Lecture Notes on Lichens

Introduction

• Presenter recently went on a hike and highlighted lichens as often overlooked yet amazing organisms.

What are Lichens?

• Composite organism: Result of algae or cyanobacteria living among the filaments of multiple fungi species in a mutualistic relationship.
• Mutualistic Relationship:
  • Algae/Cyanobacteria: Produce carbon compounds through photosynthesis.
  • Fungi: Protect algae/cyanobacteria from the environment, help gather moisture, and provide an anchor.

Characteristics of Lichens

• Not plants, despite plant-like behavior.
• Structures:
  • Tiny leafless branches
  • Flat leaf-like structures (flake-like)
  • Powder-like substance
• No roots: Don't tap into water reservoirs like plants.
• Ability to grow in impossible places:
  • Bare rock, sand, monuments
  • Acts as epiphytes on trees
• Survive extreme drought conditions.

Ecological Importance

• Cover about 6% of Earth's land surface.
• Long-lived; considered some of the oldest living organisms.
• Act as pioneer species after disasters (e.g., on bare rock post-volcano).

Competition and Growth

• Compete with plants for sunlight.
• Thrive in areas difficult for plants due to small size and slow growth.

Conclusion

• Lichens are significant ecologically and biologically.
• For further information on lichens and mutualistic relationships, refer to additional resources.
• Encouragement to subscribe for more educational content.