Where are the limits?   Robert Leverett   May 19, 2004 07:27 PDT  ENTS:        With the confirmation of enormous volumes of the Middleton live oak and the Sag Branch tuliptree by Bob Van Pelt as currently the largest volume hardwoods measured in the East and with Will's new 154.7-foot red spruce and Jess's confirmation of the 168.2-foot pignut hickory as currently the tallest IN THE WORLD for those two species, we're riding a wave of firsts. Jess Riddle obviously has a phenomenal area to search and he's just the person to do it. Will has possibly the finest temperate hardwood forest in the northern hemisphere in which to roam and confirm new champions. He also has the tallest coniferous forest in the East in which to do the same. Meanwhile Dale Luthringer is going gangbusters in Pennsylvania, giving us an increasingly detailed look at the taller forests in the Allegheny plateau region and on the border of lake Erie. Through a mountain of work, the Tree Amigos have verified 61 white pines in MTSF that top 150 and most are still growing teenagers - lots of potential yet to realize.        Well, the list of accomplishments goes on and on and just when we think we've exhausted the possibilities, we discover a new site and so it is here in Massachusetts. My son Rob took the time to look carefully at Laurel Park in Springfield MA and it blew him away. Very large red and white oaks. Very large black birch. Tuliptrees. Oh boy! So sometime in the next week or two, we'll begin roaming Laurel Park and documenting its arboreal delights. As Tom Diggins often says, so many trees, so little time.        Where and to what do the continuing ENTS discoveries point? All these super trees. Well, of course they tell us something about species potential, but not just of isolated individuals - the circus freaks, so to speak. We are gradually homing in on what a species can do over its full geographical range, and more importantly, with what probability. That's my current focus.        We shouldn't be satisfied to just know where the largest pines are and the individual dimensions of the champs. We should be able to answer questions as to how likely or unlikely any particular range of dimensions can be achieved for a particular species, what's common and what's not for a species in a particular growing habitat.        While a lot of us have rough ideas about species growth potential over fairly broad ranges, we have a long way to go to fine tune our understanding even for a relatively local area, an area of perhaps a few as ten of thousand of acres. Each new discovery can make previous notions obsolete and the job of fine tuning our understanding of species potential can seem more and more elusive.        But in actuality, we're making enormous strides. However, those strides have required that we first served our period of apprenticeship, even though we had to be apprentices to ourselves. We also had to rid the business of tree measuring of some real handicaps. We have had to counteract: 1. The hobbyist status of big tree measuring that has been fostered by the champion big tree lists,         2. The mistaken perception that big tree knowledge is vested in the lumber producing occupations,         3. The unfortunate belief that current historical accounts and data are sufficient to understand species potential,         4. The understandable but erroneous assumption that governmental organizations and officials and/or academics have the answers,         5. The industry-minded opinion that it's all goofy stuff - the only real purpose for a tree to serve is for construction, paper, or wood chips. End of story.         I used to get irritated by people (including myself) who fell prey to any or all the above notions, but have become more tolerant in my old age, partly because ENTS has made lots of converts and we don't have to any longer to yell so loud to be acknowledged. Lee Frelich may have had the most to do with our growing acceptability in the East by making it safe for other PhDs to follow suit. As proof of our new found acceptance, Friends of Mohawk Trail State Forest has concluded two long term special research permits with the Commonwealth of Massachusetts. Both permits recognize our role in a couple of areas of research that other Massachusetts organizations and institutions could claim as equally within their purview. However, in terms of inventorying, mapping, and documenting old growth on public lands in Massachusetts, we ARE it. Exciting times are upon us.       So now maybe we can roll up our sleeves and get down to business - no longer any need for internet admonishments of the doubters or pretenders to the throne. So what's next? The impending research and associated data collection efforts for MTSF will concentrate in the following areas:      1. Continued perusing the area looking for the superlatives (can't easily break us of that),      2. Development of increasingly accurate methods for measuring annual growth,      3. Testing different independent variables for ease of measurement and tracking,      4. Developing statistical distributions that we can ultimately use to compute the probabilities associated with the achievement of different growth thresholds.      It is the last area that will occupy the attention of several of us over the coming summer, because if we can assign realistic probabilities to growth potential, we can convey to others how rare or common a growing habitat for a species currently is or could be under existing environmental conditions. For example, the population of white pines that reach the dimensions of 12 feet in circumference and 150 feet in height is very small. In Massachusetts, we currently have only two single-stemmed pines that make reach this threshold. We have one documented in New Hampshire. There are several in Pennsylvania and quite a few in North Carolina. Michigan has had a few in recent years as has Wisconsin, I suspect. New York has one or two and so the numbers go.       From these numbers, it is clear that the likelihood of a white pine eventually reaching the 12-150 combination is low to very low. In some areas, the probabilities is extremely small, practically zero. In highly favorable growth areas that include several to many 150-footers, it is unclear how much natural stand thinning is needed to allow good diameter growth along with continued height growth. Presumably, when we see both good diameter and height growth continuing at a location, we have identified a top white pine site, but for how long? Making predictions about maximum potential is risky when trees are only 50 years old - unless there is a prior site history to turn to. That's where MTSF becomes so valuable as a research site.      In MTSF, we are blessed with several pine locations in the 45 - 60 year age class, several in the 90 - 120 class, and a few in the 135 - 175 class. We can study 3 sub-populations, 50, 100, and 150-year-old age classes. We can even add a few in the 175-year age class.     We want to be able to compute probabilities with which pines achieve various size thresholds within the three age classes. To do this we have to have population numbers. How many pines do we have on each site within each age class? Answering that question has become the focus of my attention. As some general observations, at this point 50 stems per acre appears common for the less dense areas and 100 for the more dense areas. Small areas will have 150 to 180 pines per acre. However, these densities are not sustained.      Based on what we've mapped as white pine habitat, we currently believe that there are between 5,000 and 10,000 pines in MTSF. We are, or at least I am, very shaky on this number. We'll see how our estimates/calculations evolve over time. My current guess is about 6,500. Bob   Home