Tree services glossary
Short, plain-English definitions of the terms you'll meet when choosing a tree service provider in Westchester County, NY.
- What are codominant stems?
- Codominant stems are two or more main trunks of nearly equal diameter that grow from a single base point on a tree, creating a structural weakness where they meet.
- What are girdling roots?
- Girdling roots are tree roots that grow in a circular pattern around the trunk or other roots, constricting nutrient and water movement and eventually weakening or killing the tree.
- What is a critical root zone?
- The critical root zone is the circular area surrounding a tree's trunk where most of its absorptive and structural roots are located, typically defined by the tree's drip line or canopy edge, and protected during construction or soil disturbance.
- What is a hazard tree?
- A hazard tree is one with significant structural damage or disease that, combined with proximity to a target such as a building or roadway, creates an unreasonable risk of failure and injury or property damage.
- What is a root flare?
- The root flare is the visible widening where a tree's roots transition into the trunk at the soil line, typically visible as a natural buttressing at the base.
- What is a spotted lanternfly?
- A spotted lanternfly is an invasive planthopper insect native to Asia that feeds on tree sap and damages a wide range of plants, with populations now established across Westchester County and subject to New York state quarantine rules.
- What is a tree preservation ordinance?
- A local law that requires permits or imposes restrictions on removing, topping, or damaging trees that meet a minimum diameter threshold, typically to protect the community's tree canopy.
- What is a tree preservation plan?
- A tree preservation plan is a document that outlines specific protection measures for trees on or near a construction site, typically required by municipal permits in Westchester County.
- What is a tree removal permit?
- A tree removal permit is authorization from a local municipality allowing the removal of a tree on private property, typically required for trees above a specified diameter threshold.
- What is an emerald ash borer?
- An invasive beetle from Asia that feeds under the bark of ash trees, disrupting nutrient flow and killing trees within a few years of infestation.
- What is an ISA Certified Arborist?
- An ISA Certified Arborist is a professional credentialed by the International Society of Arboriculture after passing a comprehensive exam covering tree health, pruning, diagnosis, and risk assessment.
- What is anthracnose?
- Anthracnose is a fungal disease caused by fungi in the Colletotrichum and Glomerella genera that infect the leaves, twigs, and branches of trees, particularly sycamores, maples, and oaks.
- What is cabling and bracing?
- Cabling and bracing involve installing steel cables and rods through or around a tree's trunk and limbs to reinforce weak structural points and prevent splitting or failure.
- What is crown raising?
- Crown raising is the removal of lower branches from a tree to increase clearance between the canopy and ground-level structures, driveways, or walkways.
- What is crown reduction?
- Crown reduction is a pruning technique that selectively shortens branches throughout a tree's canopy to decrease its overall height and width while preserving its natural form.
- What is crown thinning?
- Crown thinning is the selective removal of branches throughout a tree's canopy to improve light penetration and air movement while maintaining the tree's overall form and height.
- What is DBH (diameter at breast height)?
- DBH (diameter at breast height) is the trunk diameter of a tree measured at 4.5 feet above ground level, the standard reference point used in municipal tree ordinances and arboricultural assessments.
- What is deadwooding?
- Deadwooding is the removal of dead, dying, or diseased branches from a tree to improve its health and eliminate safety risks from falling wood.
- What is included bark?
- Included bark is bark that becomes trapped within a narrow angle where a branch meets the main trunk or a larger limb, creating a weak point that compromises attachment strength.
- What is oak wilt?
- Oak wilt is a vascular fungal disease caused by Ceratocystis fagacearum that kills oak trees by blocking water and nutrient flow, spreading through connected root systems and beetle vectors.
- What is TRAQ (Tree Risk Assessment Qualification)?
- TRAQ is a specialized credential from the International Society of Arboriculture that certifies arborists to systematically identify and evaluate tree hazard risk on residential and commercial properties.
- What is tree risk assessment?
- Tree risk assessment is a systematic process in which an arborist evaluates a tree's structural condition and likelihood of failure to determine potential risk to people or property.
- What is tree topping?
- Tree topping is the indiscriminate removal of upper branches and the main stem of a tree, cutting it back to large lateral branches or stubs; it is widely discouraged by arborists because it causes structural weakness, disease vulnerability, and vigorous regrowth of weak branches.
- What is verticillium wilt?
- Verticillium wilt is a soil-borne fungal disease that infects trees through their root systems, causing vascular damage and progressive decline, particularly in maples and other shade trees.