. Invasiveness is highly determinant on location - what may be considered invasive in one area may very likely NOT be considered invasive everywhere else.

FWIW, native or indigenous species by definition are NOT considered "invasive" - that designation is limited to non-native ('alien', 'exotic') species that threaten local ecology, according to the USDA, which is the governing authority on invasive species in the US. Natives may be weedy or aggressive spreaders/seeders but are not considered invasive.

Been home watching the kid thanks to the weather. After shoveling the driveway I found this list. I was humored by the inclusion of Bradford Pears, the points on the map where it has escaped cultivation are priceless! I promise to screen capture it and post it in every thread discussing them this spring.

Invasive plants on their list I own:

Whatever kind of honeysuckle that is the previous owners blighted me with

Barberry, Crimson Pygmy Berberis thunbergii, oops I planted that one.

The Bradford the previous owners planted.

Huh, Zoysia isn't listed...must not be a problem in the wild I suppose.

My there are some weeds on the list I am sure I have plucked and will pluck again.

Here is a link that might be useful: USDA Invasive species list

Zoysia is one of those plants that seems like it would be invasive, but isn't. Even in the warmer parts of the country, it doesn't become a serious environmental problem. I don't know of anywhere in the US (even Hawaii) where any of the Zoysia species are considered invasive.

I started to list the USDA site above, but didn't because I don't always find it helpful. It does have a lot of good invasive information indexed, but sometimes finding things is like pulling teeth. Sometimes I can find information faster with just a quick google search.

Ah, what grace ranchers and their cattle reap upon the land...puke.

I call it "welfare ranching"...need to make sure Americans can eat red meat 7x a week, no matter what the cost to the land.

I did not know that Bradfod Pears, while being hideous and over-planted, are also invasive...?

"Redcedar" is a favorite native tree of mine, resilient and competitive, like cottonwoods, which frequently bust up through the pavement of neglected abandoned lots.

Natives are typically referred to as "aggressive" or "weedy". Exotics typically are referred to as both weedy and invasive.

I think most of us here realize this, but there is a good reason for differentiating between invasive and aggressive. Invasives actually disrupt native habitat. They displace native species and are often detrimental to native fauna as well as flora. Native aggressive plants may be a pain to us as we garden, but are part of the natural ecosystem and are often beneficial to wildlife.

'Native' plants/trees can be invasive - and although I'm sure that he thought he was strengthening his argument that natives cannot be classified a invasive, brandon7 has touched on some of the essential criteria - disrupting native habitat; displacing native species and having detrimental impact on native fauna and flora. See the linked article below.

I'm not the only person who considers sweetgum to be an undesirable invasive plant - even if it is 'native'. In my native AL, it is enough of an overweening invasive, that I've made it a goal to eradicate every one of the damnable things that I find growing on my farm here.
In various areas of the country, there may be other native trees/plants that certainly could qualify as undesirable invasives, despite 'native' status.

Here is a link that might be useful: Invasive Natives

Interesting points of discussion. So the two terms we are debating are "invasive" and "aggressive"/"weedy"?

Certainly EVERY plant besides corn is invasive in them fields I pass on the way to work by that definition though. The same can be said for cotton fields....

I propose invasive is a larger term involving invading a geographic area not a plot of land like a farm field or my garden.

Weedy or aggressive describes species which are native to a geographic area but readily proliferate. Something like "Redbuds are weedy trees since little ones sprout up all over my garden". The natural oddities created by human activity seem to create more habitat for pioneer or weedy species like silver maples then the slower to mature eventually dominate trees.

Lucky,

While I can understand Nathan Klaus's ideas in the link you posted, they do conflict with most definitions that I've seen of the word invasive. Klaus refers to water oak and sweetgum as invading changed/disturbed ecosystems. This flies in the face of of typical definitions which frequently include wording like "displaces natives in a naturally functioning ecosystem". Indeed, Klaus's article goes into detail describing that the problem is initiated by changes in the environment brought on by human activity. Even an exotic that multiplies rampantly in a disturbed system is not necessarily considered invasive by most EPPC's and similar agencies. The Zoysia that we were talking about earlier is an example of this.

While one is free to try to redefine terms, especially in a scholarly article like the one you linked, that doesn't mean that the popular scientific definition is somehow wrong. From what I've seen, Klaus is using a non-standard definition and even points that out when he says, "Perhaps a better way to define an invasive species..."

BTW, plants can be exotic on a smaller scale than even a single state. Although examples of plants becoming invasive when introduced only a short distance from their native area are far more rare, that by no means clashes with the more normal definitions. In Toronado's initial post, I had a pretty good idea of the scenario he was describing concerning Juniperus virginiana. When I said, "Juniperus virginiana is NATIVE...", I was pretty certain that the conversation he was describing was not considering the species moving into an area where they hadn't been before.

Yes they're not finally classified as invasive until its well been over-proven that they've been taking over counties.. decades ago. Until then they're just considered "weedy". I imagine it takes quite a few steps to classify a plant in that manner.

Toronado,

Earlier, I missed your excellent point above when you said, "Certainly EVERY plant besides corn is invasive in them fields I pass on the way to work by that definition though." That is so true AND the main problem I have with Klaus's proposal. The subject is a "can of worms" to start with, but Klaus may be opening up that can a little more than he realizes.

I don't understand some of his points in the article like when he calls the pine/water oak/sweetgum forest unnatural when its obviously part of a succession?? The problem with the longleaf savannas is not the pioneer species its the fire suppression.. Seemed like a fairly un-useful article.

Native Plants are not invasive. This is an idiotic idea and contrary to current scientific, horticultural, and botanical definitions. Please see the link...and read the quote "outside of it's native range".

Here is a link that might be useful: Definition of Invasive plants from the USDA and USNA

Natives may be weedy or aggressive spreaders/seeders but are not considered invasive.

===>>>> OK attorney time ...

words mean things .... and i used them interchangeably.. starting this debate ...

i meant the cedars were aggressive spreaders/seeders ... my bad ... i will take a time out ... go sit in the corner ...

i will have to be more careful in the future ...

all i know is that i have a hundred of those pesky junipers all over the yard ... and there has to be something better if someone is contemplating their use ...

regardless .... i have atoned...

anyway ... as to the title of the post ....THE BEST LIST/reference ... is the list that tells you want to hear ... and then .. you ignore the rest .... lol

ken

OK Ken, your time-out is over. You can go play now. (-;

Ya know, I hadn't even realized how far off-track this thread had gotten. Invasives really can be a "hot topic". I've thought about starting a thread about some of the more controversial philosophical aspects of the subject just to see where it leads, but have resisted so far. It's probably a good thing I haven't done it. LOL

hey brandon.. its winter.. we need the discourse ... better to take it out.. verbally .... on each other.. in a spirited debate.. than go kickin the dog .. and the kids.. lol ...

thx for paroling me..

ken

We'll just have to agree to disagree. Or, we'll just disagree.

I'll assure you that in my experience in the area of The South where I grew up - and where I still visit on a regular basis, Liquidambar styraciflua is every bit as invasive, and damaging - if not more so - than Pyrus calleryana, Sapium sebiferum, and Albizia julbrissin all combined - and all are present there.
Its 'native' plant status does not preclude its inclusion in the 'invasive' category.

finis

Lucky,

Can you point to an example of where Liquidambar styraciflua is aggressively increasing its range and displacing natives in a naturally functioning (unchanged by man) ecosystem? I think that's the thing that would make the difference according to the standard definitions. The fact that the tree has been present in most area of the south for ages makes it unlikely that it would suddenly become aggressive without human intervention. If the problem is with environmental change as opposed to the nature of the plant, then what is the purpose of redefining the word "invasive" (as Klaus appears to try to do) to cover this example? And, is the change worth the price of watering-down/broadening the definition and effectively reducing the usefulness of the word?

Maybe the term "pest plant" would be a more appropriate choice? I don't think it has the same strict implications often attributed to the word "invasive", but would still sufficiently categorize the plant as a potentially aggressive spreader.

"Sweetgum".... Its not an invasive.... its a pioneer species.... its SUPPOSED to fill in the gaps... quickly....

Early successional species always get a bad rap on here - consider cottonwood, willows, boxelder, silver maple, redcedar, sweetgum etc. They are all aggressive seeders and colonize new bare ground. Sorry they didn't read the elitist gardening books and manuals.