Nitrogen Cycling: Building Background Understanding

By the end of this Unit your students will have put the nitrogen cycle into the context of their local watershed.

Unit Overview

Students need a general sense of the nitrogen cycle, so that they can think about how nitrogen moves in a watershed like their study site(s) and can begin to consider how changes in season can result in different patterns of nitrogen in a stream. How does the nitrogen cycle fit into our local watersheds? It is one thing to think about the nitrogen cycle in the abstract, but in this Unit we are asking the students to put the nitrogen cycle into the context of their local watershed.


This project is about developing an understanding of a system, and then testing that understanding. A research project with a hypothesis- a test of the understanding of a system- should grow out of some kind of a model of the system or mechanism under investigation. A student ought to have some idea about why the outcome predicted by the hypothesis would happen; and possibly, an explanation of why it might not. For that reason we need to build the students’ background understanding of the nitrogen cycle and forested watersheds.


Students understand the basics of the nitrogen cycle and how that cycle pertains to their local watershed.

Instructional Strategies

There are many different ways to express the movements and species of nitrogen in the nitrogen cycle. We are most interested in the ways that nitrate cycles through a forested watershed. It is important to keep students focused on nitrate as much as possible.