A team of researchers from the University of Oviedo is working with EDP in an innovative project to employ different types of lichens as environmental biosensors. It is a pioneering experience in the Principality that has been backed by the Council of Economy and Employment through its financial aid to enterprises for R&D&i projects.

Tenured Professor of Ecology of the University of Oviedo José Ramón Obeso coordinates the research that started at the end of 2013. The use of lichens as atmospherical sensors is one of the main objectives of the study. To achieve this, the team led by Obeso is analyzing the spread of Xanthoria parietina, a yellow-colored lichen that is specially resistent to harsh environments.

Lichens are organisms that draw the nutrients they need from the air passively. They cannot avoid consuming them nor expel them afterwards. The population of Xanthoria parietina grow very slowly, as Obeso explains, so the presence of this lichen in a specific area would allow for the analyzis of the concentration of certain chemical elements that have been accumulated throughout a relatively long period of time. "The detailed analysis of these lichens in different places will allow us to know how the concentration of different elements is distributed in the area", claims the Tenured Professor of Ecology.

The use of lichens as bioindicators allows researchers, on the one hand, to simplify the processes of sensorization without needing to use expensive equipment and to therefore take advantage of the services that ecosystems may lend to society; and on the other hand, it allows them to determine the level of contamination in areas where there are no automatic systems to measure it.

A Natural Process

The lichens are gathered in areas where atmospherical pollution is very low. The researchers have gathered lichen of the Pseudevernia furfuracea species in mountain zones such as the Peaks of Europe. Once they have been gathered, the lichens are spread in eleven stations that monitor the pollution in the central area of Asturias. There, they are placed on a mesh that allows air to pass through freely, so that the lichens may absorb the elements.

The researchers revise each of the stations once per month to check how much the elements of reference have accumulated and in when the lichens reach maximum saturation. If it were so, they would be replaced with other samples of lichen.

An important step in the process is the analysis at the laboratory of the concentrations of each substance. The team led by Tenured Professor of Analytical Chemistry José Ignacio Alonso will be in charge of conducting as thoroughly as possible the measurements that will detect even concentrations in nanograms.

Tuning the Method

The project seeks to refine a method that allows for the measurement of the quality of the air using lichens as bioindicators.

If the project yields the expected results, the next step would be looking for the standardization of the method. Future research will be directed at isolating a clone of the lichen that may homogenize the process and offer it commercially to conduct standardized measurements.

Research Team

• José Ramón Obeso
• José Ignacio García Alonso
• Mariella Moldován
• Jorge Álvarez Sostres

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Samples of Xanthoria parientina and Pseudevernia furfuracea, the two types of lichen used in the research.