Competition, they try to grow taller than other trees to get more sunlight
Deforestation speeds up the process of soil erosion because trees are vital in keeping soil intact. The roots of trees help prevent soil erosion because they absorb the water in soil. If there are no trees to absorb the water, flooding can happen more. In turn, flooding can cause the soil to weaken and this can cause landslides and other natural disasters.
You forgot to include the following choices but no worries I did this question before and the answers are:
advances in technology
increases understanding on environment
etc
Soil scientists use the capital letters O, A, B, C, and E to identify the master soil horizons<span>, and lowercase letters for distinctions of these horizons. Most soils have three major horizons: the surface horizon (A), the subsoil (B), and the substratum (C). Some soils have an organic horizon (O) on the surface, but such a horizon can also be buried. The master horizon, E, is used for subsurface horizons that have a significant loss of minerals (eluviation). Hard bedrock, which is not soil, uses the letter R.</span>
I have the answer to dead zone hoped it helped you in some way!☺❤
