Biodiversity

Exploring biodiversity in your schoolyard is an excellent way to engage students in learning about the natural world, and provides them with the skills and knowledge that will help them be more successful at understanding ecosystems.  You don’t have to be an expert at identifying organisms in order to allow students to see that diversity exists everywhere, and there are many simple ways to explore biodiversity in your schoolyard.  

Biodiversity is a rich and complex idea that scientists use to frame the organizing principles of ecology.  Biologists view biodiversity as the unifying, central theme of how we understand the structure of ecosystems.  It is a multi-faceted concept that includes the number (richness) and proportional representation (evenness) of species in a defined area, the interactions among species, the structure of communities, and the changes in these metrics over space and time.  However, it can be used loosely in science classrooms, often to describe species diversity in far-away places such as rainforests or coral reefs.  The lessons provided here engage students in exploring their own backyard, and highlight the importance of biodiversity not just for ecosystem health but also human health, such as in the case of Lyme disease.     

In our work with K-12 students, we have identified three key ideas about biodiversity that are both critical for student understanding, and yet not well grasped: 1) all ecosystems contain representatives of all kingdoms, including microbes and fungi; 2) variation exists within larger groups in any ecosystem; and 3) both kinds of variation are critical for shaping how ecosystems function.  The activities provided here will help you and your students begin to understand these big ideas! 

As a pre-assessment to teaching about biodiversity, ask your students what types of things live in their backyard or schoolyard. If you’d like, ask them to make a diagram and prompt them to include abiotic (non-living) as well as biotic (living or once-living) components. You can go further by explaining the idea of an “interaction web” – all of the interactions among the components of a community or ecosystem, including abiotic resources and conditions – as it differs from a “food web” (which only focuses on food interactions).  We’ve asked hundreds of middle and high school students to describe life in their backyards, and what we’ve found is that they don’t have a very good understanding of the variety of life that exists, nor the complexity within the large, familiar groups (see figure below). 

Most students ignore microbes and fungi, even though these organisms comprise most of the life on Earth and are responsible for incredibly important ecological functions.  Students who mention plants or animals use very broad categories to describe what they know – trees, grass, bugs, or birds.  Few students can identify specific species unless they are extremely familiar to them, like a blue jay or a chipmunk.  Their interaction (or food) web will give you insights into both of these big ideas, plus it will help you understand how they view the way the diversity of the ecosystem relates to key functions like growth or decomposition. We believe that unless students recognize that biodiversity exists everywhere, and that there are important differences within large groups of taxa, they cannot begin to explain how biodiversity persists and that diversity is important for ecosystem function.  Fortunately, students are incredibly curious about living things, and middle school is the perfect time to allow them the time and space to explore and to become excellent observers of living things.   

Recognizing that biodiversity exists, and that the world isn’t just covered by a few familiar organisms (e.g., plants, bugs), requires careful observation.  If you’ve noticed that your students ignore entire kingdoms of life, we suggest going outside and exploring one group in depth.  This could be plants, microbes, fungi, invertebrates, or even larger organisms!   

We asked 776 students (369 middle school, and 407 high school) in five states to name as many organisms as they could that lived in their backyard or schoolyard.  The most common type of organism that students mentioned were vertebrates (birds, squirrels, dogs and cats), followed by invertebrates (most common answer: bugs!), and then plants.

Very few students mentioned fungi or microbes; when they did, students simply said “microbes”.  Additionally, it was much more common for students to provide the names of big groups of taxa such as “trees” or “bugs” rather than specifics like “sugar maple” or “ladybug”.