This Life Science module begins with an exploration of a simple predator-prey model to consider who eats whom—and what happens when one population grows faster than another. After learning more about ecosystem dynamics, producers and consumers, and interdependent relationships within an ecosystem, students develop their own model of a local ecosystem. The primary goal of this unit is to engage students in simple interactive activities to explore ecosystems concepts, and in the use, modification, and creation of an agent-based model of a simple virtual ecosystem.

Prerequisites and assumptions:
This lesson assumes that the teacher has already introduced ecosystems concepts such as a) the definition of an ecosystem, b) indirect interactions within ecosystems, c) direct interactions between organisms in ecosystems, d) food chains and food webs, 3) energy flows in ecosystems, f) trophic levels, and g) biomass in ecosystems.

Here's a video introduction to the Module and a background document on ecosystems. 

Lesson 1: Ecosystems as Complex Adaptive Systems

In this lesson students will be introduced to ecosystems concepts through an activity called “Papercatchers”. Papercatchers is a participatory simulation in which students play the part of agents in a simulation. After playing the “game” that illustrates population dynamics and carry capacity, students will view a computer model of a simple ecosystem projected from the instructor’s computer. Through the model, students will review concepts of population growth, producers and consumers, and the movement of energy through an ecosystem.

Lesson 2: Rabbits and Grass Model

In this lesson students will participate in two activities that USE the Rabbits and Grass model. The first activity is a look under the hood at the model to understand what was included and left out of the model (abstraction). In the second activity, students will learn to design and conduct systematic experiments using the model as an experimental test bed. They will use a line graph to visualize data, then report out on their findings.

Lesson 3: Adding a Predator

Now that we have created a simple ecosystem with two trophic levels, we might want to ask some questions about more complicated ecosystems with more trophic levels. In this lesson students will modify the Rabbits and Grass model by adding a predator, a Mountain Lion, to answer a new question. “Does adding top predator increase or decrease the stability of an ecosystem?” In the second activity, students will design and run experiments to see if adding a predator has an impact on the ecosystem. This activity will reinforce the concepts of energy flow through ecosystems and the often unexpected results of interactions in complex adaptive systems.  

Lesson 4: Create your own Ecosystem Model

In this lesson students will design their own ecosystems projects consisting of a question, experimental design and model. In the first activity, students will learn about the computational science cycle and use it to scope their project. This leads to a second activity where they start designing and implementing their model. 

Lesson 5: Designing and Running an Experiment and Sharing your Findings

In this lesson students will complete their ecosystems models and then design and run experiments using their models as experimental test beds. The second activity is the preparation of a presentation on their model, experimental design and findings.