Forestry 101: How much management?

By Tim Holland

Trees are a crop, just like corn, cotton and soybeans, but take a good bit longer to reach financial maturity than within a year.

Once plating pine seedlings for a client who was in his mid-90s, I was asked when would be the first cutting on the trees. I told him, “Mr. Preston, we will do a first thinning of pulpwood in about 15 years.” He looked at me and said, “Well good, I will probably need the money then.” 

Talk about a positive outlook!

We are all called to be good stewards of our environment. As landowners, we must strive to do the best we can with overseeing the property we have been entrusted to handle during our brief time we are here on Earth. We will not “own” this land forever, but while it is in our name, we should do a good job with the “management.” 

Timber management has a wide range of good ideas. As with most platforms, there are differences of opinions on how to accomplish various goals.

You could just leave the land alone and it would grow a crop, of something. Our perspective on timber and how we handle that timber and all that goes along with timber, has indeed changed. When I first started working in timber in 1980, I visited an 80-acre clearcut, it was indeed a clearcut. You could see all the way across it, not knowing that about half way across the clearcut was a creek. 

Today, we install Streamside Management Zones along all creeks and drains, reducing erosion and taking care of the ecosystem along that waterway. We have gotten much better at taking care of our environment.

Good timber management can reach across a broad spectrum. Our idea of what management we want on our property comes from what we want to accomplish, our goals for the property while we are the caretakers: financial return; wildlife habitat; aesthetics; recreation; water. Some landowners are more concerned with how much money that the property can generate. 

Hopefully, we can tie all the aspects together with good, sound timber management. You could refer to the concept as ecosystem management. Remember, trees are a crop and we want to grow the best trees we can and capture that growth to utilize for the enhancement of society.

You need to conduct timber sales to capture the timber growth.

Assuming you conducted a “final harvest” sale, you will need to reforest the area. There are many different avenues you could travel down as you accomplish this feat. You will need to do some type of site preparation work; generally, this includes some herbicides to control the brush so that the small planted trees can get a foot hold. 

For the record, in the South, we are talking about planting Loblolly pine seedlings. Remember, all establishment costs are capitalized through the life of the stand.

One plan of action is simply referred to as “spray-burn-plant.” The first step is to conduct an aerial application of herbicide in the summer or early fall; conduct a site-prep burn on the site about 40 days after the herbicide; and then plant the Loblolly pine seedlings in the winter, usually December through early March. 

A herbaceous weed control can be applied in the spring following the planting to deter grasses which will compete with the young seedlings. 

Genetics are important. The new young pine seedlings you plant need to be the best seedlings you can get for your price range. And there is a wide range of prices for seedlings. 

You need to decide if you want bare root seedlings or containerized seedlings. Containerized seedlings are more expensive, but they can be planted earlier than bare root seedlings. 

What density — the spacing of the trees per acre — do you want to plant? The spacing most often used is 8-by-8-foot or 681 seedlings per acre. This spacing can vary depending upon the desired goals. 

The seedlings survival rate depends upon various factors as well. The seedlings were doing just fine in the nursery, when suddenly a large machine passed over them and they are plucked up out of the soil, placed on a conveyor belt, taken to a building, put in bags or boxes and shoved into a giant refrigerator. The process is stressful on the little trees. 

The point is, handling the seedlings is crucial to their well being. The tree planters must take care in the planting process. The roots of the seedlings must not be exposed to the air — this dries out the roots and seedlings die. The seedlings must be properly planted in the ground and if you can arrange for a nice rain shower following the planting, that would be great. You also need to make arrangements for some rain during the summer months following the planting. If the young seedlings make it through the first year, they should be good to go.

Wait until about the third year before looking at the planting. In the first year, the little seedlings are fighting to get established and most people go look and they say, “There are no seedlings out there!” They are there, just be patient. The third year they will have their heads sticking up above the material on the ground and you will be able to see them.

Should you fertilize? This is a question you need to discuss with your forester. Most small, private, non-industrial landowners do not fertilize. The cost is difficult to justify for many for the amount of good gained. 

Somewhere at about age 15, maybe 13 or 17, depending upon your management strategy, you will conduct the first thinning. The first thinning will be for pulpwood. The trees would need to have an average DBH (diameter at breast height — a standard measure of 4.5 feet above the ground line) of around 7 inches and have a merchantable height of around 40 to 50 feet. The trees need to be big enough to make an economic job for a logger. 

This process thins out the stand to leave the better trees to grow. Removing a portion of the trees eliminates some of the competition for water, minerals and nutrients and the remaining trees get the benefit. The thinning process must allow for the trees to be removed from the stand. This will include cutting some corridors within the stand and will include a staging area to load the trucks. 

The corridors can be cut with the planted rows, if the rows can be discerned. The corridors are referred to as “down rows” or “clearcut rows.” The down rows can be put in every third row or every fifth row. I would say the norm is every fifth row. 

Cutting every fifth row will leave four rows in between the down rows. You need to do some thinning within the four rows to accomplish a good thinning operation. The thinning operation should thin the stand of pulpwood trees back to a good basal area, generally 70 to 75 square feet is accepted. 

Basal area is a measure of the surface of a square acre taken up in wood. If you took a sharp knife and sliced off all the trees on an acre at DBH, you would have a lot of round circles. A square acre has 43,560 square feet and when we measure all the circles of the trees, we want to have somewhere around 80 square feet of trees evenly dispersed over that square acre.

Normally, a pine plantation that was planted on an 8-foot by 8-foot spacing or 681 seedlings per acre, would have a basal area of around 145 at the time of thinning. Your timber management goals will determine how heavy you thin this pulpwood stand. 

Are you wanting short fat sawlogs or are you wanting tall, straight sawlogs. This factor may be determined by your location to the nearest mill and the type of that mill. You may want to thin down to a basal area of 60 square feet per acre or you may only thin back to an 80 basal area. 

All of our timber management practices go hand in hand with wildlife management. The thinning operations open the tree canopy to allow sunlight on the ground, which in turn promotes deer browse and turkey food.

Understory burns are great for the trees and the wildlife. Understory burns can be implemented about two years following the thinning operation. The burn will “clean-up” the forest floor by burning the debris left from the logging operation. The fire will turn the debris, limbs and pine straw into ash and it goes into the soil as fertilizer. The burn will enhance the wildlife habitat for deer, turkey, rabbits as well as song birds. 

The new material which begins to grow immediately produces food for all wildlife. There are numerous fire following species which are greatly beneficial to the wildlife. Understory burns are done on a 3 to 5 year rotation, as suggested by most wildlife management programs. A word of caution, if you initiate a burn program, you must continue the program. Do not burn one time and walk away. 

The next timber harvest will normally occur 10 years after the first pulpwood thinning. The number of timber thinnings will be determined by your timber management goals and the predetermined rotation age. Some owners operate on a shorter rotation, maybe 32 to 35 years, while some other owners prefer a longer rotation age of 45 to 50 years. 

The shorter rotations will have two thinning operations, age 14, age 24 and then a final harvest (clearcut) at age 32 to 35. The longer rotation will have three thinning operations, age 15, age 25 and age 35, followed by the final harvest at age 45 to 50.

The scenario just discussed assumes a clearcut and pine plantation. 

However, you may have an older mixed stand of timber with pine and hardwoods. Your management plan would be different. You will still do thinning operations. The products and the timing will be a little different. 

I love hardwoods scattered within my stands. Most pine plantations will have some hardwoods mixed within the pines. I generally leave the nice red oaks within the plantations.

How much timber management do I need? More than you may think. There is more to it than just sticking some trees in the ground. A management plan and a good forester are needed. 

(Tim Holland is a consulting forester for Mudd & Holland Consulting Foresters.)