ISA Municipal Specialist key terms

A systematic count and measurement of public and sometimes private trees, recording species, size, condition, and location so managers can quantify the resource and plan work.

A statistically designed survey of a portion of the tree population, used to estimate whole-city totals with a known margin of error at lower cost than a full census.

Dividing a city into homogeneous zones such as land-use types or maintenance districts, then sampling within each zone so estimates reflect every area fairly.

The share of ground area shaded by tree crowns when viewed from above, often measured from aerial or satellite imagery to track canopy goals over time.

A free suite of USDA Forest Service software tools that estimates the structure, environmental benefits, and monetary value of urban forests from inventory data.

Assigning dollar or other values to benefits trees provide, such as stormwater interception, air pollutant removal, carbon storage, and energy savings, to justify program investment.

A structured process of evaluating the likelihood of a tree or tree part failing and the consequences of that failure, used to set inspection and mitigation priorities.

People, property, or activities that would be struck if a tree or limb failed; risk only exists where a target is present and can be reached.

A grid that combines likelihood of failure with severity of consequences to rank tree risk into categories such as low, moderate, high, or extreme.

Any action taken to reduce tree risk, such as pruning, cabling, bracing, installing a root barrier, moving a target, or removing the tree.

Pruning young trees to develop a strong central leader, well-spaced scaffold branches, and sound attachment geometry so future failure risk is reduced.

Reducing the length or weight of competing or overextended limbs to slow their growth and shift vigor toward a desired leader or branch.

The cut made to remove a branch, ideally just outside the branch collar without leaving a stub or wounding the parent stem.

The swollen tissue at the base of a branch containing the tree's chemical defenses; cuts made outside it allow the tree to seal the wound.

A defined area around a tree, usually calculated from trunk diameter, where construction disturbance to roots and soil is restricted during development.

The soil area containing the roots essential to tree survival and stability, often drawn as a circle with a radius of about one foot per inch of trunk diameter.

A site drawing and written specification showing protected trees, fencing, limits of disturbance, and required construction practices, approved before work begins.

A local law regulating removal, injury, or replacement of specified trees, often requiring permits, mitigation planting, or payment into a tree fund.

Trunk diameter measured at a standard height above ground, commonly 4.5 feet in the United States, used as the basis for ordinance thresholds and fees.

A tree designated for special protection because of size, age, species, historic association, or landscape value, usually subject to stricter removal standards.

A dedicated municipal account holding fees paid in lieu of on-site replacement planting, restricted to tree planting, establishment, and related program uses.

Money a developer pays instead of planting required replacement trees on site, calculated from a published formula and deposited in the tree fund.

A document identifying which trees will be retained on a development site and the measures that will keep them alive and undamaged through construction.

Choosing tree species suited to the site's soil, water, climate, space, and maintenance capacity while advancing diversity and program goals.

The principle of matching a tree's mature size and requirements to the planting site so conflicts with utilities, pavement, and structures are avoided.

Distributing plantings across many species and genera, often guided by a rule such as no more than ten percent of the population in one species, to limit pest losses.

Evaluation of a planting location's soil volume, drainage, light, overhead and underground utilities, and space for mature growth before a tree is specified.

The years after planting during which roots grow into surrounding soil and the tree needs supplemental water and care before it is considered self-sufficient.

A layer of organic material spread around a tree over the root zone, kept away from the trunk, to conserve moisture, moderate soil temperature, and suppress weeds.

Planting stock lifted and shipped without soil around the roots, typically cheaper and lighter but requiring dormant timing and careful root handling.

A local law governing public tree care, removal permits, planting requirements, or protection of trees on private land within the community.

An appointed citizen advisory body that reviews tree policy, educates the public, and advises elected officials on urban forestry matters.

A long-range document setting goals, strategies, responsibilities, and measures for managing a community's trees over a defined planning horizon.

A measurable target for the percentage of a city shaded by trees by a stated year, used to focus planting, preservation, and budget decisions.

An annual or multiyear schedule translating management plan goals into specific tasks, timelines, staffing, and costs for a given period.

A defined standard for how often or how quickly a maintenance activity such as pruning or hazard response is performed across the tree population.

The planned interval between pruning passes over a defined group of trees, set by species, age, and available budget rather than by complaint alone.

A prepared protocol assigning roles, equipment, call-out procedures, and communication steps for storm damage and other tree-related emergencies.

A formal arrangement among jurisdictions or agencies to share crews, equipment, and support during emergencies that exceed local capacity.

A competitive solicitation describing the scope, specifications, evaluation criteria, and terms for contracted tree work or professional services.

Managing a signed contract through scheduling, inspection, change orders, payment approval, and documentation to confirm work meets specifications.

Written requirements in a solicitation that define materials, methods, standards, and measurement so competing bids can be compared fairly.

Recruiting, training, scheduling, supervising, and recognizing community volunteers so their work is safe, useful, and consistent with program standards.

A structured training and service program that prepares residents to care for, monitor, and advocate for community trees under municipal guidance.

Planned communication with residents, businesses, and officials to build understanding and support for tree programs, ordinances, and projects.

Involving affected groups early and meaningfully in decisions about tree removal, planting, or policy so concerns are heard and plans improve.