1.We monitor the sugarbush for insects and diseases that threaten health; and
2.We referee the competition between trees that threaten vigour.

In this sugarbush the greatest threat to health is the infectious fungus Eutypella parasitica that causes the 'cobra-shaped' cankers on the trunks. Decay travels from the sapwood into the heartwood and stem breakage often results. This fungus spreads by spores that come in direct contact with exposed tree wounds and since each taphole is such a wound, the existence of the fungus in the sugarbush must not be permitted. Infected trees must be removed, tapholes should be plugged at the end of the syrup season and great care must be taken during felling and skidding operations to prevent damage to residual trees.
Competition between trees is very beneficial when the trees are young seedlings and saplings because it causes the high-vigour, physically superior ones to overtop the inferiors and gain crown spread at their expenses. That competition becomes detrimental however when those same trees approach the pole stage at approximately 10-15 cm diameter because they shade one another and their lower branches die from lack of sunlight. We need to thin the sugarbush so that the spacing between trees does not prevent crown expansion and cause lower branch mortality.

In order to provide a supply of sugar rich sap, we must identify the existing trees that have it and create favorable conditions for them to grow, mature and reproduce similar trees for the future. We accomplish this in two ways:

1.We measure the sugar content of their sap during the spring run; and
2.We manage the sugarbush as a sustainable uneven-aged forest.

A refractometer is used to measure the sugar content of one drop of sap extracted from a 9/64" diameter hole drilled ½" into the sapwood at the stump. The instrument has an accuracy of 0.1% Brix which is percent sugar by weight. Following every test each hole is plugged with a 1/8" hardwood dowel against fungal spores, each tree is numbered with an aluminum tag and its sweetness is recorded.

Sugarbush management requires an understanding of basal area, which is the surface area of all the tree trunks measured 1.3 meters above the ground and is represented as square meters per hectare. An optimum basal area for this sugarbush would be from 12-16 square meters/hectare. When we measure readings that that are higher than that, we know there are too many trees too close together. This crowding prevents crown expansion; causes lower branch mortality and therefore a reduction in leaf surface, which costs the sugarbush owner sugar. We adjust the basal area back to the low end of the range by 'removing the worst first', namely trees that are in poor physical condition and with low sap sugar contents in that order. By thinning during late summer and fall when the ground is not frozen tractor driving and log skidding will scarify the forest floor and expose bare soil where regeneration will take place. Great care must be taken to prevent soil compaction, rutting and damage to residual trees at this time of year, however.

This sugarbush is relatively even-aged now, since most of the trees are medium and large in diameter and a gradual conversion to an uneven aged stand would be beneficial. We have very few recruits coming up through the present system as seedlings and saplings and this limits our choices for future trees to tap. A model of an ideal uneven aged stand would look like a pyramid with a few mature trees at the top (less than 50/hectare) and many seedlings at the bottom (greater than 10, 000/hectare). A sugarbush is dynamic with trees growing, maturing and declining constantly. It is not possible to manage it to a desirable stage where it will stay on its own. It is difficult for us to remove large trees that will reduce our number of taps but we must not lose sight of the need to promote crown expansion for our upcoming poles and increase seedling regeneration for the future.

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