There are a couple of biological topics in The Lorax but as a whole, the main topic of the book is the way in which ecosystems interact and the different relationships that exist within them. In terms of content, the book teaches many different things. For example, there do exist symbiotic relationships – the Bar-ba-loots live harmoniously with the Lorax, the Swomee Swans, the Humming Fish, and the Truffula Trees. Relationships within systems like this cannot exist if part of the system is missing. Beyond this, The Lorax teaches readers to take care of their environment and to find a balance. It acknowledges that business might be important, but it is also extremely important to take into account the damages we create, such as poor air
