Natural Disturbances

Key Indicators of Past
Natural Disturbances:

• Wind Damage — broken tops and limbs, crooked tree trunks, downed trees
• Fire — charred tree trunks (sometimes called catfaces)
• Ice — broken tops and limbs, bentover trees
• Flood — roots exposed near stream or river, debris trapped in branches
• Wildlife — browse lines, nests, beaver ponds
• Insects/disease — dead trees, damaged leaves or needles, tree decline

Several types of natural disturbances may occur on your land; each has the potential to degrade forest quality. Examples of natural disturbance include insect infestations, weather,  inhibiting vegetation, disease, and wildfire. It is not uncommon to have multiple natural disturbances on your property, but not every disturbance means disaster.

Forests have been responding to natural disturbances since the beginning of time. Measures for preventing weather-related disturbances and insect outbreaks are very limited. However, some other disturbances such as undesirable competing and wildfire are more preventable. But it’s always important to consider the impact management practices may have on otherwise healthy trees and clean water since money spent fighting an inevitable disturbance may cause an even greater, future problem.

Insect Infestations

Examples include the hemlock wooly adelgid and the Southern pine beetle. The hemlock wooly adelgid has been found in several Kentucky counties.

Insect infestations are common and there are several ways they can affect a tree. Each insect has distinct signs, but in general: defoliators eat the leaves or needles off of the tree; bark beetles and borers drill holes that excrete sap or pitch onto the bark and wood; and piercing and sucking insects eat select portions of the tree.


Ice storms, drought, tornados and lightning strikes occur somewhere in the south almost every year. They can uproot, wound and break trees. If you lose a group of trees to weather, you may choose to replant with seedlings or allow the area to naturally regenerate. You may find that a small area in transition will change the wildlife you see on your property.

Fire scars, also known as 'catfaces,' leave the tree susceptible to insects and disease.

Don’t just scrap the damaged trees. Often, sections of even small trees can be utilized for interesting projects like gourmet mushroom cultivation or small building projects. Some enterprising people have even built an entire home with timber felled during an ice storm.

Appalachia — Science in the Public Interest (ASPI) can provide you with more details about their cordwood buildings that can be constructed for as little as $8 a square foot!


Fire can be beneficial to your forest. Prescribed burns are used as a management tool that can promote the health and vigor of your forest, but only under the guidance of a professional who will gauge temperature, wind conditions and relative humidity.

Arson is the leading cause of forest fires in Kentucky. Whether intended or accidental, 99% are the result of some activity of man. On an average, these fires consume over 66,000 acres of forest a year. Report arson by calling 1-800-27-ARSON. You may remain anonymous and may be eligible for a cash reward of up to $1,000 if the information provided leads to the arrest and indictment of an arsonist.

Insects, such as beetles and wood borers, are attracted to trees stressed by fire damage. Scarring is a good indicator of past fire damage. Fire scars usually occur at the base of the tree and normally on the uphill side where there is a slope. Charred areas are normally present on the bark of affected trees. Fire damage can be more apparent on younger trees, with a loss of bark or foliage in the crown.

Invasive Vegetation

Invasive, or nuisance vegetation, such as grape vines, poison ivy and kudzu can strangle or suppress the growth and vigor of a tree.

If this vegetation doesn’t destroy the tree it will stunt its growth and vigor. Invasive vegetation does not discriminate against any tree species and, if uncontrolled, can damage very large areas of forest. Recommended procedure for removing nuisance vegetation often relies on manual labor — physically cutting and destroying unwanted vines and plants. Early detection and treatment is key.


Disease can affect tree foliage, branches, and the main stem, typically resulting in fewer leaves or defoliation. In cases of severe impact you’ll notice decay, broken limbs and even tree mortality. There is no tree species that is immune to disease. Conifers show disease through distorted limbs and needle spots. Hardwoods will show leaf spots or distortion of the main stem and branches. A moderate hazard in Kentucky is annosum root disease, in which a fungus appears at the root collar of the tree. Spores, which are airborne to freshly cut stumps or wounds, germinate rapidly to infect the tree.

Disease control is usually costly in terms of forest stand management. The best action to take is preventive management. Keep an eye on signs of disease or abnormalities. Contact your local extension agent or the Kentucky Division of Forestry as soon as you suspect symptoms.

Loss of Natural Pollinators

For every bite of food you eat, you should thank a bee, butterfly, bat, bird or other pollinator. Pollination, which is the transfer of pollen from one flower to another, is critical for plant reproduction. Many insects and animals contribute to this process. It's an invaluable service considering three-quarters of our staple crops and 90 percent of all flowering plants in the world depend upon natural pollinators.

The decline of natural pollinators is a concern for everyone. This decline is due to a number of variables including loss of habitat, disease, pesticides and climatic fluctuations. Although these variables may seem to be beyond your control, you can encourage habitat for natural pollinators. Encourage multistory growth to promote flowering plants, shrubs, and understory tree species. This will create a healthy habitat to help sustain natural pollinators. Keep pesticide use to a minimum. Remember, bug sprays and insecticides don’t differentiate between natural pollinators and pests.

Loss of Understory Grasses, Herbs, Shrubs, and Trees

As forests become more fragmented, they encourage larger populations of animals that thrive on the understory plants, grasses and shrubs. White tail deer in particular present a threat to the natural diversity of the forest. Their grazing habits reduce the forest understory and consequently, reduce the habitat and food supply of many plants and animals.

In heavily impacted forests, a deer browse line, where deer can no longer reach leaves and buds of branches can be clearly seen several feet from the ground. In your management plan, designate some areas to be left wild, or in their natural state. It will create habitat for birds, butterflies and small foragers.


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