Learning Objectives Describe how human activities affect soil and land. Describe how human activities affect water resources. Describe how human activities affect air resources.
Soil Resources
Healthy soil supports both agriculture and forestry.
The mineral- andnutrient-rich portion of soil is called .topsoil
Soil Erosion
Erosion is the removal of soil by water or wind.
The process of turning farmland into desert is called
________________.desertification
Deforestation
Healthy forests:•protect fresh water•absorb carbon dioxide•moderate climate
, or loss of forests, can have negative effects on soil quality.
Deforestation
Soil Use and Sustainability
Best practices in agriculture and forestry:
•leaving stems and roots
•crop rotation
•contour plowing
•terracing
•selective harvesting
Freshwater Resources
Fresh water is considered a renewable resource, but supplies are limited.
The Ogallala aquifer is expected to run dry within decades.
Water Pollution
• Industrial and agricultural
chemicals
• Residential sewage
• Nonpoint sources
Water
Producers
1
1,000
10,000
100,000
1,000,000
10,000,000
Zooplankton
Small fish
Large fish
Fish-eating birds
Water Pollution
Water
Producers
1
1,000
10,000
100,000
1,000,000
10,000,000
Zooplankton
Small fish
Large fish
Fish-eating birds
In a food chain, the concentration of a pollutant as the number of organisms at a trophic level .
increases
decreases
Air Pollution: Acid Rain
Formed by the chemical transformation of nitrogen and sulfur
Statues and buildings Plant life
Air Quality and Sustainability
Automobile emission standards and clean-air regulations have improved air quality in some regions.