One of our newest staffers, Diana is helping out with some restoration work. She wrote this blog about erosion and trees. Thanks Diana!
Erosion on a slope like the Niagara Escarpment occurs when rainfall causes the nutrient filled topsoil to be carried off downslope. Trees stand in the way of the rain hitting the ground at full force and carrying the soil away. In particular, conifers intercept more moisture because they keep their needles all year round.
Oversaturated soil can trigger landslides. Trees can absorb large portions of that water through their roots and are used for the basic functions of the tree such as photosynthesis and nutrient transport. Any excess water is released back into the atmosphere through transpiration from the leaves.
Stabilization is maximized when there is a multi-level canopy that has trees, shrubs and groundcover because the combination provides deep and shallow spreading roots. While groundcover and shallow rooted plants are good for prevention of surface erosion, large deep rooted trees are essential to the stability of slopes. The more trees planted and growing along the slope form a lock of interwoven roots that hold the soil in place and prevent it from dislodging.
Overall Health of the Soil
Deeper roots can penetrate the lower more compacted layers of soil. As the roots help to decompact the soil, there is a greater opportunity for other plants and soil fauna (ants, worms etc.) to move in. They help create a healthier soil which in turn encourages more species to move in!