1. Soil
(Chapter 14)

2. True soil consists of four main parts:
Minerals, Bacteria & Organic Materials, Air, and Moisture
1. Minerals
come from parent material (usually rock)
Minerals become part of the soil when the rock is broken down into smaller pieces by weathering
Many minerals (ex. calcium) are nutrients that plants need for growth

3. 2. Bacteria and Organic Materials:
as bacteria break down dead plants and animals (organic material), nutrients are released into the soil forming humus
Humus provides nutrients and moisture for plants and gives the soil its dark colour
3. Air:
plants need air around their roots
Humus helps produce air in the soil due to it’s air pockets
Worms, insects and small animals that tunnel through the soil also create air pockets

4. 4. Moisture:
Water dissolves nutrients into the soil
Water is needed in chemical and physical processes that weather rock and decay organic materials

5. Soil Formation: (See page 161 for diagram)
Topsoil is formed by humus
Leaching = water moves downward through soil (in areas of high precipitation); dissolves nutrients and carries them away from plant roots
Calcification = water moves upward through soil (in drier areas); water evaporates from topsoil leaving behind minerals and water from below is drawn up to replace it = in a thick topsoil rich in minerals

6. Use symbols to chart the Natural Vegetation Regions of Canada on your map
(see page 163)