Silviculture is the art and science of managing forests for desired outcomes.
Management decisions about your woodland can be challenging.
Any harvesting operations have the potential to create undesirable and destructive results.
Although there are no guarantees, arming yourself with basic knowledge and advice from professionals can help you make informed decisions about your valuable land.
In this blog, we’ll look at silviculture and everything you need to know as a landowner.
1. What is silviculture?
Silviculture is the art and science of controlling the establishment, growth, composition, health, and quality of forests and woodlands to meet the diverse needs and values of landowners and society.
This includes wildlife habitat, timber, water resources, restoration, and recreation on a sustainable basis.
The term silviculture is derived from Latin with silvi- meaning “forest” and culture meaning “growing.”
Silvology is the study of the forest and woods, and silviculture is the science of growing and cultivating forest crops based on the knowledge of silvics.
Specifically, silviculture aims to control the establishment and management of forest stands.
2. What are the aims and objectives of silviculture?
The primary goal of silviculture is regeneration.
Regeneration is essential to the continuation of forested land (as well as the afforestation of treeless land).
It can occur through self-sown seeds, artificially sown seeds, or planted seedlings.
In addition to regeneration, here are some of the other main goals of silviculture:
To make a plan for different types of silviculture treatments
- This may include thinning, harvesting, planting, pruning, prescribed burning, and site preparation
- Intermediate treatments such as thinning are designed to enhance growth and quality
To produce the greatest quantity of wood or other produce per acre and year
To produce the highest possible money and return on the invested capital
To meet the goals of the land/forest owner
To balance the biological, economical, and ecological concerns for the forest in question
Keep in mind that a reasonable silvicultural system will meet at least two of the following four goals:
Provide for forest regeneration
Produce forest products for the good of the owner and society
Improve the quality and health of the forest
Satisfy the desires of the forest owner
3. What are the advantages of silviculture?
Advantages of silviculture include:
Increased forest cover, which is necessary for the conservation of wildlife
Maintain a natural water cycle
Prevent floods by preserving forest cover
4. What is a silviculture prescription?
A silviculture prescription is a document that has a planned series of treatments designed to change the current stand structure and composition to one that meets management goals.
All vegetation activities, including prescribed fire, wildlife habitat improvement, timber harvesting, and cutting trees in campgrounds require a silviculture prescription, which considers ecological, economic, and societal objectives and constraints.
In order to implement a given project or treatment, silvicultural prescriptions are prepared or reviewed by certified silviculturists.
5. What is a silvicultural system?
According to the USDA Forest Service, a silvicultural system is defined as “a planned series of treatments for tending, harvesting, and reestablishing a stand.”
There are three primary silvicultural systems used in western forests.
Even-aged silvicultural system: This system consists of a planned sequence of treatments designed to create or maintain a stand with predominantly one age class.
The range of tree ages for an even-aged forest is generally assumed to be within 20 percent of a given age.
Two-aged silvicultural system: This system is a planned sequence of treatments designed to create or maintain a stand with two age classes.
Uneven-aged silvicultural system: This system is a planned sequence of treatments designed to create or maintain a stand with three or more age classes.
These different silvicultural systems include cutting methods that are designed to obtain regeneration, modify tree density, and contribute to the development of an immature stand.
6. What are age-based silvicultural systems?
First, let’s start by defining even-aged stands and uneven stands.
Even-aged stands have trees that are the same age; for example, a plantation that was established in a single year.
An uneven-aged stand theoretically contains trees of every age.
This will range from seedlings that became established this year to mature veterans that are several centuries old.
Even-aged stands and uneven-aged stands stand on two endpoints of a continuum and most stands found in nature resemble something found in the middle.
7. What is even-aged management?
Even-aged management involves applying the methods of regeneration and intermediate cutting to create and maintain an even-aged stand.
Even-aged regeneration cutting methods include clearcutting, seed-tree cutting, and shelterwood cutting.
The even-aged silvicultural system also includes thinning, improvement cutting, release, and other intermediate cutting methods.
8. What is uneven-aged management?
Uneven management uses regeneration and intermediate cutting to create and maintain an uneven-aged stand.
These regeneration treatments are individual-tree and group selection cutting.
Uneven-aged management also includes intermediate cutting methods (i.e., thinnings and improvement cuttings), which help to adjust stand density and accomplish other cultural objectives for treatment areas containing immature trees.
One key difference between even-aged and uneven-aged silviculture management is the regulation of growing stock.
Even management regulates yield by controlling the area occupied by each age class.
On the other hand, uneven-aged management regulates growing stock to sustain yields rather than area.
The section system of silviculture management is a common example of an uneven-aged management system.
9. What is a selection system?
Adopting a selection system can help to encourage the growth of different tree species.
It helps to maintain a diverse, well-aged forest with a wide range of species of different sizes and ages.
Here’s how a selection system may work:
Individual or groups of mature, unhealthy, or other selected trees are harvested periodically.
The other trees around them are left to regenerate the stand naturally.
However, before any harvesting occurs, an inventory of the forest is taken.
The inventory helps to identify the following:
The tree species
The different sizes of the trees
The quantity and health of the trees
The availability of habitat in the forest
With this information, a tree marking prescription is written and all trees that will be cut are marked with yellow paint.
Crop trees are typically marked with blue paint.
Crop trees are trees that are allowed to grow for future commercial value.
Every 8-15 years, the stand will be thinned to give crop trees room to grow.
Additionally, some unhealthy and mature crop trees will be harvested.
Care will be taken during the thinning and harvesting operations to avoid damaging the site and the crop trees.
During this process, it’s important to avoid damaging the young and old trees as it can lower the future value of wood.
Keep in mind that a selection system is best suited to mixed hardwood forests where the small periodic cuts mimic the forest’s natural cycle of renewal.
These forests rely on small-scale natural disturbances such as lightning, fire, wind, ice storms, and disease to kill individual trees or groups of trees.
This helps to create space that younger trees require to grow.
Selection systems are beneficial because they…
Preserve the genetic diversity of the forest
Provide a full canopy that protects from erosion, creates an area for recreation, and offers wildlife habitat
Maintains a natural-looking, diverse forest
Generates long-term income and a steady supply of wood produces
However, they do have their disadvantages, which include…
Requires investments in evaluating the forest ecology (this includes selecting and marketing trees as well as thinning and harvesting)
Requires assistance from forestry experts
Requires large areas to generate sufficient volumes of wood and income
Potential for crop trees and regeneration to be damaged during harvest operations
10. What factors should you consider when choosing a silviculture system?
As a landowner, it isn’t easy to choose a silviculture system.
To help you contemplate your decision, we’ll talk through the variety of factors that you must consider when it comes to making your decision.
Evaluate your goals
What are your goals (both short-term and long-term) for your property?
Take a look at the following possibilities and rank them in terms of importance to you.
This will help you to assess your priorities as you consider a silviculture system.
- Immediate revenue from wood products or fuelwood
- Long-term revenue from wood products or fuelwood
- Wood products for personal use
- Wildlife habitat
- Natural-looking forest for recreation
- Revenue for maple syrup production
- Maple syrup for personal consumption
Assess climate and site conditions
Different tree species grow in a range of conditions.
That said, their growth and survival rates vary greatly with climate, bedrock type, and soil type.
Use the following list to assess your site for the best tree species.
- What forest region is your tree stand located in?
- Great Lakes-St. Lawrence
- What type of bedrock lies under the stand?
- Canadian Shield
- How deep is the soil?
- 0-50 centimeters
- 50-120 centimeters
- Greater than 120 centimeters
- What kind of soil is it?
- How much rain and snow falls on the site?
- How hot does the site get in the summer?
- How long is the growing season?
- Is the site so steep that cutting the forest will make it vulnerable to erosion that could damage the site and the nearby streams and rivers?
Determine stand and species characteristics
To determine the volume and value of the trees in your forests and how much work you must do to realize your goals, you should evaluate the tree density, health, and species composition of your forest.
Here are some questions you can ask yourself regarding stand and species characteristics.
- How big is the area that your stand covers?
- How many trees are in the stand?
- What species are present in the stand?
- How old and how big are the trees of each species?
- How many of the trees in your stand are mast species that provide fruits and nuts?
- How many cavity trees and snags are there in your stand to provide nesting, denning, escaping, and feeding holes for birds and mammals?
- Is there a carpet of organic matter and decaying wood on the ground that enriches the forest soil and provides a habitat?
- Are there any tall pines poking through the canopy that should be preserved for their value as nesting and roosting sites for birds?
Decide based on the desired species
Different silviculture systems favor various species.
When you identify the species you want to regenerate or grow, you will be able to choose the best system for those needs.
For example, if you want to regenerate shade-intolerant species like poplars or cedar, then you should choose the clearcutting system as it provides the sunlight that this species needs.
On the other hand, if you want to regenerate mid-tolerant species like red oak or white pine, then you should choose the shelterwood system.
Then again, if you want to regenerate tolerant species (maple, beech, or hemlock) or maintain a forest with different species, a selection system is your best option.
Another factor in this process is cost and amount of labor.
To determine the best system, here are some questions you can consider:
- What species do you need to regenerate to achieve your goals?
- What methods work best for regenerating your desired species?
- Are there sources of seed for natural regeneration in the present forest?
- Are there sources of seed for natural regeneration nearby?
- Can you regenerate desired species by stimulating coppice growth?
- Can you afford the time and costs of artificially regenerating the site by seeding or planting?
- Are you willing to weed or use mulches, fire, or herbicides to hold back grasses and other plants that might compete with the regeneration?
Make your choice
You’ve now evaluated all the factors in the context of your goals and options.
Here are some points you should review as you consider the potential compromises.
- Consider the selection system of silviculture if you want a natural-looking forest with wildlife habitats, and continuous supplies of timber, fuelwood, maple syrup, or other forest products.
- Consider the shelterwood system if you want to regenerate mid-tolerant species like oaks or if you want to quickly establish a new sugar bush. This system maintains wildlife habitats and doesn’t increase the potential for erosion or fires.
- Consider clearcutting if you want the fastest returns or to regenerate an intolerant species like poplar. Although, keep in mind that regenerating a clearcut can take a long time and can be difficult and costly.
Forests provide numerous benefits for humans and ensuring they are well taken care of is part of our stewardship.
As a landowner, understanding silviculture is essential.
It’s the planned series of treatments for tending, harvesting, and reestablishing a forest stand.
If you’re uncertain of the next steps, don’t be afraid to contact a forester to help.
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Disclaimer: we are not lawyers, accountants or financial advisors and the information in this article is for informational purposes only. This article is based on our own research and experience and we do our best to keep it accurate and up-to-date, but it may contain errors. Please be sure to consult a legal or financial professional before making any investment decisions.