May 22nd is

International Day for Biological Diversity!

What is biological diversity?

Biological diversity–or biodiversity for short–refers to the variety of life forms found in a habitat or ecosystem as measured on a global scale. When scientists talk about diversity, they are generally most concerned with the passing on of genes that enable a species to survive. Biodiversity is a useful and necessary concept to understand when attempting to teach about human impact on the environment.

As a species, humans are responsible for most environmental degradation on Earth. In fact, some consider us to be in the geological age known as the Anthropocene, or the age of humans. Polluted oceans, species extinction, and climate change provide evidence for the argument that humans a greater (detrimental) effect now than at any other moment in Earth’s history.

Why does biological diversity matter?

Because humans rely on natural resources for our own survival, we have a vested interest in protecting these resources. Biodiversity is a factor in resilient ecosystems. A thriving ecosystem has complex relationships between plants, animals, microbes, etc., so the quantity and heterogeneity of these living organisms signal the strength of an ecosystem.

Take soil, for example. So often when digging in the dirt, kids will announce: “I found a worm.” Often, the inclination is to celebrate the humble worm as an important indicator of soil health. However, I like to take it a step further and ask questions like, “If you found one worm, how many pill bugs, beetles, and millipedes do you think there are?” My intent is not to discredit the worm for its role, but to acknowledge that, worms are not the only creatures that break down organic matter so nutrients are available for the plants we eat.

How to school gardens promote biological diversity?

School gardens are ideal places for creating a model of biodiversity and teaching children how to notice the variety of relationships in an ecosystem.

• Plant a tree. Trees provide shade for humans, keep soil in place, and offer homes for many kinds of animals, but their roots also form complex networks of mycorrhizae: fungi that improve soil microbial life.
• Leave weeds be. Although most gardeners hate weeds, they also have a role to play in an ecosystem. When I had a circle of unsightly “weeds” in the garden this spring, I put a string round them and attached a sign explaining their purpose: trapping insects that might otherwise feast on my crops.
• Host a garden tour. Invite friends, neighbors, and community neighbors to enjoy the diversity in the garden. Explain (or, better yet, have kids explain) that diversity doesn’t just mean different (e.g., flower color can be different, but if it’s all the same flower, it’s not as strong as having several species of flowers). Share your tour on social media.