Urban Forestry Practice Questions

Correct answer: B. Leaves evaporate water drawn up from the roots, using heat from the air

EPA describes evapotranspiration as trees taking up water through their roots and evaporating it through their leaves. The energy needed to evaporate that water is drawn from the surrounding air, so the air cools; shade is a separate cooling effect. Reflecting sunlight is how light-colored cool roofs and pavements work, not evapotranspiration, and the oxygen released in photosynthesis does not cool the air.

• A: Reflecting sunlight describes cool roofs and pavements, not evapotranspiration.
• C: Trees do not store daytime heat in the trunk; the cooling comes from evaporating water.
• D: Oxygen given off in photosynthesis has no meaningful cooling effect.

Source: Benefits of Trees and Vegetation (Heat Islands), U.S. Environmental Protection Agency

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Correct answer: D. The west wall

In summer the sun strikes the east side of a house in the morning and the west side in the afternoon, when temperatures and electricity use peak, so the USDA Forest Service Northeast Community Tree Guide calls the west side the most important side to shade. The east side is second. Trees that shade the south wall can block the low winter sun and raise heating costs, and the north wall gets little direct summer sun.

• A: The north wall gets little direct summer sun, so shading it saves little.
• B: Shading the south wall can block winter sun and raise heating costs.
• C: The east side ranks second, not first, in importance for shading.

Source: Northeast Community Tree Guide: Benefits, Costs, and Strategic Planting (PSW-GTR-202), USDA Forest Service, Pacific Southwest Research Station

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Correct answer: D. 3.0:1

A BCR divides total benefits by total costs: $2.4 million divided by $0.8 million is 3.0, or about $3 in benefits for every $1 spent. The tempting 2.0:1 comes from dividing net benefits ($1.6 million) by costs, which is a return-on-investment figure rather than the BCR. A ratio of 0.33:1 is the BCR turned upside down, and 1.6 is the net benefit in millions, not a ratio.

• A: This divides costs by benefits, the inverse of a BCR.
• B: $1.6 million is the net benefit, not a ratio of benefits to costs.
• C: Net benefits divided by costs is a return-on-investment figure, not the BCR.

Source: Midwest Community Tree Guide: Benefits, Costs, and Strategic Planting (PSW-GTR-199), USDA Forest Service, Pacific Southwest Research Station

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Correct answer: C. Cost, income, and sales comparison approaches

Purdue Extension's summary of the 10th edition lists the cost approach, the income approach, and the sales comparison approach, and Mississippi State Extension names the same three. Replacement, reproduction, and repair are the strongest distractor because they are real terms, but they are methods within the cost approach rather than separate approaches. Condition and location are factors that affect value, and the trunk formula is a technique within the cost approach.

• A: Condition and location are factors that affect value, not appraisal approaches.
• B: Repair, replacement and reproduction are methods within the cost approach.
• D: The trunk formula is a cost-approach technique, and i-Tree estimates benefits rather than appraised value.

Sources: Tree Appraisal and the Value of Trees (FNR-473-W), Purdue University Extension ; Casualty Losses of Shade Trees and Landscape Elements (P3871), Mississippi State University Extension

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Correct answer: C. Re-examine the result, since a value must be reasonable and defensible

Purdue Extension warns that a tree's estimated value may not be in proportion to the property's value or to the price someone would actually pay for the tree, and that legitimate appraisal values must be reasonable and defensible. A tree valued at nearly two-thirds of the whole property's selling price calls for a second look at the inputs and at other approaches. Reporting the number unchanged skips that check, and picking whichever approach gives the highest value is not an unbiased appraisal.

• A: Formula results still need a reasonableness check before they are reported.
• B: Adding the tree value on top of the property value double counts and ignores the reasonableness problem.
• D: An appraiser must give an unbiased value, not pick the approach that favors the client.

Sources: Tree Appraisal and the Value of Trees (FNR-473-W), Purdue University Extension ; Tree Appraisal and the Value of Trees (FNR-473-W), Purdue University Extension

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Correct answer: B. Street tree ordinance

A street tree ordinance governs trees in public rights-of-way: how they are planted, maintained, and removed, and sometimes how private trees that endanger the public are handled. A tree protection ordinance, the most tempting alternative, instead protects designated trees or canopy, often on private land, usually by requiring a permit before removal. View ordinances settle disputes over blocked views or sunlight, and landscape ordinances set planting requirements for development.

• A: Tree protection ordinances protect designated trees or canopy, often on private land, through permits.
• C: View ordinances resolve conflicts when trees block views or sunlight.
• D: Landscape ordinances set required plantings, such as trees in parking lots, for development.

Sources: Developing Successful Tree Ordinances, NC State Extension ; Tree Care Ordinances, Illinois Department of Natural Resources

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Correct answer: B. Leave that branch in place until the nest is no longer active

The U.S. Fish and Wildlife Service explains that the Migratory Bird Treaty Act makes it illegal to destroy a nest that holds eggs or chicks, and that people are usually required to wait until a nest is inactive before removing it. The American robin is a protected migratory songbird, so the branch should stay until nesting is finished. Moving the nest is not a legal workaround, because taking or possessing a migratory bird nest also requires a federal permit.

• A: Moving an active nest still takes it, which requires a federal permit.
• C: The MBTA protects most native migratory birds, not only endangered species.
• D: Destroying a nest that holds eggs is illegal under the MBTA.

Source: Bird Nests, U.S. Fish and Wildlife Service

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Correct answer: D. It is quicker and cheaper but usually can't guide day-to-day work

A sample inventory measures trees on a random sample of street segments or areas and expands the results into estimates for the whole street tree population. i-Tree's guidance notes that it is quicker and less expensive and provides baseline data for decisions, but it usually can't be used to manage trees day to day, because most individual trees are never recorded. Sample inventories are collected in the field, and their species and size data can be used to estimate benefits.

• A: A sample inventory is the cheaper option, not the more expensive one.
• B: Sample data such as species and trunk diameter can be used to estimate benefits.
• C: Sample inventories are collected in the field on randomly chosen segments or plots.

Sources: i-Tree Streets (legacy), i-Tree (USDA Forest Service and cooperators) ; What Is a Tree Inventory? (fact sheet), Massachusetts Department of Conservation and Recreation, Urban and Community Forestry Program

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Correct answer: C. Spending at least $2 per capita a year on tree care

The Arbor Day Foundation's four Tree City USA standards are a tree board or department, a public tree care ordinance, documented spending of at least $2 per capita each year on community tree care, and an Arbor Day observance with an official proclamation. Inventories, certified staff, and canopy goals are good practice, but none of them is one of the standards. Standard 1 can be met by a board, department, or position; it does not require a certified arborist.

• A: An inventory is useful but is not one of the four standards.
• B: A tree board, department or position is required, but not a certified arborist.
• D: Canopy goals are not part of the four standards.

Source: Tree City USA Standards, Arbor Day Foundation

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Correct answer: D. Work with all stakeholders in a process open to every group

NC State Extension says balance comes from working collaboratively with all stakeholders to produce an ordinance that is acceptable and workable, through a decision process open to every group that wants to take part. It specifically recommends early dialogue with developers, because carrying out an ordinance depends on their support. Copying another town's ordinance ignores local conditions, and drafting in private or deciding by head count undermines the community support an ordinance needs.

• A: Drafting in private undermines the community support an ordinance needs to work.
• B: One ordinance does not fit every community; it should reflect local goals.
• C: Balance comes from collaboration among all stakeholders, not from crowd size.

Source: Developing Successful Tree Ordinances, NC State Extension

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