An Introduction to Tree Marking
Travel our rural landscape and the evidence can be seen first-hand. Some of our past forest management practices, such as clear-cutting and diameter cutting (where the largest and most valuable trees are cut leaving behind the less valuable or poorer quality trees) have left us with a forest landscape dotted with degraded woodlots.

It is important that we learn from our past because experience has shown us that these types of poorly managed woodlots will not provide us with a sustainable supply of quality forest products or suitable wildlife habitat-and they will not maintain a healthy, diverse forest ecosystem.

Cutting trees is an important management tool landowners can use to enhance the health and biodiversity of their woodlot. However, for this tool to be effective it must be done in a manner that is consistent with good forestry practices. This can be best achieved through a good tree-marking plan (prescription) and tree marking.
Good forestry practices - means the proper implementation of harvest, renewal and maintenance activities known to be appropriate for the forest and environmental conditions under which they are being applied and that minimize detriments to forest values including significant ecosystems, important fish and wildlife habitat, soil and water quality and quantity, forest productivity and health and the aesthetics and recreational opportunities of the landscape.
(Forestry Act, R.S.O. 1990)
Why have my woodlot marked?

Tree marking involves the careful selection of trees for harvest (under a partial cutting system), based on a forest management prescription. The decisions made by a tree marker are complex -- part art and part science. The tree marker must assess each individual tree and give consideration to a number of variables (e.g., regeneration, tree health, site conditions, wildlife habitat, diversity and the overall forest objectives) before a final decision is made whether to leave the tree or mark it to be cut. It is important to understand that the selection process is not just based on tree size.

Having your woodlot marked by a qualified tree marker is an important step that links the objectives of your woodlot management plan (and prescription) with the actual harvesting operation. Here are some of the reasons why you should have your woodlot marked prior to harvesting:

Identifying which trees to cut: In its simplest form, tree marking will identify (to the logger) the trees that are to be harvested (i.e., paint is applied to the tree to be cut at breast height and on the stump).
Prescription – describes a series of actions to be taken to meet the management objectives (e.g., improve growth and quality of the forest, ensure regeneration, provide wildlife habitat, etc.) for a specific area based on an assessment and inventory of that area. In Ontario, provincial legislation requires that the development (or approval) of a prescription is the responsibility of a Registered Professional Forester, or an Associate Member, of the Ontario Professional Foresters Association.
Regeneration: A tree marker can mark your woodlot in a manner that will maintain a healthy woodlot while ensuring that a new forest of desirable species grows after cutting.

Tree health, vigour, genetics and site conditions: Evaluating a tree’s health, vigour and its future growing potential can be tricky. This is because not all trees are created equal, and a small tree is not always a younger tree. Many of the small trees in your woodlot are small because of their age. However, the size of a tree may also be due to poor genetics, stunted growth or site characteristics. It takes experience to tell the difference, and an experienced tree marker can provide you with this expertise.

Wildlife habitat: Tree markers can identify the trees in your woodlot that should be retained to provide valuable wildlife habitat and to maintain biodiversity (e.g., mast and cavity trees).

Long-term sustainability: Tree marking, based on sound forest management principles, will optimize your economic return, enhance future timber quality and quantity and has the capacity to ensure the long-term sustainability of your woodlot.

It is important to realize that anyone with a can of spray paint can claim to be a tree marker. It is only when tree marking is applied in conjunction with good forestry practices that the opportunity for high-grading can be minimized. That is why it is highly recommended, if you are planning to undertake a commercial harvest, that you should consider hiring a certified tree marker and/or a forest consultant to assist you.

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Certified tree marker - the Ontario Ministry of Natural Resources (OMNR) provides tree marking certification training. The training involves a one-week course covering silvicultural systems, silviculture, silvics, wildlife habitat, tree defects and tree vigour characteristics. Participants are field tested, and successful trainees are issued a certificate endorsing their skills as a certified tree marker. To maintain OMNR's certification, a tree marker must attend and successfully complete a refresher course every three years.
The dollars and cents of tree marking.

Over the long term, the cost of tree marking is a small investment for a landowner. This is because the value of sawlogs from a managed woodlot increases with time. Why?

Factor #1 - It is a simple case of supply and demand. Over the past 40 or more years the stumpage1 a landowner has received for quality sawlogs has continued to increase year over year. The rationale for this steady increase is simple - it can be attributed to supply and demand. With a shrinking supply, and an increase in demand, markets are driving stumpage upwards, and we are experiencing ever increasing stumpage prices for quality hardwood sawlogs. Figure 1 illustrates this point. For example, from 1959 to 2002 the annual stumpage values (after inflation) for red oak have increased by 2.8%, and sugar maple sawlogs have increased by 2.2%. Meanwhile, lower value products such as firewood or pulpwood, which are readily available in most markets, have only risen marginally at 0.001% per annum over the same time period. Refer to Figure 1.
Figure 1: This graph shows the stumpage values after inflation (1959 US dollars) for the State of Maine for red oak, sugar maple and hardwood pulpwood from 1959 through 2002. These figures were compiled by David B. Field, Department of Forest Management, University of Maine. Conversion factor 1,000 fbm = 2.0 cords.
Factor #2 - In a managed woodlot, trees between 12 inches and 20 inches in diameter can easily grow 2 inches in diameter every 10 ten years. At this rate, they are increasing in value by 50% to 100% every 10 years, because they are growing large amounts of high-value wood suitable for lumber, and the quality of the lumber, as reflected in log grade, is improving. Not only are the trees accumulating board feet rapidly, the price per board foot in the tree is also increasing. Refer to Table 1.
Anyone can grow poorer quality trees, produce lower end products, and receive minimal return on their investment. However, by implementing good forestry practices, and using tree marking as a tool in your management activities, you can begin to maximize your financial returns that will continue to increase in value with each cutting cycle.3 Using this approach, you will be managing for a sustainable timber supply while maintaining and enhancing the integrity and biodiversity of your woodlot.

Tree marking 101.

So where does this leave landowners who would like to cut a small volume of wood (such as firewood) for personal use? The help of a qualified tree marker would still be of value to you. However, should you wish to go it alone, here are five basic principles of tree marking that can be applied to improve your woodlot.

#1 - Cut the worst first. Thinning increases the future growth and value of trees in your woodlot. The decision of where to start can be simply stated as cut the worst first. With the objective of retaining healthy, well-formed trees to grow and improve in your woodlot, the priority for trees to be cut can easily be determined.
Thin a woodlot by removing:
  • trees that show evidence of disease (cankers or fungi);
  • severely damaged trees (broken tops), major crown dieback or trees with dead tops;
  • poorly formed trees subject to windthrow (severe lean >10% or major fork or sweep); and
  • trees showing low vigour (small and poorly formed crown, narrowly fissured bark).
An important point to remember is that you shouldn’t overharvest by attempting to remove all the poor quality trees in your woodlot in one cutting cycle. Your objective should be to maintain an optimal density of trees in all diameter classes, and in some cases, this may require that you retain some poorer quality trees in your woodlot until the next cutting cycle (in 20 to 25 years).
Here is an example of a woodlot prior to harvesting (left) and after harvest (right). Note in the after photo the retention of high quality trees at an optimal density.
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#2 - Maximizing future growth. The objective is simple – try to retain the optimal density of trees on the site (refer to Figure 2) to maximize the growth on the best quality trees left after harvest. As a rule of thumb, always ensure that you retain a minimum 2/3 of the pre-harvest basal area (BA) or 20 m2/ha, whichever is greater.
Basal Area - is the area in square metres per hectare of the cross-section of all the trees measured at 1.3 metres above ground level. Knowing the BA tells a forestry practitioner whether or not a stand is overstocked, understocked or growing at its optimum rate. BA is most easily measured with an instrument called a wedge prism. (A Landowner’s Guide to Selling Standing Timber)
Figure 2: A tolerant hardwood woodlot in eastern Ontario can be managed to produce an additional 60 board feet per acre by removing low-quality trees (thinning) and retaining an optimal number of sawlog quality trees. Over a period of 20 years, a 100-acre woodlot could realize an additional 120,000 board feet of lumber through good management. (A Landowner’s Guide to Selling Standing Timber)
#3 - Retain trees of all sizes. As well as maintaining a suitable stocking level (basal area), it’s also important to maintain a balanced diameter distribution. As a general rule of thumb, retain trees of the following diameter classes:
  • 1/3 in the 4 to 10 inches (polewood) diameter class;
  • 1/3 in the 11 to 16 inches (small to medium sawlog) diameter class;
  • 1/3 in the 17 to 24+ inches (medium to large sawlog); and
  • regeneration (stems < 4 inches).
By maintaining the appropriate basal area and diameter distribution you will be able to maximize the growing potential of the site. At the same time, you will ensure regeneration by maintaining quality seed trees and you will provide wildlife habitat. For example, red oak does not achieve its maximum output of mast (acorns) until trees reach 20 inches in diameter (dbh). For white oak, the diameter for the best acorn production is 25 to 28 inches (refer to Figure 3). Knowledge of the biological features of oak is important to ensure that the optimal diameter of this species is retained as a seed tree for regeneration
Figure 3: Acorn production for oak species by diameter at breast height.
#4 - Maintaining diversity. It’s important to maintain a diversity of tree species in your woodlot. This will help to ensure the continued natural diversity of the various forest types across the landscape. It will also help to protect or maintain the diverse fauna and flora habitat of your woodlot. This can best be achieved by applying appropriate silviculture practices and by addressing site-specific habitat features (see Principle #5) during your harvesting activities.

#5 - Wildlife need a home too. As a landowner, there are a number of simple things that you can do to address the common wildlife features found in your woodlot. Here is a short list of things you may want to do to assist wildlife.
During your harvesting activities retain the following wildlife trees:
  • cavity trees - 6 per ha (40 m spacing);
  • mast tree (i.e. oak, beech, black cherry and hickory) - 8 per ha (35 m spacing);
  • conifers - 10 per ha (clumps preferred); and
  • provide protection to all active and inactive raptor stick nests.
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A more comprehensive list of habitat features, and a summary of management guidelines on how to protect them, can be found in Table 4.4.1 in A Silvicultural Guide to Managing Southern Ontario Forests or in the extension note Promoting a Healthy Forest Through Tree Marking
References

A Silvicultural Guide to Managing Southern Ontario Forests. A copy of this guide is available from the Ministry of Natural Resources ($27.50) by calling 1-800-667-1940 or it can be downloaded from the Internet at <www.ont-woodlot-assoc.org/silvic/index.htm>.

A Tree Marking Guide for the Tolerant Hardwood Working Group. A copy of this guide is available from the Ministry of Natural Resources ($27.50) by calling 1-800-667-1940 or it can be downloaded from the Internet at <http://ontariosforests.mnr.gov.on.ca/>.

Promoting a Healthy Forest Through Tree Marking. A copy of this new extension note is available free from the LandOwner Resource Centre by calling (613) 692-2360 or it can be downloaded from the Internet at <www.lrconline.com>.
Acknowledgements - information included in this article, in part, was based on a presentation made by Martin Streit, Domtar (Upper Canada Forestry) at a landowner workshop.
Footnotes

1 Stumpage - is the price paid (i.e. dollar value per cord, tonne or thousand board feet) to a woodlot owner by a contractor/logger for the right to harvest trees.

2 Mill gate price - is the price paid by the mill for logs delivered to the mill.

3 Cutting cycle - is the planned interval between major harvesting operations in the same stand.

This article appeared in the Summer/Fall/ 2004 (Volume 36) edition of the S&W Report the newsletter of the Ontario Woodlot Association.

© Ontario Woodlot Association

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