Why Measure Trees?
Andrew Joslin recently observed: "At a very basic level the study of nature and biology requires quantification as an important step in understanding the subject. What is the form, how big is it etc." Our tree measurements serve this purpose. Using the NTS methodology we ca accurately measure the height of a tree to within a foot of its actual height. We are mapping the canopy structures of great trees to better understand how they function. We are doing detailed documentation of individual sites and making comparisons between sites. Without accurate measurements many of the subtle relationships between the environment and the trees growing on a site cannot be distinguished. Without the detailed measurements we cannot understand the potential for growth contained within a single tree, a species, or a population. Accurate measurements are the cornerstone of scientific enquiry.
Dr. Don Bragg may have said it best. I quote from a recent email he submitted:
"There is definitely a need in the scientific community for the maximum dimensions of trees to be accurately measured and available for use. The use of champion tree data to help certain aspects of research programs can be quite pervasive, even if not well recognized. For example, a lot of forest simulation models (the popular gap models, for instance) define parts of their optimal growth equations using species-specific maximum heights and diameters. A number of height models use champion tree heights as an asymptote to fix the upper height possibilities of a species, while other models use parameters like maximum tree age to define response functions. I believe the evidence is strong that we can use champion trees to help better define the shape of height:diameter functions that are used in many vegetation simulators. Other issues related to relative tree size include the ecological role of supercanopy species (e.g., eastern white pine) in managed landscapes, or vertical structure of forests and their relationship to ecosystem function, etc. Most people using the champion tree data do not likely pay close attention to the source of the data, and its reliability. This, in turn, could have dramatic results on the outcomes of their simulations."
In the past, Dr. Tom Diggins also made eloquent arguments for getting
the numbers right for tree height measurements. He pointed out that
accurate measurements were necessary to differentiate the exceptional
sites, needing protection, from the ordinary ones. Zoar Valley, NY. was
the example he gave. I could give other examples to include Mohawk
Trail State Forest, Cook Forest, and other exemplary sites that have not
received their just due. So, our insistence on accuracy is not a trivial
issues unless accuracy doesn't count, which is hardly a credible
scientific position. (post by Robert Leveret, May 9, 2008)
In the western United States canopy researchers such as Dr. Steve Sillett, Dr. Robert Van Pelt, et al. are doing large scale scientific research on these big trees to understand the physiology more completely. This includes figuring out the tree's internal plumbing, epiphytes it lives with, parasites on it, etc. We may dramatize a few interesting tree statistics in NTS for comparative purposes, but they are PhD-level researchers who go very deeply into tree morphology. Will Blozan's posts to NTS are spectacular, but are meant only to inform us of his participation in an extensive study. It is the mere tip of the iceberg in terms of information being gathered for scientific purposes. The information gathered from these climbs is like no other and will help scientists to understand how these trees grow, cope with a changing environment, create ecological niches, etc. - a very long list. (post by Robert Leverett October 8, 2009)