Trees Do Not Match up to the Soil

[AfraidChocker]

I have a USDA based Forest Management Plan and one prerequisite of having it done to their standards is, it must have a lot of information on soils. My forester included a soils map and then a host of pages on what common tree species were, what their crown heights should be and what their growth should be based on cubic feet per acre per year. Simple stuff.

Here is my question however. Despite having a list of 2 dozen different types of soils, none even mention Eastern Hemlock even though it comprises a staggering 1/3 of my woodlot. I don't mean it is found in 1/3 of my woodlot, hemlock comprises 1/3 of the volume of timber on my woodlot!! I find that odd. I thought maybe the USDA calls that tree by a different name, but that was not the case. There are some variations, but they all have hemlock in the name.

What I was trying to do was see where my forest was in terms of comparing its growth now, to what the ideal growth rate was based on the individual stands predominant type of soil. I cannot do that however if the soils listed do not match the trees that are growing there.

Very, very strange.

Does anyone have an idea as to why this would occur (soil types not matching tree species)? These are natural forests and were never cultivated?

[curdog]

I'm not sure if I'm on the same page as you, but I know the soils book for my county will give the site index for, let's say off the top of my head around 6 of the most commonly grown timber species for a particular soil type. We have lots of areas with hemlock, but I'm not sure if it's listed on the site index charts for any of the soils I've looked at. I'm pretty sure that they list the trees with higher productivity and value. Around here there's not much hemlock harvested. Most soils list the pines, oaks,  yellow poplar, cherry etc. for site index data.

[clearcut]

Couple of things could be at play. Tsuga canadensis, eastern hemlock, is a relatively slow growing tree early in its life cycle. It is shade tolerant and often develops in the understory. Historically the wood is not very valuable and older trees are susceptible to ring shake. It makes ok pulp and poor firewood. So from a crop tree standpoint, it is generally less than desirable. Thus there is less interest in research on its growth and development.

Site index curves, which predict the height of a given species at particular times, are based on trees free to grow throughout their lifetimes. With hemlock being a slow growing, shade tolerant tree - it is difficult to find examples to generate accurate site index and growth curves from - or trees to estimate a given stand's site index. Hemlock's ability to tolerate a variety of site conditions further makes predictions difficult.

Since it is difficult to characterize, and not highly valuable, it is simply left out of the tables.

I did find "Growth and Stocking of Eastern Hemlock in New England" within the Proceedings: symposium on sustainable management of hemlock ecosystems in eastern North America.


     http://www.nrs.fs.fed.us/pubs/gtr/gtr_ne267/gtr_ne267_043.pdf

     http://www.nrs.fs.fed.us/pubs/gtr/gtr_ne267/gtr_ne267.pdf

[Clark]

I'm a little familiar with the type of soils report you are referring to. I've yet to see one that was really accurate in regards to forestry information. I think they are more keyed into agriculture or more likely, just soil information.

Soils are very important in forestry but there are a host of other factors that come into play when you talk about growing trees well for a site.

Clark

[AfraidChocker]

Clearcut; after exhausting research online, that is what I found as well; its ability to be shade tolerant and lack of a commercial species makes it unlisted and almost unchartable based on cubic feet per acre per year of growth.

That being said I did some major number crunching and came to some stark conclusions. Because that same soil report gives recommendations on the trees to manage, I scored how many times those tree species were recommended. In the end I should be primarily focusing on White Pine, White Spruce, Fir and Larch based on the soils I have. It clearly shows, growing hemlock at such high concentrations is really bogging down my wood lot production wise.

How much though?

I am at 60% of what I potentially could be; again based on my soil types. IF I was growing more ideal tree species better adapted to my soils, conceivably my woodlot would be worth about $110,000 more then it is now, in 10 years time versus what I am currently growing. Since I am only 41 years old though, if I cut the wood lot at age 71; 30 years from now, I would have an additional $330,000 for my retirement account over what my woodlot now would be worth 30 years from now.

It is the information you can glean through number crunching like this that you generate better decision making.

[AfraidChocker]

I'm a little familiar with the type of soils report you are referring to. I've yet to see one that was really accurate in regards to forestry information. I think they are more keyed into agriculture or more likely, just soil information.

Soils are very important in forestry but there are a host of other factors that come into play when you talk about growing trees well for a site.

Clark

You make a very valid point. Why would Hemlock grow in such a grove if it was not ideally suited to the soils, climate, etc that is there. This is further muddied by the fact that at the turn of the 1900's century, 90% of this area was field/pasture and only 10% was forest. Today 90% is forest and only 10% is field; that is a vast change in 116 years.

Since I am a 10th generational farmer here, I am fortunate to have documentation of what occurred years ago. For instance I know this one "ten acre field was felled, burned of brush, and pastured in the summer of 1838". Considering these two brothers (my Great Uncle and Great Grandfather several times removed) did so with an axe and oxen is just mind blowing really. I am sure it was soon cleared of rocks and stumps in ensuing years. That was also when they switched from growing barley to growing potatoes, something we did up until 1988, but in the early 1900's, with tractors replacing horses, with steel wheels, no four wheel drive or posi-traction like we have today, only the best fields would work for the new steel mules. In other words, well drained fields with no mud. So it is no surprise when I cut some massive Hemlock there last summer for my barn, I counted the rings and deduced it was an 90 year old tree; 1926, just about the time tractors were replacing horses here.

I actually am quite fond of hemlock personally. I build a lot of stuff out of it because it makes nice lumber, holds a nail well, and is strong, yet I can sell my spruce and pay for the building materials that I cannot make for myself like windows, doors, roofing material, etc. However I will admit that it is concerning; 1 out of 3 trees I am currently growing is a slow growing, low grade wood and there is time to redirect the course my woodlot could take.

[CJennings]

Markets do change and vary by location. I know for a fact a state forester managing some state lands in Maine one of my forestry classes spent time with a year and a half ago had a strong market for hemlock and wished he had more but that was specific to that location. I think someday hemlock will be more fully appreciated. It's a strong wood with good decay resistance properties. The shake problem is a major issue unfortunately which hampers the growth of the market for hemlock. Hemlock will respond to release and do better than it normally does on its own in the shade. It won't be as fast as some trees but then red spruce, white pine, white cedar, and sugar maple aren't known for being fast growers either and are still managed for. If the adelgid isn't active there killing the hemlock, I'd lean towards keeping a significant amount of hemlock. Perhaps not 1/3 of the stand's volume (how big are these trees anyways?) but still plenty to keep it present to a large enough degree that it regenerates. It has issues regenerating when it's numbers are too low. It's great deer winter habitat. It will be a serious blow to many northeastern deer herds when the adelgid becomes more widespread. So I will say manage that stand with the knowledge that someday the hemlock could be hit hard by that invasive pest.

Hemlock isn't too picky about soil. It often grows on very poor soil that won't support some more valuable trees.

[AfraidChocker]

They are no redwoods that is for sure, but pretty darn big for Hemlock in Maine. I have had many people claim they were no good, but I cut a couple of 30-40 inch diameter trees down and they were surprisingly solid, and I also figured they would be a wee bit older than 90 years.

These are not our biggest Hemlocks, but you can see from the hemlock beside my wife (posing as Little Red Riding Hood for a photo shoot) they are fairly big.

[CJennings]

One of the reasons I don't look at hemlock that badly is because I've found several 100 year old (give or take) trees around the 24"+ DBH size, which really isn't bad growth if you consider the volume in those trees and what a white pine or red spruce does in the same century. 90 years and the size you have is pretty good. If the 1/3 by volume is in a relatively small number of large stems and there is plenty of growing space for other species I wouldn't be in a big hurry to whack the hemlock. It is mature and will over time decline in quality (go hollow frequently) but we're not talking a rapid process unless a pest like the adelgid hits.

[AfraidChocker]

I have a little of both. In the managed stands (where my little tractor can go and some skidder logging was accomplished), the Hemlock has done well, but in other unmanaged stands, some of which have yet to see a chainsaw; they are smaller in diameter and just out of control.

One of the reasons I hope to upgrade to a bulldozer is so that some of these inaccessible locations will be opened up so that I can manage them better. And another aspect is, I can actually pull out some of the bigger trees. I grew up with the mantra, "if you always cut the junk wood, you always have good wood." That is true to some extent as saw logs holds far more value than pulpwood; a lot more! In terms of investment, old growth pays, but at some point they must be cut! Really the only thing I can do is be grateful to my father, grandfather and forefathers before me that resisted the urge to make a quick buck and log everything off. I too will be conservative for my son-in-laws sake.

As for hemlock, I have always enjoyed working with it. I have built a lot of stuff because of its low value. In short I can sell my Spruce, Fir and Pine logs and buy the non-wood building materials with it, and instead use hemlock to frame and board with. But like you I see some value in Hemlock. I have always used cedar for shingles, but I see no reason why hemlock shingles could not be produced, it is billed as prone to decay but the old houses here used hemlock for sills because they considered it the opposite, rather rot resistant. I do know the University of Maine is currently working with the North East Lumber Association to get hack certified as structural lumber, and hemlock is close in properties. A new certification has not been done in 80 years so it is a promising new market for us in the North East.

I guess my biggest pet peeve today is, we pump oil out of the ground half a world away and then mix it with rocks and drive over it. I cannot believe that with all the resins that resides within wood we could not extract it and use it as a binder instead. It is rather radical thinking I know, but with paper mills closing all over the place, there must be another marketing avenue for wood?

[AfraidChocker]

I was in a hurry this morning and did not have a chance to post pictures, but here are some to give you an idea of what I have for hemlock stands. I would love to get your take on how to manage these areas. I do have some areas that I do intend to clearcut and destump to make room for more fields and sheep, but not in these stands.

I apologize for making you look at the trees behind my wife in this photo. I don't just go taking photos without a reason, so I was taking some photos of her as Little Red Riding Hood just for fun, but you can see some yellow birch regeneration in the background, as well as some bigger hemlocks and hardwoods.



Here is another showing some of the various trees interspersed within the stand. A couple of hardwoods directly behind us, a big hemlock just to the right of where she is standing, and then a rotted spruce tree in the far background. A mix, but very little regeneration on the ground.



Here is a totally unmanaged stand. It has never seen a chainsaw, and was pasture at the turn of the century as evidenced by rusty old barbed wire down this boundary line which leads to a small stream.

[Tarm]

Afraid;
My best advice to you is to work with what you have. With 30 years of management you can put 6 inches of diameter on the slow growing hardwoods (yellow birch & maple) and  8-10 inches of growth on the softwoods (white pine and spruce). Pick your crop trees in the unmanaged sections of the farm and release them on 2 to 4 sides. Select hemlock trees to harvest that can release seedling and pole size pine and spruce. Since you are in Maine perhaps plant some red spruce. If you have some overstory white pine cutting a few canopy gaps and scuffing up the forest floor could get you some abundant white pine regeneration. To sum up, tend the quality hardwood, work to reduce the hemlock and start regenerating the pine and spruce.

[ppine]

I used to work with NRCS soil sites a lot. The descriptions for vegetation are usually the potential habitat types that should exist after some succession.  Forest management can move succession to an earlier seral stage and prevent the expression of the site potential based on soils.  Clearcut alluded to this earlier.  Since eastern hemlock is shade tolerant it is likely a middle seral stage species in your forest.  Soil forest sites are by definition, an average of what to expect. There is no substitute for being on the ground and examining what is actually there.

[Gary_C]

I am at 60% of what I potentially could be; again based on my soil types. IF I was growing more ideal tree species better adapted to my soils, conceivably my woodlot would be worth about $110,000 more then it is now, in 10 years time versus what I am currently growing. Since I am only 41 years old though, if I cut the wood lot at age 71; 30 years from now, I would have an additional $330,000 for my retirement account over what my woodlot now would be worth 30 years from now.

By your own numbers you are putting a severe limit on the future value of your woodlot and I have to ask why?

There is a high risk of declining values of the Hemlock and a only a slight chance of finding some additional value for the Hemlock down the road. Since mother nature leaves no possibility for do overs, why take that chance and hang on to the Hemlock?

If it was me, I'd clean out most of the best Hemlock and only save some that has the most potential growth down the road and clear out the rest. This seems like a good time to move on to better species with more potential and less risk.

I do get it that you have some emotional attachment to those Hemlock so by all means do not clear them all out. But you will never be rid of them completely anyway so get that 1/3 down to a low percentage.