You do not want to be near a tree during a thunderstorm. When you think about the rules we were taught about lightning as children, you can see why the main one exists. An arborist can check if your trees have been weakened by these new threats. The storm which pillaged Victoria's Dandenong Ranges last year toppled many old, strong trees and led to long-lasting power outages because the winds came from a different direction. If the wind comes from an unusual direction, a tree can be damaged or fall despite its age and past experience. But now we're seeing strong winds and severe storms coming from different directions. In places like Victoria, trees cope with the prevailing winds from the west or north west by developing stronger root and branching systems. You may well need an arborist to help with a related climate change driven threat to trees. An inspection by a qualified arborist would be a good investment. For some trees, the full impact only becomes clear in the following spring when they fail to recover or resume normal growth. Often, the serious damage is not immediately obvious and will only be revealed in the weeks and months ahead. If you know a tree has been struck by lightning, you would be wise to keep an eye on it. It is possible to install a lightning protection system on a tree, but they're costly and rarely installed in Australia. I've seen a number of pines and other conifers die after a strike, for instance, while many eucalypts and oaks recover and remain healthy. Some trees do seem more susceptible to lightning than others. Wild storms saw thousands of trees fall in the Dandenong Ranges last year. But you and I know a secret-its trunk is hollow but strong. If you go past today, you will see no evidence of wounds or scars. As more years passed, its trunk broadened and the scar eventually grew over. Over the following years, I observed the long, narrow lightning scar deepening as the wood decayed. Many of us thought it would die, but it defied the odds. There is a splendid variegated elm growing at Melbourne University's Burnley Campus which was struck by lightning almost 30 years ago. Trees can often recover from strikes like this, if the scar and decay are not too great. The wood behind the scar often decays over time, leaving a hollow behind. You'll notice the lightning scar on trees like these, as it's very visible. Such a strike often kills the tree's living tissues in a strip running along a large branch, vertically down the trunk to the ground, or even ending a meter or two above the ground. Sometimes, lightning will strike one side of a tree. You may well notice the tree will appear to be undamaged and continue to grow well. You can sometimes see the sooty residue left on parts of the tree after a strike like this. If the trunk of the tree is very wet from rain, the lightning will course through the water and dust on the trunk down to the earth, causing little damage to the tree itself. Trees are not very good conductors of electricity. It would be an excellent idea not to be under a tree when this happens. The sap inside the tree instantly turns to steam, which can cause it to literally explode, or lose great strips of wood and bark. For a tree unlucky enough to be hit by one of these events, it's all over. Strikes can be up to a million volts, generating temperatures up to 20,000℃. The lightning strike pictured hit a tree in Sydney’s Royal Botanic Gardens. The damage done depends on the tree species, whether it was sheet or forked lightning, how wet it was and where the lightning hits the earth and dissipates. In fact, the effects can vary enormously. You'd think a lightning strike would be game over for most trees. When lightning strikes, they are more likely to be struck. How do these rules apply from the perspective of a tree? Old trees are often the tallest thing around. Lightning never strikes in the same place twice. Don't shelter under a tree during a thunder storm. Most of us are used to the rules we were told about lightning and trees from childhood. And that means our tallest trees will be hit more often. As storms intensify in our new climate, we're likely to see more lightning strikes. These all contribute to trees falling or dropping large branches.īut there's something you might not think of as linked to climate change. This is what we can expect as our climate changes, with storm events more frequent, wind speeds stronger and rainfall heavier.
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