Don, It's quite rare around these parts, being pretty much confined to the lower Saint John river valley, around where I live. I've been trying to find as many as possible. I came across a nice one about a month ago growing on a small island in the Saint John river - it was absolutely loaded with nuts. What does the blight look like?
Mike On Sep 28, 10:11 pm, Lee Frelich <[email protected]> wrote: > Don: > > You mean a positive reinforcement of negative effects. There are plenty > of those involving shade and an allelopathic chemical, or changing the > chemistry of the litter layer, say to a lower pH and then throwing in an > allelopathic chemical and shade (i.e. black walnut). Or making the > litter layer poor in nitrogen plus an allelopathic chemical and shade > (Bracken fern), and all of the above smothering competition with > litterfall (e.g. sugar maple, the latter reinforces chemical and > resource changes with a physical effect). Trees keep out their > competition with multiple strategies. > > Lee > > DON BERTOLETTE wrote: > > Lee- > > Can you suggest an allelopathically positive effect (chemical > > combinations that turn out to be synergistic come to mind)? > > -Don > > > > Date: Thu, 24 Sep 2009 14:18:13 -0500 > > > From: [email protected] > > > To: [email protected] > > > Subject: [ENTS] Re: Marion Brooks Natural Area, Elk County, PA > > > > Don: > > > > Most ecologists take allelopathic to mean negative effects on other > > > plant species. The plants that benefit could be either directly and > > > positively affected by the allelopathic chemical (but this is > > unlikely), > > > or benefit indirectly by being insensitive to the allelopathic > > chemical, > > > but being freed from competition by removal of other species sensitive > > > to the allelopathic chemicals (this is the most likely case, but no > > proof). > > > > Lee > > > > DON BERTOLETTE wrote: > > > > Lee/Mike- > > > > In my time wandering through Kentucky woods, black walnut trees were > > > > the only thing I saw that could alter the advance of a field of poke > > > > salat! > > > > My question? What would negative allelopathic refer to? I can see > > > > that it would be positive in this case for black walnut and negative > > > > to most anything else, but I suspect it may refer to something else > > > > entirely? > > > > -Don > > > > > > Date: Thu, 24 Sep 2009 07:50:26 -0500 > > > > > From: [email protected] > > > > > To: [email protected] > > > > > Subject: [ENTS] Re: Marion Brooks Natural Area, Elk County, PA > > > > > > Mike: > > > > > > We had a discussion a while ago on this topic, probably before > > you were > > > > > on the list. Black walnut and butternut produce the allelopathic > > > > > chemical juglone, which can stunt growth or even kill certain plant > > > > > species, although I have seen raspberries and a species of > > coneflower > > > > > (Rudbeckia triloba, the branched coneflower), growing under black > > > > walnut > > > > > trees. > > > > > > Sugar maple and bracken fern have also been found to produce > > > > > allelopathic chemicals that reduce germination and growth of > > competing > > > > > plants. There are probably many other examples. > > > > > > Lee --~--~---------~--~----~------------~-------~--~----~ Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en To unsubscribe send email to [email protected] -~----------~----~----~----~------~----~------~--~---
