iDRY Vacuum Kilns

Sponsors:

Tell me about how you do tree inventory today?

Started by eugene_fv, July 16, 2019, 02:57:54 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

eugene_fv

Hi everybody. Anybody works at forest management company that task e.g. tree inventory? Im doing research at forest management tools and I have some questions about your experience.

Ron Wenrich

I use a point sampling technique.  I use an angle gauge, and run it on a grid of every 200'.  The BAF of 20 yields about a 10% sample.  I also break the area into the differing forest types.  I do this by notation on a map of the property.  I use a dot grid to get the area and run the plots that are in that forest type into the inventory.  Each timber type has a volume as well as size distribution and BA in each size class.  Volume and size class can also be broken down by species.  Mgmt recommendations can be made for each forest and timber type.  Combine everything together and you have a forest mgmt plan.  

I've run my sample cruise against actual sale output, and it runs within 5% or less.  I've run these cruises pre-sale to determine approximate cutting volume and sale price appraisal.  That also works well. 
Never under estimate the power of stupid people in large groups.

Texas Ranger

Ron is old school, so am I.  That is what we are used too, and works.
The Ranger, home of Texas Forestry

eugene_fv


Quote from: Ron Wenrich on July 16, 2019, 11:20:14 AM
I use a point sampling technique.  I use an angle gauge, and run it on a grid of every 200'.  The BAF of 20 yields about a 10% sample.  I also break the area into the differing forest types.  I do this by notation on a map of the property.  I use a dot grid to get the area and run the plots that are in that forest type into the inventory.  Each timber type has a volume as well as size distribution and BA in each size class.  Volume and size class can also be broken down by species.  Mgmt recommendations can be made for each forest and timber type.  Combine everything together and you have a forest mgmt plan.  

I've run my sample cruise against actual sale output, and it runs within 5% or less.  I've run these cruises pre-sale to determine approximate cutting volume and sale price appraisal.  That also works well.

Quote from: Texas Ranger on July 16, 2019, 12:57:58 PM
Ron is old school, so am I.  That is what we are used too, and works.

How long did it take? e.g., 100 hectares

Ron Wenrich

I used a compass and pace system to locate points.  A lot would depend on terrain and understory.  I  could pull about 40-50 plots in a day in my younger days.   It took me about 5-10 minutes to find a plot and do the necessary data recording.  Crunching data takes about as much time.
Never under estimate the power of stupid people in large groups.

BaldBob

Quote from: eugene_fv on July 16, 2019, 01:28:24 PM




How long did it take? e.g., 100 hectares
In addition to the terrain and understory, the variability (ie CofV) of the stand(s), which will determine the number of plots needed for a specified level of confidence,  will have a significant impact on the time needed.  100 hectares could take a half day or less for cruising and calculations for a very uniform single type stand on level ground with a clean understory. Or it could take 3-5 days on a very complex property with rough ground and thick understory.  Whether or not high quality aerial photos are available which can speed up pre-stratefying of stand types can also be a big factor.

eugene_fv

Quote from: BaldBob on July 16, 2019, 11:00:26 PM
Quote from: eugene_fv on July 16, 2019, 01:28:24 PM




How long did it take? e.g., 100 hectares
In addition to the terrain and understory, the variability (ie CofV) of the stand(s), which will determine the number of plots needed for a specified level of confidence,  will have a significant impact on the time needed.  100 hectares could take a half day or less for cruising and calculations for a very uniform single type stand on level ground with a clean understory. Or it could take 3-5 days on a very complex property with rough ground and thick understory.  Whether or not high quality aerial photos are available which can speed up pre-stratefying of stand types can also be a big factor.


Quote from: Ron Wenrich on July 16, 2019, 07:32:26 PM
I used a compass and pace system to locate points.  A lot would depend on terrain and understory.  I  could pull about 40-50 plots in a day in my younger days.   It took me about 5-10 minutes to find a plot and do the necessary data recording.  Crunching data takes about as much time.


wow, it's not fast  :o

Do you use any tools or tricks to help you get inventory done? mb hardware, software... will it speed up your work?

Texas Ranger

I use a sonic plot center, about the only "modern" equipment I use.  Prism and field note book.  Along with the common stuff, compass, knife, machete, etc.  Oh, and in Texas a small handgun for hogs, dogs and snakes.
The Ranger, home of Texas Forestry

Ron Wenrich

You can do fewer plots.  It all depends on the accuracy that you need.  Go a little further apart on your plot centers and your sample becomes 5%.  Takes half the plots.  

In my area of Pennsylvania, it is common to have several different timber types on a property.  For large ones, there can be quite a few.  Timber quality, size, and species will change as you go up a slope.  It will change from one side of the ridge to the other side.  Past land uses will also cause changes.  Some areas may be overgrown fields from different eras.  For me, it was a lot easier to spend more time taking plots and having a good idea what the property contained.  I would have an accurate map and accurate timber types.  I also had more confidence in what I presented to a client.

Spreadsheets have sped up the process.  I come from a time when computers and calculators were a rarity.  We thought that a calculator with a memory was a technological improvement.  I'm not up on the newer software, but I know there's some that you input the data in the field, then dump to a computer for compiling.  
Never under estimate the power of stupid people in large groups.

timberking

I finally joined the prism crowd after 35 years of 1/10 acre plots.  Cruised a small tract this morning and seem to have attracted some seed ticks even though I sprayed down.  Mainly for skeeters.

ID4ster

I do a systematic grid with the number of plots determined by the size of the stand(s) and the value of the timber. I do a variable plot cruise using a 20 factor prism. Generally I do a 5 chain by 2 chain grid, which is 1 plot per acre or a 5 chain by 4 chain grid which is 1 plot per 2 acres. Some of my plots are measure plots, which is where I measure height and diameter of each tree in the plot, and some are count plots where I simply record the number and species of each tree in the plot. I just write all that down on a cruise form and then enter that data into my computer program once I'm back at the office. Generally once you've measured about 20 trees of each species in your stand you'll have the information to determine average height, diameter and form class, after that the count plots let you know density and species composition. 

You can get data recorders that will allow you to dump your data directly into your computer and you can use something like a Relaskop (Approx. $2,600) that can do a lot of functions for you. The problem for me is justifying the expense of those instruments and/or the fact that I take down a lot more information at each plot than those instruments will allow me to record and save.

Basically unless timber cruising is all you do you don't need a whole lot of expensive equipment to cruise timber. Experience is what really helps to determine the accuracy of a cruise. As for you 100 hectare stand. It will depend on the consistency of the timber, the number of different species, the terrain and how what type of cruise you want (straight volume, stand condition, wildlife potential, etc.)   
Bob Hassoldt
Seven Ridges Forestry
Kendrick, Idaho
Want to improve your woodlot the fastest way? Start thinning, believe me it needs it.

SwampDonkey

I sample 1 point per ha, but at least 3 plots per cover type. I put the sample grid on a GPS and usually have a paper copy of the aerial tucked into a plastic bag and stuffed into the vest. But the aerial I can put on a GPS. These days I can get the most current aerial off Google. I have for a number of years used my own cruise database program loaded onto my GPS. The standardized volume tables I use come from the government from research and statistics. There are 4 height curves for hardwoods and also for softwoods, and accompanying tables. These are driven by site index data. I sample by both fixed plot size and point with prism. Mostly point with prism. I use a BAF = 2 m2/ha. The tally sheet method is still a good way to keep score and it don't crash. Although, I have never seen my GPS crash a cruise database sheet.

I usually take a full day on 40-50 ha, there are no parkland forest around here, lots of tall shrubs and shade tolerant trees growing out there unless in mature hardwoods and cedar that are not disturbed much. Those are rare. Some areas are very rocky, others are like ground around the yard, and so on. Not too much for steep ground, but there are sharp hills in places....all adds up on the time clock. I already use the GPS for other work and at this stage I rare cruise timber any more. There is no demand for it, not much is done on mill ground either, they now use LiDAR and other devices on aeroplanes to estimate timber. I was told this a couple years ago at a mill meeting. The Irvings are heavily into it. The only time a site is measured the old way is on permanent sample plots these days. Besides we have good data on height/volume by species now that allows this technology to do a good job.

In the far north where it is remote and no road access, this is being promoted big time by the feds especially because of the carbon debate.Comes under the National Forest Carbon Monitoring, Accounting and Reporting System (which calculates greenhouse gas emissions and removals from Canada’s forests).

Bill
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

eugene_fv

 :P
And how much can a manual cruise cost (100 acres)? 

SwampDonkey

Depends on what is asked for during the sampling, but I would say a minimum of $CDN 400.00 around here. On larger tracts without a lot of travel from parcel to parcel that can go down to $2.50/acre I suspect. Here in NB, cruising on public land is only approved for RPF of CFT's. But, I never could understand why because they don't do peer audits in NB, so what is it really worth? I have seen mill cruises (licensee for public timber rights) that I know were from the windshield. They come up when the government is disposing of small isolated parcels. If it is a real estate sale, well they aren't even interested in a cruise.
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

Thank You Sponsors!