Native Tree Society BBS

ENTS: I agree partly with Ed and partly with Neil. Clearly in ecology, we have not come up with any exciting new theories in a long time (I use theory in its scientific sense--a set of ideas that explains how something works--and not the slang usage that is so common--as an alternative to a fact). W...

Kouta: I agree with your assessment (in many cases) of boreal retrogression in Sweden and North America. Perhaps secondary retrogression is a valid concept. However, some of those sites also have almost no soil on top of granite, so in some cases its not just that the nutrients are unavailable in th...

Bob:

Thats as close to a squid, or to one of those creatures from an Aliens movie, as a tree can probably ever get. However, I do feel sorry for the tree.

Lee

Bob: Well, your winter must be colder than ours, we have not had a zero degree day yet. Joe: The upside of global warming is not having to drive as often in the blizzards that used to be more frequent. Ecologically, all changes lead to negative effects on one group of species and positive effects on...

Bob: Yes, but there are fewer of them this year than last year. Have you seen James Hansen's latest analysis of temperatures in the U.S. and other parts of the world? It shows that the last 30 years, as compared to 1951=1980, had a shift to a warmer mean, but that also the variance of the distributi...

ENTS: Although there have been some cold winters in New England in recent years (especially last year with its negative Arctic Oscillation), winters in Minnesota have been getting steadily warmer. We have not had a day yet with a low of zero F or lower this 'winter', and if this does not happen by W...

Kouta: Old tropical rainforests can have mechanisms and plant species adaptations that allow them to retain and very tightly recycle nutrients, and losses to the ecosystem may be so small that atmospheric inputs can replace them, even for P (see page 512 of the article). This would allow retrogresse...

ENTS: I read the paper: Eloy, C. 2011. Leonardo's Rule, self similarity, and wind induced stress in trees. Physical Review Letters. 107, 258101. Also analyzed, was a tree with random branch angles, which looks a lot more like a real tree: Picture1.png With this stochastic tree, Leonardo's exponent r...

Kouta and Neil: I think the forests in Finland are quite different--they don't have balsam fir which is susceptible to the native (and poorly named, since it mainly infests fir and not spruce) insect spruce budworm. So, the time for retrogression is uniquely short in boreal forests of central North ...

Gary: Yes, I think they can meet the criteria listed in your slide after being logged. If you look at the second-growth forests inside the Boundary Waters Canoe Area Wilderness, Voyageurs National Park, and Isle Royale National Park, and many other places in the Midwest, that were logged once, or lo...