Not wasting my keystrokes beyond this:

Here is a link that might be useful: Native vs non-native

Invasive non-native plants can and have caused native plants to become rare or endangered; I don't know if any species have beome extinct, but there are a number of them that are no longer easily found in the wild. This is not acceptable to many people, including me. Perhaps you should do some research on it?

Not worth wasting MY keystrokes beyond posting this:

http://arnoldia.arboretum.harvard.edu/pdf/articles/483.pdf

But, to add a bit...IMHO it really depends on many factors, including the invasive in question, the area it is growing, and the agronomic history of that area. As I've previously pontificated, I can't get too worked up about certain non-natives in the surburban or ex-urban parts of the US east coast, because those areas have already passed through the ecological tumult of human habitation and are never going to be "right" again. The only way to make them right would be for everyone to pack up and leave and let the suburbs revert to 100% forests. Since there are now millions of linear miles of forest edge that would otherwise not exist, heck yeah I'd rather them be filled with english ivy than poison ivy. We should try to get rid of invasives when they truly threaten pristine environments that are not otherwise threatened. That isn't always the case with how they are promoted, though. The blanket notion they are superior for every landscaping requirement is hogwash. It's an example of the creeping intellectual indolence affecting our culture. For example, the 95 rest stop in Cecil County used to have some camellias planted outside, along with various standard east coast landscaping shrubs like cornuta hollies. I'm sure they required no special care because they were there for years and certainly wouldn't have gotten any. They looked nice when they bloomed in the fall. The reincarnated version of it has some hideous politically correct "eco-landscaping". The irony is it looks more out of place than what was there before. They've taken some lower Delmarva savannah look with little grassy things underplanting Pinus taeda. Well, look around bozos...what is surrounding this HW rest stop? Rich oak and tulip poplar woodlands, on loamy not sandy soil. I could have at least accepted them planting _that_...but no. Suddenly you're transported to a weedy abandoned lot along I-13...they ought to throw in a replica Virginia state trooper with radar, set up for a speed trap. Utterly idiotic yet I'm sure someone will win an award for it. Such is this country's lamentable "landscape design" industry.

This post was edited by davidrt28 on Wed, Sep 10, 14 at 17:46

under the same logic.. you should be happy when weeds choke out all your grass ...

and there might be logic.. that once they invade ... its no longer a virgin native habitat .. but a man made problem .. and that is probably near the root of the argument ... the invaders.. are not natural ... not nature itself ...

ken

The most persuasive argument lately is the lack of support that non-native plants provide to the local ecosystem. Very few bugs eat them so therefore there are few bugs for birds to eat and feed them chicks.

Reduced native plants = reduced native insects = reduced native birds (and others that rely on insects and/or birds for their meals).

And yes, this mostly applies to invasive exotic plants because they reproduce so much, but suburbia has in many places turned into ecological wastelands with all the native plants replaced by parking lots, lawns and non-native ornamental plants.

Therefore when invasive plants disturb roadsides and forests, they are further shrinking what little land we left for native plants/insects to live.

refer to your state's Native Plant Society linked below. I see they have a great Fall Conference lined up next month in Texarkana, check it out.

Here is a link that might be useful: Arkansas Native Plant Society

because they provide limited ecological services.....they throw off the natural cycles in places....for example many of our butterflies are host specific and only lay eggs on one species of tree.....if you got a Bradford pear growing in a field that could be taking up space for a tree that could otherwise be producing butterflies. Many other animals also feed on the caterpillars so if you planted all non natives you wouldn't get a fully functioning ecosystem.

Because SOME foreign species that move to new habitats have no natural enemies and breed like crazy, out-competing the native species and creating monocultures. Native mulberry are quite rare.

Many species (eg butterflies) evolved to use the native species as food sources,homes or symbionts. Often they can't use the foreign plants.

The black locust is completely changing the ecology of cape cod. It is a super-effective nitrogen fixer...and fertilizes the soil beneath it so well that all sorts of foreign species grow beneath it, completely changing the habitat.

In parts of California, English Holly have completely replaced the native understory trees. When the older trees die, we will have holly forests. The species that do well in a conifer forest with no low branches may not be as happy in a holly forest.

Having said all that, I can't see a "weed" tree growing in a vacant lot as a bad thing...I feel good if any trees take hold in the tiny bit of green that form by accident in a city.

I think people need to cut the bs about non native vs native. Too much of a blanket statement to state natives only support local ecosystems, no?

Its about invasives that need to be eradicated whether they're native or non-native.

Just to point out, something like 50% of the weedy annuals/perennials/grasses in fields are of non-native origin & have been for a long time -- brought over by colonists. Those can't be eradicated & long ago blended into the ecosystem.

For my part, I'm just happy to see a rather nuanced discussion unfolding here. I see I'm not alone in being frustrated with some of the unintended consequences of the "natives only" movement, even though to a large extent, I'm a part of that movement, or at least a supporter of its main tenets. I think it really comes down to the fact that there are a few really bad actors, and then a whole bunch of stuff somewhere in the middle. I'm a big fan of Norway spruce-obviously not a native tree-and I know of some woods which are mostly native, but have a few big , old monsters of this species mixed in. In my view, absolutely not a problem, in any way. But those same woods are truly being "choked" by common buckthorn. That will be their demise, as that plant really does have the ability to crowd everything else out.

It just depends on the situation, but to not realize there is a problem with non-native, invasive plant species proliferating in the environment indicates that you, OP, just haven't yet seen the light. Since you're interested enough in the topic to bring it up, I suspect you will in time come to see the havoc. A part of it really depends on your managing to fall in love with the native plant communities which have not yet been destroyed. Then once you cross that threshold, I think it will become clear what something like Callery pear, garlic mustard, or common buckthorn is doing to the landscape.

+oM

Every time you introduce an aggressive, vigorous non-native, you are gambling. There is a risk it will go terribly wrong. It might not, of course.

Now, planting non-natives that have trouble surviving in this area. (Zone pushing, tropicals, inbred cultivars that have had flowers scaled up at the price of general vigorousness) It creates a more subtle problem. They often need a lot of chemical fertilizers and pesticides to keep alive around here.

When a piece of land is allowed to revert to habitat, (abandoned farmland, vacant lots) what plants colonize it? Often it is the plants the neighbors grew in their yards. I like the idea of planting aggressively spreading natives in the hopes they will colonize the local vacant lots and median strips.

I don't see anyone making a "natives only" statement here. The question was asked and people are answering. The question was about non-native trees in the wild and of course that applies about 99% of the time to invasive trees.

Yes, there are non-natives that can contribute to the local insects (host plants like parsley and fennel are good substitutes as are many of the nectar rich plants) and non-natives that provide sustenance to foraging critters (berries, nuts).

Agreed. I could care less if folks plant dozens of acer palmatums in their yards. Those things just don't spread and change the local ecology.

Now planting honeysuckle and mimosa is TERRIBLE. In the big sense it won't lead to the end of civilization but it does make St Louis look less like St Louis and they will replace natives eventually. Think Kudzu.

Oh, on the extreme end. What if I start an invasive plant farm upwind from the kings canyon. Our kids will be unable to go see the redwood forests. Not that they'll die. They just won't have that experience.

And aren't we always hearing that every extinction could remove a plant containing the keys to curing cancer, AIDS, HIV, and ugliness (ok, I made the last one up)...but the point.
Invasive alien plants contribute to that extinction...both in plant species and animal species that depend on them. Frogs and toads have been responsible for a lot of recent drug developments...but they're dying off (probably not due to invasive trees, but who knows).