Methods of thinning?

[gman98]

Hello guys, I've been doing some reading on some older posts here in the forum that talk about thinning in plantations.  It seems to me that there is a lot of mechanical strip thinning going on.  I understand that this is desirable for liability and cost issues, but how are the trees in the middle of the unthinned strips affected?  Wouldn't it be more effective to do a whole stand thinning with a manual chainsaw/cable skidder outfit?

Thanks, Alex

[Corley5]

Not in terms of economics.

[Ianab]

I agree, it's to do with the economics. Those first thinning are small low value logs. Realistically you may only be recovering the cost of the harvest, and locally they are usually just "thinned to waste" and left to rot. Most of the terrain that's growing pines is too steep to allow selective thinning. So you just wander through with a chainsaw after about 8 years and drop the poorer trees to leave the final crop spacing. The exact spacing of the final trees doesn't make a big difference, they don't have to be spaced evenly. So leaving rows intact and taking out whole rows leaves the space the remaining trees

[Rural]

I have little doubt that it depends upon where you are and the species being grown but the 'standard' way of doing it used to be taking out every other row, this seems to be, to me, a waste of resources given that there will always be a wide variation in growth between trees. In my own plantation which received NO maintenance for over 20 years before I bought it, and was struck with a pine bud worm infestation after abt 15 years the variation is particularly noticeable. There are white pines which have been totally outgrown by their neighbours and are dead or dieing due to lack of light, those that have grown to large diameter due to the effects of the bud worm and healthy trees somewhere in between.
I have been getting good results both in terms of pine growth and deciduous regeneration by taking out the larger diameter pines (12 – 16 dbh) to 'let the light in' and removing those little ones that will not come back.
In a younger plantation I am sure a different regime may be more appropriate but I still cannot see removing rows of trees irregardless of the condition of individual trees. As one has said it all depends upon the economics and if its a small private plantation or a massive commercial set up.
Having said that you should be aware that trying to drop a pine tree in the middle of a bunch of others is a pain in the butt and invariably you will have to 'drag' it down to get the top to let go, which is why I presume they say to take out a row!

[1270d]

In the pine thinnings I have cut we took a row and thinned two on either side.  Also did some where we left four thinned rows in between strips instead of two.   This was all first entry stuff, 25 years old or so.

On the thinned rows I always tried to cut the smallest poorest formed trees first. Even if released it is doubtful they would ever be as vigorous as their larger counterparts.  If Everything was uniform, every fifth tree was taken.

It seems like the best bet even if cable skidding to cut an operational row.  Unless maybe you have lots of spare time or money.

[Riwaka]

Depends on the tree spacing - selective thinning can be done if the machines are agile enough for the post-thinning tree spacing objective.
https://youtu.be/ld_YCcZCq6s

[Riwaka]

Pine thinning - easy terrain - Taupo NZ.

Shears on SK140 Kobelco.
Taking down the (hairy) unpruned trees and leaving the pruned crop trees. (A bit of bark damage - probably not easy having a cameraman walking around on the job)

Pine Forest Thinning In New Zealand With 3 TMK 400's - YouTube

[Texas Ranger]

Southern yellow pine plantation thinning depends on planting density and soil productivity.  It can be any pattern, every other row, every second, every third.  Then come back and thin the leave in a year or two.  Now adays our plantations tend to be short rotation, so they plant to the goal, 12 or fifteen years, longer seldom go past 25.  Our growing season is longer, and that helps.

[barbender]

 Yes, your growth rates are easily twice what ours are up here.

 We usually do 5th row thinnings with CTL equipment. You take one row, and can reach across 2 rows on each side.