Nitrogen Cycling in the Terrestrial Environment Rebecca Aicher Analu Garcia UCI GK12 2008

Ecology Standard 6. Stability in an ecosystem is a balance between competing effects. As a basis for understanding this concept: b. Students know how to analyze changes in an ecosystem resulting from changes in climate, human activity, introduction of nonnative species, or changes in population size. d. Students know how water, carbon, and nitrogen cycle between abiotic resources and organic matter in the ecosystem and how oxygen cycles through photosynthesis and respiration. e. Students know a vital part of an ecosystem is the stability of its producers and decomposers.

How do nutrients move within terrestrial ecosystems? Producers Consumers Decomposers Created by Rebecca Aicher UCI GK12 2008 How do nutrients move within terrestrial ecosystems?

Nitrogen in the Terrestrial System Created by Rebecca Aicher UCI GK12 2008

Let’s get mov’N:Learning how nitrogen moves through the environment Each of you is a molecule of nitrogen cycling through the terrestrial ecosystem. There are 8 possible places for nitrogen in the terrestrial ecosystem. Each of you will start at the station closest to your table. You will work alone today, so be sure to keep track of how you move through the ecosystem. Let’s get to our stations!

Let’s get mov’N 1. Make your hypothesis about where you will spend the most time and why. 2. Role the die and find out where you will go next…will you move from the atmosphere into nitrogen fixing bacteria? When in a plant will a deer eat you? Let’s see! 3. Fill-in the questions for each step of your movement through the terrestrial ecosystem. BE SURE to predict where you will go next!

Post-lab Discussion Did you make it to all the different places nitrogen is found in the ecosystem? Explain why you might not visit all the stations? Where did you spend the most time? Why was your hypothesis supported or refuted?

How do you predict humans might change nitrogen cycling? Created by Rebecca Aicher UCI GK12 2008

Human Impacts on Nitrogen in the Terrestrial System Created by Rebecca Aicher UCI GK12 2008 Discussion Questions: Why does it matter if humans are changing the nitrogen cycle? What type of impacts does this have on natural ecosystems? What type of impacts does this have on humans? What can we do to slow the impacts of enriching our environment with nitrogen?