My new favorite concept mapping activity: depicting whole-system ecological flows

Concept mapping is increasingly becoming an important part of my overall approach to teaching. I started out using it in my own research, and quickly realized how valuable it can be as a teaching tool. Because the only real goal of making a concept map is to explore and express understanding of a topic, concept mapping can be used to challenge students to confront what they do and do not understand in a great variety of contexts. I have used concept maps to compel students to lay out complete plans before writing their research papers, and I have found that concept mapping before getting into the “making” phase of a creative project can be invaluable. I am pretty sure that concept mapping has the potential to increase student understanding of almost any topic, but some are particularly amenable to this approach. After a couple of semesters of using concept mapping to get students thinking about ecological flows, the activity I describe below has become one of my favorite ways to use concept mapping in the classroom.

I think that ecosystem ecology is a fascinating and very important topic, but it can be a bit difficult to teach. In large part this is because by the time to you get to the scale of the ecosystem, our understanding of ecology gets pretty abstract. Animals eating plants, members of the same species competing for prey, and frugivores dispersing seeds are all phenomena that happen at a scale that we can understand. But at the extent of different ecological communities interacting, our intuition fails us. I like to joke with my students that ecosystem ecologists do not even care about organisms: their passion is for flowing elements like nitrogen and carbon. Like a lot of jokes, this depiction is half true. In reality the interactions between organisms are what mediate the flow of nutrients, so to fully understand ecosystem ecology, one has to be be able to make the abstract jump between actual interactions and the overall flow and/or cycling of nutrients that these interactions create.

You can find diagrams that try to make this abstraction comprehensible all over the web. Here’s one that I use when I teach about the nitrogen cycle:

The problem with this image is that it really only follows nitrogen, selectively depicting interactions that mediate the cycling of this particular (important!) element. That is fine if your focus is on how nitrogen moves, but what if you want to understand the general nature of ecological flows? As I take a look at that rodent in the image, I am not just thinking about its role in the flow of nitrogen: it also plays a role in the flow of carbon, water, energy, and a whole host of other important elements and compounds. “Ecological cycling” is the sum of all these flows, and I want my students to have at least a coarse understanding of how these different flows are inter-related to each other and to the actual ecological interactions going on at the population and community levels.

So, after doing some readings on ecological cycling and briefly introducing how carbon, nitrogen, and water cycle and how energy flows in ecosystems, I ask my students to create a concept map that simultaneously depicts all of these processes.

The general learning objectives of this activity are to:

1. Consider how cycles of matter (carbon, nitrogen, and water) and flows of energy are inter-related in ecosystems;
2. Do appropriate web research to better understand how these cycles/flows are inter-related.
3. Construct a concept map designed to teach others that explicitly shows how these cycles/flows are inter-related; and
4. Present your concept map to the rest of the class so that we can:
   • discuss how these ecological flows are inter-related; and
   • compare and contrast different ways of representing information on a concept map.

Students are given specific instructions that their concept maps should:

• Represent the major components of the earth (such as the biosphere, lithosphere, hydrosphere, atmosphere) that relate to ecological cycling.
• Show how matter and energy flows through each of these cycles (in other words, there should be at least four identifiable “flows” in your diagram).
• Show how ecological interactions (e.g. predation, parasitism, mutualism, competition, or commensalism) and other ecological activities (e.g. photosynthesis, respiration, excretion/elimination, decomposition) are involved in these cycles.
• Clearly demonstrate where and how these cycles are inter-related.
• Where appropriate, indicate the source of information represented on the map.

Full instructions for the activity can be downloaded here.

The activity is completed in a computer lab with nice large monitors so that student groups of three can use one computer to construct their map while adjacent computers are called into service for web research. This presents a conundrum for students, because while there are hundreds of images for each of these individual cycles from which to draw inspiration, they will not find many quality images that provide a model for their own map. A big part of their challenge is to think about how to best depict the concepts captured in particular cycle diagrams in a more holistic diagram meant to depict all cycles. In doing so they need to make design choices that have to align with an accurate understanding of how these cycles work. Common design mistakes often reflect a lack of understanding of ecological cycling.  For example:

• The choice to depict carbon, water, nitrogen, and energy as separate concepts quickly leads to a confusingly intricate map, because all of these need to be depicted as flowing from one reservoir to another. The most clear maps use connectors color-coded to represent carbon, water, nitrogen, and energy.
• The choice to make the biosphere, hydrosphere, lithosphere, and atmosphere as concepts leads to a map that fails to depict how inter-related these spheres are. The best maps use some kind of color- or shape-coding to indicate which components of the map are part of each sphere, which allows for more meaningful and complete interaction between components of each sphere.

What I love about this assignment is that it forces students to engage that intersection between understanding, design, and communication. A lot of students start out taking a very literal approach to the assignment, using my requirements to just populate a map filled with the required concepts. But they soon realize that this does not work, that instead they need to think about how to best use design to depict a more synthetic understanding of ecological cycling that then meets my requirements. This process of trial-and-error and modification of their approach to the task is critical to their learning.

During the sixty to ninety minutes that I give students to do this assignment, I mostly lay back and let them work. Often this is not the first time they have used concept mapping software in my class, but if they need a quick introduction to the software I will spend five minutes showing them what it can do. After they have had some time to get something together, I will circulate a bit to give feedback and point out areas that are not clear. Some groups really get bogged down and need to be pushed to translate their research into some sort of initial design, but most groups will get enough done in the first half of the activity that I can provide some minor feedback midway that allows them to refine their maps.

At the end of the class session, students post their maps to a learning management system so that all other students in the class can see their work. I allow students to give each other feedback as an extra credit assignment, and then I provide comments on the strengths and weaknesses of each map from both a scientific and design perspective (I have done this activity for long enough to have built up a stock set of responses, so contact me if you want those). Because both the maps of other students and my comments in response to those maps are made available to all students in the class, there is the opportunity for students to learn not just from the strengths and weaknesses of their own maps, but also from others. I spend a good portion — sometimes up to an hour — of the following class session reviewing all the maps, prompting students to explain the strengths and weaknesses in each map.

Below is a small gallery of student maps; you can download the maps as PDF’s by clicking on the images (that will probably be necessary, as most of these are pretty complex and intricate):

As you can see, none of these perfectly represents the inter-relationship between ecological cycles. In my eyes, that is not a sign that this activity was a failure; instead, it is a learning opportunity. Because it is very difficult (but not impossible) to represent all these ecological flows clearly on one map — especially in the time I allot for this activity — students end up producing maps that are strong in some areas and weak in others. This gives us the opportunity to use a critique of these maps to better understand how these ecological flows are inter-related and how to best represent this inter-relationship in a concept map.

Although I am not a graphic designer, I have spent a lot of time thinking about what constitutes effective information design, so I feel comfortable leading the class in looking at the strengths and weaknesses of visual representation on these maps. Perhaps this is easier at an architecture, art, and design school, although I am frequently surprised by how much my students struggle to articulate “best practices” for visual design on these maps. One might argue that really we are looking solely at “best practices for concept mapping”, a medium that is foreign to most students, although I have the strong sense that the principles that make for good concept mapping are also principles that make for good graphic design in general (graphic designers who know better feel free to let me know how wrong I am by leaving a comment below!). Even if you are not comfortable spending a lot of time critiquing these concept maps from a visual information depiction perspective, you can still discuss what is clear and what is not clear based on how the maps are constructed.

The critique is as important as the concept map construction in this activity. Given the chance to compare their own maps to the maps of their classmates, students begin to understand the full breadth of information that must be incorporated into these maps to fully represent just these four ecological flows. For most class sections, the intersection of all the best elements of student maps — if combined into one map — would make a pretty comprehensive depiction, although I am always surprised by how few groups come to realize that they need connectors for each of the four “flows” in order to fully depict how the movement of carbon, nitrogen, water, and energy are inter-related.

After my sabbatical this fall, I will resurrect and re-vamp my Ecology (MSCI-270) course, and I will be using a lot of the new stuff that I have been doing in Ecology for Architects. Given how successful this activity has been so far, it will definitely be one of the “new teaching technologies” that I employ in my renewed Ecology course.

Thanks to students from the Spring 2015 sections of Ecology for Architects for giving me permission to post their maps!