Arborist Practice is independent and not affiliated with the International Society of Arboriculture. These are original Identification and Selection practice questions written for study. They are not real ISA exam questions, not official ISA material, and not a substitute for the current ISA exam outline or official study materials.
Start here if Identification and Selection is your weak domain
Free ISA Identification and Selection practice questions are useful when you need to test tree ID clues, site matching, species traits, mature size, tolerance, diversity, and nursery stock quality without taking a full mock exam. This domain is easy to underestimate because it looks like memorization. On the ISA Certified Arborist exam, it is usually more practical than that: choose the tree that fits the site, reject poor stock, and read identification clues carefully.
Use the questions below as a closed-book diagnostic. Answer first, then review the explanation for every item. If you miss several site-fit questions, go back to the main ISA Identification and Selection exam questions guide. If you want broader exam prep after this set, use the ISA Certified Arborist study guide or try mixed free ISA Certified Arborist practice questions.
How to take this Identification and Selection quiz
Do this like a short domain drill:
- Give yourself 20 minutes for all 15 questions.
- Do not use species lists, nursery catalogs, or notes while answering.
- Mark each answer as confident, uncertain, or guessed.
- After scoring, label each miss as tree ID, site tolerance, mature size, nursery stock, diversity, or wording.
- Re-study the weakest category before taking another mixed practice test.
ISA publishes the current Certified Arborist credential information and exam outline. Use the official ISA Certified Arborist credential page and the Certified Arborist Exam Outline PDF as the source of truth for current exam policies and domain details.
15 ISA Identification and Selection practice questions
1. Site matching in a narrow planting strip
A city wants a street tree for a narrow downtown planting strip with overhead conductors, reflected heat, limited soil volume, and winter deicing salt. Which selection principle should guide the recommendation first?
A. Choose the fastest-growing tree available
B. Match mature size and site tolerance to the space before considering appearance
C. Choose the largest-caliper nursery tree to create immediate shade
D. Choose a species only because it is native to the region
Answer: B. Selection starts with site fit. Mature height, crown spread, rooting volume, heat, salt, and utility conflicts matter more than speed, caliper, or a single label such as native. A native tree can still be wrong for a restricted urban site.
2. Leaf arrangement as an ID clue
A twig sample has leaves and buds arranged directly opposite each other along the stem. What is the best use of that clue?
A. It proves the tree is a conifer
B. It narrows the identification choices but should be checked with other traits
C. It eliminates the need to inspect fruit, bark, or buds
D. It proves the species tolerates compacted soil
Answer: B. Opposite arrangement is a strong identification clue, but tree ID usually uses multiple features. Buds, twigs, fruit, bark, leaf type, site context, and mature form can all confirm or challenge an early guess.
3. Mature size and overhead utilities
A client wants a large shade tree directly under energized overhead lines. Which answer best reflects good selection reasoning?
A. Select a large shade tree and plan to top it every few years
B. Select a species with mature height and form compatible with the overhead clearance, or choose another planting location
C. Select any species if it is planted far enough from the trunk of the utility pole
D. Select the fastest-growing species because early establishment matters most
Answer: B. Mature size should be considered before planting. Repeated topping or hard clearance pruning creates poor structure and recurring maintenance problems. The correct answer prevents the conflict instead of creating it.
4. Nursery stock root defects
A container-grown tree has a buried root flare and several large circling roots against the container wall. What is the best selection decision?
A. Accept it because roots will straighten naturally after planting
B. Plant it deeper so the circling roots stay covered
C. Inspect whether defects can be corrected; reject the tree if defects are severe
D. Remove half the live crown to balance the root system
Answer: C. Poor nursery stock can create long-term establishment and stability problems. Some root defects can be corrected before planting, but severe circling or girdling roots are a reason to reject the tree. Deep planting and heavy crown pruning do not fix bad stock.
5. Species diversity after pest loss
A municipality lost a large share of its street-tree canopy to a pest that favored one overplanted genus. Which replacement strategy best reduces the same type of future risk?
A. Replant the same genus because it performed well before the pest arrived
B. Plant a diverse set of site-appropriate species across the program
C. Choose one new fast-growing species for visual uniformity
D. Avoid all trees from the region where the pest was first noticed
Answer: B. Diversity reduces system-level vulnerability, but the species still need to fit their sites. The exam may frame this as urban forestry, but the selection decision starts with avoiding overdependence on one species or genus.
6. Poor drainage and root oxygen
A planting site has heavy clay soil, slow drainage, and standing water after storms. Which selection factor is most important?
A. Tolerance of wet or poorly drained soils
B. Flower color during nursery inspection
C. Whether the species has the smallest available leaves
D. Whether the tree is currently taller than nearby shrubs
Answer: A. Drainage affects root oxygen and establishment. A tree poorly matched to saturated soil may decline even if it looks good at purchase. Site tolerance is not a decorative detail; it is a survival factor.
7. Pest susceptibility and regional fit
A proposed species has a known serious pest problem in the local area, and the planting plan would use it heavily along several streets. What is the best selection response?
A. Use it anyway if it is inexpensive
B. Consider pest susceptibility and diversify with better-suited alternatives
C. Plant it deeper to reduce pest pressure
D. Fertilize all trees at planting to prevent future pest problems
Answer: B. Selection includes known pest and disease tendencies in the region. Cost and familiarity do not override predictable failure risk. Planting depth and fertilizer are not substitutes for selecting appropriate species.
8. Co-dominant stems in nursery stock
A young shade tree in the nursery has two upright co-dominant stems with included bark at the union. Why does that matter during selection?
A. It may indicate a weak future attachment and structural problem
B. It proves the root system is healthy
C. It guarantees faster wound closure after planting
D. It only matters after the tree is mature
Answer: A. Included bark can prevent strong wood-to-wood attachment. Structural defects in nursery stock are easier to prevent or correct early than after the tree is large. Selection is partly about not buying long-term problems.
9. Native status as one factor
A candidate answer says to choose a species solely because it is native, even though the site has restricted soil volume, reflected heat, and salt exposure the species does not tolerate well. What is wrong with that reasoning?
A. Native trees are never appropriate for streets
B. Native status does not override site constraints and species tolerance
C. Salt exposure only affects shrubs, not trees
D. Soil volume only matters after the tree is mature
Answer: B. Native species can be excellent choices, but they still need to fit the planting site. The exam often rewards balanced reasoning: site constraints, mature size, tolerance, objectives, and maintenance reality all matter.
10. Simple versus compound leaves
A question describes a leaf made of several leaflets attached to a shared stalk. Which term is most likely being tested?
A. Simple leaf
B. Compound leaf
C. Entire margin
D. Adventitious root
Answer: B. A compound leaf has multiple leaflets. Simple versus compound leaves are basic identification features. Do not confuse leaflets with separate leaves; bud placement often helps distinguish them.
11. Salt exposure near roads
A planting location next to a high-speed road receives winter salt spray and runoff. Which selection response is most defensible?
A. Choose a species with documented salt tolerance and appropriate site fit
B. Choose a species with thin bark because it will dry faster
C. Ignore salt because roots are below ground
D. Choose the largest tree available so salt has less effect
Answer: A. Deicing salt can affect roots, soil, buds, and foliage depending on exposure. Salt tolerance is a practical selection factor for roadside and urban sites. Bigger stock does not make a poorly matched species appropriate.
12. Shade tolerance
A proposed planting area receives only limited direct sun because of buildings and established trees. What should the arborist consider before recommending a species?
A. Whether the species can tolerate the available light conditions
B. Whether the tree can be planted with the root flare buried
C. Whether pruning can force any species to tolerate shade
D. Whether the nursery tree is taller than the surrounding understory
Answer: A. Light availability is part of site matching. Shade-intolerant trees may become thin, stressed, or poorly formed in low light. Pruning cannot turn a shade-intolerant species into a shade-tolerant one.
13. One clue is not enough
A candidate identifies a tree from leaf shape alone even though the question also gives bud arrangement, fruit, bark, and site information. What is the risk?
A. Leaf shape is never useful
B. The candidate may ignore more diagnostic traits in the stem
C. Buds and fruit are only used for shrubs
D. Site information is always irrelevant to identification
Answer: B. Leaf shape is useful, but many species share similar leaf forms. Identification questions often include several clues because one trait can be misleading. Read all the clues before committing.
14. Matching objective to species choice
A park manager wants long-term canopy shade in an open lawn with adequate soil volume and no overhead restrictions. Which selection concern is most directly tied to the objective?
A. Choosing a species with mature size and form capable of providing canopy shade
B. Choosing the smallest ornamental tree available
C. Choosing only by current nursery height
D. Choosing a species that requires the most annual corrective pruning
Answer: A. The objective matters. If the goal is long-term shade and the site can support it, mature canopy size and form are relevant selection criteria. A small ornamental may fit a restricted site but fail this specific objective.
15. Accepting or rejecting stock
A nursery tree has trunk wounds, dieback, poor taper, and signs of drought stress. The species itself is appropriate for the site. What is the best conclusion?
A. Species choice alone makes the tree acceptable
B. Poor condition and structural quality can still make the individual tree a bad selection
C. Planting deeper will correct trunk wounds and dieback
D. The tree should be topped before planting to remove stress
Answer: B. Selection includes both species and individual plant quality. A well-chosen species in poor condition can still fail. Exam questions may separate the right species from the wrong specimen.
Score guide
Use the score to decide what to study next:
- 13–15 correct: This domain is probably not your biggest leak. Review uncertain answers, then take mixed questions or a timed mock.
- 9–12 correct: You understand the broad ideas but need more reps on one category. Sort misses into ID clues, site tolerance, mature size, diversity, or stock quality.
- 0–8 correct: Pause mixed mocks. Review the Identification and Selection guide, make a site-constraint checklist, and drill short sets before moving on.
Do not overread one 15-question result. The pattern matters more than the number. Missing three nursery-stock questions is different from missing three leaf-arrangement questions.
What Identification and Selection questions usually test
This domain is practical. Expect questions that ask you to connect a tree trait to a decision:
- Tree ID clues: leaf arrangement, leaf type, buds, fruit, bark, twigs, form, and site context.
- Mature size: height, crown spread, root space, overhead clearance, buildings, sidewalks, and sight lines.
- Site tolerance: drought, salt, compaction, shade, heat, poor drainage, pH, and limited soil volume.
- Nursery stock quality: root flare, circling roots, trunk wounds, poor taper, included bark, damaged leaders, and stress signs.
- Diversity: avoiding overplanting one species or genus where pest, disease, or climate risk could create large losses.
If you want a full blueprint view, read the ISA Certified Arborist exam domains guide. If you want focused review before another quiz, use the Identification and Selection exam guide.
How Arborist Practice fits into this domain
Use Arborist Practice as the practice-and-feedback layer after you review the concepts. Drill Identification and Selection separately, review explanations for wrong and guessed-right answers, bookmark species or site-fit scenarios that keep tripping you up, and use timed mixed quizzes when the domain feels stable.
A practical sequence:
- Review common ID features: leaves, buds, twigs, bark, fruit, and mature form.
- Make a checklist for site constraints: soil volume, drainage, salt, shade, utilities, heat, and mature size.
- Answer 25 to 50 Identification and Selection questions.
- Sort misses by category instead of only tracking total score.
- Retest the weak category before taking a full mock exam.
Use official ISA materials for credential rules and current exam policies. Use original practice questions to measure whether you can apply tree-identification and site-selection reasoning under test conditions.
FAQ
Are these real ISA exam questions?
No. They are original practice questions written for study. They are designed around the kinds of reasoning this domain requires, but they are not real ISA exam questions and are not official ISA material.
Is Identification and Selection only tree identification?
No. Tree ID is part of the domain, but selection reasoning is just as important. Expect site constraints, mature size, tolerance, pest susceptibility, stock quality, and diversity decisions.
How should I study tree identification for the ISA exam?
Study traits in groups instead of memorizing isolated leaves. Pair leaf arrangement and type with buds, twigs, bark, fruit, form, and site context. Then practice deciding how those traits affect species selection.
What are common traps in this domain?
Common traps include choosing a favorite species, ignoring mature size, overlooking overhead wires or soil volume, accepting poor nursery stock, treating native status as the only criterion, and using one leaf clue when the question gives stronger evidence.
When should I take a full mock exam?
Use short domain drills first if you are still missing basic ID or site-fit questions. Take a full mock when you want to test pacing, stamina, and mixed-domain decision-making across the whole ISA Certified Arborist blueprint.