ISA- Arborist Review Exam Study Guide with Complete Solutions 100% Verified 2024

ISA- Arborist Review Exam Study Guide with Complete Solutions 100% Verified 2024 abiotic - Correct Answer pertaining to the nonliving parts of an ecosystem, such as soil particles, bedrock, air, water. abscisic acid (ABA) - Correct Answer a plant hormone that stimulates stomatal closure and promotes seed and bud dormancy. abscission zone - Correct Answer a wall of cells at the base of a petiole, that allows the leaf to separate from the stem. - two functions: leaf drop and to protect the region of the stem against desiccation acceptable risk - Correct Answer the amount of risk that an owner is willing to accept before tree failure. acidic soil - Correct Answer having a pH less than 7.0, in contrast with alkaline which has a pH that is higher than 7.0. actinomycetes - Correct Answer microorganisms that have some characteristics of fungi and bacteria. Soil actinomycetes are very tolerant of water stress and contribute through their actions to that "good earth" aroma after a rain. action threshold - Correct Answer the point at which a pest requires the implementation of a management tactic or control. acute crotches - Correct Answer stronger and wider than a co-dominant crotch, they are not likely to be a branch that will fail in high winds and are considered desirable. adaptive growth - Correct Answer an increase in wood production in localized areas on a tree, in response to a decrease in wood strength or external loading to maintain an even distribution of forces across the structure. adsorption - Correct Answer adhesion on contact of molecules to the surface of solids or liquids with which they are in contact.