Shelterwood cut

[Frickman]

I have a question about shelterwood cuts. I understand the theory behind it, no problem. But most of what I've heard and read says that after the new stand is established, you reenter it and remove the shelter trees. How, in a mixed, appalachian hardwood stand, are you supposed to do this without damaging or destroying the new stand? Felling these trees will damage whatever they hit, and then you're supposed to use a skidder or forwarder to get them out. I can't see how you can perform this operation until the new stand is at least post-size, if not pole-size. Can some of you foresters explain this to me?

I ask this because I recently looked at a woodlot I cut about twelve years ago. I left alot post and pole-size red oak and tulip poplar to provide a seed source for the new forest. Now, twelve years later there is a very nice stand of young, sapling-size red oak and poplar, along with scattered seed trees. I can't see any practical way of harvesting these seed or shelter trees without destroying what we worked so hard to propagate.

[Ron Wenrich]

For a true shelterwood system to work, you let the new crop of seedlings develop, then remove the overstory.  You don't wait 20 years, closer to about 5 or less.  Removing the overstory will make it look like a clearcut, but you will have a better amount of good quality seedlings to take over.  Its an even-aged management technique.

The problems with leaving pole timber as a seed source is that the forest isn't nearly ready for the rotation cut.  You did a thinning in the upper diameters.  And that's assuming that the poletimber wasn't merely stagnated growth.  They don't necessarily make the best seed source.

You have to be careful on your management systems.  A lot of loggers are very well intentioned, but sometimes do unintentional mismanagement.  It seems to me that when you left your poletimber stand, you probably established a 2 age forest.  I've seen some of these that were successful, and many that were not. 

The problem with the 2 age forest is that you have to thin pretty hard to get adequate regeneration.  When you do that, you end up getting sucker sprouts on the residual.  That adds to the defect.  The other problem is that you are leaving trees that weren't strong enough to become dominant or co-dominant as your seed source. 

Even aged management and uneven aged management are 2 different things, for the most part.  Trying to use even-aged techniques in uneven-aged situations usually ends up confusing.

[Phorester]

I have to agree with Ron on his analysis of this situation.

You are correct on damage.  Some of the reproduction will be damaged and destroyed when the larger trees are taken out in a true shelterwood system.  This is a drawback of the shelterwood system of regenerating a forest.  But when done right and in the proper location with respect to soil types, existing forest conditions before the initial cut, etc. there should be enough reproduction present so that you still have an adequately stocked new forest even with this damage.   One way to lessen this damage, of course, is to skid out log-length and not tree-length, leaving the tops in the woods.

[SwampDonkey]

I agree with Ron also. I've seen so called shelterwood on hardwood and those pole sized hardwood are as old as the cut crop and are for the most part suppressed, flat-topped junk. The volume remaining is usually to low for the follow-up cut. Then, what's worst is sometimes these trash trees hang on a long time and prohibits the thinning (PCT) of the new crop underneath. It happens mostly on private woodlots where there is no supervision. I've also seen it on crown where an excellent job was done is spruce stands, only to have a big wind storm uproot the spruce in a big cris-cross mess.  It's worst on rocky terrain and landscape prone to heavy direct winds. You have better luck in sheltered valleys or behind big hills that protect from the NW, W and SW winds.

[Frickman]

I guess I should have had more detail about this particular woodlot. It was a two-aged stand, common for this area. For most of a century many tracts were cut heavy for posts and other coal mine timbers on a more or less continual basis. Some professional foresters from other areas have disagreed with me in the past, but not all of Pennsylvania is an even-aged forest. When I said alot, I didn't mean fifty stunted, codominant or supressed trees per acre. It was more like two or three per acre, and these were dominate trees in their corner of the woodlot. They were just smaller than the large trees we removed as they grew in openings created by post cutters years ago. When you look at the acreage involved it might appear that I left alot of trees, but per acre there weren't that many.

These trees all have good genetics, which is why I left them. I knew that they'd sprout extra branches and possibly be damaged by wind, but they were worth more as a seed source than to harvest them at eight or ten inches dbh.

This harvest did not leave what you see on a poorly managed diameter limit cut. Many of those diameter limit cuts leave supressed and damaged trees, or less desirable stock for this area like soft maple and black birch. This stand was in need of a regenerative clearcut to start a new stand, i just left some good seed trees to help out. Everything else, and I mean everything, was cut during the harvest. Every soft maple and black birch sapling was cut as I walked from tree to tree. Because of this the oak, poplar, and cherry had alot of sunlight on the ground to get them going.

I just mentioned this tract because it is the closest thing I've seen to a shelterwood cut. Technically it's probably a seed tree cut. Anyway, Ron answered one question I had, in when you return to remove the shelter trees.

Ron is right, applying even-aged techniques to uneven-aged stands is sometimes confusing. In our area we have to do the best we can with alot of tracts that have been abused in the past. I don't encounter many true uneven-aged stands, with all age classes represented. I do find, however, many, many two-aged stands, due to the above mentioned post cutting. The older trees are around eighty or ninety years old and the younger are between thirty and fifty years old. I do alot of work in these stands, removing the older, mature trees and leaving the younger stock. I cut logs to length at the stump and use a small skidder along with a forwarder to reduce damage to the residual stand.

My main question though was, how do you get the shelter trees out without tearing everything up? You guys have cleared alot up for me.

[SwampDonkey]

My best advise to you Frickman would be to use flagged trails where the wood/trees stand. So instead of starting out behind the wheel of the skidder, flag your trails ahead time with some highly visible tape. This minimizes damage as best as you can. Other than that, higher a heli-logger. If you have alot of aspen coming in, those trails will soon fill in. ;)

[Frickman]

Swampdonkey,

Flagging trails is a good idea, I usually do that before any harvest. As far as a helicopter, I thought of that, but it's too expensive and impractical on most jobs I have. You have to have a landing zone, and many jobs I get barely have room for a load of logs at the landing, and we park the truck on the paved road when loading. As far as aspen, it doesn't grow much here and where it does it we cut it. In our area aspen has zero market value, except to haul as pulpwood three hours away. After trucking it's still worth near zero. When I cut it I use it in the woods for constucting brush piles for animal dens and other things like that. It makes the landowners happy and I don't have to get rid of the wood.

[SwampDonkey]

Yes, you'de have to have some pretty valueable timber as well. There was one member (swampwhiteoak) that posted some pics of his heli-log in some hardwood and he kinda indicated it was very expensive.

Link to thread

[Ron Scott]

It sounds like you are quite aware of sustainable forestry and leaving an acceptable forest landscape by trying to do the best job that you can with the timber harvest depending upon all the conditions at the time. 

It is often difficult to not damage some regeneration when removing a stand's overstory trees above areas of heavy regeneration. As previously mentioned, keep damage to a minimum by locating and flagging your skid routes in advance, use existing routes and openings from past harvests, plan your cutting and falling lanes and patterns, "short wood" forward only, etc. to minimize damage as much as possible.

[Ron Wenrich]

Most 2 age stands that I see come from diameter limit cutting.  The ones that have been fairly successful comes from not having a very big dbh at harvest.  That's mainly in areas where there is a high competition for stumpage, lots of hunting clubs, or where the population needs cash.

We do have areas to the north of me that cut mine props.  Most of those guys cut ahead of strip mines and seperate props, pulp, and sawlogs. 

[crtreedude]

I am more than a little interested in this because something we are trying is this: We are using the plantation trees as pioneer species. This is because often permanent rainforest trees will not grow without shade. So, we have to do one cycle of faster growing trees.

In between, we lose about 5% to 10% of the trees to genetics, a worker with a machete who got a little too close, etc. We replace these with slower growing trees that require shade to grow correctly.

After all the plantation trees are removed (25 years) these slower growing trees will be left which will provide the base for the permanent forest.

We have a cycle where after 6 to 8 years (it might be only 5 looking at the current growth rate) we have to start thinning trees - the 2.25 year old teak are about 40 feet tall and between 4 to 5 inches in diameter. Unless something very odd happens, they will be about 9 inches at the first thinning.

Dropping a tree like that with the spacing isn't terribly hard - but at the end of the cycle they could be 100 feet tall and 2 feet in diameter! Oh well, the trees between were not planted for wood - but for genetics and a future forest. I assume we will lose some. Besides, I figure we will drop them in rows creating corridors. This is what happens in the rainforest. A monster of a tree falls and it looks like a domino effect at times.

I hope I am still around when we are dropping the 25 year old trees (I will be about 77 then) All I have to do is keep FDH's swingblade off them for that long!