Certified Arborist Practice Test

Soil compaction refers to the process whereby soil particles are pressed together, which leads to a reduction in the volume of soil pore space. When soil is compacted, the air pockets or voids between soil particles decrease, thereby reducing the overall porosity of the soil. This can lead to negative effects such as decreased water infiltration and reduced root growth, as the density of soil makes it more difficult for roots to penetrate and for water to move through.

The assertion that soil compaction increases pore space is inherently contradictory to the principles of soil mechanics and agronomy. Therefore, the correct answer accurately reflects the effect of soil compaction on pore space.