Nitrogen Pollution Review

Pollution, Acid Rain, Sustainability, and the Global Nitrogen Cycle

Take home message:

“Element cycles interact and control many environmental problems — they can’t be studied in isolation. “

Main Terms:

N-fixation, denitrification, mineralization (= decomposition)

Acid Rain (acidity)

Base saturation

Buffering capacity

Dead zones

1. Concepts — Nitrogen Cycle:

  • What are the different forms of nitrogen?  Do these forms make the nitrogen cycle more or less complicated than the carbon cycle?
  • Accounting of nitrogen on Earth  —  what are the major reservoirs for nitrogen? 
  • What are the pathways and reactions that transfer nitrogen (generally)?
  • What is the residence time of nitrogen in the atmosphere?  Which is more reactive, N2  vs. NOX?
  • Understand how element “reactivity” is related to residence time and the size of reservoir.

2. Concepts — Acid Rain:

  • What are the controls on nitrogen that are related directly to acid rain?
  • How does acid rain affect nutrient cycling and rock weathering?
  • What effect does acid rain have on trees and other plants, and on fish and other aquatic organisms?
  • How is buffering capacity of the soils related to the effects of acid rain?
  • How are the sulfur and nitrogen cycles related when it comes to forming acid rain?

3. Concepts — Dead Zones:

  • What are the two most important nutrients that control plant (algae) growth in lakes and oceans?
  • How are algal blooms related to the creation of dead zones? 
  • Why is a dead zone called “dead” – can no organisms live there?
  • How does the stratification of water layers in lakes and oceans help create dead zones?
  • What solutions are available to help reduce dead zones?