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?