Chapter 3 Section 4

Soils and Vegetation

Section 4 Preview

Soils and Vegetation Soil and climate help to determine the

vegetation of a region. Human land use alters the vegetation in

both positive and negative ways.

I. Soil RegionsA. Shaping Human Existence

1. Soil is a thin layer of weathered rock, humus, air, water.

2. Topsoil refers to the top 6” of soil.

3. Soil characteristics vary with climate.

4. Type of soil determines type of vegetation that can be supported.

5. Type of vegetation determines type of possible human activity.

Skillbuilder: Interpreting Charts1. Place: What characteristics would soil in a cold, dry climate

most likely have?2. Region: How does the soil on warm and wet climates differ from

the soil in cold and dry climates in terms of depth and texture?

II. Vegetation RegionsA. Natural Environments.

1. Ecosystem—interdependent community of plants and animals.

2. Biome—the ecosystem of a region.

3. Biomes are further divided into:a. Forest

b. grassland

c. Desert

d. tundra

B. Forestlands1. Forest regions categorized by trees they support—

broadleaf or needle.

2. Deciduous—broadleaf trees: maple, oak, birch, cottonwood.

a. mostly in Northern Hemisphere.

3. Rain forest—tropical forest covered with broadleaf trees.

4. Coniferous—needle leaf trees; cone bearing: pine, fir, cedar.

a. mostly in Northern Hemisphere.

5. Deciduous and coniferous trees together form mixed forest.

C. Grasslands1. Flat regions with few trees.

2. A savanna is a tropical grassland.

3. Steppe, or prairie, are temperate grasslands of Northern Hemisphere.

D. Desert and Tundra1. Plants in these regions have adapted to climate

extremes:a. tundra plants (mosses, lichen) hug the ground.

b. desert plants (cacti, sagebrush) conserve water, withstand heat.

III. Human Impact on the EnvironmentA. Altering the Landscape

1. Humans either adapt to land, or alter it to meet their needs.

2. Some human activities that affect the environment:

a. building dams

b. installing irrigation systems

c. planting crops

d. slashing and burning vegetation

Lake Powello 186 miles longo 1900 miles of shorelineo 500 feet deep