How to Measure a Tree

Transcription

1 How to Measure a Tree

2 What to look for? When a forester is assessing a tree, they will look for many factors. These factors determine whether the tree is useful or ready to harvest. These include: Disease Insect Infestation Height Diameter

3 Common Tree Diseases There are over 20 tree diseases documented in North America. The following are some of the 20 that can cause the most health problems and death in trees. These diseases affect both forest type trees and trees found in urban yards.

4 Amillaria Root Rot The disease attacks hardwoods and softwoods. Caused by the fungus Armillaria. Major cause of oak decline. Can kill trees that are already weakened by competition, other pests, or climate factors. Can also infect healthy trees, either killing them outright or weakening them to attacks by other fungi or insects.

5 Anthracnose and Leaf Spot Diseases Affects mostly hardwood trees, such as white oak. Causes dead areas or blotches on the leaves. Greatest impact is seen in the urban environment as it tends to go after trees that are commonly found in yards.

6 Aspen Canker Trembling aspen is the most affected tree. Wound-invading (causes holes in the tree) fungi infect the tree. Eventually burrowing into the core and making the tree unusable.

7 Diplodia Blight This disease attacks pines. Considered the most damaging diseases for trees in urban areas as the fungus not found in natural tree stands. The risk is if it does go into the natural stands, there is no immunity to the disease. Symptoms are brown, stunted new shoots with short, brown needles.

8 Dutch Elm Disease Primarily affects North American and European species of elm. The economic loss resulting from death of high value urban trees is considered by many to be "devastating". Fungus infection results in clogging of vascular (water moving) tissues, preventing water movement to the crown (center core) and causing visual symptoms as the tree wilting and dying.

9 Dwarf Misltoe Affects mainly black spruce. Affects the branches and needles of the black spruce, causing growths that choke out needle growth on the tree. Essentially a weed that grows on a tree,

10 Common Tree Insect Infestations: Dutch Elm Disease Although also considered a tree disease caused by fungus, it is transmitted by elm bark beetles. The beetles will tunnel under the bark, carrying tiny spores of the fungus Ophiostoma ulmi with them. This results in a sick-looking tree with shriveled, brown foliage and deformed twigs. Abnormally small leaves appear during re-growth in the spring. Trees usually die within 2 years. Best way to control it is to try to prevent it. Some methods include making sure to prune the tree regularity, using chemical insecticides, or using sticky bands around the trunk of the tree. If a tree is already infected, you cannot just treat infected areas. The whole tree must come down. Firewood from these trees cannot be used as it can hold the beetle in it.

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12 Common Tree Insect Infestations: Birch Leaf Miner Birches are highly susceptible to leaf miner infestations. White or brown areas are created on leaves and are caused by the larvae of the birch leaf-mining sawfly as they eat the material. Hence the term miner. While leaf miners can damage trees, they are in no way deadly. The most effective measure for controlling these tiny larvae is to remove and destroy affected leaves as soon as damage is apparent.

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14 Common Tree Insect Infestations: Aphids Small sluggish insects that suck the sap of trees, especially maples. They tend to cluster on the undersides of leaves and make them sticky with excrement, thereby damaging leaves and covering it with sooty (black powder-like) mould. These infestations stunt (delay growth) and distort (change shape) leaves, causing them to drop prematurely. Aphids also attract swarms of ants, which feed on their gooey excrement. One of the best ways to get rid of an aphid is to release ladybugs and lacewings. Another method is to hose down trees with a strong blast of water, or spray the bugs with a mix of garlic and mineral oil.

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16 Common Tree Insect Infestations: Gypsy Moths Gypsy moth caterpillars can be identified by six pairs of red bumps and five pairs of blue bumps on their backs. They like to eat over 500 different tree and plant species, including oak, birch, and tamarack. These larvae are voracious feeders and can defoliate (remove all leaves) an entire tree in two to three days. Prevention must be done in early spring as the egg masses will over winter in crevices in the bark of the tree. You can spray the egg masses with dish detergent and then scrape them off the tree. The egg masses then need to be soaked in hot water and ammonia to kill them before they are disposed of. If the eggs have hatched and larvae are present, you can use bands of burlap to trap them.

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19 Common Tree Insect Infestations: Tent Caterpillars There are 2 types of tent caterpillars: forest tent caterpillars and eastern tent caterpillars. The forest variety is easy to identify due to their dark brown bodies with broad bands of blue along each side and a prominent row of whitish keyhole-shaped spots down the back. The eastern tent variety can be identified by a white or yellow stripe down the back. Forest tent caterpillars like trembling aspen leaves, but also like many types of trees. They will even eat pole or fence rails. Eastern tent caterpillars prefer cherry or apple trees. Forest tent caterpillars don't form a tent, but they do make a silken mat on the trunk or branch where they congregate together. Eastern tent caterpillars form silken tents in the forks of branches.

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22 In fall and winter, you can identify tent caterpillars by bands of eggs laid by the female moth. An egg band encircles a twig and is covered with a dark foam-like substance. To get rid of the eggs, you can prune and burn the branches that contain them. If the eggs are on the main stem or on branches that should not be pruned, you can scrape them off with a dull knife. Applying mineral oil spray to the egg bands in late winter will also kill them. Tent caterpillars move about by day, feeding on leaves and returning to their nests at night. To control them, wait until the larvae gather for the evening, then remove their nests and destroy them. In extreme cases, break nests open with a stick and spray with bug poison. A species of fly known as Sarcophaga aldrichi serves as a natural control. The fly lays its young inside the caterpillar, eventually killing the host.

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24 Diameter of the Tree Tree trunk diameters are measured at Breast Height. This is called DBH or (diameter at breast height). Because all people are not the same height, this is approximately 1.4m from the ground up the tree. Diameter is important as it is used to calculate the number of foot wide logs a tree could yield and show the growth of the tree over time.

25 How to Calculate Diameter 1. Using DBH or a meter stick, measure approximately 1.4m up the side of the tree. 2. Take a flexible measuring tape and wrap it around the tree at this height. Make sure the tape is level around the entire diameter of the tree. 3. This will give you a circumference measurement in centimeters. Divide this number by 3.14 to get the diameter for the tree.

26 How to Measure Diameter of a Tree

27 Height of a Tree Height of a tree is a bit more difficult. The height is important as it shows how long the 1 foot boards could be. This also shows how the tree can be divided up. It also shows growth of the tree over time.

28 How to Measure Height of a Tree You will need 2 sticks of the same length and 1 meter stick. 1. Stand in front of the tree 2. Find the centre point of one of the sticks and hold the other stick perpendicular to it. Essentially, make a T shape out of your sticks. 3. Slowly walk backwards away from the tree until you can see the top and the bottom of the tree. 4. Put the base of the T between your eyes, then walk away or towards the tree until the top and the bottom of the long part of the T line up with the top and bottom of the tree. 5. Make a mark in the grass and measure from where you are to the tree using the meter stick. 6. This is the total height of your tree.

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