Part 4: Planting design
6. Plant functions
Erosion and water control
Plants prevent soil erosion from both wind and water, and they also prevent the soil from drying out too quickly. Without plant cover, erosion levels are high; bare soil is susceptible to being swept into rivers and carried away from the land into the sea. Plant roots bind soil particles together which reduces erosion.
List three plants which would be suitable to plant on a steep bank to reduce erosion of the soil.
Noise and odour
A thickly planted barrier between the site and the source of noise or odour will reduce the effects. If the site is subject to air pollution, there are some species of plant that are more tolerant than others, especially if the soil has been well prepared before planting. Evergreen trees and shrubs will provide effective year-round screening. A wide and densely planted area between the site and either an industrial facility or a busy main road, will lessen any noise, pollution and smell from passing traffic, or an industrial activity.
List 3 evergreen hedging plants which would create a dense hedge to reduce noise and odour from a road.