Farming Your Forest

BY BILLY RYE

Many landowners absolutely love their hardwoods. These trees provide their owners with beautiful landscapes, habitat for various forms of wildlife, and timber sale revenue to assist with future forest management. Some of these landowners are willing to forego the higher return on investment that pine plantations yield just to enjoy the benefits provided by hardwoods. However, most landowners also want to manage their hardwoods in a responsible manner to encourage sustainability. To help landowners reach their objectives for the property, all timber harvests should be orchestrated by the overall forest management plan prepared by a Registered Forester.

Before describing the different types of harvests implemented by foresters, it is important for landowners to have a basic knowledge of how forests work and some of the criteria used to compare timber investments. Below is a brief explanation of forest ecology and timber investment analysis.

Forests in the South tend to occur naturally in even-age stands. An even-age stand is one where most of the trees in the upper canopy are of the same or nearly the same age. Prior to the arrival of man, even-aged stands were established when natural disturbances such as wildfires, tornadoes, floods, or hurricanes would destroy the trees in the upper canopy. These disturbances allowed sunlight to reach the ground which freed the sprouts, seeds, and seedlings already in place to race each other to occupy the canopy of the next forest. Over time, the forests would improve in both the quality and quantity of wood as the trees with the best genetics would out-compete the others for valuable sunlight, water, and nutrients.

The EF5 tornado that hit Hackleburg in 2011 removed the canopy of this forest and allowed the next generation to become established.

Even those landowners who are willing to accept the lower return on investment provided by hardwoods don’t want to lose money managing them. Economists have several methods of measuring the economic rate of return for long-term investments like hardwood management. The two most common investment criteria include Net Present Value and Internal Rate of Return. The time value of money is a basic concept in each of these methods of comparison. In short, a dollar today is worth more than a dollar tomorrow. Therefore, the sooner a landowner receives significant income from a harvest, the higher the rate of return. Since hardwoods reach their economic maturity at a later stage than pines, their return on investment is usually much lower. This makes the proper management of hardwoods more challenging.

Even though hardwoods grow slower than pines, they can still yield an acceptable return on investment if properly managed.

Once the landowner has a basic understanding of these two concepts, they can better grasp the various harvesting methods recommended by foresters. In general, most harvest types fall into one of two categories: intermediate and final. Intermediate harvests are often known as selective harvests and are conducted prior to the final harvest. The final harvest is conducted at the end of the life cycle of the forest stand (often referred to as rotation) and sets the stage for the regeneration of the next stand. Below is a brief description of some of the harvesting methods implemented for hardwoods on private forestlands in the Mid-South and the advantages and disadvantages of each method.

1) Diameter limit. Using this method of harvesting, a pre-determined diameter size is selected and only those trees equal to or larger than this size are removed. The intent of many landowners using this method of harvest is to remove the larger or older trees and allow the smaller or younger trees to grow and mature. Unfortunately, the trees that are larger are not necessarily older and often the smaller trees present in the forest are either undesirable species that grow well in the shade or they are genetically inferior to the larger trees. This type of harvest is known to foresters as a “high-grade” and will diminish the forest’s ability to produce wood in the future. It is not recommended if timber production is an objective.

• Easiest method of select harvest to administer. • Yields the highest revenue of the select harvest methods.

• Can result in a “high-grade” which reduces future timber production and revenue. • As with all select harvests, damage will occur to residual stems.

2) Timber Stand Improvement. Using this method of harvest, trees that are smaller, damaged, diseased, or of undesirable species are removed and the more desirable trees are retained. Using this method, the resources necessary for tree growth are

This is an example of a diameter-limit harvest. The larger trees were removed with the misguided notion that they were older. Instead, the trees with the best genetics were removed which diminishes the ability of this forest to produce wood in the future.

focused on the desirable trees and the rate of return on investment should be increased. Unfortunately, due to the poor quality and low volume of the wood being removed, this type of harvesting method is usually unattractive to most timber buyers. For this reason, TSI is often limited to either very large tracts of timber or large landowners who will serve as repeat customers for the timber buyers.

• Improved timber production and return on investment. • Relatively easy to administer.

• Harvest volumes and quality may be so low that buyers are not interested. • Higher value trees will be damaged during harvest.

3) Combination. To avoid the disadvantages of the methods mentioned above, many foresters choose to implement a combination of select harvesting methods. Using the combination method, a forester will typically mark enough valuable trees to attract a timber buyer while removing some of the undesirable species or poor-quality trees so that the forest will improve in the future. The trees selected for removal will include trees from different size groups and product classifications.

• Enough value to attract timber buyers. • Results in more future growth and revenue when compared to a diameter-limit harvest.

• Difficult to administer. • Will not improve future growth and revenue as much as a TSI.

Even when properly implemented, some residual trees will be damaged during a select harvest. Fortunately, this sale was conducted by a Registered Forester and these damaged "turn trees" were removed upon the completion of harvesting in this area.

1) Merchantable Clear Cut. Using this method of harvest, all the trees of merchantable (sellable) size are removed during a single harvesting event. The timber purchaser harvests all the timber which they think that they can harvest and re-sell at a profit. Merchantable clear cuts imitate natural disturbances such as a strong wind event or wildfire. From this standpoint, it may be considered the most natural method of establishing the next stand. This is the most common harvest method in the Southeast.

• Generates the most revenue of any of the harvesting options. • Facilitates even aged management of the next stand. • If converted to pine, this method of harvest facilitates increasing internal rate of return by at least a factor of 2 on most sites.

• Is often unsightly. • Results in a long period of time before realizing significant timber sale revenue.

2) Silvicultural Clear Cut. Unlike a merchantable clear cut, all woody material is harvested. The only practical approach for utilizing this method is a whole-tree chipping harvest. When using this method, all the merchantable wood is harvested and sold while the woody debris generated from the harvest and the wood of pre-merchantable-sized timber (too small to sell) is chipped and blown into a trailer. The trailers containing the chips are then hauled to an area mill where it is burned in the boiler to generate electricity or used to make charcoal. The landowner is normally paid for the merchantable timber but is paid very little, if any, for the wood chips.

• Facilitates easier hand planting of pine or change in land use such as conversion to pasture or subdivisions. • Improves habitat for deer and turkey. Followed up by biannual burning, this technique will maintain an “early successional” habitat which is beneficial to most game species.

• Limited number of harvesters with this equipment available. • The logger normally must subsidize the chipping portion of the harvesting by lowering the stumpage paid for merchantable timber to the landowner.

3) Group Selection. Foresters implement this method of even-aged harvesting to create an uneven-aged forest. Typically, small groups of trees are removed to establish an even-aged stand. The small harvest areas may be planted or allowed to naturally regenerate. Group sizes and locations depend on landowner objectives. Some landowners use this method to harvest a certain portion of their property at one time (example: 1/5 of total acreage in each harvest). Due to certain “scales of economies,” this type of method is typically implemented on large properties.

• Even though this harvest type will result in an even-aged stand, it is a method of creating an un-even-aged forest. • Multiple harvests spread out timber sale revenue over a longer period. • Improved wildlife habitat.

• Higher sale administration costs. • Opportunity costs compared to selling all the timber in one sale.

4) Shelterwood Harvest. The shelterwood method of harvest is designed to encourage the natural establishment of a desirable species. It is most often implemented in oak regeneration. Using this method of harvest, the canopy or upper portion of the forest is removed over a series of harvests. The length of time between the harvests is determined by the target species and the stocking rate of the trees providing the seeds. The first harvest is intended to stimulate the growth and seed production of the remaining trees, the second harvest is designed to provide the needed amount of sunlight for the newly germinated seeds, and the final harvest is conducted to remove the competition of the overstory from the desirable seedlings which are now well established.

• Facilitates regeneration of a desirable species (particularly oaks). • When completed, the total harvest revenue should be relatively high.

• Loss of some of the most valuable trees through windthrow and lightning damage. • Opportunity cost vs. commercial clearcut.

By understanding the methods of harvest available for private landowners in the Mid-South, landowners are more likely to reach their objectives for their hardwoods. A basic understanding of forest ecology and timber investment analysis can help the landowner avoid costly mistakes associated with improper hardwood timber harvests.

This one tree has a financial value that is higher than an entire acre of timber on most properties in the Mid-South. A proper understanding of harvesting methods allowed this landowner to reach his objectives for these hardwoods.