5. Litter: upper most layer of soil composed of partially decomposed leaves and/or grasses. Acts like a blanket, limiting temperature fluctuations and trapping moisture. Topsoil (A horizon): beneath the litter is a layer of more fully decomposed organic matter (plant and animal) with some mineral material (sand, silt, clay). This layer is dark in colour, contains much of the nutrients needed by producers and is commonly referred to as humus.

6. Subsoil (B and C horizons): these layers contains successively less and less organic material and more an more mineral material. As you approach the bedrock the smaller mineral particles may be mixed with larger cobble stones and boulders Bedrock (parent material): top of the bedrock marks the extent of soil depth. Most minerals in the soil are derived from the break down of the parent material.

7. Soil begins to form as bedrock is weathered and broken down into smaller particles. Once plants begin to grow they speed up the weathering process by further breaking down rock (roots and chemicals) As the soil deepens and gains more and more nutrients larger producers (trees) are able to grow and mature in the environment Water moves through the soil by percolation (downward flow of water) this distributes organic particles from the humus to deeper in the soil

8. When water dissolves nutrients and mineral and removes them from the reach of surface plants it is called leaching The type of soil present in a function on the parent material as well as the plant community living in it. Coniferous forests in the Canadian shield (granite) tend to be situated in acidic soils (pine needles are acidic) Deciduous forest on the Niagara Escarpment will have higher pH values (limestone) Soil pH can also be impacted by acid deposition