In the United States and most of the developed world, when timber harvesting is not deforestation. Today’s forest industry is probably one of the most sustainable industries in the world, as tremendous efforts are taken to maintain healthy forests and a sustainable supply of timber. Toward this end, logging and timber companies often plant trees and forests after harvests as a way to ensure the sustainability of future timber supplies. Every year, over one billion trees are planted in the United States, and the majority of these trees is planted by timber companies. While forests do not necessarily need to be planted to regrow, planting secures the forest’s ability to grow healthy, valuable timber–and much more quickly than if an acre was left to regrow naturally.
Planting is a serious and complicated business, however. Companies cannot simply stick seeds in the ground and walk away, only to come back to a beautiful and mature forest decades later. Planting trees requires careful planning, monitoring, and execution to achieve superior silvicultural outcomes. In this article, we will dive into why logging and timber companies plant trees and what the process involves, as well as the challenges and controversies it entails. First, let’s start with the basics.
Planting Is a Part of Sustainable Forestry
The principle behind planting trees is simple: as trees are cut down and harvested, more trees are planted to replace them. Over time, these planted trees grow into mature timber, at which point they can be harvested again, thus continuing a sustainable cycle. Because of the simplicity of this model, planting trees (also known as plantation forestry) is a key and crucial part of modern forestry. It assists timber companies in better predicting the flow of timber to allow for continuous inventories and cashflows. In other words, it isn’t just eco-friendliness that spurs these companies to plant trees: It’s good business.
When Timber Companies Plant Trees, They Invest in the Future
Planting trees is a long-term investment. It is an enormous upfront cost with a long pay off period, taking decades before the timber companies will see a return on their investment. Conversely, leaving forests regrow naturally can be far cheaper, so why would these companies plant trees? Simply stated, Planting is an investment in the future. By planting trees, companies and landowners can regrow trees far faster than the alternative, ensure the trees that grow are valuable species, and even repair and rehabilitate forests that have been ravaged by diseases or invasive species. Because of these benefits, planting provides a way for timber companies to not just guarantee a future supply of timber, but provide a better supply for the next generation.
Replanting Gives More Control Over Species Composition
Not all tree species are created equal: At least not in the eyes of the timber industry. Every species is best suited for specific products. Softwoods like spruce, pine, and fir, for example, are used for dimensional lumber. Hardwoods like Maple and Hickory are excellent for furniture, veneers, and more boutique products. Other species, like aspen and beech, don’t have many uses beyond being sold as pulp.
A primary goal of all forest management is to guide the growth of forests toward more desirable and valuable species. Indeed, when acres of forest are cut and left to regrow naturally, there are silvicultural methods foresters can use to help tilt the odds in favor of desirable regeneration, but ultimately, the fate of the forest will be determined by nature, and often natures chooses poor species. The forest will grow what it wants–unless it is planted. When logging and timber companies and landowners plant trees, they gain total control over the species, density, and volume of regeneration, providing a massive advantage.
In the photo below, a stand of planted spruce signifies a secure future of this forest in growing lumber for future houses. Without the planting of these trees, it may have regrown to balsam fir, red maple, beech, or some other less desirable species.
Planted Trees Grow Much Faster
In optimizing species composition, it may come as no surprise that timber companies choose to plant species that grow faster. Typically, softwoods are planted for their fast growth and more predictable and manageable growth. However, even compared to individual trees of the same species found in the wild, planted trees grow faster. This is because planting stock is often genetically improved.
Genetic improvement is not the same as genetic modification, mind you. Instead of modifying genes, seed orchards that provide the seeds for planting stock select individual trees with superior growth and other desirable qualities and cross-pollinate them. Over the course of generations of selecting trees with superior traits, the nursery stock that is produced inherits and demonstrates these vastly superior genetic traits relative to a natural stand. Not only do these traits improve growth, but they can also improve form and disease and rot resistance as well.
In the photo below, a planted stand of Norway spruce only 50 years old has already undergone two harvests since planting. Such growth vastly outpaces the growth that can be found in a natural forest.
Restoring Unhealthy Forests
The decision by timber companies to plant trees is not always motivated by the need to improve already-functional forests. In some cases, natural forests become unhealthy, being overwhelmed by disease or invasive species. Such is the case with so many maple forests that have been ravaged by beech bark disease in the American northeast. In these situations, it may be best for the future of the forest if these stands are clearcut and planted to reintroduce healthy growing stock on that given acreage.
In other cases, planting can even help restore rare or endangered tree species. This is mostly done in South America, but even in the United States, species that have been devastated by invasive diseases, such as American chestnut, have been the target of replanting programs.
Do Trees Have to Be Replanted After Harvest?
Planting trees is a great way for timber companies and landowners to maintain sustainable practices and even improve the value of their forest. However, trees have been growing without human help for millennia, so they do not necessarily have to be replanted after a timber harvest for the forest to regrow. If companies make the decision not to plant, it does not mean the company is being irresponsible or the land is being deforested. It simply means the foresters decided to regenerate the stand through natural means.
In fact, planting trees is only a relatively small part of forestry practices. Timber companies, loggers, and foresters use a vast array of tools to regenerate forests without the help of planting, including shelterwood cuts, seed tree cuts, and selection cuts. During a shelterwood harvest, for example, trees are harvested, but enough trees are retained to produce seed, and with a more open canopy, enough sun can hit the forest floor to allow these seeds to grow into thriving seedlings.
Costs of Planting Trees
One reason timber companies may choose not to plant trees, opting instead for natural regeneration, is the substantial upfront costs to planting. The costs of planting trees include the production of seedlings, site preparation, the planting itself, and follow-up treatments that may be necessary.
Seedlings
The first and most obvious cost to establishing a plantation is purchasing or producing the seedlings. This is no small task. Modern tree nurseries are complex facilities that utilize a great deal of automation and genetic research to produce the best, most vigorous, and healthiest seedlings possible. The production alone can be a capital-intensive proposition, but the seedlings still must be transported carefully to the planting site without being damaged. There are several ways to accomplish this, including loading them on specialized pallets that can be stacked on a truck, such as in the photo below, but they can also be frozen and kept in dormancy and shipped in boxes. It largely depends on the species, location, and logistics of the operation. In any case, the production and safe transport of seedlings is not small (or cheap) task.
Site Preparation
After a forest is harvested, the site may still need some special preparation. A forest floor may have a substantial amount of organic matter covering mineral soil that does not provide the most optimum medium in which to plant seedlings. Additionally, very soon after harvest, the planting site may become inundated with competing vegetation that can quickly choke out planted trees. To help protect against competition as well as provide a better planting bed, timber companies may opt for a site preparation treatment prior to planting trees.
Site preparation can consist of dragging large chains, bars, and other equipment to lightly tear up the top of the soil to reduce competition and expose mineral soil for planting. The chains used in this treatment can be seen in the photo below. Alternatively, herbicide can be applied to reduce competition and allow newly planting seedlings more space and light to grow. Herbicide treatments, however, do nothing to disturb soils, which can be beneficial on more sensitive sites. In other cases, prescribed burns can be used to burn away dry logging slash and competing shrubs and grasses. This is less common in industrial settings, however.
Planting Labor
After the seedlings have been grown and delivered and the site has been prepared, it is time to plant. While you may have seen videos of automated tree planting machines, these are not the norm. In most cases (particularly where terrain is more uneven) planting still requires a human being to create a hole, pick up a seedling, and drop it in. It is incredibly labor intensive and back-breaking (and thus expensive) work. For large-scale operations, it can even be a challenge to find enough workers to get it done. For this reason, this is one of the most substantial costs in planting trees.
Follow-up Treatments
Once the trees are in the ground, the work doesn’t still does not end. It is incredibly common for a plantation to need follow up treatments. These treatments can include selective herbicide treatments to kill unwanted weeds and ingrowth, fertilizer applications, and pre-commercial thinning to space out trees once they reach a larger, but still unmerchantable size. The type and number of follow-up treatments can be somewhat unpredictable, as they will largely depend on the trajectory of growth after planting. Any planted trees will require consistent monitoring for years to determine what treatments may be necessary.
Is there a Financial Return on Planting Trees?
With all these costs associated with planting trees, is there even a financial return for timber companies? Yes! Because of the enormous benefit of having control over species composition and boosting the growth rates substantially, planting can be an extremely profitable venture. Depending on region, species, and site quality, planting trees can yield an 8-10% annual return on investment. Not too shabby! Without a doubt, the ROI of these operations is one of the largest selling points and the reason great effort is undertaken to put trees in the ground.
What Species Do Timber and Logging Companies Plant?
While virtually any species of tree can be planted, the vast majority of planted trees are softwood species used for dimensional lumber, such as spruce, fir, and pine. Second to that, poplar trees are often planted for pulp, and internationally, eucalyptus plantations dominate in warmer climates.
The reason why softwood is grown more than hardwood is because softwood growth is far more predictable. A softwood derives its value from volume in most cases, while hardwoods derive their value from the quality of their wood. It is difficult to manage hardwoods in such a way that they grow high-quality wood in a predictable manner. Branches, forks, and bends can drastically reduce hardwood value, and these defects happen almost randomly. On the other hand, spruce and pine trees grow predictably, and little can happen to destroy their value so long as they continue growing and producing volume.
Do Most Timber Companies Plant Trees?
Most larger timber companies incorporate planting to some degree into their forest management regimes. Whether they exclusively plant or plant only on a small scale depends entirely on their business model and the conditions of the forest. Planting is more common in the American southeast and west and less common in more northern climates. However, in Scandinavia, forest management is almost synonymous with planting trees. They plant almost exclusively. In many cases, it also depends on local culture and industrial infrastructure. Because of the need for seed nurseries, planting labor, and more, it can be difficult to plant trees unless it is already an established practice in the area.
Planting Trees Can Be Controversial
Though it may sound strange, planting trees isn’t always a completely eco-friendly practice, and it comes with a fair amount of controversy. These controversies revolve around an aversion to monocultures and the business model of planting itself.
Planting Can Create Monocultures
The core criticism of plantation forestry is that it can create monocultures. Monocultures are seen as reducing the critical biodiversity that make forests so vibrant and resilient. The loss of biodiversity can lead to a disruption of critical components of a forest ecosystem. When timber companies plant trees, they can easily create monocultures unless they take active steps to prevent it, such as planting a diversity of species or retaining patches of natural forest throughout a planted stand. Indeed, many companies do go through efforts to maintain diversity in planted stands, and third-party certification organizations like SFI and FSC help promote diversity-enhancing practices.
The aversion to monocultures has become so great that many forests in the world are undergoing “rewilding” efforts to restore planted forests to a more wild state and promote forest biodiversity. As planting becomes more popular and foresters, conservationists, and the public become more averse to monocultural practices, diversity enhancement and rewilding efforts are likely to become more popular as well.
Planting Enables Companies to Cut More Timber
A second criticism is that, though paradoxical, planting trees enables timber and logging companies to cut more timber. Because planting drastically increases the growth rate of a forest, it increases the overall cords per acre per year a property produces, and so it increases the annual allowable cut, or the total amount of wood that can be cut off a property without reducing the overall stocking. While this in itself is not necessarily a problem, it can be seen as dishonest by a scrutinizing public if tree planting programs are promoted as being something other than a means of timber production. It is important for foresters and timber companies to clearly communicate to the public the aim, intent, and reasoning behind tree planting programs, so to not mislead the public about intentions.
Planting Is a Crucial, but Singular Tool in Forestry
When companies decide to plant trees, they make a conscious commitment to the future of the forest, but it is only one tool in a vast tool box. Used in moderation and in sync with the nuances of the forests, planting can be an incredibly powerful to to ensure future generations have both healthy lumber supplies and healthy forests. Next time you recreate in a planted forest, take the time to appreciate the great effort and thought that went into it’s establishment.