Gary: Yes, but only for short segments of the range limit. Of course community composition often shifts with changes in moraines or other glacial features, because the different soil composition leads to a different mix of species.
Lee Gary A Beluzo wrote: > Lee, > > Interesting topic. Have you seen any tree species ecotypes that seem > to follow a natural boundary like terminal moraine, shift in soil > taxon, etc? > > Gary > > On Nov 3, 2009, at 3:24 PM, Bob <[email protected]> wrote: > > >> Lee >> >> Thanks for weighing in on this topic. In the future, I'll be >> cautious about accepting that explanation when I hear glaciation given >> as defining the range for a species. I'm embarrassed to admit that >> I've often repeated the glaciation explanation for cucumber magnolia's >> absence from part of New York. >> >> Bob >> >> Sent from my iPhone >> >> On Nov 3, 2009, at 3:06 PM, Lee Frelich <[email protected]> wrote: >> >> >>> Bob: >>> >>> I am always amazed that people attribute ranges of various trees or >>> other organisms to glaciation. It seems unlikely that a glacier that >>> existed 14,000 years ago can control the range limit of species >>> today, >>> especially for trees that can grow in a wide variety of soil types. I >>> have been told the same about native earthworms--that they only >>> occur in >>> unglaciated areas, but in WI they occur only in the glaciated part >>> and >>> not in the unglaciated part of the state. There is always a >>> possibility >>> that a species could grow on either side of the glacial boundary by >>> chance. There are also areas where the glacier scraped the soil away >>> down to bare rock, which does have an influence on what grows there, >>> but >>> this effect does not occur at the scale of tree species ranges. >>> >>> Lee >>> >>> [email protected] wrote: >>> >>>> Kirk, >>>> >>>> Yes, I see the distribution goes fairly far north. Those >>>> distribution >>>> maps existed at the time I was told about the limited range factor. >>>> I'm now puzzled. The ecologist who told me about the glacial >>>> boundary >>>> is well respected. I wonder what he knew that we don't. >>>> >>>> Bob >>>> >>>> ----- Original Message ----- >>>> From: "Kirk Johnson" <[email protected]> >>>> To: [email protected] >>>> Sent: Wednesday, November 4, 2009 12:16:59 AM GMT -05:00 US/Canada >>>> Eastern >>>> Subject: [ENTS] Re: King Pennisula, Allegheny River, Forest County, >>>> PA >>>> >>>> Bob, >>>> >>>> I don't remember hearing that before, so I don't know if it's true. >>>> However, the attached distribution map I found online seems to >>>> indicate otherwise (showing range into NYS all the way to Lake >>>> Ontario). >>>> >>>> On the other hand, the Allegheny NF & environs does seem to be a >>>> good >>>> home for cucumber magnolia anecdotally speaking. There are a lot of >>>> them here and some of them are large, so they seem to like it here. >>>> (They are one of my favorites.) >>>> >>>> Kirk >>>> >>>> >>>> >>>> >>>> >>>> >>>> Kirk, >>>> >>>> I was once told by a forest ecologist from Vermont that the >>>> cucumber magnolia appears south of the glaciated zone in western >>>> NY-PA, but not in it. I presume there isn't a sharp line of >>>> demarcation, but practically so. Is this explanation for the >>>> distribution of cucumber magnolia still in vogue? >>>> >>>> Bob >>>> >>>> ----- Original Message ----- >>>> From: "Kirk Johnson" <[email protected]> >>>> To: [email protected] >>>> Sent: Tuesday, November 3, 2009 11:32:59 AM GMT -05:00 US/Canada >>>> Eastern >>>> Subject: [ENTS] Re: King Pennisula, Allegheny River, Forest >>>> County, PA >>>> >>>> Bob, >>>> >>>> That is true. To the west of the Allegheny River and to the east >>>> of the Big Level was glaciated. But what is today Allegany State >>>> Park in NY and the Allegheny NF was not glaciated. >>>> >>>> Kirk Johnson >>>> >>>> >>>> >>>> >>>> Ed, >>>> >>>> I am jealous. The Connecticut River corridor has some fine >>>> trees, but the Allegheny River has sycamores and silver >>>> maples that exceed any I've found along the Connecticut. >>>> If I remember correctly, the area of the Allegheny in PA >>>> wasn't glaciated. Is that correct? >>>> >>>> Bob >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> > > > > --~--~---------~--~----~------------~-------~--~----~ 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] -~----------~----~----~----~------~----~------~--~---
