Native Tree Society BBS

ENTS,

As the clock ticks away, NTS seems to be fading away. Lately, we've been indebted to Brian Beduhn for keeping us afloat with meaningful data on the southern Appalachian tall tree hotspots. Different people have taken a turn at posting, but the daily number of posts for such a distinguished organization as we have been has been anemic. Our accomplishments over the years and the many references to and use by others of our data speaks to a continuing need for our contributions.

Over the past three years, I've devoted a lot of my time to assisting others quantify the amount of carbon stored in trees. Ten years ago, it was not a predictable direction for me to be traveling today. So, what precipitated the added mission?

With the rise of biomass for energy generation, growth rates of trees came under increasing scrutiny. Biomasss advocates made claims about when trees grow the fastest that favored what they had in mind. But it isn't as though there haven't been plenty of fine minds working on the carbon sequestration issue for decades. The USFS research stations, prominent academics, government scientists, tree companies, etc. have all been involved. And today, we find a number of computerized volume-biomass models available to researchers, managers, and the general public. So, why should I have thrown my hat into the ring. Please have a look at the attachment. It tells the story of Monica's Pine (MP) in back of our house, only 88 horizontal feet away. I have plenty of access to it, and have volume modeled it.

The 51-diameter reticle measurement made of MP's trunk giving 282.7 ft^3 of trunk volume is probably accurate to between +/- 1 and 2%. Adding limb volume from the FIA-COLE model percentage factor adds another 44 ft^3. I maintain that the 326.7 ft^3 is the above ground volume to as an accurate a determination as we can make using our methods. Converting this volume to biomass and then carbon is accomplished through accepted factors. For example, oven-dried white pine weighs 22.3 lbs/ft^3, green volume. White pine biomass is 52.1% carbon. Going from elemental carbon to CO2 is merely the case of multiplying by 3.664 (usually given as 3.67). So going from green volume to dried biomass and then to carbon, and finally carbon dioxide is through a completely accepted process. For MP, we have 326.7 x 22.3 x 0.52.1 x 3.664 = 13,907.4 lbs of CO2. Expressed in metric, we have 6,311 kg or 6.321 metric tons.

Now, you'll see in the attachment that other models range from 7,980.8 down to 3,118.3 kg. That's a heck of a spread, and the popular I-Tree model gives 3,840 kg. We in NTS have a role in the game if we want it and that is to evaluate these other models. I hope others of you see this as a valuable mission and will join me. So far, it is Jared Lockwood and myself. We'll happily share all our tools to go from soup to nuts.

Bob

Hi Bob-

I have always enjoyed our site and glad to part of such a great organization.
There have been a few glitches on the BBS in the past and I think that
has been the reason for nonparticipation.

I switched my postings about trees to our Facebook Page these last couple of years.

I'm excited to help you get data with the volume of Live Oaks and looks like we can
get back on that Project.

Things are coming back to normal in my region.

Thanks for all your help and others to make our organization second to none.

Larry

Ents,

Well, I haven't exactly been swamped with comments about a carbon mission. Perhaps it is too much of a stretch for NTS, and again maybe not. I would like to hear the thoughts of others on what you think is important to pursue now and into the future. Thanks in advance to anyone willing to share their thoughts.

Bob

Hi Bob,

I do think this is an important mission to be pursuing. I was not able to do as much tree measuring this last season as I had planned and would have liked to. This was largely due to a transition into full-time-ish ecology-oriented work, whereas previously this has been something I've pursued more at my own leisure and direction. Even so, I am often thinking about how the other sampling skills and areas of knowledge I'm exploring in my current work can be brought back to bear on the kinds of questions ENTS is uniquely equipped to explore. Admittedly this finds me a little less prone to just going out and collecting height and girth information. There is such a wealth of information about ecosystem processes in any given acre of habitat in addition to the trees and sorting out how best to interact with that is an ongoing process. The systematic approach and detailed ecological data contained in Will Blozan's Tsuga Research Project has had a lot of influence on my thought process recently. At the same time some historic data from my home region in some old books, juxtaposed with the White Pine site we found at Halfway Brook in the adirondacks three years ago, has me wondering about a missing chapter in the story of that species and how the speculations I've come to might be tested.

It's very encouraging that some of the available models do such a good job with Pinus strobus, as you've demonstrated (even if troubling that others are so poor). The question that always remains on my mind is how well the models can handle trees of advanced age. For most of eastern north america, studying the carbon dynamics of mixed and hardwood forest systems in which trees are allowed to live out their natural lifespans seems like the big challenge. Does simply quantifying gaseous flux across the canopy and in the understory tell us all we need to know about carbon dynamics in a forest? Or could physical measurements and allometrics be a more efficient and flexible way to approach at least some of that subject, or in conjunction with it to improve our understanding of the "how" and "why" of the forest processes leading to the results measured by eddy flux methods?

I wish I could clone myself into multiple brain-linked bodies that didn't have to sleep. There's so much to do, so little time, and usually even more limited energy. I really value the time and effort you are putting into developing the tools to approach these questions. I wish I was able to be more engaged at this moment, but I want to affirm that I believe in this pursuit.

This spring I wanted to at least update Zoar Valley's RHI10, but only wound up being able to get to about half of the rucker trees before leafout. I'd like to share here the most satisfying single measurement of the bunch: The tallest Sycamore, first identified during the "Tally in the Valley" and subsequently regaining height after its original leader died back, finally reached 160.2' tall as measured with the utmost care with the 200LR. Its position at the edge of the terrace allowed measurement in full leaf on June 6th.

Erik

Erik,

Thanks for a most thoughtful and insightful response. I'm am glad that you see a continuing role fro NTS in areas where we can practice our trade. We function in an arena filled with heavyweights, but whose collective work reflect highly conflicting results. When one digs into the scholarly papers on allometric volume models for the species with which we have familiarity, there are plenty of caveats and disclaimers by the coauthors, but they are systematically swept aside in the application of the models by others. For example, there's a statement on the American Forest website that claims that the "average" mature tree sequesters one metric ton of carbon (actually they're changing that to 0.6). Now let's take an "average" mature tree, which of course must include hardwoods and softwoods and give it a dry biomass density of 30 lbs/ft^3. Let's give it a circumference of 5.8 feet, a height of 70 feet, a trunk form factor of 0.42, and a limb to trunk volume ratio of 0.14. We get 89.7 ft^3 of above ground volume. The corresponding biomass is 2,691.7 lbs. Lets average the percent carbon of hardwoods and softwoods as 51%. This gives us 1,372.8 lbs of carbon and its equivalent CO2 of 5,029.8 lbs. The metric ton equivalent is 2.28 tonnes. If we discount some percentage of this amount as lost to decay, then the AF one-tonne figure may not be far off.

Now in natural forests, lots of trees die young and of those that reach maturity or advanced age, many will be suppressed. I suppose that if they are averaged in, the tonnes will drop to a tonne or less at the landscape scale. But is this a fair way to assess the performance of a tree in a forest as an absorber of CO2? It becomes a serious numbers game with no simple answer. If an owner of a large tuliptree in his/her front yard reads the AF statistic, will that influence the owner to value or de-value the tree. There's a tradeoff between too much and too little information. I'm not the best one to judge where the dividing line lies, but I don't believe AF has it right, or I-Tree for that matter.

BTW, I'm presently re-testing my LTI TruPoint 300 mini-surveying station. Please take a look at the attached results. In the past, I chose trees at random on which to test the 300's diameter routine. However, that saddled me with trees in poor light and indistinct trunk boundaries. But in serious use of the instrument, I wouldn't force its use where I could predict before hand that the results would be compromised by poor visibility. These new tests will be conducted only where visibility is acceptable.

Thanks again for weighing in.

Bob