Don, You're on the mark. We have tended to be more casual on our girth measurements. We know how to be precise. We just need to apply our knowledge.
Bob -------------- Original message -------------- From: DON BERTOLETTE <[EMAIL PROTECTED]> Bob- It's hard for me to not think of an array of curves (comparing height change and girth change) and lines (of regression where periodic annual increments go from net loss to net gain). Not! Seeing the gnarly red maples, er, they meant red oaks, in yesterdays posts I see O-g bark characteristics!! But in their latter years, growth is hard fought at the tips and the cambium, and the tree's decisions as to where they bank their earnings could be determined by such 'curves and lines'. My earlier question came from musing about how accurately we measure circumference. Playing the devil's advocate, I'd probably weigh in on the side predicting problems with precision. As a challenge, I would expect that ANY five Ents measuring gurus, measuring girth at breast height/base height would come up with readings that varied in tenths of a foot, if done independently (with no prior knowledge of where others took their measurement). I pose the opinion that girth is typically measured relatively casually. I would suggest that from the pool of all tree girth measuring images that ENTS has, most of them (more than half) visually appear to be taped incorrectly (in the case of a perfectly vertical tree, the tape will wander above and/or below a level (perpendicular to an assumed perfectly vertical pith) line around the trunk; and in the case of an imperfectly vertical tree, the tape will also wander above/below (perpendicular to an assumed IMperfectly vertical pith) the plana r (but not level) line around the trunk. I'm posing this scenario, with best-case-scenario perfectly circular girthed sample trees. I am quite familiar with the challenges added by 'real world' trees with irregular circumferential shapes. In a perfect 'measurers' world, we would determine the "path" of the most accurate circumference measure, and mark the tree (discreetly of course) such that subsequent measurements could be taken, that more accurately replicate past 'plane' of past measurements. Sorry for the rambling, just had my morning coffee! -DonRB From: [EMAIL PROTECTED] To: [email protected] Subject: [ENTS] Re: The long update process has begun Date: Mon, 22 Sep 2008 13:37:57 +0000 Don, I record both. I present a lot of height data on the list, but I have the corresponding circumference data and could present it. I've tracked particular trees very closely over the years, others less so. I've also experimented with various lists and thresholds, some more for promotional purposes than scientific investigation. Either way, I have a ton of data. At a broad-brush level of treatment, I guess one could simply say that on good sites, left to grow for up to 120 years or more, predictably tree volume continues to increase. That's a no-brainer. The big question for all of us is: at what rate? That's where the additional measurements that some of us ENTS are taking may one day point the direction to a reassessment of the roles of the bigger trees - if for no other reason that the real amount of carbon sequestration. Then maybe not. What are your thoughts? Bob -------------- Original message -------------- From: DON BERTOLETTE <[EMAIL PROTECTED]> Bob- Does your updating of heights include updating of cbhs? What kind of precision would you anticipate on repeated replication of cbh measurements? I think it would be very interesting to have comparison data between meristematic growth (at the top, as measured by height) and cambial growth (at the bottom, as measured by circumference). -Don From: [EMAIL PROTECTED] To: [email protected] Subject: [ENTS] The long update process has begun Date: Mon, 22 Sep 2008 02:31:07 +0000 ENTS, Today I returned to MTSF with the intention of continuing to update my white pine measurements for that unique Massachusetts state forest. I concentrated on the Trout Brook region of Mohawk, which has a scattering of pines, most of which are relatively youngn and growing fast. I'm pleased as punch to announce that 4 more pines have entered the 10-foot circumference, 140-foot height class. In addition, one very large pine, the Trout King Pine has made it to 12.0 feet in circumference and is now 148.8 feet in height. It will make it to the 12 x 150 club in one or two more years. It is a single-stemmed tree - not cheater. A second tree has made it into the 11.0-foot circumference, 140-foot height class. The last time I measured the tree, it was under 11 feet in girth and 140 feet in height. Its exact dimensions are: Girth = 11.1 feet, Height = 140.2 feet. The Trout Brook watershed now has two single-stemmed pines in the 12-foot girth, 140-foot height class. I am fairly sure that the Trout King's volume approaches 700 cubic feet. At present, I think it is around 670 cubes. It is packing on the wood and will certainly exceed 700 cubes within 10 years. In Trout Brook, there are two 150-footers, or at least was the last time I measured them. On my next visit, I'll confirm them. I don't think Trout Brook has any other candidates for the 150-foot club for the present. The amount of labor to update the MTSF white pine inventory is daunting. I am alternately opmistic and pessimistic. I basically am doing the update solo, but for the most part, it remains a labor of love. Hopefully, I won't run out of measuring gas. My fascination with big trees not withstanding, I do think updating the big pines list is an important job to complete. For one thing, the list points to what kind of performance we can expect out of a white pine forests on good sites that are left to grow for different lengths of time. In Mohawk, we presently can examine stands that are about 60 years old and compare them to adjacent stands that are around 100 years old. We can carry the comparison process further by examine stands between 130 and 150 years old, and finally, examine a stand with trees around 170 to 190 years. The self-thinning process can be observed as it has progressed over decades. The huge sizes of the pines in the Elders Grove speak eloquently to the capabilities of the great whites to pack on wood for over 200 years. Of course, forest managers will not likely manage for such ages, but what modern day lumberman pass off as maturity in white pines is not maturity - not even close. An entire generation of lumberman may have lost sight of the full capabilities of the species. Oldtimers may understand, but their time has passed. Mohawk Trail State Forest has the power to educate. Bob </HTML<BR --~--~---------~--~----~------------~-------~--~----~ Eastern Native Tree Society http://www.nativetreesociety.org You are subscribed to the Google Groups "ENTSTrees" group. To post to this group, send email to [email protected] To unsubscribe send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/entstrees?hl=en -~----------~----~----~----~------~----~------~--~---
