Kirk: Probably a coincidence. If you look all along the glacial boundary, you can find all sorts of fragments of species ranges that happen to correspond for short segments, but that does not mean the glacial limit is the cause of the species limit.
Lee Kirk Johnson wrote: > Lee, > > Even though the cucumber tree occurs elsewhere in western NY and western PA > where there was glaciation, there does appear to be a correlation between > the termination of the glaciation in Cattaraugus County, NY and the northern > extent of the cucumber's range in that county. > > Do you think that is just a coincidence? Perhaps that is what Bob's Vermont > ecologist was referring to? > > Kirk > > > > > >> 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] -~----------~----~----~----~------~----~------~--~---
