Watch out for those norway spruce seedlings, they will grow large and kill the surrounding hardwoods with shadow. It's really are a pest over here, in its native area. More than 40% of all trees here are norway spruce, and it is really a crappy tree for wildlife and herbs. It's not even good for firewood.

Whereever someone has got an abies grandis fir tree there are seedlings all over the area. That is kind of surprising since it's supposed to only barely survive away from the coast here. It seems way hardier than that.

Not a big hmmm, but I potted up several Acer griseum this fall from the yard of a gardener with I believe four griseum in her landscape.

I've heard that to get viable seed of griseum, a minimum of eight + trees are needed.

Dax

I'd be delighted to see Picea abies regenerating on my land! I think of this tree as anything put a "pest".

Truth is, I find it hardly ever happens. I do know of some naturalized NS, but that's way up in NW WI, in fact, right where they want to put that giant iron mine. Very, very rare occurrence, which we have in fact speculated about on these pages.

I'd suggest too that where oak wilt is established, future regeneration of oak is quite likely not the best course of action.

+oM

"I'd suggest too that where oak wilt is established, future regeneration of oak is quite likely not the best course of action."

I strongly agree with that. P. abies may become a pest here, but I don't think we're anywhere near that tipping point. At what point does a non-native become invasive? Is there a formula for making this judgement?

Huggorm is from Sweden so its no wonder they have so many Picea abies there.

I've seen occasional propagation of it in New Jersey, but pretty rare. Plus, it seems to struggle in competition with hardwoods there, so I'm not expecting a problem.

The biggest "hmm" I've noticed was the natural propagation of Acer palmatum in northeastern New Jersey (Palisades Park). That was like, woah.

Dax ~ That doesn't bode well for my one and only A. griseum, not that I really expected it to produce seedlings. Heck, I'd be thrilled if it survives this winter, which is turning out to be a doozy. I am a bit more optimistic about A. triflorum, which produced a bumper crop of seeds this past summer. Who knows, maybe I'll have Three-flower Maple crowding out the Amur Honeysuckle and Buckthorn. Now that would be a surprise.

basic,
Curious as to how old your A. triflorum is? Ours has yet to flower, though the tree is probable 10' tall now. We have had it now for about 5 years. Not that flowering really matters, was jsut curious.

Arktrees

Basic, to address your question, I know of no formula describing the point at which naturalization becomes invasion. FWIW, I've got a problem with the way the term invasive sometimes gets used. Invasion of an old field by species of trees growing in the surrounding forest is not only acceptible, to me it is one of the most satisfying things to see. But it really is "invasion". Then you've got the prairie nazis-sorry, I work with this plant community too, although it's not native where I live-who regard a perfectly fine native tree like white pine "invading" their prairie patch as a problem. I guess you could say I've had my fill of that sort of thinking!

There probably does exist some scholarly work somehwere describing exactly what you ask about. But for your (And our) purposes, you are absolutely correct, the few NS coming up in your compromised oak stand are not only not a problem, they're a good thing.

I too have noted Huggorm seeming to have quite the dislike of NS. To each their own. But so long as I'm active on this board, a swift and strong reaction can be expected, any time my favorite tree is so besmirched, lol!

+oM

"I too have noted Huggorm seeming to have quite the dislike of NS. To each their own. But so long as I'm active on this board, a swift and strong reaction can be expected, any time my favorite tree is so besmirched, lol!

+oM"
Well, that's propably true. I don't know how many hundreds, maybe thousends I have cut down. It has to be done as soon as possible since nothing else will grow at the spot for several years. It seems like some toxic stuff is released from fallen needles and even more from dead or dying roots. Something similar to juglone. I like woods with many species of trees, bushes and herbs and the norway spruce is a master in preventing that. Where there is NS, there is nothing else, all you see on the ground is dead needles, moss and maybe some oxalis. And lots and lots of NS seedlings of course.

This post was edited by Huggorm on Mon, Jan 20, 14 at 13:30