Slow Growing Trees

[MountainDon]

A short time ago in another topic I made mention of our slow growth mountain ponderosa pines. Don_P expressed some surprise or amazement at what I described.  I was cutting this tree up into 4 foot lengths on the weekend when my mind clicked. I brought a slice home and planed it smooth. The tree was cut this spring. After cleaning up it appears to have 55 growth rings, some very tight ones.



The last 6 or so years have been rather dry. Very slow growth.

[Shawn B]

Scientists have discovered that the tree rings do not always represent a yearly ring, but rather just a period of growth. In years when spring rains continue into summer, or if there is a early or wet fall some trees will have multiple rings per year.


Don, maybe the slow growth of your trees is due to the volcanic soil having low nutrients?

[MountainDon]

I've heard that too, but there still seems to be a preponderance of the one ring one year belief.

According to a USFS ranger we know and a state forestry ranger this tree falls in line with what they estimated our trees of this size to be.

The slow growth is likely the result of a combination of things, soil fertility being one part. Others are the 8800 foot elevation with the resultant shorter growing season, compared to thousands of feet further down. 13 or 14 inches total moisture in a year doesn't help growth either.

The point was that it takes many more years to grow a large tree up there. Down at 5500 we have a 25 to 30 year old pine that is already passing 15 inches diameter.  We have an experiment in process up in the mountains. If I live long enough maybe I'll be able to make something of the results. We have some ponderosa pine and douglas fir seedlings marked and plotted for future growth. They are all still very small at 3 to 4 years old. We started with 18 each but have lost two of each. They were all volunteers in the first area we thinned out.

We'd like to have more firs and have felled several pines of good size simply to give some of the DF's more room, more water and more sun.

[rick91351]

The small trees on the ridge were all from seeds that were distributed from a forest fire in 1989 or 1990?  They are about six to eight feet high and six or eight inches at the butt.  So about 20 years old.  We have also gone through several years of bad drought in that time span.  This is from the 5000 foot level.

That fire was the largest in the nation that year.  It was started by lighting about 30 miles away.  It ran through that country in the third of forth day.  It was eradicated by Mother Nature some thirty miles further on east and north about a month latter.  We really never got hurt with fire there because a good neighbor back fired most of this the night before when the winds changed.  The fire certainly did sew a lot of new trees in its run.   

[Pine Cone]

Your picture appears to be from a Douglas-fir log, not a ponderosa pine.

As a forester, your slow growth at over 8000 feet is not surprising.  Height growth is somewhat independent of tree density/spacing, but diameter growth is influenced by how close together the trees are.  Wider spacing means faster growth since there is less competition for water and nutrients.

Conifers don't like to live in places that get less than 30" of precipitation per year, so if you only get 13-14" per year they are doing well just to survive.

Volcanic soils vary in nutrient availability.   Lighter colored, heavy to silica volcanic rocks (rhyolite and related rocks) are low in nutrients and water holding capacity.  Darker colored volcanics like andesites and basalts have lots of nutrients if the soils are old enough. 

While there are conditions that can give more than one tree ring per year,  if you look at the wood cells with a hand lens or microscope you can usually tell if there are more than one "ring" per year.   Trees growing in tropical areas don't have good annual growth rings, but PP and DF in New Mexico will almost always have very distinct rings.

I live in the PNW because it rains 40 to 120+ inches per year, the winters are relatively warm, and the region grows trees pretty darn fast.  That means I can make a living in the forestry biz.  In New Mexico, forests don't produce much of an economic return.  New Mexico forest values come from wildlife habitat and open-space, but harvesting timber in most of the region is non-renewable timber mining, not sustainable forestry unless you adopt 200 year rotations.  In my dreams, I would be able to afford living in a ponderosa pine/Doug-fir forest because I like how they look and smell, but they have biomass productivity of less than a fifth of where I live. 

As a point of comparison, a 55 year old tree around here is at least 120 feet tall and 2x to 4x larger in diameter than the trees Mtn. Don has around his cabin.  Big trees here would be over 150 feet tall and 2 feet in diameter.

Keep that experiment going.  I'd be glad to help you analyze the results in another 20 years.  I love looking a stuff I did 20-35 years ago.  The time frames in forestry research are quite humbling.  Projects that look good for 5 or 10 years can go to heck after that.  All of written human history can be surpassed by the lifespans of a few redwoods or bristlecone pine trees.   The earliest work I did in forestry is only about 35 years ago, which is hardly an instant in a tree that can live for more than 400 years.

[rick91351]

I think the bark cross section looks like pine, the grain and wood looks a little like fir.  However Mt. Don certainly knows the difference.  Could this be one from minerals in the soil or two the planing of it end grain?

Could I pose another question.  Could you post or PM me some pointers for thinning and limbing pines  or let me know of some good publications of such.  I certainly would like to become more proactive in management of the pines on my property.  Reasons are many fold just a few.  One less stressed trees survive bug infestations better; another reason they also survive fires better.  Three greater marketability on down the line in both property value and timber value.       
 

     

[MountainDon]

Pine Cone, I certainly could have mixed a DF into the woodpile, but I'd be surprised as we don't have many in that size range. However, it's been several months and I suppose it is possible. Are you going by the coloration of the wood? The bark between the two is different enough that I don't think I'd make an error on that. ??  But the tops are long gone so I can't check via that route. I have another similar slab I brought back too. I'll have a look at it in the AM. It's about the same size and it's got some blue in it... pretty sure it's a ponderosa. In any event they are about the same but I'm saying that without counting rings.

Our land did definitely have too high a tree density until our recent thinning efforts. The last half dozen years have been 13 -15 inches. Prior to that it was wetter with a fair amount of that being winter snow. We've created a few small ponding areas; no idea if or how much they will help. They have kept some of the monsoon rain water from becoming surface run off though. In the grand scheme of things it may be for naught.

NM used to have a good number of small saw mills but most all are gone with the larger trees. As we hike around the area I'm amazed at the numbers of truly large stumps, large for present day here that is. I'm talking 40 inch diameters, probably small for the PNW. Our largest living trees are in the 24 to 28 inch range and there are not too many of them. They must be very old. Here and there in the NF there are some larger living ones.

We have a lot of pumice, which if I'm right is related to rhyolite. ??  Anyhow we're sitting on huge piles of the stuff. In many places there is a layer of nice black earth mixed in the top few feet. It does become lighter colored after three feet.

[MountainDon]

Rick, we're basing our thinning on information from assorted sources. The first was our neighbor, a forest ranger with 40 acres. A second was one of our state foresters. He pointed out trees that we should keep in a small area on a trip that was abbreviated by severe lightning. We never saw him back, but had another USFS ranger talk with us a couple years ago. The state foresters talk a good talk on the phone but it is very hard to get them out to a small property. Same story on trying to get the people running the federal thinning assistance program. We also taked with one of the few remaining loggers who does contract thinning for the FS.

We did our thinning in the beginning by first getting rid of the smaller trees, those three inch and smaller and those that were bent from snow falls. Before that we cleaned up deadfall. We went through a second time removing larger trees, up to five inches or so and also reducing tree numbers where there were several in close proximity. We have taken a one small step at a time approach as at first it was difficult to cut so many. It was enjoyable, it felt good, but somehow it also didn't seem totally right, although I really knew it was for the best. I took out a few larger pines where they were too close to DF's we wanted to promote. We also took out any pines that were infested with mistletoe; we were lucky in not having much of that. We removed a few trees that had suffered large areas of bark scuffed off by other trees. Sometimes that was from a natural fall of one tree against another. Due to the crowded conditions on occasion when I cut one it got caught and damaged a nearby tree. So sometimes the thinning plan was modified in process.

In essence the goal is to reduce what the foresters call the basal area per acre. The goal is to have 100 to 120 square feet of basal area to an acre maximum. There is a prism like tool available, but I've never seen one.  Basal area is calculated by measuring trees at a height 4 1/2 feet above ground level. The cross sectional area at that height is calculated and added up.

Here's a little chart...



When we started we had maybe 400 sq ft to the acre. We're still too dense in places. I actually don't know if we will get down to the recommended figure. We have a large area (hundreds of acres) near us that the FS has thinned. The density seems low, but they have more larger trees than we do.  But at least most of the small stuff we had is gone. We have saved some small gambrel oak and as many DF's as we could. We also have a handful of some other pine that I have not yet completely identified. Last weekend I marked another batch of trees that hopefully we'll have taken by firewood collectors from the dance and 4wd clubs. We also have some aspen but most of the large ones are older and failing. There is a spot we opened up by clearing out a bunch of dead aspen that is regenerating lots of baby aspen. Looks like too many, but we'll see.

I have a few files buried in the computer. I'll email them to you in a day or so...

[rick91351]

This year I did some real concentrated thinning in some nice little pine groves.  I wished I would have taken some before and afters  I when I got done with some way over half the trees were gone.  I have stopped until the weather changes.  The last thing I need is to get some fire started.  The people that lease the ranch usually have the cattle in there early and that really cuts down on chances of fires.  This year we have grass and fuel everywhere.  There just was not enough cattle to go around.  Lucky we did not have hardly any lightning.

The Forest Service timber ranger for that area stopped and talked to me a couple times this year when I was working in the trees.  He did no seem to have much more info than I already had. 
His best advise was thin all tree that the tops have been broken out of them.  Knock down all the one the snow has bent over   Trim out all the twins and open them up so the air and breezes can filter through them.  He does not seem like to see them so close that they touch anywhere.  He says when they get that close again come through and harvest some more out.   On mature trees limb them up as far as you can reach.       

[MountainDon]

Maybe I should have mentioned that I wet the end of the slice to make the grain easier to see?

There ya' go Rick, I completely forgot to mention that we have also removed a lot of dead branches, ladder fuel, from the trees. That can make a big difference in some fires. And the idea is to keep space between crowns.

Hundreds of years ago lightning caused fires would start in June or July and might burn for months. Back then apparently the fires would most often burn slower as there were fires every few years and the ground fuels would be burned up.

[dug]

I can't find it, but years ago I saw a photo of a particular spot on a mountain near where I lived taken about 100 years ago vs. a modern one taken from the exact same spot after years of fire suppression. The old photo showed large, well spaced trees with little undergrowth and resembled a park like setting. The new one was choked with saplings and brush, impenetrable to anything other than a bunny, or similar sized creature.

Fire suppression may be necessary in our urbanized world, but it has changed the nature of our forests.

[muldoon]

I have recent anecdotal experience with this as well in one area that I started working on in the past few months.  On the west side of the pond was a stand of a few hundred very small diameter cedar trees.  They were spaced roughly 6" to 18" apart and literally covered about an area of 50' by 50'.  They were getting water from the pond, but obviously starved for nutrients and light under the canopy of the larger white oak.  

In this picture you can see the general area that was just sawed; which is generally the area that looks like it has been mulched.  The "sticks" beside it are these slow growing cedar trees.  Each tree is roughly 2" diameter and incredibly have 20-25 rings visible when cut.  

[Pine Cone]

Don & Rick both seem to have gotten good forestry thinning advice. 

Here is a link to various ways of measuring basal area.  The cheapest is the cruise angle guage shown about halfway down the page.  http://oregonstate.edu/instruct/bot440/wilsomar/Content/HTM-trees.htm

You can get them from Ben Meadows. http://www.benmeadows.com/BEN-MEADOWS-Cruise-Angle_s_102336/Cruising-Prisms-and-BAF-Tools_31221837/?isredirect=true&refr=http%3A%2F%2Fwww.benmeadows.com%2Fstore%2FForestry%2FTimber_Cruising%2FCruising_Prisms_and_BAF_Tools%2F%3Fnoredirect%3Dtrue

Here is a picture of a Douglas-fir tree "cookie"  The heartwood would be darker if you wet the wood.
 

Unfortunately I couldn't find a similar picture of a ponderosa.  The bark of ponderosa pine doesn't have the lighter regions, the branch in your cross section is too narrow to be a pine branch, pine often have blue stain, and doug-fir never gets blue stain.  Most smaller pines will also have a very visible pith section at the center of the log.  The center ring/pith area on a pine is almost always larger in diameter than the one shown in your picture. 

While ponderosa's aren't found near where I currently live, I did have a 6-month research job where we cut down Douglas-firs, ponderosa and sugar pines, incense-cedars and white and red firs, cut tree cookies out of them up and down the bole and then measured the heck out of them to collect data for a forest growth-and-yield model, so I have seen and helped measure thousands of cross-sections of both DF and PP trees.

In any case, you clearly have slow growing trees, and the thinning guideline of 100 square feet of basal area is a good one for either species. 

[MountainDon]

Pine Cone, thanks for the gauge and prism info. I just may get one of those.

Well, I dredged up the other slab/cookie I brought back and planed it. Sure is ugly with the blue stain. Anyhow it is definitely pine; matches another big old one I have. I can see the bark is different too. So yes I was a tad unobservant when slicing these two off logs I had piled in spring. I must have cut a DF and forgotten about it. That's not the first memory lapse. Anyhow I counted the rings and some are so narrow, so tight I'm not positive I counted them correctly. I come up with 63 or maybe 65 years. I'm 64 so let's say the tree started out in 1946; 64 years ago.

It's virtually the same diameter of the first cookie I posted; the DF.  This picture is not as good. I had to use flash with it being late and dark.



From around 1966 to the early 90's the rings show most of the trees growth.

Thanks again for the info and for confirming we're on the right track with the thinning.

[Pine Cone]

Interesting PP cookie.  Looks like growth increased slightly in the last 8 years or so.  So any idea what happened about 10 years ago?  The first cookie doesn't show the same trend at all.

In any case, if I were you, I wouldn't plan on funding your grandchildren's college education from timber revenues off your property.   While I've seen slower growth than 7" diameter in 64 years, that makes an average annual radial growth of only about 1/20" per year, similar to the growth rate on lands I used to help manage south of Bend, Oregon.

I was checking out some research plots on my company's property in Western Washington today and the average diameter on the better plots is about 13 inches in diameter at 21 years, a bit better than 1/3" per year.  That's more than 6x what you are getting.   By comparison, I worked in New Zealand for most of 1982, and the average radial growth on my study trees there was more than 1/2" per year, or 1" in diameter a year,  about 150% of the growth of our better trees in WA.  Seems like there is always a greener pasture somewhere else...

I would guess that with an aggressive thinning program you might be able to double your current growth rate.  The main problem is figuring out what you can do with the trees you cut down so you don't increase your fire danger.  You can pile and burn the tops and limbs, but that takes some effort.  The real problem is to  figure out what you might do with the small logs you are creating.   Maybe you can build hundreds of rustic gazeebos

[MountainDon]

I have no idea on what might have happened 10 years ago. I have access to daily weather records history but only from 2001-2002 and onwards. To maybe complicate things a little these logs were piled at the bottom of a draw and I have no idea if the logs came from the north or south sides; and at the bottom where these were the south facing side opens onto a meadow to the western end of the draw. Talk about differences in sun within a small area.  There are some differences in patterns of growth of the grasses as well.

We're not planning on making money off the timber.    Our goal is simply to make it look better, be healthier and more firesafe. 

We burn the tops and limbs. You are right about that taking some effort. At present we have several piles drying out and will tarp them before it snows. Then with snow on the ground we'll snow shoe in and burn. We've found that firewood size timber is readily gathered and hauled off by friends and acquaintances when they are told it's free for the taking, although we've also been a little surprised at how picky a couple of people have been. 

[MountainDon]

We thinned some more. Sort a shame to cut some it seems, but three ponderosa pines were crowding one of the largest of the small douglas firs that we have. The DF's being vastly outnumbered we decided a while back that they would have to go.

After felling the three PP...



Two slabs from the cut trees...   74 years by the count



and 84 years...



Not planed as smooth as the last time.
I ordered an angle gauge too.

[John Raabe]

Wow - great discussion on forest management.

My place on Whidbey island, WA needs thinning but I know the fir, cedar and white pine are about double the height and girth they were when we built the house in '84. The Alder are the first into a disturbed area but they are quickly replaced by evergreens.

[NM_Shooter]

You've got my curiosity up...

BLOK Ranch was last logged about 50 or 60 years ago, and it is terribly overgrown now.  We have issues with corkbark that have sprung up like weeds. 

We have the luxury of being on the south tip of the Rockies, right below Wolf Creek pass, and we get lots and lots of moisture.  It will be interesting to cut down a tree or two and check the ring density and compare them to yours, Don. 

I am planning on heading up to the Ranch one more time to bring down a load of firewood and button up the cabin for the year     I'm waiting until the last elk party is off the ranch before I fire up my saw. 

-f-

[MountainDon]

Frank, is there enough length on the stump of that big big tree you cut down a year or so ago, to cut a cookie off it?

[Don_P]

I was working with one of our slowpokes today. This is an end slice from a white oak 8x8. I oiled it to bring out the grain more. The small end diameter is about 11". I put a red dot every 10 years, it's about 90 years old.

[NM_Shooter]

Frank, is there enough length on the stump of that big big tree you cut down a year or so ago, to cut a cookie off it?

Yeah... heck, I have one sitting next to my garage.  I forgot about that thing.  My daughter wanted it to practice throwing knives 

[NM_Shooter]

Here is the slice from the tree that was getting a bit sick and leaning towards my cabin.  I counted 169 rings. 



Fastest growth period was here... It really slowed down during the last 20 years or so. 

[MountainDon]

That's a NM grand daddy!!    Now if you get a chance it would be interesting to compare something in the 7 to 9 inch range.  We have a small number, less than a handful, of pines that are in the s foot range. I'll measure them next time. What height would that have been from; fairly close to the ground?

[Pine Cone]

What height would that have been from; fairly close to the ground?

For what it's worth, maximum diameter growth occurs just below the base of the live crown.

And remember, since it is volume that trees put on each year, not just diameter, if volume growth remains constant, diameter growth has to decrease as the tree gets larger.  Diameter is a square function (radius X radius X PI) while Volume is a cubic function (radius X radius X PI X height)  It's more complex than that since tree trunks are somewhat cone-shaped, not simple cylinders, but the energy from photosynthesis drives all tree growth at growth occurs all the way up and down the stem.

As you go out from the center of the tree there is heartwood (dead wood cells, holds up the tree, cells are filled with crud that often makes them darker and more decay resistant), sapwood (wood cells are dead, but water and nutrients move mostly up the tree from the roots in the sapwood), cambium (live cells, only a few cell layers thick, creates both wood and bark cells), phloem (live cells, AKA the inner bark, where nutrients, growth hormones, and sugars created by leaves during photosynthesis move down the tree) and outer bark (dead cells, provides for protection of the living and dead cells inside the layer of bark. 

Diameter growth is a function of sapwood area and leaf area.  More leaves = more food, more sapwood aids in water transport. 

Trees close together compete for water, limiting potential sapwood area, and compete for light, limiting how many leaves can stay alive.

Thinning forests allows water, soil nutrients, and light to get used by the trees that remain.  More water, nutrients, and light makes for more diameter and height growth.

Maximum site potential for growth is a function of how warm it is and how much water is potentially available.  Trees grow best where it is warm and wet without seasonal drought. 

High elevation forests in New Mexico and lots of other western forests have lots of cold and a drought that starts about the time it starts to warm up.  Higher elevations may have more summer rain, but a shorter growing season.

For those of us who are foresters, its a wonderful ecosystem to work and live in...  Always more to learn