Nitrogen Curriculum

This curriculum supports a scientist-teacher-student partnership investigating seasonal and landscape influences on nitrogen cycling.

The overall goals of this curriculum are to support:

• Teaching of science as a process that involves inquiry and reasoning
• Integration of data literacy into the teaching of science
• Understanding of place- and time-specific drivers of natural cycles and systems
• Understanding of the nitrogen cycle and nitrogen as an essential, but often growth-limiting resource, which exemplifies complex, system thinking
• Application of scientific essentials, such as the conservation of matter, to real world research

Target audience:

Upper level high school teachers and their students- chemistry, ecology, environmental science, AP courses.

Total instructional time:

Based on our Mercury in Watersheds curriculum teachers can expect to spend between 15 and 30 instructional periods on this project. This span takes into account the course, teacher and student motivation, and other curriculum demands. (Note: Some teachers have conducted the Mercury in Watersheds project in as little as two weeks (10 instructional periods- this is not recommended.)

Curriculum Layout:

Although research is an iterative process, the school year is not and therefore this curriculum is linear.  The curriculum follows a sequence from question development through sharing research results, including the following Units:

• Developing  background understanding
• Refining and enriching background understanding
• Asking questions, proposing hypotheses
• Field sampling for hypothesis support
• Data analysis
• Sharing research

Climate in the northeastern US is changing. For example, New England has had the greatest increase in extreme precipitation events (61%) in the US since 1948 (Madsen & Figdor, 2007). Snowpack depth declined or snow density increased in 18 of 23 sites sampled in or near Maine from 1926-2004 (Hodgkins & Dudley, 2006). A significantly lower proportion of annual precipitation fell as snow at 11 of 21 sites across New England from 1949-2000 (Huntington et al. 2004). Recent studies suggest that nitrogen (N) cycling will be dramatically altered, directly and indirectly, under most climate change scenarios and by extreme events, particularly those that affect winter snowcover, frost, or summer soil moisture (Groffman et al. 2009; Campbell et al. 2009).

One potential effect of changing snowpack and snowmelt is a change in the timing or amount of nitrogen that flushes out of stream watersheds when snowpack melts in spring. If snowmelt is earlier, smaller, or absent, what would this mean for nitrogen budgets in watersheds? How would vegetation potentially be affected? Would this shift in nutrient delivery amount and/or timing affect biota, vegetation, or other watershed processes? Our overarching research question is: How does changing snowpack and snowmelt change the timing or amount of nitrogen that flushes out of stream watersheds when snowpack melts in spring?

Overview

In order for the students to develop a model (mental or otherwise) to frame their questions and develop hypotheses about nitrogen, they need a background understanding about-

• The nitrogen cycle
• Seasonal and landscape influences on the nitrogen cycle

Classroom Activities

An Introduction to the Nitrogen Cycle (essential)

This activity introduces the nitrogen cycle in the context in which we will be conducting our research: forested landscapes influenced by four distinct seasons. The video associated with this activity also addresses why we should care about nitrogen and perturbations to the nitrogen cycle.

Expanding the scope: a larger picture of the nitrogen cycle (optional)

Students use text and visual resources to gain a basic understanding of the whole nitrogen cycle, and then use that understanding to add to the diagram of the nitrogen cycle created in Activity 1.

Nitrogen- too much of a good thing (optional):

Students interpret graphical data that have come from a long-term study of nitrogen additions to a forested ecosystem.

Overview

Classroom Activities

A watershed for all seasons (optional)

This is a reading and discussion activity. Students discuss the effects of watershed and season on the nitrogen cycle.

Linking hydrology to nitrogen in streams (essential)

Students work with time series data to understand the seasonal changes in water flow through the watershed. This activity helps to plan the schedule for field sampling at your site.

Overview

This unit takes students from examining their models through sharing and peer reviewing  scientific claims. First, students must reflect on their view of the system in which they are working. The students then pose questions about the system and assert a claim about the way they think the system works.  Optionally, the students share claims with, and peer-review claims from, students from different schools.

Classroom Activities

Research Questions and Hypotheses (essential)

A brainstorming activity to explore student understandings of the system that they are studying.

Peer Review (optional)

In-class structured constructive criticism.

Scientific Claim Proposal Video (optional)

Students present their claims to students in other schools via video.

Scientific Video Claims Review (optional)

Students then review each other’s videos and provide feedback.

Overview

Tied tightly with the previous Unit the students must develop a general approach for a research project that will help them support their claim.

Classroom Activities

Experimental Design (essential)

The guiding question for this activity is: How will you go about collecting evidence to support or refute your hypothesis?

Preparing for Sampling (essential)

This activity prepares the class for the field sampling. Or, as one teacher put it: Prior preparation prevents poor performance. (The British Army puts it more colorfully)

Environmental Sampling (essential)

Takes the class out to their field site collect information about the watershed, weather and collect water samples for nitrogen analysis.

Sample Submission (essential)

Guidance for successful classroom-lab interaction and sample submission.

Overview

It is a toss-up whether hypothesis development or data analysis is the more challenging aspect of the research process. Regardless, the material in this Unit is extremely challenging.  This Unit begins with data literacy skill building then proceeds to data organization before concluding with data presentation and determining support or non-support for the students’ claim.

Classroom Activities

Data Warm-ups (essential)

Skill building exercises for working with environmental data.

Data organization (essential)

In order to make sense of the data and get any meaning from it, it will be necessary (and most efficient) to have the data all together and organized. The goal of this activity is to get all of the data together in one spreadsheet or table.

Presenting the data (essential)

This activity will produce the information students need to determine whether their hypothesis was supported or not. Students will calculate basic descriptive statistics and then will analyze the data using three basic principles: whether two things are related (correlation), whether groups of things are different, and whether things are changing through time. Which technique is used depends in part on the data and the research question. The primary goal is for students to produce meaningful graphs depicting results, and to interpret the results to judge whether the hypothesis was supported or not.

Data Interpretation (essential)

The outcomes of this activity can be simple: a statement addressing whether or not the hypothesis was supported, and a few statements or bullet points discussing why or why not.

Overview

In this unit, students will learn how to produce meaningful posters and make oral presentations to communicate the results of their research project. The poster presentation is a capstone event and is essential to the project.

Classroom Activities

Outlining the Project (essential)

In this activity students get together all of the information they need to begin authoring a poster – notes, reports from other activities, data, graphs, etc. Then students think through the ‘storyline’ of their project and outline the elements that will be on the poster.

Authoring a Poster (essential)

The goal of this activity is for students to get all of the pieces together and put together their posters.

Presenting a Poster (essential)

The goal of making an oral presentation is to quickly summarize the research and allow others to ask questions of the student research team. Students should be thinking about their ‘take home message’ – the most important finding of their work – and be sure it’s clear to the audience.

Peer Review (this activity is discussed in Presenting a Poster)

At the poster session students ‘interview’ and provide written feedback on other students’ posters and oral presentations.

This curriculum will only become better with constant input and feedback from scientists, teachers and students working together, reflecting on the project and its parts and reporting their thoughts and comments.

Campbell, J.L., L.E. Rustad, E.W. Boyer, S.F. Christopher, C.T. Driscoll, I.J. Fernandez, P.M. Groffman, D. Houle, J. Kiekbusch, A.H. Magill, M.J. Mitchell, and S.V. Ollinger. 2009. Consequences of climate change for biogeochemical cycling in forests of northeastern North America. Canadian Journal of Forest Research 39:264-284.

Groffman, P.M., J.P. Hardy, M.C. Fisk, T. Fahey, and C.T. Driscoll. 2009. Climate variation and soil carbon and nitrogen cycling processes in a northern hardwood forest. Ecosystems 12(6):927- 943.

Hodgkins, G. A., and Dudley, R. W., 2006, Changes in late-winter snowpack depth, water equivalent, and density in Maine, 1926-2004: Hydrological Processes, v. 20, p. 741-751.

Huntington, T. G., G. A. Hodgkins, B. D. Keim, R.W. Dudley, 2004c. Changes in the proportion of precipitation occurring as snow in New England (1949 to 2000), Journal of Climate, 17:2626-2636.

Madsen, T., and E. Figdor. 2007. When it rains, it pours: global warming and the rising frequency of extreme precipitation in the United States. Environment Maine Research and Policy Center 57 p.