A new method to assess air pollution using lichens as bioindicators.

Area of Science:

• Environmental Science
• Botany
• Ecology

Background:

• Lichens are valuable air quality biomonitors due to their efficiency, low cost, and ease of use.
• However, validation studies for lichen biomonitoring methodologies are limited.
• Standardized methods are crucial for reliable air quality assessment using lichens.

Purpose of the Study:

• To compare the reliability and efficiency of three foliose lichen biomonitoring methods.
• To evaluate traditional North American and European templates against a novel computer-generated random points template.
• To determine the most suitable method for ecological studies and routine air quality biomonitoring.

Main Methods:

• Field tests were conducted in San José, Costa Rica, a tropical urban environment.
• Laboratory simulations were used to assess template accuracy.
• Three templates were tested: 100 uniform squares (North America), 200 uniform points (Europe), and computer-generated random points (100 and 50 points).

Main Results:

• Observer variation ranged from 2-14%, and template error varied from 0.2-11%.
• The 100 random point template showed high reliability for ecological studies.
• The 50 random point template demonstrated acceptable reliability for biomonitoring, reducing time and costs by approximately 50%.

Conclusions:

• The 100 random point template is recommended for ecological studies requiring high accuracy.
• The 50 random point template is recommended for routine air quality biomonitoring due to its cost-effectiveness and reliability.
• The novel random point templates offer practical improvements for lichen-based air quality assessment.