Trees have a significant beneficial effect on soil conservation.
Tree roots hold soil in place reducing erosion. 10,886 tons of soil is saved annually with tree cover in a medium-sized city.
- Roots reduce soil compaction, increasing the rate at which rainfall infiltrates soil and the capacity of soil to store water, reducing overland flow.
- Decaying leaves form an organic layer on the ground that allows water to percolate into the soil, which also reduces runoff and soil erosion. The leaves also act as mulch, reducing evaporation in times of low rainfall.
- Trees reduce soil erosion by diminishing the impact of raindrops on barren surfaces.
- Trees and other plants help remediate soils at landfills and other contaminated sites by absorbing, transforming, and containing a number of contaminant.