ISA BCMA cheat sheet

Primary growth occurs at apical meristems of root and shoot tips; secondary growth occurs at the vascular cambium, which produces xylem inward and phloem outward.

Xylem transports water and dissolved minerals upward from roots; phloem translocates photosynthate from sources (leaves) to sinks (roots, fruit, storage tissue).

CODIT walls: 1 = plugged xylem vessels; 2 = inward-facing cells; 3 = rays and axial parenchyma; 4 = the suberized barrier zone formed by the cambium after wounding.

Trees compartmentalize rather than heal; the barrier zone separates wood present at wounding from wood formed afterward.

Most fine roots occupy the top 12-18 in (30-45 cm) of soil, and root spread commonly reaches 2-3 times the canopy radius, well beyond the dripline.

Photosynthesis is 6CO2 + 6H2O + light -> C6H12O6 + 6O2 in chloroplasts; respiration consumes O2 and sugars in all living cells, day and night.

Reaction wood: tension wood forms on the upper side of leaning angiosperms (pulls); compression wood forms on the lower side of leaning gymnosperms (pushes).

Sapwood is conductive and stores starch; heartwood is nonconductive, provides structural support, and in some species resists decay through extractives.

Dichotomous key traits in order of usefulness: leaf arrangement (alternate, opposite, whorled), leaf type (simple vs. compound), margin, venation, bud and twig features, bark, fruit.

Opposite arrangement occurs in maples (Acer), ashes (Fraxinus), dogwoods (Cornus), buckeyes (Aesculus), and viburnums; most other trees are alternate.

Gymnosperms bear naked seeds usually on cones with needle or scale leaves; angiosperms bear seeds enclosed in fruit and typically have broad leaves.

Monocots such as palms and yuccas show parallel venation and scattered vascular bundles, have no vascular cambium, and form no true annual rings.

Right tree, right place: match mature height and spread to available space first, then screen for hardiness zone, soil pH, drainage, drought and salt tolerance, and pest susceptibility.

Cultivar selection should weigh pest resistance (e.g., Dutch elm disease-resistant elms) and known structural defects as well as ornamental traits.

Native vs. non-native is a site-fit question, not a rule; natives often suit local soils and wildlife, while non-natives may be selected where natives fail site extremes.

The soil texture triangle classifies soil by percent sand, silt, and clay; loam is roughly 40% sand, 40% silt, 20% clay and suits most trees.

Bulk density above about 1.6 g/cm3 generally restricts root growth; clay soils can be limiting above about 1.4 g/cm3.

Cation exchange capacity is the soil's ability to hold exchangeable Ca, Mg, K, and NH4; it increases with clay and organic matter and reduces nutrient leaching.

Most trees perform best at pH 5.5-7.0; above pH 7.5 iron and manganese become less available, and below pH 5.5 calcium, magnesium, and molybdenum may be limiting.

Compaction destroys macropores and reduces oxygen; roots require adequate soil oxygen, and saturated soils turn anaerobic within days.

Apply organic mulch 2-4 inches deep out to the dripline or beyond, kept pulled back from the trunk to avoid stem decay and rodent damage.

Amend soil over the whole planting area when possible; amending only the backfill can create a texture contrast that impedes water movement.

Fertilizer is labeled by N-P-K percentages; apply based on soil or foliar test results and avoid high nitrogen when the goal is root growth or drought hardiness.

Dig the planting hole two to three times the root ball's width and no deeper than the root ball, so the root flare sits at or slightly above finished grade.

Nursery guideline: about 10-12 inches of root ball diameter per inch of trunk caliper.

Remove wire basket, burlap, and twine from at least the top third of the ball (preferably all), and cut or straighten circling and kinked roots before backfilling.

Establishment generally takes about one year per inch of trunk diameter, up to roughly three years, with irrigation most critical in the first two seasons.

Irrigate at planting to settle soil and close air pockets, then supply about 1 inch of water per week absent rainfall, delivered as deep, infrequent soakings.

Stake only when the root ball cannot support the trunk; ties should permit some trunk movement, and stakes should be removed after one to two growing seasons.

Do not fertilize at planting; nitrogen can push top growth before roots establish and can injure new roots.

Deep planting with the root flare below grade, and mulch piled against the trunk, lead to girdling roots, stem decay, and chronic decline.

Diagnosis sequence: identify the plant, define the problem, look for patterns, examine the site and history, form a hypothesis, then test it before treating.

Abiotic disorders are typically uniform, affect one species or one exposure, and show no pest signs; biotic problems are often patchy, progressive, and show signs.

Signs are direct evidence of the agent (frass, mycelium, fruiting bodies, egg masses); symptoms are plant responses (chlorosis, necrosis, wilt, gall, dieback).

Nitrogen deficiency shows general yellowing starting on older leaves; iron deficiency shows interveinal chlorosis on new growth, common at high soil pH.

Potassium deficiency causes marginal scorch and necrosis on older leaves; magnesium deficiency causes interveinal chlorosis on older leaves.

Growth-regulator herbicide injury (2,4-D, dicamba) causes cupping, twisting, epinasty, and leaf strapping, often on the side facing the application.

Root and vascular problems mimic shoot symptoms: Phytophthora in wet soils, Verticillium with one-sided flagging and vascular discoloration, Armillaria with mycelial fans.

Check the base first: girdling roots, a buried root flare, and mulch volcanoes explain many declines before any pathogen is implicated.

IPM order of tactics: prevention and cultural controls, then mechanical/physical, then biological, then chemical only when thresholds are exceeded.

Set action thresholds before monitoring begins; treatment is justified only when the pest population or damage exceeds the threshold.

Monitoring tools include visual inspection, pheromone traps, sticky cards, and growing degree day models used to time treatments to susceptible pest stages.

The pesticide label is the legal document; follow PPE requirements, the restricted entry interval, and the pre-harvest interval.

Manage resistance by rotating modes of action (FRAC groups for fungicides, IRAC groups for insecticides) and by not treating below threshold.

Biological controls include predators, parasitoids, entomopathogenic nematodes, and Bacillus thuringiensis for caterpillars; they work best when broad-spectrum sprays are avoided.

Fertilization is not a pest cure; it helps only when a nutrient is deficient and can worsen problems such as aphid or mite outbreaks.

ANSI A300 pruning types are cleaning, thinning, raising, reduction, restoration, and vista pruning, defined by objective rather than by tool.

Make the final cut just outside the branch bark collar; flush cuts and stubs remove or expose the tree's natural defense zone.

Three-cut method for large limbs: an undercut, a top cut further out, then the final cut at the collar to prevent bark tearing.

A reduction cut is made to a lateral branch at least one-third the diameter of the removed limb; smaller laterals invite vigorous sprouting.

Remove no more than about 25% of the live crown in a single pruning cycle, and prune mature trees more conservatively.

Dormant pruning is preferred for most species; avoid pruning oaks in spring where oak wilt occurs and elms where Dutch elm disease vectors are active.

Wound dressings are not recommended; research shows no decay-prevention benefit and some products interfere with woundwood formation.

Topping and lion tailing are discouraged: topping yields weakly attached sprout clusters and decay, while lion tailing causes sunscald and epicormic growth.

The critical root zone is commonly a radius of about 1 foot per inch of trunk diameter; the tree protection zone is often set at 1.5 times that radius.

Install sturdy fencing at the protection zone boundary before demolition or grading begins, and allow no storage, parking, or material washing inside.

Even a few inches of fill over roots reduces oxygen diffusion, and lowering grade severs roots, so both require a root management plan.

Avoid cutting roots larger than about 2 inches in diameter, and never sever more than about 25% of a tree's root system in one operation.

Tunneling beneath roots is preferred over trenching; use an air spade or vacuum excavation to expose roots when digging is unavoidable.

Spread mulch 2-4 inches deep across the protected zone to reduce compaction, moderate soil temperature, and conserve moisture during construction.

ANSI A300 Part 5 addresses tree management during construction and Part 8 addresses root management; project specifications should cite them.

Risk = likelihood of failure x likelihood of impact x consequences; a defect with no viable target poses no risk.

Assessment levels: Level 1 limited visual, Level 2 basic with a 360-degree walk-around and optional sounding, Level 3 advanced with diagnostic tools.

Included bark in a co-dominant union is a high-risk defect: trapped bark prevents wood formation and the union can split suddenly.

Common failure indicators include cavities, cracks, cankers, decay, conks or fruiting bodies, lean, root plate lifting, co-dominant stems, and severed roots.

Decay detection tools include sounding with a mallet, the resistograph, and sonic tomography; results are interpreted alongside species traits and targets.

Mitigation hierarchy: eliminate or move the target, then prune, install support, or treat, and remove the tree when risk cannot be reduced acceptably.

Ratings are reported as low, moderate, or high with a reassessment interval, and findings must be documented and communicated to the tree owner.

Urban forest inventories are either complete (100% of trees) or sample-based; data are collected with GPS/GIS and managed in software for work planning.

i-Tree Eco quantifies structure, air pollution removal, carbon storage and sequestration, and stormwater effects using inventory and local weather data.

The trunk formula appraisal method calculates value as unit tree cost x trunk area x species rating x condition rating x location rating.

Urban forest benefits include air quality, stormwater attenuation, energy savings, carbon sequestration, property value, and public health effects.

Tree ordinances typically address preservation, replacement ratios, heritage tree designation, removal permits, and right-of-way planting standards.

Canopy cover targets (many communities use 40%) are measured from aerial imagery and used to direct planting programs and budgets.

Program management relies on ANSI A300 standards, ISA best management practices, a trained workforce, and a budget covering pruning cycles, removals, planting, and inventory.