Why in news?
Scientists recently discovered new lichen species in the Western Ghats of India, highlighting the need to protect these delicate organisms. Lichens are also being studied as indicators of air quality in rapidly urbanising regions.
Background
Lichens are composite organisms formed by a partnership between a fungus and a photosynthetic partner – either algae or cyanobacteria. The fungus provides shelter and minerals, while the algae or cyanobacteria supply food through photosynthesis. This symbiotic relationship allows lichens to colonise harsh environments from tree bark and rocks to arctic tundra and desert stones.
Types and characteristics
- Crustose: Flat, crust‑like lichens that adhere tightly to surfaces like rocks and roofs.
- Foliose: Leafy, flat structures that are loosely attached and can be peeled from their substrate.
- Fruticose: Shrubby or hair‑like lichens with branching structures, often hanging from branches.
- Slow growth: Lichens grow at just a few millimetres per year, sometimes living for centuries. They survive extreme conditions but are sensitive to pollutants, especially sulphur dioxide.
Ecological roles
- Soil formation: Lichens break down rock surfaces, helping to form soil in barren landscapes.
- Food and habitat: They provide food for animals like reindeer and insects, and nesting material for birds.
- Air quality indicators: Because they absorb water and nutrients directly from the atmosphere, lichens are highly sensitive to air pollution. A decline in lichen diversity often signals environmental degradation.
- Traditional uses: Lichens have been used in dyeing fabrics, making perfumes (oak moss), and as medicinal remedies in some cultures.
Conclusion
Lichens illustrate the power of cooperation in nature. Protecting them not only preserves biodiversity but also provides insight into the health of our environment. Monitoring lichen communities can guide pollution control measures and conservation efforts.
Source: National Geographic