The World of Lichens

Lichens are incredible symbiotic organisms that can survive in some of the harshest environments on Earth. They serve important roles in ecosystems as pioneering species, and they are used by earth scientists to learn about the timing of past events and to monitor pollution. 


Lichens are symbiotic organisms made up of a fungus (providing structure) and an algae or cyanobacteria (providing nutrients through photosynthesis). In ecology, lichens play important roles in soil stabilization and development, nutrient cycling, and succession. In earth sciences, scientists make use of lichens to monitor pollution and to estimate the age of rock surfaces. 

The World of Lichens module includes a student-driven project and gives students hands-on practice with the scientific method.

Lesson Components

Download or view the following: 

Science Standards

The following NGSS are addressed by this unit. 

Disciplinary Core Ideas:

  • LS2.C: Ecosystem Dynamics, Functioning, and Resilience
  • LS4.D: Biodiversity and Humans
  • ESS3.C: Human Impacts on Earth Systems
  • ESS2.E: Biogeology

Science and Engineering Practices:

  • Asking Questions and Defining Problems
  • Planning and Carrying out Investigations
  • Analyzing and Interpreting Data

Crosscutting Concepts:

  • Patterns
  • Stability 


Ruth Heindel with exhibit
The John Sloan Dickey Center