ISA Arborist Chapter 3 questions with correct answers

Actinomycete CORRECT ANSWER Group of soil bacteria resembling fungi. Actinomycetes play a role in the decomposition of organic matter and the release of mineral elements. Aggregate CORRECT ANSWER Close cluster or mix of small particles of soil and or organic matter of varying sizes that bond together; sand, gravel, small rocks. Anion CORRECT ANSWER Ion that carries a negative charge. Contrast with cation. Buffering capacity CORRECT ANSWER Ability of a soil to maintain (I.e. To resist change) in its ph. Bulk density CORRECT ANSWER Mass of soil per unit volume. Often used as a measure of compaction. Capillary water CORRECT ANSWER Water held in the capillary pores of the soil; much of this water can move in any direction and is readily available to plant roots. Cation CORRECT ANSWER Positively charged ion. In soils, the most abundant cations are calcium (Ca), magnesium (Ma), potassium (K), sodium(Na), and aluminum(AI). Contrast with anion. Cation exchange capacity(CEC) CORRECT ANSWER Ability of a soil to absorb and hold cations. Affected by soil ph. Measures soil fertility, clay composition, and engineering characteristics.