The Most Important Factor in Forest Management
This piece of wood changed my life!
20 years ago, I cut through this Red Oak 4X4 and looked at the grain pattern. Everything I believed Changed!
In forestry school back in the 70s, I was taught that Red Oak should be managed as an even-aged crop. The small trees in the stands were the same age as the large trees, (genetically inferior & suppressed) and would not respond to release - so that clear- cutting was needed to regenerate the forest to a new crop of timber.
When I began helping forest owners with timber harvests as a consulting forester, what I saw in the forest did not match what I had been taught in classes. The oak forests in SW Wisconsin were really diverse stands of many ages. Clear-cutting or "regeneration harvests" were clearly quite wasteful, messy, and unnacceptable to a thinking forest owner.
The above grain pattern teaches a different story: A Red Oak tree in our forest was 80 years old and 6" diameter, suppressed from being under larger oak trees - barely alive. The loggers took the big Red Oaks and left this scrawny little tree. With sunshine and room to grow, it quickly began to flourish with great vigor. It grew with 1/4" growth rings until oak wilt killed the tree. I salvaged the tree, had it sawn at a local sawmill, and used the lumber for projects here at the farm.
Since this epiphany, I have seen the growth pattern thousands of times. Trees of all species - all over the world - do respond to thinning and can be managed with selective Full Vigor Forestry. I have shown this very piece of wood to professional foresters across the country, and they all cover their eyes, close their minds, and refuse to accept that oaks ( and Douglas Fir and Yellow Pine..... ) will respond to thinning. They choose to maintain industrial forest management that uses large machines to harvest large volumes of timber - to protect their jobs and avoid change. Sad. Very Sad.
Managing Diameter Growth is the Key to Full Vigor Forestry!
Every time I cut a tree, I pause and look at the growth rings. Learn to read the Story in the Stump! The history of the forest is recorded right there for you to see.
Trees need to grow to live. The competition for light keeps them always stretching to grow taller and wider. If they stop growing, or grow too slowly, other trees will over-top them and steal their light and suck up the water and soil nutrients below them.
A forest tends to become overcrowded and stagnate after 20-30 years. Whether a newly planted field, or a harvested woodlot - stands become crowded and growth rates slow.
White Oak growth rings tell the tree's life story
This tree sprouted from an acorn after a heavy timber harvest and had full sunlight and lots of room to grow. The first three years show good growth. The next five years, the tree grew very slowly and it is hard to see the growth rings because they are so thin. These years, deer ate the buds from the tree, limiting the growth. Gradually, the tree grew taller and then escaped the browsing of the deer, and expanded its leafy canopy. At year 12 the tree was in Full Vigor - growing with 1/4" growth rings. After ten years, the tree began competing with other trees. After another ten years, the diameter growth was only about 1/32" - the young tree was beginning to die. The forest stagnates and the stuggle to live is intense.
Our goal is to constantly thin our forest, to avoid any stand from getting overcrowded and stagnant. We want our good trees to grow with a steady growth rate throughout its life. 1/8" to 1/4" growth rings are best for quality and quantity production.
For a tree to grow with a 1/8" to 1/4" growth rings, (1/4" to 1/2" annual diameter growth) it needs a healthy leaf surface to catch the sunlight. Hardwood trees with a tree crown that has a width equal to 1/3 of the tree's total height - will be able to support this level of diameter growth. Conifers should have a crown width of 1/4 of the trees height. This crown width tells you how far apart the trees should be spaced. Most forest stands are too crowded!
A tree with a skinny crown will grow slowly. A tree with a wide funnel shaped crown will grow well. An open grown tree with a large round leaf canopy will grow too fast and be too branchy for valuable timber production.
Watch the Story in the Stumps - each time you see a cut stump.
Monitor the Diameter Growth of a number of your good trees.
Thin the forest to allow the crowns to attain the 1/3 crown width to tree height ration.
You will soon have Full Vigor!