Storm events such as tornadoes, severe thunderstorms, hurricanes, and ice can considerably impact trees. Below are some of the impacts caused by hurricanes, tornados, or storm events and information to assist homeowners and community officials to prepare and respond quickly and safely before and after storm events.
Wind
Wind is often the first sign of a hurricane approaching. Leaves and branches may be stripped off and entire trees may be twisted, broken or uprooted altogether. Some trees are more susceptible to wind damage than others. Trees with healthy root systems have better chances of survival. However, if remaining trees survive one storm, and another hurricane encompasses the same area in a short period of time, those remaining trees are considered stressed and may not make it through subsequent storms. Hurricanes can also produce tornadoes with winds measuring more than 200 mph. Trees may be completely debarked by small, flying debris or downed altogether. In either case, these trees will need to be removed.
Lightning
Hurricanes also are typically accompanied by thunderstorms and lightning.. Because of their height, trees are a prime target for lightning. However, damage caused by lightning varies greatly. The damage may be minimal if the electricity is conducted along the outside of the tree. In this case, blown off bark and scarring will be apparent. The damage may extend to a more serious condition known as trunk shatter. In this event, lightning charge penetrates into the tree's trunk, turning moisture into steam and causing the tree to explode. The most commonly struck trees are oaks, elms, poplars and pines. These trees typically are found in most yards.
Flooding
After hurricanes strike, many low-lying communities are impacted by short-term flooding. Flooding has been known to damage trees by loosening and/or removing the soil that supports root systems. In areas that have been flooded for extended periods of time, trees can suffer from the accumulation of organic toxins in the soil and the reduced flow of oxygen to the roots. Various characteristics of a tree, including height, age and species, along with environmental factors like season, temperature and flood water duration, affect a tree's flood tolerance. The typical warning sign of flood damage in trees is curling and wilting of the leaves, followed by chlorosis (pale-colored leaves that have lost chlorophyll). Chlorosis is generally followed by leaf browning and ultimately, leaf loss.
Ice
Ice storms are caused by rain that supercools or freezes as it passes through below-freezing air. These ice coatings can grow to be several inches thick in various places. The weight of the ice, combined with any wind or outside forces, breaks the trees’ branches. Normally, the taller and older a tree, the more susceptible it is to ice damage because older trees have larger crowns, more internal decay, and less limb and trunk flexibility. The severity of the ice damage depends on ice load and resistance of the trees determined by their physical characteristics - wood strength, elasticity and growth form, and on condition of the growing environment. In general, trees with brittle and weak wood, fine branches, and greater canopy surface, such as pine trees which retain their needles, are more likely to suffer ice damage. Some trees that have a high ice storm survival rates include: yellow birch, American hornbeam, beech and oak.
An effective storm plan should include the following:
Preparation
For homeowners, this may include contacting a certified arborist. For community officials planning includes: an early warning system for severe weather, a disaster response plan, identification of roles of municipal entities during a disaster, and identification of sources of additional assistance during an emergency.
Homeowners
Urban trees provide health, environmental, economic, and aesthetic values to communities, businesses, and homes. Trees that are not properly maintained or which are stressed can quickly become major liabilities to people and property from weather phenomena.
Immediate responses may be either to prune or remove your trees. These “do-it-yourself” efforts sometimes result in personal injuries, fatalities, or property damage that homeowners are attempting to avoid. You can cause greater harm to the urban forest by removing healthy trees that do not need to be cut.
Preparing for storms is as easy as …
- Giving Routine Tree Care - Trees need watering, fertilizing, and mulching. Certified arborists can help you determine which trees will need certain care at various times of the year. Add this information to your surveys for future reference!
- Hiring Certified Arborists - They know how to remedy hazardous tree situations (pruning and/or removing trees) and should be consulted every other year to update tree assessments and provide major tree care, if needed. Certified arborists are trained to plant, care, and maintain trees. They have at least three years experience and have passed a comprehensive exam by an industry association. Certification relates to their knowledge of trees and tree physiology and requires them to remain updated in the latest arboriculture techniques. It does not govern individual performance, though.
Community Officials
An effective storm plan will help to minimize a storm's impacts on your community forest.
Response - immediate activity during and after the disaster. Examples include tree damage clean up, clearance, office/field communications, identification of debris disposal options, and the use of efficient record-keeping methods. The following information is aimed at assisting homeowners and community officials to prepare and respond quickly and safely after storm events.
Homeowners
Many homeowners feel the overwhelming need to clean up tree debris left behind by storm events. Tips for managing the volume of downed trees, branches and other debris include:
- First, assess safety conditions of your family, home and neighborhood.
- Homeowners who spot downed trees on primary roadways may notify local officials by calling state or county EMA offices. Teams from various agencies will be dispatched to clear downed trees that are blocking primary roadways, so roads can be reopened for official vehicles to respond to emergencies. Primary roadways include county and state maintained roadways. Roadways may include private roads, if life and/or property are in danger and emergency vehicles are blocked from responding.
- Call insurance providers if there is structural, vehicular or property damage and follow their instructions to accurately file claims.
- Follow instructions of local, state and federal officials for your area prior to attempting to remove tree debris in your yard or neighborhood. Local governments have different debris cleanup procedures. They will tell you where to place debris for pickup; what branch lengths, bundle sizes and number of accepted bundles will be picked up; and when pickups will occur.
- In cleaning up tree debris, keep trash bags and heavy cord handy. Pile debris where it will not restrict your movements, the movements of tree crews or your neighbors, and be sure to allow access for other debris to be removed. Determine what part of the debris may be recyclable and pile it separately. Most woody debris can be recycled.
- Only attempt to clean up minor tree debris.
- Tree trunks and large limbs can be very heavy and their movement should not be attempted by one person.
- Do not attempt to remove leaning trees or large branches on roofs. Improper movement could cause additional structural damage.
- Be very careful when moving downed trees and branches laying over one another. They are likely to be under tension and when you move them, they could snap violently and cause personal injuries.
- Operating a chainsaw on storm-damaged trees is dangerous. Historically, more people are injured by chainsaws than the storm that caused the tree damage. Never operate a chainsaw alone or without proper instructions. In addition, always use the necessary safety equipment, including leather gloves, a full face shield or safety goggles, hearing protection, a hard hat, long sleeves and pants, over-the-ankle leather boots (with a steel toe, if possible) and chainsaw chaps.
- Call certified arborists for major tree debris removal and proper maintenance of remaining trees.
- Certified arborists can assist homeowners who have trees that have been struck by lightning. Hazardous trees and limbs should be removed. However, major pruning should be delayed six to 12 months (preferably during the winter months). Sometimes, tree mortality takes at least that long or even longer to occur, so major expenditures before then would be wasted. When it appears the tree will survive, more careful pruning and continued fertilization (with deep watering, if necessary) is recommended.
- County extension offices can also conduct a soil test to determine pH and nutrient levels. Based on the results, homeowners may need to enhance a tree's vigor by fertilizing the tree, aerating the soil, mulching the tree's root area and watering if soil conditions become excessively dry.
- Have patience. Storm debris cleanup can take weeks or even months.
Homeowners
Storm recovery may take several months. In addition to remaining patient and safe, the following steps can assist you in your storm recovery:
- Provide Tree Care - The impact of the storm will be visible in the trees for years to come. Many trees can be salvaged by pruning broken and damaged limbs. Make sure to hire a certified arborist to ensure that proper pruning practices are being used. Poor pruning can lead to cavities that could cause the tree to fail at a later date or which may make the tree more susceptible to breakage during a future storm.
- Hire Certified Arborists - These tree care professionals should be hired to remedy hazardous tree situations. After a storm, it is common in some areas for people to show up at your door offering their services to remove or repair trees. Chances are the tree service companies who are qualified to do tree work have plenty of work to do without soliciting door to door. To be certain you are dealing with a professional make sure the person has the appropriate credentials.
- Planting Trees - State forestry agencies have seedlings available for purchase or lists of tree planting stock suppliers.
Community Officials
An effective storm plan will help to minimize a storm's impacts on your community forest. Communities with active urban forestry programs are more prepared to cope with tree damage from storms. In addition, they may find themselves at a advantage when it comes to funding for tree removal and replacement. The Federal Emergency Management Agency (FEMA) has established guidelines for removal and replacement of trees on public property that may have become a hazard to the general public as a result of the storm. In order to qualify for these funds, a community must be able to demonstrate that prior to the storm they had a program for maintaining trees on public property.
Chainsaw Safety Tips
- Historically, more individuals are injured by chainsaws than by the storm that caused the initial damage.
- Safety equipment required before operating a chainsaw includes: leather gloves, full face shield or safety goggles, hearing protection, hard hat, long sleeve shirt, long (blue jean) pants, over the ankle leather boots and chainsaw straps. Also required: first-aid kit, knowledge of chainsaw operation, patience.
- Never work alone; have a partner close by and carry whistles for emergencies.
- Never use electric power tools near standing water.
- Trees and limbs can weigh several tons; beware of limbs that may “kick back” when they are sprung from under the tension of other tree parts.
Flooding Tips
- Saturated ground and rising waters have loosened soil around tree root systems, which may cause trees to lean or fall.
- Never attempt to right a leaning tree.
- Warning signs of flood damage in trees include curling and wilting of leaves, followed by “chlorosis,” or pale-colored leaves, which is generally followed by leaf browning and ultimately, leaf loss.
- Excessive water can impact a tree’s overall health. The accumulation of organic toxins in the soil and the reduced flow of oxygen to the roots can cause the tree to suffer.
- Certified Arborists can remedy hazardous tree situations and provide advice on proper species placement and maintenance.
Credit: Southernforests.org
