Nutrients and microbes to nourish plants are basically present in topsoil
Gold is less valuable than Topsoil. Yet Gold is now valued more than Topsoil, and Forests. I'd rather ask "How does selective logging protect Forests?"
topsoil supports structures built on top of it
crop rotation : )
crop rotation : )
decayed organic matter
decayed organic matter
decayed organic matter
Topsoil contains all the most recently decomposed bio-matter . It is therefore the most nutrient rich layer, best for growing plants and such.
It is important because the soil:It is fertileIt has vitamins and nutrients
If we don't plant some trees on this slope, the topsoil will wash away with the first rains.
Topsoil is important because it is easy for plant roots to find their way through. It also has better drainage than the hard clay underneath.
I have heard that the best topsoil is any composted material that consists of important nutrients or potting soil mixes. Here is a link to a video all about topsoil. http://www.ehow.com/video_4754112_best-types-topsoil.html