Epiphytic lichens as indicators of environmental quality in Rome

Area of Science:

• Ecology
• Botany
• Environmental Science

Background:

• Epiphytic lichen flora is a sensitive indicator of environmental conditions.
• Rome's urban environment presents unique challenges and influences for lichen diversity.
• Previous studies have documented lichen populations in Rome, but a comprehensive synthesis over two decades was needed.

Purpose of the Study:

• To synthesize and analyze changes in Rome's lichen diversity from 1982 to 2003.
• To assess the impact of environmental factors, including air pollution and maritime influence, on epiphytic lichens.
• To update the known taxa of epiphytic lichens in Rome.

Main Methods:

• Application of the Lichen Diversity (LD) method for data synthesis.
• Analysis of environmental variables, specifically air pollution (CO, NOx, SO2) and proximity to the Tyrrhenian Sea.
• Comparison of lichen flora data across different sectors of Rome over a 20-year period.

Main Results:

• The epiphytic lichen flora of Rome currently comprises 102 taxa.
• Significant changes in lichen distribution and diversity were observed over the 20-year study period.
• Lowest lichen diversity is concentrated in the urban center and eastern/southern sectors.
• The extent of the "lichen desert" has decreased, correlating with reduced air pollutant concentrations.
• The influence of the Tyrrhenian Sea is a significant factor affecting lichen distribution, alongside air quality.

Conclusions:

• Air quality improvements have led to a reduction in "lichen desert" areas in Rome.
• Maritime influence plays a crucial role in shaping Rome's epiphytic lichen communities.
• Continued monitoring is essential to understand long-term ecological shifts in urban environments.