SOILS AND NATURAL VEGETATION Chapter 13

The Soil Base - MOMA  Mineral  Come from rocks  Become part of the soil when the rock is broken down by weathering  Calcium, potassium, phosphorous  Organic Materials  Humus: dead plant and animal matter  Moisture  Water that is taken up by plant roots  Air  high humus layer helps produce air  Air space created by worms, insects and small animals

The Layers The ”O“ horizon is a thin layer of humus (dead leaves and other organic matter). The ”A“ horizon is topsoil, dark and rich in humus. The ”B“ horizon is subsoil, poorer in humus, but rich in minerals from the topsoil. The ”C“ horizon is infertile, weathered rock fragments. The ”D“ horizon is infertile, solid bedrock.

Vegetation  Vegetation is a general term for the plant life of a region (which very much depends on soil quality)  In Canada, we have everything from desert cactus to massive rainforest trees, and everything in between  Mosses  Plants  Shrubs  Coniferous trees  Deciduous trees

Vegetation Regions – Fig. 13-5

Tundra  Types of Natural Vegetation  Shrubs, mosses, lichens, small flowers  Temperature Characteristics  Cold, short growing seasons  Precipitation Characteristics  Very little precipitation. Less than 40mms  Soil Characteristics  Thin soils and permafrost (ground that doesn’t completely thaw in the summer)

Boreal and Taiga Region  Types of Natural Vegetation  Coniferous trees: black spruce, balsam fir, pine  Temperature Characteristics  Cold, short growing seasons  Precipitation Characteristics  Rain and snow  Soil Characteristics  Lack of humus, high acidity, leaching effect (continuous downward movement of water)  Unsuitable for agriculture

Mixed Forests  Types of Natural Vegetation  Coniferous and deciduous trees, and small shrubs  Temperature Characteristics  Cold winds and harsh climate. Warm summers.  Precipitation Characteristics  Regular and abundant  Soil Characteristics  Humus holds water and fewer soluble minerals are removed from the soil.  Suitable for farming

Deciduous Forest  Types of Natural Vegetation  Deciduous trees,  Temperature Characteristics  Long, hot summers, with mild winters  Precipitation Characteristics  Lots of rain  Soil Characteristics  More humus and less acidity.  Dark brown in colour  Most fertile of Eastern Canada

Grasslands  Types of Natural Vegetation  Grass, sagebrush, cactus  Temperature Characteristics  Very dry  Precipitation Characteristics  Little rain  Soil Characteristics  Calcified soils that are unsuitable for crops

Cordilleran Vegetation  Types of Natural Vegetation  Grasses, shrubs, coniferous and deciduous trees  Temperature Characteristics  warm  Precipitation Characteristics  Heavier rain on the west side of the mountains  Soil Characteristics  Vary depending on elevation

West Coast Forests  Types of Natural Vegetation  Lush forests of Douglas firs, sitka spruce, red cedars, and hemlocks  Temperature Characteristics  Mild climate  Precipitation Characteristics  Heavy rainfall  Soil Characteristics  Excellent growing conditions  Lots of humus but also strong leeching effect which causes minerals to be deep in the soil