Silviculture 101 - Phase 2
The Silviculture industry is a far-reaching industry with many moving parts. In an effort to unveil some of the mysteries of the industry’s inner workings, Leader Silviculture is releasing educational articles on the industry, and going in-depth about some of the processes that take place between when a forest is harvested and is regrown to be harvested again. This article will cover all of the main steps between when a tree is planted in the ground, and when it’s ready for reharvest. We covered the processes that come before planting in our last article. To learn more about those, click here.
Planting:
Once a planting company receives a prescription, they can begin coordinating their teams, and ultimately, getting trees in the ground. There are two main jobs on a planting site that are required to get the job done: the management, and the planters.
Management:
Contrary to popular belief, the site supervisors on a planting team actually DOES do stuff every day. When a planting company gets hired, it’s the management team’s job to organize its staff, lodging, stock, and everything else that will be required to complete the work. The trees need to be ordered several weeks in advance of when they will be needed. In order to prevent the trees from growing once they hit the correct size, the nurseries will freeze the trees to prevent growth. Once on-site, the trees must be thawed for several days before they can be planted. To add one more ball to juggle, once thawed, the trees must be planted within seven days. After that, the probability of that tree’s success starts to diminish. Because of this, the primary job of the site supervisor is to monitor the job’s progress and try to project how many trees will be needed in 3-5 days so that they can begin thawing the stock they need. This is a tricky job, because if they thawed too many trees and the team isn’t planting fast enough, they run the risk of losing the optimum window. On the other hand, if they are too conservative and run out of thawed trees, then the planters will be sitting with no work to do, and the job will run long. Neither option is very good, and both cost the company a lot of money when they happen. That’s why it’s so important that the management team does a good job of monitoring progress and projecting stock needs.
Planters:
The planter’s job is to get their trees in the ground as quickly as possible while staying within the terms of the prescription. Tree Planting companies pay planters based on how many trees they plant each day. This means that it’s in the planter's best interest to be as productive as possible, without making mistakes. You’re only paid for the first time you plant a tree, but when planters make mistakes, they may have to replant the trees that do not meet the contract requirements. That’s why clearly communicated standards and constant quality monitoring are vital.
Good technique comes down to making sure you’re planting with the correct ergonomics. To read more about ergonomic planting, read our blog on the topic by clicking here. A good planting headspace is also very important to high productivity. Once you get the hang of the technique, the next piece of the puzzle is how to get into the flow state and reduce your idle time. This is the biggest thing in breaking through your plateaus, and you can read more about it in our article that you can find here.
Establishing a Free Growing Stand
Most of the forests in British Columbia are owned by the crown, and need to be returned to the government after the company is done with it. Once all of the trees are all planted, the focus will be on ensuring that the block becomes a free growing stand. A free growing stand is a set of standards outlined by the BC Ministry of Forestry, and is required when replanting a forest before it can be returned to the crown. For the next seven or so years after a stand is planted, it will be monitored and maintained to create the best chances for its survival.
Brushing
The highest mortality for a stand is in the first three years. At this stage, their small size means that other plants can easily smother them by taking up their space, nutrients, and sunlight. In the first three years, the main competition for the trees is herbaceous. This includes smaller plants such as grass, fireweed, ferns, and timbleberry. To reduce the competition, companies can do some mechanical brushing, using brush saws, similar to weedwackers, to remove the vegetation. Companies can also use chemical brushing, which is essentially spraying herbicide on the plants to kill them.
After the first three years, the trees will still have competing species that will need to be removed. Now that the crop trees are larger, however, these species will be considerably larger as well, called woody competition. This mostly consists of other trees or large vegetation. Removing this competition is also important and may involve larger powersaws and clearing saws.
Returning to the Ministry
Brushing is the main job for the forestry company to perform until the trees are considered free to grow. Once the maintenance period ends, a representative from the Ministry of Forestry will assess the site and determine whether the stand is free to grow. If not, then the company may have to make changes, or lose the ability to lease another plot of land in the future. If the site is certified as free to grow, then the site will be returned back to the Ministry, and the government will be responsible for all of the maintenance on the site from now until the stand is ready to be harvested again. Some common tasks that may be performed in that period are the following:
Thinning/Juvenile Spacing
Once the trees have made it through the first few years, their chances of survival will increase considerably. When they reach the juvenile stage, coniferous trees begin dropping cones, which can lead to more trees beginning to grow. Sometimes, this leads to the overpopulation of trees in the area, which can have several problems. First, tightly spaced trees become competition for each other, which could lead to a lower quality stock. Dense forests can also spread disease quite quickly, which could reduce the survival rate considerably.
The best way to solve this problem is to go back through the forest and remove the extra trees. A company will go through and identify the best and worst trees in the area, and will cut the lowest quality trees. This reduces competition for the best trees and allows them the best chances of survival. When disposing of the waste trees, you must cut the tree up into smaller pieces, and make sure that the wood is laying directly on the ground. This helps promote decomposition, and not doing so could lead to the wood drying out and becoming a fire hazard in the future.
Fertilization:
As the stand grows with age, the surveyors may decide that the trees need some more nutrients. When this happens, a company will fly a plane over the stand, and drop fertilizer pellets onto the ground below. These fertilizers will help replenish the soil with the nutrients needed for the trees to continue growing and produce the highest quality wood possible.
Pruning:
The most valuable trees in the forestry industry are ones that don’t have many knots, and don’t taper off too heavily from the base to the tip. Both of these things take form as the tree transitions from its juvenile to adult stages of growth. As a tree grows, the lowest branches will eventually start falling off, as they lose access to sunlight to the branches above them. This causes two things. First, this means that the lower sections of the tree will have no knots, because there are no branches to create them. Second, this signals to the tree that it’s reached its adult stages, and rather than using its energy to grow upwards, it will begin growing in thickness instead, reducing its taper. This is the natural way for a tree to become more desirable over time, however, it takes quite a while. Luckily, to speed things up, we can manually replicate this natural process by walking through the stand and cutting the lower limbs off each tree. This tricks the trees into thinking that they are reaching their adult stages, and will make them start to grow thicker, and reduce their knots.
Commercial Thinning:
As the trees get older and larger, processes like thinning can actually become a source of revenue rather than waste. At a certain point, the company will still need to thin the trees to remove competition for the stock trees, but the competition trees are large enough that when removed, they can actually be processed and used in forest products. Because these are smaller and lower-quality trees, they will mostly be used in things like particle board and OSB.
