Managing Your Woodlot For Sustainable Yield

In this report we are looking at the small woodlot used primarily for firewood production with some wood for other uses. In a large woodlot, firewood production may be a byproduct of the harvest operation and the sustainable yield will include both timber and firewood. Many of the principles outlined here apply to larger operations but instead of harvesting every year the big scale timber/firewood operation will take larger harvest at less frequent intervals.

In the past, the small woodlot was often owned by a single family and was large enough so members of the extended family would all cut firewood for their homes from the same lot. Around our area, it is common to see 50 to 100 acre forest used both for as a woodlot and sugar bush for maple syrup. Harvesting firewood was a good way of cleaning up the sugar bush and keeping the access roads open.

Let's start by looking at a woodlot somewhere in the range of 20 to 100 acres. The purpose of a woodlot is to supply you with the firewood you need each and every year. People who work in the woods commonly form a strong attachment to their land and many woodlot owners hope to hand the woodlot on to the next generation. Many of the improvements you make to your forest may not come to completion in your life time. So an important consideration in managing your woodlot is to make sure that you look to the future so you and your heirs will be able to go on harvesting from your woodlot for generations to come.

If you set up to cut under a sustainable yield forest plan, you can be sure that you and those who come after you will never run out of firewood. That is something to hand on to the next generation. In a time when most people heat their homes with oil and oil is rapidly running out, if you are managing your forest so that you will never run out of wood then it's like having your own oil well that never run dry.

Woodlot Inventory: The first step in setting up a sustainable woodlot system is to take a survey of the present state of your woodlot. If you are buying a woodlot this is especially critical. Taking an inventory involves taking a survey of the trees (what kinds, how many, and how big) this information can be set out on maps to give a picture of what the different parts of your woodlot look like and you can make a "cord wood tally". A cord wood tally is just forest talk for how much wood is standing in your wood lot. It is usually measured in cords. By counting the trees and their size you (or the forester) can calculate how many cords of wood you forest contains. It is an estimate of how many cords of wood you would have if you cut all the trees down. It gives a good indication of how much wood is there so you can get a good idea how much you can cut each year without running out. Another term you will run into if you talk to foresters is "diameter at breast height" (d.b.h). This is just a handy way of measuring trees. If you reach your arm straight out and touch a tree, then you are ready to measure the diameter at breast height. There are tables that show if you have so many trees per acre at so many inches d.b.h. then you will have a certain number of cords of wood per acres. This is useful for giving you an idea of how much standing wood you are starting with. The more mature the forest (more trees with a larger d.b.h.) then the more wood you have to start with. If you have a really young forest (i.e.: mostly 6 inch d.b.h. trees) then you will need to harvest lightly until your forest gains some volume.

How accurate does this inventory need to be? If I were buying a piece of land for a woodlot or for commercial harvesting of wood, I would have an official inventory done by a forester. If I already had a woodlot and I looked over the general guidelines (see below) and I saw that my woodlot was much bigger than I needed then I would do a general survey myself to give me an idea of what the different areas of my forest looked like so I could make a more informed plan for harvesting.

How Much Can I Cut And Still Have Sustainable Yield Forest? When your take an inventory of your land you are looking at the current situation. You need to know that you have at least enough wood standing to even consider cutting. For example, a few acres with 3 or 4 inch d.b.h. trees will not have enough volume to supply your firewood needs. But the real issue is how fast the trees grow in your area. If live way up north you may have a couple of months less growing season than a person who lives in the south. Trees like all plants need sun and warm weather to grow, the longer they have to grow the more wood they produce. So the first thing we want to say is that you really need to check with your Environmental Conservation Department (state or county) or your cooperative extension office for detailed information on your area.

Having said that we will look at some "ball park" numbers we have for New York State. According to "Managing Small Woodlands For Firewood (A Cornell Cooperative Extension Publication - Information Bulletin 208 - we highly recommend this 32 page booklet),

"On an average site in New York State, about 5 (full) cords of wood will be removed from each acre every 10 years, an average of 1/2-cord/acre/year."

"Poor sites produce only about 1/4 to 1/3/(full)cord/acre/year."

"Once a compartment is under management, a firewood harvest should be done about every 10 years to remove about 25 percent of the total wood volume; this represents approximately the growth that has accrued since the last harvest."

"A standard cord of firewood is a well-stacked pile of wood 8 feet long, 4 feet wide, and composed of sticks 4 long. A face cord is also 8 feet long and 4 feet high but is composed of sticks less than 4 feet long (usually 16 inches)."

Given the yield estimates (above) of 1/3 full cord/year harvest on poor sites to 1/2 full cord on good sites equals a harvest of about 1 face cord harvested per acre per year. So if you measure your firewood in face cords (most common 16 inch - stove length) then you are taking about 1 face cord/acre/year as a sustainable harvest level in an average forest in New York State. It's best to somewhat underestimate what your forest will produce and later revise your harvest higher if conditions warrant it. If you are much further south you can cut a little more unless you are at higher elevation (i.e.: in the mountains).

Setting Up To Cut On A Sustainable Yield: The only practical way to harvest wood is by working a small area and doing a good job thinning out the trees and moving to another area the following year on a rotation. We have 50 acres of land. 20 acres of forest under management for sustainable yield, 25 more acres of forest not currently under management (i.e.: natural in reserve for the future) and 5 acres cleared for present and future gardens. We use a 10 year rotation on the 20 acres under sustainable yield management. The 20 acres is divided into approximately 2 acre compartments. Each year a 2 acre compartment is harvested. According to the above cutting rate, at 1 face cord/acre/year we can cut up to 20 face cords in a 2 acre compartment per year. By the time we return to the same 2 acre compartment in 10 years the amount we removed should have grown back. We currently remove less than 20 face cords each year so the compartments are gaining standing cord wood each year and the average size of the trees is getting bigger. Our forest is a little young so we are cutting at less the we could to let the forest gain in volume and size.

With a good woodstove most homes burn between 10 and 30 face cords of wood in a year. Given the above numbers, it looks like a 10 acre wood lot may just squeak by if you had a really good forest, a really small well insulated house, and were very careful. In general, I think a 25 acre woodlot is a good size and a 50 acre is even better. I would strongly recommend if you are considering buying a woodlot that you do a professional survey of your woods and keep in mind that in the future you may want to move to your woodlot and have your house there, so plan for expansion. I would also strongly suggest you get hold of some soil maps (soil conservation service, cooperative extension, etc) and make sure you have at least 5 acres of potentially tillable soil in your woodlot for possible gardens in the future. Remember you may be handing this wood lot down to the next generation so plan for the future. Who knows your kids or your parents may decide to join you in the woods and you may want room for expansion. If times get hard, (or should I say when times get hard) there is nothing like a piece of land to help you though times of unemployment or under employment. If you are interested in gardens, check out [ The Affluent Peasant (Garden Site) ]

Doing Your Own Woodlot Inventory Survey: Now that we have some "ball park" figures for sustainable yield, you need to go out to your woodlot and at least take a general survey of what you have. The best way to do this is to try and get some air photos of your land. Soil Conservation Departments usually have these maps or your county tax mapping departments may have them. You can usually get a photo copy for a small fee. You can also map your own map on a piece of paper.

Get your deed out and put the boundary dimensions on the map. It's a good idea to walk your boundaries and check that you have posted signs at least the corner markers. If you are new to owning land, you have to think about land differently than you do in the city. I know in the city a few inches difference in a boundary is a big deal and grounds for a law suit, but not in the county. The general rule of thumb is that preexisting boundary markers like fence lines, old posted signs, old large boundary trees are accepted boundaries by usage. So save your money on getting a professional surveyor. If the boundaries of your land are clearly marked and there is no dispute, then leave it at that. Put up your posted signs along the current boundary at the currently accepted spacing in your area (not on every tree!!!!). Your neighbors know the boundaries. It is more important to get along with your neighbors than to get an "accurate" survey and squabble about a few feet.

The Woodlot Survey: Getting Out In The Woods. Get your self a good compass ($15) and if possible a friend or better yet a neighbor who knows the area and its history. Check one of your side boundaries to see what the compass reading is. Then go somewhere near the middle of your road frontage and head off at that same heading so you are taking a cross section of your land parallel to the side boundary (i.e.: same heading). Now if you know the woods or your companion does then you can move right along stopping every once in a while and writing down in your notebook:

- what kind of trees are within seeing distance (at least hardwood vs. non hardwood)
- how big they are in inches at d.b.h or at least small medium or large (above 1 foot d.b.h)
- stocking rate: is there large openings in the forest canopy (can you see the sky with no branches) large openings can mean poor soil (wet, rock outcrops) or previous heavy harvests.

If you are a beginner with a compass make sure you know how to use it before you head off and make sure you know the compass heading to get back to the road. Also when you take a reading on your heading pick a tree or other identifiable object that is in the correct heading and head to that object. Stop do your survey and then take another heading and head to that object. This will avoid trying to keep on a heading, constantly looking at your compass, tripping over braches and generally wandering around in the woods in a confused state.

Take a few passes, get a general feel for the woods. We have about 1/4 of our non cleared wooded land in young hardwood forest (mostly red maple) on thin soil with rock outcrops (interesting scenery), 1/4: old large hardwood (maple, beech, cherry, ash) and 1/2 of medium age hardwoods (red maple, ash, cherry, birch (grey and yellow) and poplar (aspen). We manage the medium age hardwoods (20 acres - about 1/2 the forested land) for sustainable yield.

Hardwood trees in the 8 to 12 range ideal for cutting for firewood. Anything much bigger than that is hard to handle, does a lot more damage to surrounding trees when it falls, and is more dangerous to cut. So if we are working in an ideal area we will take trees that meet our goals (see below) that are approaching the 12 inch size. We try to leave trees below the 8 inches size to grow bigger because they will be approaching the 12 inch size when we return in 10 years. Remember this is just one of the considerations in cutting. Consider this a preference, when consider between which trees to cut while you apply the general cutting rules (listed later).

Once you decide on what part of your forest is best suited to sustainable yield then you can pick the compartment size that allows you to return to each compartment once in 10 years. 2 acre compartments for a 20 woodlot, 1 acre for 10 acres. You do not have to measure all the compartments in the forest at once. We just go out with some plastic survey tape (not orange - that color is for boundaries) and walk off a 2 acre plot ... practice taking a step that is about 3 feet stride... an acre is about 200 feet by 200 feet. Figure out how many strides that is and then mark off your working area for that season.

Cutting for firewood is a really good method for improving your forest because you are constantly removing diseased and damaged trees. This improvement tends to increase the percentage of prime timber (straight trees, few side branches below the canopy). As part of your management plan you may want to include a small scale harvest of some of these trees for your own use. As long as you include this use in your sustainable yield calculations this harvest can fit right into your forest plan. Commercial logging operation are not normally practical in small woodlot because they need to remove too many trees to make the harvest economical to the logger. It is also important to remember, once you have someone else doing the cutting have lost control of what happens to your woodlot. This is not to say that all commercial harvest operations are going to ruin your woodlot, but you have to be very careful in making this decision. Recovery from mistakes can take a life time. Enough said.

If you decide that you would like to use some of trees for lumber or for building a log cabin "getaway". There are now a lot of options for small woodlot owners to saw some boards right in the woodlot instead of hauling them off the sawmill. If you only need a few boards or you want to level off two sides of logs for a log cabin, you might consider using an inexpensive attachment for your chain saw. Remember that chain saw attachments for cutting boards can wear your saw out prematurely and you need to talk to someone who has used them before buying one. Make sure the person you talk to is not the one trying to sell you the attachment. Some types are much better than others. For any more than a few boards you might want to consider the newer more efficient (and expensive) portable band saw mills. In many areas, owners of portable band saw mills will come to your land and cut your boards for you (saves the cost of you buying the mill) and you pay them so much per board foot of lumber cut or in some cases they will trade for a percentage of the lumber they cut as payment for their services. This approach makes the most sense if you need more than a few boards cut.

Making a decision to following a sustainable yield woodlot management plan will make sure that your land will supply wood for generations into the future while still meeting your woodlot needs.