Life under quartz: Hypolithic mosses in the Mojave Desert

Area of Science:

• Ecology
• Botany
• Environmental Science

Background:

• Dryland cyanobacteria and mosses inhabit hypolithic environments under rocks for protection.
• Milky quartz in the Mojave Desert offers refuge from solar radiation and retains moisture.
• The microhabitat beneath quartz rocks is understudied regarding its bryophyte community composition compared to soil surfaces.

Purpose of the Study:

• To investigate the microclimate conditions under Mojave Desert quartz rocks.
• To compare the moss species composition in hypolithic microhabitats versus adjacent soil surfaces.
• To understand how microhabitats influence bryophyte diversity and distribution in extreme desert environments.

Main Methods:

• Deployed microclimate dataloggers to record temperature and humidity for five months.
• Collected moss samples from under and adjacent to 18 milky quartz rocks.
• Analyzed moss samples to identify species and compare community composition between microhabitats.

Main Results:

• Quartz rocks provided thermal buffering and higher relative humidity compared to the soil surface.
• Syntrichia caninervis dominated both microhabitats but was more prevalent on the soil surface.
• Tortula inermis was more restricted to hypolithic spaces, suggesting adaptation to protected microhabitats.

Conclusions:

• Hypolithic microhabitats under quartz rocks create distinct niches that facilitate niche partitioning between moss species.
• Microhabitat conditions, particularly protection from extreme temperatures, influence the distribution of bryophytes like Tortula inermis.
• Considering microhabitats is crucial for accurate bryophyte species diversity assessments and distribution modeling, especially in extreme environments.