Lichens for Buildings

What is a lichen?

Classification

"Lichens are fungi that have discovered agriculture"

[Trevor Goward]

• Symbiotic organism
• Association of a photobiont and a mycobiont

About 25% of all fungi are lichenized.

• 98% of Ascomycetes fungi are lichenized
• 0.4% of Basidiomycetes fungi are lichenized
• 1.6% of Deuteromycetes the mushrooms are lichenized

85% of mycobionts are in symbiosis with green algae, 10% with cyanobacteria and 3-4% with both at the same time.

Notes 1/2

Preliminary research

The two symbionts live drawing mutual benefit: the fungus, heterotrophic, survives thanks to organic compounds produced by photosynthetic cyanobacterium or alga, while the latter receives in exchange protection, minerals and water.

Are characterized by a thallus and are classified based on the taxonomy of fungal species (in previous classifications were part of cryptogams).

The thallus, based on form and method of adhesion to the substrate, can have different morphologies:

Crustose

Foliose

Fruticose

Composed

Cross section of a lichen

Project: Development of a cladding element that favorite the natural growth of lichens on facade of Hotel Loffmalakoff

designed by Studio Granda

Location

Which kind of lichens grow in Iceland?

Substrate and environment preferences

Lichens draw their nutrients from the environment and are easily contaminated. They grow well in Iceland because it is one of the least polluted countries in the world.

Influencing factors attributed to the environment:

• Climate
• Thermal amplitude
• Precipitations

Over 700 lichens have been found in Iceland, over 400 of which are crustose lichens. Other Icelandic lichens are either fruticose or foliose. New species of lichen are constantly being identified in Iceland.

• Hygrometry
• Distance from the sea
• Presence or absence of vegetation

Wind Data

Influencing factors attributed to the substrate:

• Exposition
• Surface pH
• Composition of substratum

• Wetness of facade
• Architectural parameters inducing micro-humidity

Iceland moss (Cetraria islandica) is a lichen whose erect or upright, leaflike habit gives it the appearance of a moss, where its name likely comes from.

Ecological and environmental interactions

Dispersal and Reproduction

Vegetative reproduction

• a piece of lichen breaks off and grows on its own

• dispersal of diaspores containing a few algal cells surrounded by fungal cells

lichens break down raw stone and attack stone chemically, creating new fertile soil

• wide range of substrates and habitats
• weathering process
• maybe contribute nitrogen to soil when eaten
• can tolerate periods of severe desiccation
• some lichens produce allelopathic chemicals that inhibit the germination and growth of plants
• primary source of energy is the air
• accumulate pollutant present in the air
• effective biomonitors of atmospheric quality

• Soredia (singular "soredium") are small groups of algal cells surrounded by fungal filaments that form in structures called soralia, from which the soredia can be dispersed by wind.
• Isidia (singular "isidium") are branched, spiny, elongated, outgrowths from the thallus that break off for mechanical dispersal

Sexual reproduction

• only fungal partner reproduces sexually

• fungal spores must meet with a compatible algal partner before a lichen can form

• spore-producing structures are called ascomata (Ascomycetes)

Lichens and buildings

Existing building products

• Deteriorating effects of lichen of building materials

“Lichen for Skyscrapers Project”

UPC "Biological" concrete

• Treatments to prevent bio-deterioration

• Physical removal or chemical control

Benetti Moss

• Can enhance the appearance and character of buildings

• Can cause direct and indirect damage to materials and elements of construction

Prof. Elizabeth Demaray “plants” the lichen by painting lichen slurry, a watery mixture

Researchers at the UPC develop a biological concrete for constructing “living” façades with lichens, mosses and other microorganisms

Thought for interior application, Benetti Moss is made with a natural stabilized lichen, assembled on panels. It does not need maintenance, just a minimum of 50% of RH

Conclusion

References

• Ascaso, C., & Wierzchos, J. (1994). Structural Aspects of the Lichen‐Rock Interface Using Back‐scattered Electron Imaging. Botanica Acta, 107(4), 251-256.

There is literature about lichens, interaction with substrate (mostly due to studies of bio-degradation)

• Azmi, O. R., Seppelt, R. D. (1997). Fungi of the Windmill Islands, continental Antarctica. Effect of temperature, pH and culture media on the growth of selected microfungi. Polar Biology, June, Volume 18, Issue 2, 128-134.

• Barberousse, H., Lombardo, R. J., Tell, G., & Couté, A. (2006). Factors involved in the colonisation of building façades by algae and cyanobacteria in France. Biofouling, 22(02), 69-77.

The idea of using lichens as a decorative element on facades is relatively new

• Hauck, M., Jürgens, S. R., & Leuschner, C. (2010). Norstictic acid: correlations between its physico-chemical characteristics and ecological preferences of lichens producing this depsidone. Environmental and experimental botany, 68(3), 309-313.

Further investigations

• Manso, S., Mestres, G., Ginebra, M. P., De Belie, N., Segura, I., & Aguado, A. (2014). Development of a low pH cementitious material to enlarge bioreceptivity. Construction and Building Materials, 54, 485-495.

• Manso, S., de Cea, A. A., Pérez, I. S., & De Belie, N. Bioreceptivity Optimisation of Concrete Substratum to Stimulate Biological Colonisation.

Understand which kind of lichens are most suitable for the project and which are desired by Studio Granda

• Vingiani, S., Terribile, F., & Adamo, P. (2013). Weathering and particle entrapment at the rock–lichen interface in Italian volcanic environments. Geoderma, 207, 244-255.

• de los Ríos, A., Cámara, B., del Cura, M. Á. G., Rico, V. J., Galván, V., & Ascaso, C. (2009). Deteriorating effects of lichen and microbial colonization of carbonate building rocks in the Romanesque churches of Segovia (Spain). Science of the total environment, 407(3), 1123-1134.

Define quantitative parameters for both environmental and substrate properties to enhance lichen's colonization

• Moorhouse, E. (2011, October 21). Professor 'Going Green' in New York City with Lichen Project. Retrieved from: news.rutgers.edu/news-releases/2011/10/professor-going-gree-20111021#.VfAEh_ntmko

Studies on CO2 absorption and capacity to capture solar radiation, thus regulation of thermal conductivity