Open Collections

Bedaiwy, Yomna; Nayyara, Parsa

Climate change has impacted the survival of many keystone organisms, including lichens. Lichen bleaching is a growing phenomenon where pigmented lichens develop white patches or lose colour over time. Little is known about the causes of bleaching, or whether fluctuating and extreme climates might be contributors. In this study, we explored how temperature and precipitation frequency influence pigment contents in urban foliose lichens. We randomly assigned lichens into groups and exposed them to varying temperatures and precipitation frequencies for one month. Weekly, we monitored pigment contents in the lichen samples via spectrophotometry at three wavelengths of interest (320, 430, and 662 nm) suspected to be chlorophyll-a and an unidentified UV-screening pigment. We found that the impact of temperature and precipitation frequency on lichen pigment contents depended on the duration and specific combination of microclimatic conditions. Our results suggest that our lichens respond to acute stress by increasing the production of a 320 nm UV-screening pigment during periods of desiccation, and increasing chlorophyll production in saturated, high-temperature environments. Further research on the mechanisms of bleaching in this sensitive holobiont can help us understand the extent of the ecological damage caused by climate change and guide conservation efforts.

Report

eng

2023-08-24

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/85606

Unreviewed

http://creativecommons.org/licenses/by-nc-nd/4.0/