How do mosses and lichens survive in tundra habitats?

In tundra ecosystems, mosses and lichens survive the harsh, cold environment through several specialized adaptations:

Lichens

Lichens are highly resilient in extreme climates, often dominating areas where other plants struggle to grow. Their survival strategies include:1
* Drought Resistance: Many lichens, particularly those with crustose thalli, are well-adapted to dry conditions. They can rapidly lose water vapor, a protective mechanism that makes them more resistant to temperature and light extremes when dry.12
* Cold Tolerance: Their photosynthetic apparatus is remarkably resistant to cold. Many lichens can fix carbon dioxide even at temperatures below 0 °C (32 °F).2
* Water Absorption: Lichens can effectively absorb water vapor from the air, allowing them to photosynthesize even in high-humidity conditions.2
* Structural Protection: The lichen thallus provides shade for algae sensitive to strong light, and some contain pigments that act as filters to reduce light intensity.2

Mosses

Mosses thrive in tundra habitats by utilizing available moisture and tolerating extreme conditions:
* Moisture Utilization: Mosses often dominate in wetlands, near watercourses, or in areas where snowmelt provides consistent moisture during the short growing season.3
* Resilience: Many bryophytes are unusually tolerant of extended freezing and dryness, allowing them to resume photosynthesis rapidly once moisture returns.3
* Soil Formation: Mosses colonize bare rock, initiating soil formation, which creates a more stable environment for themselves and other plant species.3