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The Rural Voice, 1999-05, Page 58Agroforestry Thinning the farm woodiot pays off B.' AndrewGrindlay Just like carrots in the garden. trees in the farm woodiot will increase in diameter at a faster rate if they have plenty of space. And like carrots, they need to be thinned occasionally to ensure they have room to grow. In the long term a well-managed woodiot will develop into a mixture of trees of various ages. sizes and species. As the trees grow, room should be made for them to get ample sunlight. nutrients and water, with sunlight being by far the most important factor. The simplest way to provide the needed space is to walk through the forest and identify crop trees — those that are likely to grow into a valuable investment at some time in the future. Then clear away any trees that are crowding them. Unlike carrots. where all the plants are practically identical. trees vary — a lot — by species, size. age, health and by location. Because of these variations, deciding which trees to remove takes thought, but it is worth the effort. By thinning the woodiot a farmer can double the growth rate of the remaining trees, from 1/4" in diameter per year to 1/2" per year, for example. That means that, if not given more room, a 16" diameter tree would likely need 16 years to grow to 20", but if nearby trees are taken out, that same 16" tree could grow to 20" in eight years, or half the time. Thinning a woodiot does not make the remaining trees grow taller — just fatter, but a well-managed stand should add around 200 board feet of timber per acre per year. which, at current prices, could increase the yield from the woodiot by about $100 per acre per year. Farm woodiot con'.0 ham Marvin Smith of Listowel recommends that before thinning the stand, the owner should have a clear plan for it in his or her mind or better yet, on paper. He suggests that you decide first on your long-term objectives, be they income from sawlogs, wildlife habitat, erosion control, windbreaks, aesthetics or some combination. Then you should get an idea of the number of trees in the woodiot by size and species. Thinning should be done primarily for the long-term improvement of the woodlot, Smith says. If you are fortunate enough to have some mature trees that should be taken out, the thinning operation will generate some revenue for you. If not, you might get only fuelwood. But the important thing is to remove some low -value trees to allow those of higher -value to grow faster. "Releasing the crop trees", it is called. Trees selected as crop trees should be healthy, tall, straight, dominant and be growing vigorously. Those to be removed are those that have seams, Trees given enough room can double their growth rate ‘2,\\N L. 9� to 0OLANo SP Marvin L. Smith B.Sc.F. (Forestry), R.P.F. Farm Woodland Specialist 765 John St. West Listowel, Ontario N4W 1B6 Telephone: (519) 291-2236 Providing advice and assistance with: • impartial advice/assistance in selling timber, including selection of trees and marking • reforestation of erodible or idle land • follow-up tending of young plantations • windbreak planning and establishment • woodiot management planning • diagnosis of insect and disease problems • conducting educational programs in woodlot management • any other woodland or tree concerns 54 THE RURAL VOICE cracks, crooks, insect damage, disease, a fork in the lower half or some other serious defect. In some cases, such as where a defective tree is the best tree in the area, it is a good idea to leave it. Over time, a stand of higher quality trees is developed by' removing the low -value trees and those that are overcrowded or mature. To decide which category a tree falls into, walk around the tree and examine it from all sides, looking for defects. If you decide it is to be a crop' tree, then stand beside it and look up. You should be able to see a clear space of at (east six feet around the crown. If not, the tree is being crowded and will not grow as fast as it could. To increase the crop tree's growth rate, one or more trees near it should be removed. Naturalists encourage woodiot owners to leave a few trees that make good nesting sites for wildlife, even if removing them would improve the economic value of the stand. At one time, girdling trees was recommended as a simple way to get rid of unwanted trees but that practice is now viewed as a safety hazard and is discouraged. Unwanted trees should be cut down completely. Some trees, such as white ash, basswood, red maple, silver maple and red oak can grow in clumps from sprouts that appear from the stump after a tree has been cut down. The clumps, or coppices, should be . thinned carefully. If two stems are growing in a V shape, they should either both be cut or both left. If they grow in a U shape, one of them can be left and the other removed. Clumps should be thinned as early as possible, certainly before they are 20 years old. Care needs to be used in deciding to take out a tree on the basis of current value. The market price of different species swings wildly according to fashion. Remember that today's prices for lumber do not necessarily reflect what a tree might fetch in 10 year's time.0 – Andrew G,rindlay fauns 100 acres of trees in Huron County.