Glossary of Tree Terms

  • Ambrosia beetle – A small beetle that commonly infests stressed and dead oak trees. They excavate tunnels and release a fungus from which they feed. The process of tunneling through xylem tissue and into cambium tissue effectively girdles and kills live trees. Their frass is white in color
  • Aphid – Aphids reside on the undersides of leaves.They use a sucking mouth part (stylet) to penetrate leaf tissue to feed on plant juices.They can spread disease through their saliva. In large quantities, they weaken trees and shrubs.
  • Cambium – Is a vascular tissue that produces phloem and xylem cells. Phloem to the bark side, and xylem to the inside which becomes the heartwood. When enough damage caused by insects and pathogens or mechanical damage occurs, a plant may die.
  • Clearwing moth – Also locally known as Sycamore borer, does not bore too deeply so a tree can withstand some colonization without detrimental affects. When a tree becomes over colonized, treatment to eliminate is necessary.
  • Conk – Refers to the fruiting body of a fungus.
  • Deciduous-Perennial plant which loses all its leaves at one time during the year.
  • Feeder roots – Are the fine root mass that occurs just beneath the soil surface. From approximately four to twenty-four inches deep, these roots mine the soil for water and nutrients. These roots are responsible for tree health. They can become diseased, or they mechanically eliminated. This often leads to severe tree stress.
  • Frass – Frass is the material that is excreted by insects as they feed. In the IPM system of pest management, it is used as an identification tool to determine species of insect and severity of colonization.
  • Ganoderma – Ganoderma is a fungus which can invade, colonize and kill a tree using wounds as entry points. There are several types of Ganoderma. Ganoderma applanatum, also known as artist’s conk, is a heart rot pathogen which eats away at the sapwood and heartwood or a tree. The fruiting body of this fungus appears at the base of a tree and has a brown top and a white bottom. Ganoderma licidum causes decay of the roots and trunk and can kill a tree within 5 years. The conk is a reddish-brown.
  • Girdling – Girdling term that describes the process of destroying a plants life giving tissue. It is similar to strangulation.It generally occurs when a smaller lateral root grows over and into a buttress root.
  • Inoculumn – The part of a pathogen that can cause disease.
  • Mycorrhizae – Is a symbiotic naturally occurring fungus which attaches itself to fine feeder roots and grows its own roots,hyphae which mine the soil for minerals and water to bring into the feeder roots.
  • Nematode – Microscopic insects that bring angst to farmers, but usually not a problem to trees.
  • Oak root fungus – Is a naturally occurring fungus which is activated in warm moist environments. It is a killer of oak trees. It is encouraged to flourish in many landscapes. When lawns and other high water and fertilizer use plants are planted in root zones of these trees the conditions are perfect for oak tree root infection. The process begins and usually lasts many years. Not all trees die from the disease.
  • Pathogen – Disease organism.
  • Phytotoxic – Kills living plant tissue.
  • Photosynthate is the sugars produced by the photosynthesis process. The carbohydrate is moved to different plant parts throughout the tree.
  • Phloem -The vascular tissue in plants that transports the carbohydrate produced by photosynthesis to the roots.
  • Root zone – Area of land which encompasses all of a plants roots. The root zone of a tree can can cover three times the distance measured between the tree trunk to the drip line.
  • Scale – Small insects from the insect order Homoptera that attach themselves to the underside of leaves and bark of trees and shrubs. They suck plant juices and can inject toxic saliva into trees and shrubs.
  • Soil food web – Is an advanced network of underground/above ground organisms containing bacteria, fungi, protozoa, nematodes, arthropods, animals and birds. These organisms gather nutrients such as nitrogen by breaking down organic matter. As one organism is consumed by another, a conversion of energy occurs making energy and nutrients available to plants and other organisms within the soil. The greater the diversity of organisms in the soil allows for more diversity of plants above ground.
  • Vascular system – Tissues that function in the transportation of water, minerals, carbohydrates and other materials.
  • Whitefly -Not true flies, but small insects from the Homoptera insect order that suck plant juices (phloem) from the bottom of leaves. High populations cause leaves to shrivel, yellow and drop. The honeydew they produce may lead to sooty mold or sticky droplets on cars, sidewalks and driveways.
  • Xylem-The plant vascular tissues that transport and store water and minerals from the soil into the tree. This tissue also serves as mechanical support by becoming heart wood when they no longer function as transportation.

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