Useful Data   Robert Leverett   Jun 04, 2004 11:19 PDT  ENTS:      The chatter about our impending research at MTSF has probably been a bit much for those wanting to read about issues more relevant to their situations. We want to include all ENTS members in the discussions, but we've agreed among ourselves to move the back and forth chit chat into a private e-mail stream. The ENTS list should be reserved for material of broader interest.      With respect to the current Mohawk project, I often worry about what the results should be to justify the effort we're making. Given what is happening to our native species, if our contributions find value only as historical documentation, then for me, that is sufficient. However, we will probably obtain results of practical value to the more curious resource managers. Research results will provide us with baseline indicators that we don't currently possess. For example, what can we expect from natural regeneration on good white pine growing sites at the 100-year mark and over? There is plenty of silvicultural data collected for highly managed stands, but when it comes to natural regeneration in specific locations like the Deerfield River corridor, there are only the tables based on data from who knows where, collected by who knows who, and actually representing who knows what? There are lots of people with gut feels about growth rates, but perceptions are all over the place.       On state lands we have the Continuous Forest Inventory (CFI). There are plenty of plots in the state forests that are periodically monitored. Gary Beluzo knows the exact configuration. So far as I am aware, CFI is the principal source of information about growth rates in the public forests. I have seen many of the plots and know many of the folks who do the monitoring. I have very mixed feelings about CFI and its value. I have difficulty imagining how data from the plots I've seen can give good pictures of the growing conditions in the areas they ostensibly represent. I recall one plot on a dry ridge adjacent to a mesic area. The difference in growing conditions couldn't be more exaggerated. The ridge-side had been swept a fire perhaps 70 or 80 years ago. Loss of top soil and the southeastern exposure makes tree growth there now very slow. It would be classified as a very poor growing site. However, fifty yards downslope from the last marked tree in the plot, a terrace spreads out, covering about 4 acres. The ash growth on the terrace is spectacular. In adjacent areas, tree growth is intermediate between these extremes. So what does the CFI data from the plot tell us about the general area? Well, maybe that was just an example of luck of the draw. If the numbers from this CFI plot are dumped into a big data pot and stirred along with hundreds of others, presumably, the averages will work out, but work out to what? For what? I've seen other CFI plots that are located in areas that are not representative of the surrounding species mix or growing conditions, so I am skeptical that so much unrepresentative data will somehow magically "average out" and do the intended job of accurately conveying species mix and volume growth at modest spatial scales. I see no point in applying data to an unusual place like MTSF because it fits okay somewhere. Are we supposed to dumb ourselves down to fit some very broad average?         BTW, tree height data are not being collected for these CFI plots, just DBHs. Heights and volumes are presumably statistically derived from radial growth. Very dangerous! We have documented ad nauseam the problems associated with height measurements that use the percent scale of clinometers with fixed baselines - the common forestry method. So, can we assume that height data incorporated into existing volume models suffers from errors associated with flawed measurement techniques that vary with species - better for conifers than hardwoods. Yes, I think we can assume that. Accurate volume determinations are highly improbable from current CFI data fed to volume models. Nor do I believe that the CFI data answers other relevant questions. None of the CFI data has answered routine questions about MTSF's exemplary white pines.      From a forestry perspective, I would assume that planners would want to know the following about the Mohawk pines.      1. Total acreage within identifiable age classes      2. Standing basal area and volume within each age class a. Percentage of basal area and volume by diameter class b. Average number of stems by diameter class per acre      3. Average growth rates in each age class                         a. Radial                         b. Height                         c. Volume      4. Percentage of each age class by volume of single-stemmed versus multi-stemmed timber.       At present, DCR may have rough board feet estimates, but nothing more. So, developing truly tight stand-level baselines for the age classes will provide DCR with plenty of practical information that they don't currently have. So, this is presently my personal focus while other team members focus on other aspects.       One set of statistics I can develop fairly quickly is average stand density, i.e. stems per acre. It looks like the average density over an acreage of 100 to 140 acres is around 50. My present guess is that the number of mature white pines in Mohawk lies somewhere between 3000 and 5000. There's about 2000 young pines. So the total number of Mohawk pines lies between 5000 and 7000 - I think. It's a start. Bob Robert T. Leverett Cofounder, Eastern Native Tree Society   Home