ISA BCMA flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Vascular cambium

Lateral meristem that produces secondary xylem inward and phloem outward, responsible for diameter growth and the formation of annual rings in woody plants.

CODIT barrier zone

The fourth wall of compartmentalization; suberized tissue formed by the cambium after wounding that separates wood present at wounding from wood formed later.

Tension wood

Reaction wood formed on the upper side of leaning angiosperm stems; it contracts to pull the stem upward and often develops after heavy or improper pruning.

Fine root distribution

Most fine roots occur in the upper 30 cm (12 inches) of soil and extend well beyond the dripline, commonly two to three times the canopy radius.

Opposite leaf arrangement

Two leaves or buds attach at the same node on opposite sides of the twig; found in maples, ashes, dogwoods, and buckeyes, a key dividing trait in keys.

Right tree, right place

Selection principle matching a species' mature size, form, and site tolerances to available space, utilities, soil, and climate before purchase and planting.

Monocot stem anatomy

Vascular bundles scattered through the stem with no vascular cambium, so palms and other monocots lack true annual rings and do not grow wider each year.

Cation exchange capacity

The soil's capacity to hold exchangeable cations such as calcium, magnesium, and potassium on clay and organic matter surfaces, which reduces nutrient leaching.

Soil bulk density

Dry mass of soil per unit volume; values above roughly 1.6 g/cm3 generally restrict root growth and indicate compaction in urban soils.

Soil texture triangle

A chart that classifies soil by percentages of sand, silt, and clay; loam is approximately 40 percent sand, 40 percent silt, and 20 percent clay.

Mulch volcano

Piling mulch against the trunk, which traps moisture on bark, invites decay and rodent damage, and encourages adventitious roots; mulch should be 2 to 4 inches deep and pulled back.

Planting hole width

The hole should be two to three times the root ball's width but no deeper than the root ball, keeping the root flare at or above grade.

Root ball diameter rule

Nursery guideline of about 10 to 12 inches of root ball diameter for each inch of trunk caliper, ensuring enough roots to support the tree after digging.

Circling roots

Roots that spiral around the inside of a container; they must be cut, teased apart, or straightened at planting to prevent later girdling and decline.

Signs versus symptoms

Signs are direct evidence of the pest or pathogen, such as frass, mycelium, or fruiting bodies; symptoms are the plant's response, such as chlorosis or wilt.

Abiotic disorder pattern

Damage that is uniform, limited to one species or one exposure side, and lacks pest signs usually indicates an abiotic cause such as drought, salt, or herbicide.

Iron chlorosis

Interveinal yellowing of new leaves with veins remaining green, typical of high-pH soils where iron is unavailable; treated with chelated iron or soil acidification.

Herbicide injury symptoms

Growth-regulator herbicides cause cupping, twisting, epinasty, and strapping of leaves, often appearing on the side of the tree facing the application.

IPM pyramid

Integrated pest management orders tactics from prevention and cultural controls through mechanical and biological control, using pesticides only when thresholds are exceeded.

Action threshold

The pest population or damage level at which treatment is justified, set in advance using economic, aesthetic, or tree health criteria.

Restricted entry interval

The label-specified period after a pesticide application during which workers may not enter the treated area without the required protective equipment.

Branch bark collar

The swollen area where a branch joins the trunk; the final cut is made just outside it to preserve the tree's natural defense zone.

Three-cut method

A sequence of undercut, top cut, and final cut at the collar used to remove large limbs without tearing bark down the trunk.

Reduction cut

A cut made to a lateral branch at least one-third the diameter of the removed limb, which limits vigorous sprouting and preserves taper.

Critical root zone

The area within a radius of about one foot per inch of trunk diameter, containing most of the roots that support and stabilize the tree.

Tree protection fence

A physical barrier installed at the protection zone boundary before construction begins; no storage, grading, or traffic is allowed inside it.

Grade change root damage

Adding even a few inches of fill reduces oxygen to roots and lowering grade severs them, so both require a documented root management plan.

Tree risk formula

Risk equals likelihood of failure multiplied by likelihood of impact multiplied by consequences of failure, used to rank trees for mitigation.

Included bark defect

Bark trapped inside a co-dominant union prevents wood formation and creates a weak attachment prone to sudden splitting; prune early or install support.

Risk assessment levels

Level 1 is limited visual, Level 2 is a basic 360-degree walk-around possibly with sounding, and Level 3 is advanced with diagnostic tools.

i-Tree Eco

A free modeling tool that uses inventory and local weather data to quantify urban forest structure, air pollution removal, carbon, and stormwater benefits.

Trunk formula method

A tree appraisal approach multiplying unit tree cost, trunk area, and species, condition, and location ratings to estimate replacement value.