By: Al Koeppel, Kretz Lumber Company, with insight from Linda Williams, Wisconsin Department of Natural Resources

This spring and summer, we have found that spruce trees, which include blue, white and Norway species, are under attack. They are being impacted by a fungal disease which goes by the name of Rhizosphaera needle cast. It’s a mouthful, no doubt, and it’s wreaking havoc on our spruce population.

I reached out to Linda Williams, Forest Health Specialist - Northeastern Wisconsin from the Wisconsin Department of Natural Resources to get her insight into the disease. This is what she shared:

Friday, 09 March 2018 09:52

What happens when trees get too big?

Kretz Lumber Company, joined by landowner and logger Rick Peters, head out to the woods of Wisconsin's Shawano County to discuss economic and physiological challenges that can occur when growing large diameter trees.

In order to answer what makes a log a veneer grade log, let’s first define what veneer is. Most people understand what lumber is (logs that are sawn into boards which are generally 1 or 2 inches thick and 4 to 10 inches wide). Veneer on the other hand is produced when logs are put on a lathe and long continuous sheets of wood are peeled off. These sheets of wood are generally around 1/42 of an inch thick for hardwood. Plywood (which you see sold at retail lumber yards) is actually sheets of veneer glued together. Hardwood doors and furniture are generally made from veneer.

Now we will get to the question. Defects are what determine whether or not a log is graded as a veneer log. Knots is one form of defect. A knot is created when limbs prune off and the tree grows additional wood over the area. Knots can fall out of the sheets of veneer during production and they can be a visual deformity. Seams are a major defect, which cause the sheets of veneer to break and come apart. Other defects include bird peck, gum, ring shake, insect damage, color and mineral. Another criteria for veneer logs is diameter and length. Logs that are too small or logs that are too big in diameter affect grade and quality. Logs that are 12 inches in diameter or larger is a common size that is utilized in veneer mills. Logs that are over 30 inches in diameter are generally not desirable because there are limitations to the size of logs that a lathe can handle.

By: Al Koeppel, Forester, Kretz Lumber Company

Whether you take a very active land management approach, or are just starting to think about it, there are a number of strategies you can use to increase the yield of your hardwood stand. Here are four tips you should consider as you think about increasing your forest yield.

Volume and Value

When we talk about increasing yield, we need to consider volume and value. Let’s start with volume. Take any tree in a well managed forest and as you chart its growth, it will generally follow a typical bell shaped curve. We call this “mean annual increment” or MAI. Consider a red pine planted as a seedling. During those first few decades, it experiences a lot of growth. At around age 60, it starts slowing up on volume growth. The tree will continue to put growth on as it will typically live to 150+ yrs. old, but the volume growth per year will slow down.

Now, let’s look at this same red pine and take into consideration its value growth. Do you think that its value growth, or what I like to refer to as economic growth, is the same as MAI? That would be a somewhat typical assumption. The lion’s share of the time this is not the case though. As the tree grows in size and increases its merchantable volume, it also increases in grade. 

Grow high quality trees

Seems like a no brainer, but there is a lot that goes into determining the quality of a tree. Trees are sold by product classes. Wood product classes are based on two major factors: defects and diameter. Our red pine example is generally classified as pulpwood, the lowest valued wood. If no defects are visible, then the diameter of the tree will determine what product class the tree falls into. 

  • Product classes for red pine = pulp, bolts, utility poles
  • Product classes for hardwood = pulp, bolts, sawlogs, veneer logs
Thursday, 13 April 2017 10:44

Utilizing cut backs to improve log value

Improving log value

It’s no secret that tree cutting strategies play a big role in the log’s ultimate value. But unless you spend your days in the woods around loggers, you may not know some of the strategies we use to cut trees to their highest value. Here are a few examples:

This first image shows blocks that were cut from the end of the tree. By cutting these blocks, this particular log lost volume, however, its grade was improved. With that grade jump, the overall value of the log increased. Should the log have been cut shorter to begin with? It may have been miss cut because of the flair or bulge on the bottom left side of the butted piece. But by removing those blocks, even though volume was decreased, the grade improved, and consequently, its value.  

Friday, 11 December 2015 16:36

DNR Economic Workshop at Kretz Lumber

The Division of Forestry began conducting listening sessions in 2013 to identify gaps in relationships between the DNR, landowners and private forestry. As a result, the Division of Forestry launched a Forest Products Services Program for their employees and began planning workshops to better educate and connect DNR foresters to landowners and businesses like Kretz Lumber.

Monday, 23 March 2015 13:24

I Bought a Woods. What do I do now?

Over the years I’ve had the pleasure of meeting many people who were owners of wooded property. They acquired their property by many different avenues. Some land was passed down through multiple generations. Others were newly acquired. A common theme with many landowners is they have the property for hunting. At least, that is a statement I hear many times. Whatever the reason for ownership, many landowners would like to do more with their property but are uncertain where to look for help.

Monday, 15 December 2014 19:07

Family Deer Hunters Have a Season of Firsts

Looking back at the 2010 deer season, it was a season of firsts for one Kretz Lumber family. Beginning with a brother and sister team, Michael and Lindsay Koeppel had a season to remember. During the bow season Mike was taking advantage of parent-teacher conferences and was in his stand early in the morning with his grunt call, doe bleat and rattling antlers. Soon after daylight he started his rattling grunt sequence and had a fork buck checking things out. A little while later a 6-pointer came in but he was determined to hold out for a bigger buck. Some more grunting and rattling and an 8-pointer with attitude came in looking for a fight. Mike was surprised at how quickly and silently this deer showed up and he knew he had to take advantage of moving only when the buck looked away. Trying to calm his nerves he drew back and shot. It was a good shot and the buck made it about 40 yards. This was his first buck with a bow.

Monday, 15 December 2014 19:04

2014 Kretz Forestry Department Reflections

It’s the fall and as I sit in my deer stand I become a hunter/forester/philosopher. Reflecting on the past year we are once again fortunate. Did everything go as planned? Not anywhere close! If life was predictable it wouldn’t be anywhere near as exciting, and yes sometimes we don’t need that much excitement.


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