I've been cruising for a small timber company for about six months. I use a fixed-plot method, shooting for 10% each time. I do a lot of planted pine and natural pine/hardwood mix. Some old turpentine tracts. Done pretty well so far. Wondering if there's any advice guys in my area might have (aside from bug spray and snake boots).
A loggers tape with the diameter scale on one side is much faster to use than a regular diameter tape.
The formula for the volume of a tree is the diameter squared times the height. So, missing the diameters can lead to large volume errors since the diameter is squared. Measure often.
Check your heights every day or so to make sure that you are dialed in. It is simple to do with a clinometer and a loggers tape.
In the old days, miscalculating the acres was one of the largest sources for errors. Now with GPS, getting the acres right, especially on irregularly shaped stands, should not be as big of a problem. Focus carefully on getting the acres right.
Trees look bigger when they are wet or it is dark, like on a very cloudy day.
I knew cruisers that were very consistent. But sometimes consistently wrong, like under-estimating heights by a half log or by over-estimating heights by a half log consistently. For me, I found that it was easy for me to over-estimate the merchantable height.
Spending time on a logging deck and watching the loader operator top the logs will teach you a lot about how good loggers merchandise logs. They have to make the mills happy, so learning where that they will top a tree length log is important to learn so that you can apply that to the woods when you are tallying trees. You can say, "I would have called that a 3-log tree if I was cruising, now where did the loader operator actually top the log at. Was it really at 48 feet?" This will make you are more accurate cruiser. You might be technically right, but it is how the loggers tops it that determines the weight and ultimately how well you do.
A downed tree, like one blow over in a storm, is a wonderful learning tool. Put your tape on it and pull the height. Then, find the merch top, i.e. where the good loader operator will top it, and measure to that point. Measure the diameter at DBH and at 16.5' to see the taper. You can also spend a day in the woods measuring some down trees that have been felled by the fellerbuncher since the buncher usually is a day or two ahead of the skidders.
There is a diameter to height relationship in a stand. For example in southern pine, a 10" tree can vary in height, but on average, a 10" tree is about 60' - 65' tall. It is hardly ever 85' tall. So, once you understand this, and if it is an average looking 10" tree, then you pretty much know how tall it will be. Of course, some are open grown and short, but you can see that pretty easy. 14" trees are are generally about 72' to 75' tall. This is just how trees grow. One thing that you can do in a planted stand is to wander thru the stand and randomly select about 10 trees of the average diameter in the stand, measure their total height, and average that. That will cue you into what the heights are going to look like and can make you more accurate.
I don 't work down there but, WDH sure nailed it for here. God Bless
Why square the diameter x the hight, what happened to pi?
Volume of a cylinder is pi x radius squared.
Oops my boo boo
pi x (radius squared) x hight
My advice is tables and measure, check your measures regularly, get feed back from loggers on your cruises, if they will.
Danny,
Thanks as always for the knowledge.
I GPS everything I cruise. It takes longer, but I've caught some large mistakes in the sale acreage, some 8-10 acres difference.
You're absolutely right about watching a loader man...I spent a day or two watching and they top everything larger than the specs...so a 6" top is really an 8" top on ChipNSaw, and a 10" really a 12" in sawlogs. And that cuts some log length out.
The man who taught me how to cruise used a Short (27'), Medium (36'), Tall (45'), and Extra Tall (54'+) system for pine pulp and CNS, and hardwood pulp and pallet. Sawlogs and crossties I do in 16' log lengths. For pine, I use Scribner 78, and on hardwood Doyle.
Old catfaced timber...oh man help_me
What conversion factors (volume to weight) are you using for pine on Scribner 78 and hardwood doyle?
I'll PM you the worksheet I use in Excel. I know, I know. :D
2.7 cords/mbf (14,445 lbs/mbf) for pine, 3 cords/mbf (16,800 lbs/mbf) for HW
Pretty much what I used too, back in the day.
That's good to know....I like reading other people's cruises and seeing how they get their numbers. I tend to run a little low. Still making adjustments. What did you do on catfaced tracts?
I assume that you are referring to a canker? Usually, I called the diameter above the swell of the canker.
Trees tapped for turpentine
I thought most of that went away in the '70s?
Pro tip- don't let a horse brush you up against a cup gutter.
The turpentine industry did play out around the 70's. Some of the catfaced trees are still around, and it's hell trying to call sawlogs on them.
How high are the catfaces, why not jump butt?
Most won't be more than 5 feet above the ground. A lot of them have heart rot further up than the face though.