Question

In 3–5 sentences, construct an argument that explains why lichens are necessary during the process of succession to establish a new ecosystem after an extreme disturbance. Make sure to include what lichens do and what happens when they die

Answer 1

Lichens are often the first colonizers of bare rock after an extreme disturbance because they can tolerate harsh conditions and physically and chemically break down substrate: their fungal filaments wedge into cracks and their acids dissolve minerals, helping create fine particles. They also trap dust and moisture and, in some species, host nitrogen-fixing algae or cyanobacteria that add biologically available nitrogen to the developing surface. When lichens die, their decaying thalli contribute organic matter and nutrients, increasing water retention and forming the first thin layers of soil. This nascent soil and improved nutrient status allow mosses and vascular plants to establish, driving further succession toward a stable ecosystem.