Lichens

Lichens: Biology, Ecology, Symbiosis, and Environmental Change

Lichens Are Complex Symbiotic Systems

Lichens have traditionally been described as partnerships between a fungus and a photosynthetic organism, usually a green alga or cyanobacterium. Modern research, however, has substantially expanded this picture. Many lichens contain additional fungi, bacteria, multiple photosynthetic partners, and other microorganisms, making the lichen better understood as a complex biological consortium or holobiont rather than simply a two-organism partnership.

The fungal partner, or mycobiont, generally forms most of the visible lichen body, known as the thallus. Photosynthetic partners provide carbohydrates produced from sunlight, while cyanobacteria in some lichens can also contribute biologically available nitrogen. These interactions allow lichens to occupy surfaces and environments where either partner might have difficulty surviving independently.

Increasingly sophisticated genomic, microscopic, and experimental studies are revealing how the partners recognize one another, exchange nutrients, regulate water, respond to environmental stress, and construct the organized structures characteristic of lichens. Researchers have even begun questioning whether the lichen should be considered an individual organism, a community, an ecosystem, or something that does not fit comfortably within traditional biological categories.

The partnerships are also more flexible than once assumed. Individual lichens may contain multiple strains or species of photosynthetic partners, and the composition of these communities can change with environmental conditions or even with the age of the lichen. Research therefore increasingly describes lichenization as a continuum of fungal-algal relationships rather than a single fixed biological arrangement.

Hidden Microbiomes, Genomes, and Chemical Diversity

Modern DNA sequencing has revealed an extraordinary amount of biological diversity hidden inside lichen thalli. Alongside the principal fungal and photosynthetic partners are communities of bacteria, additional fungi, yeasts, and other microorganisms. The composition of these microbiomes can differ among lichen species and can change according to climate, altitude, pollution, urbanization, and other environmental conditions.

Metagenomic and transcriptomic studies are helping scientists determine which organisms are present and what biological functions they perform. These approaches have revealed metabolic pathways involved in carbon exchange, environmental stress responses, partner recognition, and the production of specialized compounds.

Lichens are particularly notable for their secondary chemistry. They produce a large variety of compounds, including pigments and substances that may protect the organisms from ultraviolet radiation, herbivory, microorganisms, or other environmental stresses. Some of these chemicals are being investigated for antimicrobial, antioxidant, anti-inflammatory, anti-biofilm, and anticancer properties.

Pharmaceutical potential remains an active area of research rather than an established medical application. Laboratory studies have identified promising biological activities, but researchers caution that evidence of activity in cells or experimental systems does not automatically establish clinical usefulness.

Climate Change and Lichen Physiology

Lichens are closely tied to atmospheric conditions because they have no roots and obtain much of their water and nutrients directly from their surroundings. Hydration, humidity, temperature, sunlight, snow cover, and the frequency of wetting and drying can therefore strongly influence their metabolism and distribution.

Climate change can affect lichens through warming temperatures, altered precipitation, changing snow conditions, drought, increased vapor-pressure deficits, and changes in vegetation. Experimental studies show that warming can alter photosynthesis, growth, reproductive success, carbon exchange, and the health of photosynthetic partners.

Cold-adapted lichens in Arctic, alpine, boreal, and high-elevation environments may be especially vulnerable. Some species could shift their geographic or elevational ranges, while others may lose suitable habitat faster than they can migrate or adapt.

Small climatic refuges may protect vulnerable populations temporarily, but their effectiveness can decline as regional warming intensifies. Forest structure can therefore become important in climate adaptation: old trees, canopy complexity, surrounding woodland, and locally humid microhabitats may provide environmental conditions that allow sensitive lichens to persist.

Climate change does not always produce simple responses. Milder winters, for example, can alter cold acclimation and potentially increase vulnerability to occasional freezing events. Different members of a lichen partnership can also respond differently to the same environmental stress, making prediction more complicated than treating the lichen as a physiologically uniform organism.

Lichens as Environmental Bioindicators

Lichens are among the most widely used biological indicators of atmospheric conditions. Because they absorb substances directly from the atmosphere and often respond predictably to pollution, changes in lichen abundance, diversity, chemistry, or physiology can reveal environmental stress that conventional measurements alone may not capture.

Historically, lichens became particularly useful indicators of sulfur dioxide pollution. Modern biomonitoring has expanded to include nitrogen compounds, ammonia, heavy metals, particulate pollution, trace elements, and other contaminants. Chemical and isotopic analyses can sometimes provide information about both the quantity and possible sources of pollutants deposited on landscapes.

Researchers use naturally occurring lichens as well as transplanted specimens. Transplants can be placed around factories, recycling facilities, roads, cities, and other potential pollution sources and later analyzed for accumulated contaminants.

Lichen monitoring is also increasingly integrated with remote sensing, microscopy, elemental analysis, statistical modeling, and machine-learning techniques. National and regional monitoring programs use standardized lichen surveys to evaluate forest condition, atmospheric pollution, climatic patterns, and long-term ecological change.

The relationship between a particular lichen and pollution can itself change. Declining concentrations of historical pollutants, rising nitrogen deposition, urban warming, and other environmental shifts can alter which species are useful indicators. Effective biomonitoring therefore requires periodic reassessment rather than permanent reliance on a single indicator species.

Forest Lichens and Habitat Conservation

Forests contain some of the world's most diverse and conservation-sensitive lichen communities. Lichen richness can depend on individual tree characteristics, stand age, canopy structure, deadwood, humidity, surrounding landscape, forest continuity, and the history of disturbance.

Old trees are especially important. Their large trunks, varied bark, wounds, cavities, branches, and long ecological continuity provide microhabitats that younger managed forests may lack. Veteran trees and substantial quantities of deadwood can therefore function as biological legacies that preserve species across generations of forests.

Studies comparing primary and intensively managed forests frequently find greater richness of sensitive or threatened lichens where old trees and natural forest structures remain. Some species are so closely associated with long-established forests that lichen communities can help identify stands of unusually high conservation value.

Forestry practices can have very different consequences depending on their intensity. Clearcutting can produce effects that remain visible in lichen communities decades later, while carefully designed thinning, partial harvesting, and retention of veteran trees may preserve some habitat. Maintaining tree diversity can also be important because many epiphytic lichens show preferences for particular host species.

Long-lived lichens can complicate assessments of forest health. Some populations may persist for years or decades after conditions necessary for successful reproduction have disappeared. These "ghost" populations can create the appearance that biodiversity remains secure even as long-term population viability declines.

Restoration is possible in some circumstances. Researchers have experimented with transplanting threatened lichens and moving deadwood carrying lichen communities. Such efforts demonstrate possibilities for active conservation but also show that lichens can establish slowly and that restoration cannot easily replace the ecological continuity of old forests.

Biodiversity, Taxonomy, and Newly Discovered Species

Lichen diversity remains incompletely documented. Surveys continue to discover new species, new genera, previously unknown geographic populations, and cryptic species that appear nearly identical until examined genetically.

Molecular methods have transformed lichen taxonomy. DNA evidence sometimes shows that organisms previously treated as one species actually represent numerous evolutionary lineages, while apparently different forms can occasionally prove more closely related than traditional morphology suggested.

Studies from tropical forests, Arctic environments, mountains, deserts, islands, and other regions regularly expand known lichen diversity. Even small geographic areas can contain remarkable numbers of species. Intensive sampling of leaf-dwelling lichens in Brunei, for example, revealed extraordinarily high diversity, including numerous species new to science.

Taxonomic research also increasingly examines both sides of the lichen partnership. A newly described fungal species may have an equally distinctive photosynthetic partner, meaning that cataloging lichen biodiversity involves understanding interconnected fungal, algal, cyanobacterial, and microbial diversity.

Genetic techniques also reveal organisms that conventional field surveys can miss entirely. DNA collected from leaves, bark, soil, and lichen tissues indicates that visually obvious lichens represent only part of the lichenized fungal diversity occupying many ecosystems.

Lichens in Deserts, Polar Regions, and Extreme Environments

Lichens occupy some of Earth's most physically demanding environments, including Antarctica, the Arctic, high mountains, exposed rock surfaces, and extremely dry deserts. Their ability to tolerate dehydration, intense sunlight, low temperatures, nutrient scarcity, and long periods of metabolic inactivity makes them important organisms for understanding the biological limits of survival.

In deserts, lichens often participate in biological soil crusts with cyanobacteria, mosses, fungi, and other microorganisms. These living crusts stabilize soil surfaces, influence erosion, retain nutrients, modify water movement, and contribute to ecosystem productivity.

Desert communities can depend on extremely limited sources of moisture. In the Atacama Desert, for example, lichen-dominated crusts associated with rock fragments can exploit rare fog events. Similar research demonstrates how small differences in slope, temperature, and moisture can strongly influence desert lichen physiology.

Polar and alpine lichens likewise survive conditions that exclude many vascular plants. They contribute to ground cover, nutrient cycling, food webs, and the functioning of cold-region ecosystems.

Their extraordinary stress tolerance has also attracted interest from astrobiologists. Experiments exposing lichens to simulated extraterrestrial or Martian conditions examine whether symbiotic organisms could remain metabolically active under conditions resembling environments beyond Earth. These studies do not demonstrate extraterrestrial life, but they help researchers investigate the possible limits of terrestrial life and the kinds of organisms that might survive extreme planetary environments.

Ecological Roles and Relationships with Other Organisms

Lichens are not merely passive occupants of rocks and trees. They participate in nutrient cycles, influence soil formation, provide habitat, contribute biomass, and interact with animals, plants, fungi, and microorganisms.

In northern ecosystems, terrestrial and arboreal lichens are particularly important winter forage for caribou and reindeer. Changes in forest structure, wildfire, logging, climate, or lichen abundance can therefore influence much larger food-web relationships.

Lichen mats also provide habitat for mites and other small arthropods. Different lichen species can support very different animal communities, demonstrating that changes in lichen composition can alter microhabitats as well as plant and fungal diversity.

Lichens contribute to ecological succession on exposed surfaces and can participate in the gradual development of soils. When lichen material falls from forest canopies and decomposes, it also contributes organic matter and nutrients to forest ecosystems.

Their sensitivity to habitat structure makes lichen communities useful indicators of broader ecological conditions. Large monitoring datasets have consequently been used to study forest succession, landscape fragmentation, climate gradients, pollution, land cover, stand age, and ecosystem change across extensive geographic regions.

Threats and Conservation

Lichen conservation faces many of the same pressures affecting global biodiversity more broadly: habitat destruction, forest simplification, land-use change, pollution, climate change, altered fire regimes, fragmentation, and inadequate knowledge of species distributions.

Some threats interact. Climate change can reduce suitable moisture conditions while forestry removes old trees that might otherwise provide climatic refuges. Pollution can weaken sensitive populations while habitat fragmentation reduces opportunities for recolonization. Because many lichens grow slowly and disperse imperfectly, ecological recovery can take considerably longer than the disturbance that caused the original decline.

Conservation therefore requires more than protecting individual specimens. Maintaining ecological continuity, mature trees, deadwood, diverse host species, suitable microclimates, clean air, connected habitats, and regional biodiversity hotspots can all be important.

Protected areas are valuable but are not automatically sufficient. Lichen populations can decline even within reserves when atmospheric pollution, climate change, altered disturbance patterns, or changes outside reserve boundaries affect habitat conditions.

Better monitoring is consequently central to lichen conservation. Historical records, museum collections, national inventories, genomic surveys, citizen observations, and repeated ecological sampling can reveal changes that would otherwise remain invisible.

Conclusion

Lichens illustrate how much biological complexity can be hidden inside organisms that appear outwardly simple. What was once presented primarily as a partnership between a fungus and an alga is increasingly understood as a dynamic biological system involving multiple symbiotic partners, microbial communities, complex chemistry, and interactions with the surrounding ecosystem.

Their dependence on atmospheric moisture and nutrients makes lichens unusually sensitive to environmental change. That sensitivity explains both their vulnerability and their scientific value. Lichen communities can record changes in air pollution, climate, forest structure, habitat continuity, and other ecological conditions across periods ranging from years to decades.

At the same time, lichens perform important ecological functions themselves. They contribute to nutrient cycling and soil development, create habitat for microorganisms and animals, provide critical forage in northern ecosystems, participate in biological soil crusts, and add substantial biodiversity to forests, deserts, mountains, and polar environments.

Modern genomics and microbiome research continue to overturn older assumptions about what a lichen actually is, while taxonomic surveys show that a large proportion of global lichen diversity may still be undocumented. Research ranging from old-growth forest conservation to simulated Martian environments demonstrates the remarkable range of scientific questions that these organisms can illuminate.

Lichens therefore provide more than an unusual example of symbiosis. They are living records of environmental conditions, important components of ecosystems, reservoirs of poorly understood biodiversity, and valuable models for studying cooperation, resilience, adaptation, and biological survival in a changing world.

Lichen Biology, Symbiosis, and Evolution

1. On Nitrogen Fixation in Lichens with Unicellular Cyanobionts

| Peter D. Crittenden et al. | The Lichenologist | 29 July 2026

This study examines nitrogen fixation in lichens containing unicellular cyanobacteria and expands understanding of how lichen symbioses can contribute biologically available nitrogen to ecosystems.

2. What Is an ‘Individual’ in Lichen Symbioses? An Overview of Alternative Perspectives

| Daniel E. Stanton and Abigail R. Meyer | The Lichenologist | 23 June 2026

The authors examine whether a lichen should be treated as an individual organism, a consortium, a community, or another type of biological entity, highlighting fundamental questions raised by symbiotic life.

3. Exploring the Lichenization Continuum Through the Marine Tripartite Symbiosis of Collemopsidium pelvetiae

| Sergio Pérez-Ortega et al. | American Journal of Botany | June 2026

A marine association involving fungus, cyanobacterium, and brown alga illustrates that lichenization is better understood as a continuum of symbiotic arrangements rather than one rigid biological formula.

4. The Cyanolichen Fuscopannaria frullaniae Is a Basidiolichen in the Genus Acantholichen

| Alejandro Huereca et al. | The Lichenologist | 30 April 2026

Molecular evidence radically revises the classification of an unusual cyanolichen, placing it among basidiomycete lichens and illustrating how DNA studies continue to reshape lichen taxonomy.

5. Fungal Symbioses: A Multiplicity of Fungi in the Lichen Union

| Various authors | Current Biology | 9 March 2026

Research increasingly challenges the old textbook model of lichens as simple partnerships between one fungus and one photosynthetic organism, revealing recurring additional fungi that may be functionally important members of the lichen system.

6. Lichens as Biomonitors of Air Quality and Climate

| Claudia Colesie and Kevin K. Newsham | Global Change Biology | 23 February 2026

Lichens remain exceptionally useful biological monitors because their physiology responds directly to atmospheric pollution and climatic conditions, allowing changes in sulfur dioxide, nitrogen compounds, temperature, and moisture to be detected through shifts in their communities.

7. Lichens in Times of Climate Change – Impacts and Responses Especially in Boreal and Polar Ecosystems

| Lilith Weber, Pekka Niittynen and Annina Kantelinen | MycoKeys | 3 February 2026

This extensive review examines how warming, changing precipitation, snow conditions, carbon dioxide, competition, and habitat shifts are affecting lichens, particularly in boreal and polar ecosystems.

8. Semilichen, an Unjustly Neglected Symbiotic System Between Green Biofilms and True Lichens

| Various authors | Scientific Reports | 30 January 2026

Researchers describe semilichens as intermediate symbiotic systems that may help explain how loose fungal-algal associations transition toward the highly organized structures characteristic of conventional lichens.

9. A Diverse World Within: Age-Dependent Photobiont Diversity in the Lichen Protoparmeliopsis muralis

| Various authors | FEMS Microbiology Ecology | 26 September 2025

Older lichen thalli were found to contain greater photobiont diversity, suggesting that the internal biological community of a lichen can change substantially during its lifetime.

10. Making Fungal-Photobiont Symbioses in the Lab: Past, Present, and Future of the Elusive In Vitro Lichen

| Arseniy Belosokhov and Toby Spribille | Annual Review of Microbiology | 9 September 2025

More than a century of attempts to reconstruct lichens in laboratories reveals both the complexity of the partnership and why researchers still lack a universally reliable experimental lichen model.

11. Photobiont–Mycobiont Interactions in the Lichen Symbiosis

| Enrico Boccato | University of Trieste | 16 April 2025

Experimental work explores interactions between Trebouxia algae and fungal partners, including stages involved in recognizing partners and reconstructing lichen symbioses.

12. The Plurality of Photobionts Within Single Lichen Thalli

| Various authors | Symbiosis | 6 February 2025

Individual lichen thalli can contain multiple genetically distinct photosynthetic partners, potentially giving lichens greater physiological flexibility under changing environmental conditions.

13. The Application of Haplotypes Instead of Species-Level Ranks Modifies the Interpretation of Ecological Preferences in Lichen Symbiont Interactions in Parmelia

| Emilia Anna Ossowska et al. | Scientific Reports | 24 August 2024

Fine-scale genetic differences among symbiotic partners can reveal ecological specialization that is obscured when researchers analyze lichens only at conventional species level.

14. Symbionts Out of Sync: Decoupled Physiological Responses Are Widespread and Ecologically Important in Lichen Associations

| Abigail R. Meyer et al. | Science Advances | 14 June 2024

Fungal and photosynthetic partners can respond differently to hydration and environmental stress, meaning the ecological performance of a lichen may depend on balancing physiologically distinct organisms.

15. Ecology and Evolution of Algal-Fungal Symbioses

| Gregory Bonito et al. | Current Opinion in Microbiology | June 2024

This review places lichens within the broader evolutionary history of fungal-algal partnerships and examines how such relationships develop, persist, and diversify.

16. Phylogenomics Reveals the Evolutionary Origins of Lichenization in Chlorophyte Algae

| Camille Puginier et al. | Nature Communications | 24 May 2024

Genome-scale evolutionary analysis indicates that the capacity of green algae to participate in lichens arose independently multiple times and was accompanied by important genomic changes.

17. Composition, Structure and Robustness of Lichen Guilds

| Salva Duran-Nebreda and Sergi Valverde | Scientific Reports | 25 February 2023

Network analysis shows that lichen-forming fungi and their photosynthetic partners form structured ecological guilds containing highly connected relationships that may influence community stability.

18. Fungal-Algal Association Drives Lichens' Mutualistic Symbiosis: A Case Study with Trebouxia-Related Lichens

| Various authors | Microbiology Spectrum | 2023

Analysis across multiple biomes suggests that the identity of fungal and algal partners can exert a stronger influence on lichen associations than some surrounding environmental variables.

19. How to Build a Lichen: From Metabolite Release to Symbiotic Interplay

| Various authors | Journal Review | 2023

Researchers examine chemical signaling, recognition, metabolism, and structural development involved in transforming initially independent fungi and algae into an integrated lichen thallus.

20. Evolutionary Biology of Lichen Symbioses

| Toby Spribille et al. | New Phytologist | 2022

This major review synthesizes modern research showing that lichens are evolutionarily dynamic multipartite symbioses whose fungi, algae, cyanobacteria, yeasts, and bacteria have intertwined evolutionary histories.

Lichen Microbiomes, Genomics, and Chemistry

21. From Symbiosis to Cytotoxicity: Biosynthesis, Molecular Mechanisms, and Anticancer Potential of Lichen-Derived Depsides and Depsidones

| Various authors | Scientific Review | 2026

This review examines how characteristic lichen chemicals are produced and evaluates experimental evidence concerning their possible anticancer mechanisms.

22. Lichen-Associated Endophytes from the Helan Mountains: Insight into Microbial Diversity and Application

| Xiao-Li Ma et al. | Polish Journal of Microbiology | 26 December 2025

Culturing microorganisms from lichens of China's Helan Mountains revealed diverse bacteria and fungi with potentially useful biological and biochemical characteristics.

23. Green Algal Photobiont Diversity in Lichen Communities Under Forest Fragmentation

| Various authors | Environmental Microbiology | December 2025

The study investigates whether fragmentation of forests alters the diversity of green algae living inside lichens, linking landscape disturbance with changes inside the symbiosis itself.

24. Unveiling the Ecological Processes Driving Soil and Lichen Microbiome Assembly Along an Urbanization Gradient

| Panji Cahya Mawarda et al. | npj Biofilms and Microbiomes | 10 June 2025

Comparison of urban and less-developed environments shows that urbanization alters the microorganisms associated with lichens as well as those occurring in surrounding soils.

25. Lichen and Its Microbiome as an Untapped Source of Anti-Biofilm Compounds

| Marion Millot et al. | Chemistry & Biodiversity | April 2025

Lichens and the microorganisms living within them produce chemically diverse compounds that may provide new approaches for disrupting bacterial biofilms and developing antimicrobial agents.

26. Lichens Are a Treasure Chest of Bioactive Compounds: Fact or Fake?

| Anna Pasinato and Garima Singh | New Phytologist | 27 February 2025

The authors critically assess claims surrounding the pharmaceutical promise of lichen compounds and distinguish promising biological activity from evidence that remains preliminary.

27. Complexity of the Lichen Symbiosis Revealed by Metagenome and Transcriptome Analysis of Xanthoria parietina

| Gulnara Tagirdzhanova et al. | Current Biology | 30 January 2025

Genetic and gene-expression data from Xanthoria parietina reveal numerous interacting organisms and biological processes beyond the traditional fungus-and-alga description of a lichen.

28. A Biosynthetic and Taxonomic Atlas of the Global Lichen Holobiont

| Various authors | Environmental Microbiology | 2025

Global genomic analysis reveals extraordinary bacterial and biosynthetic diversity within lichen holobionts, including metabolic pathways potentially relevant to biotechnology and drug discovery.

29. Genomics: A Window into the Molecular Mystery Box of Lichen Symbiosis

| Rebecca Yahr | Current Biology | 2025

Genomic research is beginning to reveal the molecular processes that allow independently living fungi and photosynthetic organisms to recognize one another and establish persistent lichen partnerships.

30. Distinct Bacteria Display Genus- and Species-Specific Associations with Mycobionts in Páramo Lichens in Colombia

| Maryam Chaib De Mares et al. | FEMS Microbiology Ecology | 2025

High-elevation Colombian lichens contain bacterial communities whose composition is partly associated with the identity of the lichen-forming fungus.

31. Microbial Occurrence and Symbiont Detection in a Global Sample of Lichen Metagenomes

| Gulnara Tagirdzhanova et al. | PLOS Biology | 7 November 2024

Analysis of lichen metagenomes collected around the world reveals recurring fungi, algae, bacteria, and other microorganisms, reinforcing the concept of lichens as complex microbial ecosystems.

32. Interplay of Heavy Metal Accumulation, Physiological Responses, and Microbiome Dynamics in Lichens

| Manoj Thakur, Amit Bhatt, Vaibhav Sharma and Vartika Mathur | Environmental Monitoring and Assessment | 12 September 2024

Heavy metals can affect not only lichen physiology but also the associated microbial community, adding another dimension to the use of lichens as indicators of environmental contamination.

33. Genome Analyses Show Melanins Are Important for Lichens

| Science news staff | Phys.org | September 2024

Genomic research on lichen-forming fungi indicates that melanin production contributes to protection from ultraviolet radiation and other stresses encountered on exposed surfaces.

34. Diversity Profiling of Microbiomes Associated with Selected Alpine Plants and Lichens from Mt. Suisho, Japan

| Ryosuke Nakai et al. | Microbiology Resource Announcements | 12 March 2024

Microbial profiling of alpine lichens and plants provides a reference for understanding microorganisms capable of living under cold, nutrient-poor, high-elevation conditions.

35. Metatranscriptomics Reveals Diversity of Symbiotic Interaction and Mechanisms of Carbon Exchange in the Marine Cyanolichen Lichina pygmaea

| Various authors | New Phytologist | 2024

Gene-expression analysis of a marine lichen shows how partners exchange carbon while responding dynamically to the highly variable conditions of rocky tidal environments.

36. Diversity of Lichen Mycobionts and Photobionts and Their Relationships in the Ny-Ålesund Region

| Various authors | Extremophiles | 2024

Sampling in High-Arctic Svalbard uncovered dozens of fungal species and algal lineages, demonstrating considerable hidden symbiotic diversity even in an environmentally severe landscape.

37. Chemical Constituents Isolated from the Lichen Biome of Selected Species Native to North America

| Various authors | Scientific Reference Chapter | 2024

Researchers catalog chemical compounds isolated from North American lichens and discuss the biochemical diversity generated by lichenized ecosystems.

38. The Microbiome of the Lichen Lobaria pulmonaria Varies According to Climate on a Subcontinental Scale

| Anteneh Tamirat Bogale et al. | Environmental Microbiology Reports | 2024

Bacterial communities associated with lung lichen vary across climatic regions, suggesting that microbial partners may contribute to the lichen's ability to function under different environmental conditions.

39. Recent Advances in Research for Potential Utilization of Unexplored Lichen Metabolites

| Various authors | Biotechnology Review | 2023

Lichens manufacture an unusually diverse array of secondary metabolites, many of which are being investigated for antimicrobial, antioxidant, anti-inflammatory, and pharmaceutical applications.

40. A Comparative Genomic Analysis of Lichen-Forming Fungi Reveals New Insights into Fungal Lifestyles

| Various authors | Scientific Reports | 2022

Comparison of fungal genomes identifies genetic features associated with lichenization and helps distinguish lichen-forming fungi from fungi with other ecological lifestyles.

Climate Change, Physiology, and Environmental Stress

41. Winter Collections of Sun and Shade Afromontane Lichens Show Similar Non-Photochemical Quenching and PSII Activity

| Richard P. Beckett, Farida Minibayeva and Silke Werth | The Lichenologist | 29 April 2026

Measurements of African montane lichens investigate how organisms from exposed and shaded habitats regulate photosynthetic energy during winter conditions.

42. Microclimatic Moisture and the Climate Change Resilience of Lichen Epiphytes – An Applied Model for Temperate Rainforest

| Various authors | Biological Conservation | March 2026

Fine-scale forest humidity strongly influences lichen persistence, and modeling suggests that expanding woodland around climatic refuges could improve the resilience of temperate-rainforest lichens.

43. Lichen Symbiotic Stress as a Precursor to Biodiversity Loss – Rapid Assessment Using Evernia prunastri as a Bioindicator for Nitrogen Pollution

| Various authors | Environmental and Experimental Botany | 2026

Physiological stress within the lichen partnership can appear before obvious community-level biodiversity losses, potentially providing an early warning of excessive nitrogen deposition.

44. Range Shift and Climatic Refugia for Alpine Lichens Under Climate Change

| Various authors | Diversity and Distributions | 7 September 2025

Distribution models for more than 250 alpine lichens identify potential future range shifts and locations that may function as climatic refuges as mountain environments warm.

45. Lichen Symbiont Interfaces Revisited: Ultrastructure of Intraparietal Contacts Between Fungal and Algal Cells

| William B. Sanders and Asunción de los Ríos | The Lichenologist | 5 August 2025

Electron microscopy reveals highly intimate physical connections between fungal and algal cells in several lichens, providing new information about how symbiotic partners interact.

46. Ultraviolet Radiation: A Double-Edged Sword in Old-Forest Lobaria Lichens—Reducing Growth While Enhancing Acclimation

| Ida Karina Kann, Knut Asbjørn Solhaug and Yngvar Gauslaa | Oecologia | 18 July 2025

Ultraviolet radiation suppresses growth in Lobaria while also triggering protective physiological responses that can improve tolerance of subsequent exposure.

47. Lichen Hydration, Moisture Dynamics and Climate Change: A Synthesis of Established Methods and Potential New Directions

| Various authors | Fungal Biology Reviews | June 2025

Because lichens lack roots and regulate little of their own water supply, understanding hydration and drying is fundamental to predicting their responses to increasingly altered climates.

48. The Trade-Off Between Photosynthetic Rate and Thallus Moisture-Demand Explains Lichen Habitat Association with the Temperate Rainforest

| Amaris Ormond, Christopher J. Ellis and Claudia Colesie | Oecologia | 5 March 2025

Differences in photosynthetic productivity and water requirements help explain why individual lichen species occupy different moisture niches within temperate rainforests.

49. Re-Envisioning Urban Landscapes: Lichens, Liverworts, and Mosses Coexist Spontaneously with Us

| Nicole J. Jung, Harold N. Eyster and Kai M.A. Chan | Frontiers in Ecology and the Environment | 10 February 2025

Cities contain extensive spontaneous cryptogam communities whose ecological contributions are frequently ignored in conventional urban biodiversity planning.

50. Temporal Dynamics Hidden Within Species Baselines – Multifaceted Decline of a Lichen Bioindicator

| Christopher J. Ellis, Sam Tomlinson, Edward J. Carnell, Brian J. Coppins and Mark A. Sutton | The Lichenologist | 27 January 2025

Historical records of Bryoria fuscescens show how changing pollution regimes and climate can combine to produce long-term declines hidden by modern baseline observations.

51. Simulated Climate Change Impacts Health, Growth, Photosynthesis, and Reproduction of High-Elevation Epiphytic Lichens

| Various authors | Ecosphere | 2025

Experimental transplantation to warmer elevations demonstrates that climatic warming can simultaneously alter lichen growth, photosynthesis, reproductive performance, and overall health.

52. Milder Winters Would Alter Patterns of Freezing Damage for Epiphytic Lichens from the Trans-Himalayas

| Fiona Ruth Worthy et al. | Scientific Reports | 18 November 2024

Counterintuitively, warmer winters may alter acclimation and expose high-elevation lichens to damaging freeze events rather than simply reducing cold stress.

53. Bright Orange Lichens Are Able to Use Their Own Pigments as a ‘Sunscreen’

| University of Oxford | University of Oxford | 10 February 2023

Orange pigments produced by some lichens provide protection against intense sunlight, illustrating how secondary chemistry contributes directly to environmental stress tolerance.

54. Lichen Ecophysiology in a Changing Climate

| Various authors | Botanical Review | 2023

This review explains how temperature, humidity, vapor-pressure deficit, hydration cycles, and internal thallus structure determine how lichens respond physiologically to climate change.

55. Water-Energy Relationships Shape the Phylogenetic Diversity of Terricolous Lichen Communities in Mediterranean Mountains

| Various authors | Fungal Ecology | December 2022

Moisture and temperature jointly structure mountain lichen communities, suggesting that Mediterranean lichen diversity could be particularly vulnerable to warmer and drier conditions.

56. Estimating Lichen Biomass in Forests and Peatlands of Northwestern Canada in a Changing Climate

| Various authors | Arctic, Antarctic, and Alpine Research | 6 July 2022

Repeated measurements document changes in terrestrial lichen biomass across northern forests and peatlands, with consequences for ecosystem processes and caribou forage.

57. Little Time Left: Microrefuges May Fail in Mitigating the Effects of Climate Change on Epiphytic Lichens

| Various authors | Science of the Total Environment | 15 June 2022

Small areas with favorable microclimates can protect lichens temporarily, but projected warming may eventually overwhelm some refuges unless suitable habitat persists across larger landscapes.

58. Lichens Are in an Evolutionary Race Against Climate Change

| Corryn Wetzel | Smithsonian Magazine | 17 February 2022

Research suggests many lichens may adapt too slowly to keep pace with rapidly shifting temperatures, raising particular concern for specialized and climate-sensitive species.

59. Continuous Monitoring of Chlorophyll a Fluorescence and Microclimatic Conditions Reveals Warming-Induced Physiological Damage in Biocrust-Forming Lichens

| Various authors | Plant and Soil | 2022

Continuous physiological measurements show that warming can damage photosynthetic performance in lichens forming biological soil crusts.

60. Climate Warming Causes Photobiont Degradation and Carbon Starvation in a Boreal Climate Sentinel Lichen

| Various authors | American Journal of Botany | 2022

Experimental warming damaged photosynthetic partners and disrupted carbon supply, demonstrating one mechanism through which rising temperatures can threaten cold-adapted lichens.

Environmental Monitoring, Pollution, and Landscape Indicators

61. Magnetic Biomonitoring by Lichen Transplant for the Preventive Conservation of Cultural Heritage

| Various authors | Environmental Research | 15 September 2026

Lichen transplants around Lisbon's Jerónimos Monastery demonstrate how magnetic particles accumulated by lichens can help monitor pollution threatening historic buildings and cultural heritage.

62. Shifting Urban Baselines Limit the Abundance-Based Resolution of a Classical Lichen Indicator

| Michaela Kropik and Harald G. Zechmeister | Ecological Indicators | August 2026

Vienna's declining nitrogen-dioxide concentrations have reduced the usefulness of Xanthoria parietina abundance as a pollution indicator, demonstrating that biomonitoring systems must evolve as pollution regimes change.

63. The Role of Lichens in Biomonitoring of Pollution, Climate Change and Sea Level Rise in Tropics

| Various authors | Ecological Indicators | August 2026

Tropical lichens can provide information about air quality, changing climate, and even coastal environmental shifts, expanding biomonitoring beyond its traditional temperate-zone applications.

64. Decline in Epiphytic Diversity in Response to Air Pollution in a High-Altitude City

| Various authors | Atmospheric Pollution Research | July 2026

Surveys along an urbanization gradient in Cuenca, Ecuador found declining lichen and bryophyte diversity associated with atmospheric pollutants including nitrogen dioxide, sulfur dioxide, carbon monoxide, and particulate matter.

65. Biomonitoring of Airborne Trace Elements Using In Situ and Transplanted Lichens Around a Recycling Industry

| Various authors | Environmental Monitoring and Assessment | 30 June 2026

Researchers used naturally occurring and transplanted Evernia prunastri lichens to identify patterns of trace-element deposition surrounding an industrial recycling facility.

66. Review of the Role of Elemental and Isotopic Composition of Lichens in Air Quality Assessment

| Various authors | Atmospheric Pollution Research | April 2026

Chemical and isotopic analysis of lichen tissues can reveal where atmospheric contaminants originate and how pollutants are deposited across landscapes.

67. Towards a New Interpretative Framework for Air Quality and Climate Biomonitoring With Lichens

| Hugo Counoy et al. | Global Change Biology | December 2025

A meta-analysis of European biomonitoring studies identifies dozens of lichen indicators associated with ammonia, nitrogen oxides, sulfur dioxide, and climatic variables.

68. Urban Environmental Risk Assessment Through Biomonitoring: A Multivariate Approach Using Mangifera indica, Lichens, and Air Pollutants

| Lorrany Marins Mota et al. | Environmental Pollution | 15 November 2025

Combining lichens, tree leaves, measured pollutants, and statistical analysis provides a more integrated method for evaluating environmental contamination across cities.

69. Lichens as an Indicator of Air Pollution – Integration of SEM/EDS and Machine Learning Methods

| Mirosław Szwed and Dariusz Pasieka | Geographia Polonica | 2025

Combining microscopic elemental analysis with machine-learning techniques demonstrates how traditional lichen biomonitoring can be strengthened with modern analytical tools.

70. Can Saxicolous Lichens Be Used to Monitor Atmospheric Deposition?

| Various authors | Environmental Research | 2025

Researchers investigate whether rock-growing lichens reliably record atmospheric contaminants while accounting for confounding influences from underlying geology and surrounding vegetation.

71. Lichens as Bioindicators

| National Park Service | National Park Service | 2025

Differences in lichen sensitivity allow scientists to translate community composition into information about air pollution and broader ecological conditions.

72. How to Assess Air Pollution's Impacts on Forests

| Mike Bell, Emmi Felker-Quinn and Ksienya Taylor | National Park Service | 29 December 2023

Lichen communities are among the biological tools used by scientists to assess how nitrogen, sulfur, ozone, and other atmospheric pollutants influence forest ecosystems.

73. Modelling the Response of Urban Lichens to Broad-Scale Changes in Air Pollution and Climate

| Various authors | Environmental Pollution | 15 December 2022

Long-term urban datasets demonstrate how declining pollution and changing climate can act simultaneously to restructure lichen communities.

74. National Atlas of Epiphytic Lichens in Forested Habitats of the United States

| Sarah Jovan et al. | USDA Forest Service | 2021

More than 8,300 lichen surveys covering over 400 taxa and thousands of forest locations provide an exceptional national-scale dataset for studying biodiversity, pollution, climate, and forest condition.

75. Tracking Lichen to Assess Air Quality at North Cascades National Park

| National Park Service | National Park Service | June 2020

Field monitoring in North Cascades demonstrates how standardized lichen surveys can provide inexpensive long-term information about air quality in remote protected landscapes.

76. User Guide for the National Forest Inventory and Analysis Lichen Database

| Sarah Jovan et al. | USDA Forest Service | 2020

The guide documents the large standardized database created from decades of U.S. forest lichen surveys and explains how researchers can use those records.

77. Lichens in Washington's Forest Resources Inventory

| USDA Forest Service | USDA Forest Service | 2018

Statewide forest inventory data demonstrate how lichen communities can provide regional information about forest condition, climate, biodiversity, and atmospheric pollution.

78. Lichens of the Arctic

| James Walton | National Park Service | 2016

Arctic lichens survive environments that exclude many vascular plants and contribute to nutrient cycling, ground cover, food webs, and the ecological functioning of northern landscapes.

79. Lichens in Puerto Rico: An Ecosystem Approach

| Joel Mercado, William A. Gould, Grizelle González and Robert Lücking | USDA Forest Service | 2015

An ecosystem-level treatment of Puerto Rican lichens emphasizes their diversity, distribution, ecological relationships, and usefulness for understanding tropical forest environments.

80. Links Between Land Cover and Lichen Species Richness at Large Scales in Forested Ecosystems Across the United States

| Susan Will-Wolf et al. | USDA Forest Service | 2014

National forest-monitoring data connect patterns of land cover with lichen richness and demonstrate that surrounding landscape structure can influence local epiphytic biodiversity.

81. Lichens

| Sarah Jovan | USDA Forest Service | 2012

This Forest Service synthesis explains why epiphytic lichens are valuable components of forest-health monitoring and how community data can be interpreted ecologically.

82. Lichen Indicator

| Paul L. Patterson, Susan Will-Wolf and Marie T. Trest | USDA Forest Service | 2009

The U.S. Forest Service describes standardized use of lichen communities as ecological indicators within national forest-monitoring programs.

83. Lichen Community Change in Response to Succession in Aspen Forests of the Southern Rocky Mountains

| Paul C. Rogers and Ronald J. Ryel | USDA Forest Service | 2008

Changes in forest succession alter available substrates, light, moisture, and tree species, producing corresponding shifts in epiphytic lichen communities.

84. Epiphytic Lichen Diversity and Biomass in Low-Elevation Forests of the Eastern Washington Cascade Range

| John F. Lehmkuhl | Forest Ecology and Management / USDA Forest Service | 2004

Research in Cascade forests measures both lichen diversity and biomass and demonstrates that stand structure has implications for lichen-dependent forest food webs.

85. Lichens Are Critical Winter Forage for Caribou

| National Park Service | National Park Service | undated

Caribou depend heavily on terrestrial and arboreal lichens during winter, creating a direct ecological link between lichen-rich habitats and the survival of northern herbivores.

86. Lichens of Southeast Utah

| National Park Service | National Park Service | undated

Desert lichens colonize rock and soil surfaces across southeastern Utah, contributing to ecological succession while surviving intense sunlight, drought, and temperature extremes.

87. Lichens – Agate Fossil Beds National Monument

| National Park Service | National Park Service | undated

This overview introduces the lichen communities of Great Plains landscapes and explains their unusual biology and ecological importance.

88. Lichens and Air Quality

| National Park Service | National Park Service | undated

National Park Service monitoring uses changes in lichen communities and accumulated pollutants in lichen tissues to detect atmospheric contamination.

89. Lichen – The Little Things That Matter

| National Park Service | National Park Service | undated

Because lichens obtain water and nutrients directly from the atmosphere, their condition can reveal environmental changes that conventional air-monitoring stations may not capture across entire landscapes.

90. Lichen Communities for Forest Health Monitoring

| USDA Forest Service | USDA Forest Service | undated

Forest-health programs use standardized lichen community surveys to identify ecological gradients and detect environmental stresses that may otherwise be difficult to observe.

Forest Ecology, Habitat, Conservation, and Restoration

91. Lichen Communities on Understory Rowans in Managed, Urban, and Old-Growth Forests in Southern Finland

| Various authors | Biodiversity and Conservation | 10 March 2026

Comparison of rowan trees across contrasting forest environments shows how forest condition and tree size influence lichen richness and community composition.

92. Biodiversity in Primary vs. Managed Forests: Biological Legacies of Old Living and Large Dead Trees Drive Lichen Diversity

| Various authors | Forest Ecosystems | December 2025

Primary forests supported greater overall and red-listed lichen richness than managed forests, with large old trees and substantial deadwood emerging as especially important biological legacies.

93. Ground Lichen Cover and Response in Relation to Forest Characteristics in Sweden 1993–2023

| Various authors | Global Ecology and Conservation | December 2025

Three decades of Swedish monitoring reveal how terrestrial lichen cover responds to forest age, structure, vegetation, and changing environmental conditions.

94. Resampling Epiphytic Lichens in Coniferous Forests of the Southern Alps: Veteran Trees Promote Compositional Stability

| Various authors | Perspectives in Plant Ecology, Evolution and Systematics | November 2025

Long-term resampling indicates that veteran trees can provide stable refuges for epiphytic lichen communities despite broader environmental changes.

95. Tree, Stand, and Landscape Scale Effects on Epiphytic Lichen and Bryophyte Diversity in Temperate Mountain Forests

| Theresa Möller, Stefan Kaufmann and Markus Hauck | Forest Ecology and Management | 15 October 2025

Lichen diversity depends simultaneously on characteristics of individual trees, forest-stand structure, and the surrounding landscape, emphasizing the need for multi-scale forest management.

96. Links Between Species Richness of Bryophytes and Lichens and Tree-Related Microhabitats on Retention Trees

| Ilze Barone, Linda Gerra-Inohosa, Diāna Jansone et al. | European Journal of Forest Research | 4 October 2025

Retaining trees containing cavities, wounds, rough bark, and other microhabitats can preserve ecological niches important to lichens during timber harvesting.

97. Litter Decomposition of Epiphytic Lichens, Bryophytes, and Vascular Plants on the Forest Floor and Canopy in a Cool-Temperate Old-Growth Forest

| Various authors | Pedobiologia | October 2025

Comparing decomposition in the canopy and forest floor illustrates how fallen lichens participate in nutrient cycling within old-growth forest ecosystems.

98. Invasive Prunus cerasifera Hosts More Lichens Than Native Tree Species – Does Quantity Reflect Quality?

| Anna Łubek et al. | Forest Ecology and Management | 15 August 2025

An introduced tree species supported surprisingly rich lichen communities, raising questions about the relationship between host nativeness, species richness, and conservation value.

99. Multi-Scale Environmental Drivers of Lichen Diversity: Insights for Forest Management

| Various authors | Forest Ecology and Management | 1 June 2025

Lichen diversity responds to environmental factors operating from individual trees to landscapes, providing practical information for conserving lichens in managed forests.

100. Enhanced Bryophyte Communities, but Challenges for Lichens Following Translocation of Deadwood in Ecological Compensation

| Various authors | Journal of Environmental Management | May 2025

Moving deadwood as part of habitat compensation can benefit some cryptogams, but lichen establishment may be substantially slower and more difficult than bryophyte colonization.

101. Ghost Species Form an Important Component of the Epiphytic Lichens in Temperate Forests

| Various authors | Forest Ecosystems | April 2025

Some forest lichens persist for long periods after environmental conditions have become unfavorable for successful reproduction, creating ecological "ghosts" that can obscure ongoing biodiversity decline.

102. The Manna Effect – A Review of Factors Influencing Hair Lichen Abundance for Canada's Endangered Deep-Snow Mountain Caribou

| Trevor Goward, Darwyn Coxson and Yngvar Gauslaa | The Lichenologist | 18 September 2024

The abundance and accessibility of arboreal hair lichens are crucial to endangered mountain caribou that depend on them as winter forage in deep-snow forests.

103. Differential Impact of Clearcut and Insect Outbreak on Boreal Lichens and Bryophytes 50 Years After Disturbance

| Various authors | Biological Conservation | July 2024

Lichen communities remain affected decades after disturbance, while ecological recovery following natural insect outbreaks differs substantially from recovery following clearcutting.

104. Sustaining Forest Biodiversity: Long-Term Natural Disturbance Dynamics and Contemporary Lichen Communities in Primary Forests

| Various authors | Forest Ecosystems | 2024

Natural disturbances create structural heterogeneity that helps maintain diverse lichen communities in forests that have escaped intensive management.

105. Can Partial-Cut Harvesting Be Used to Extend the Availability of Terrestrial Forage Lichens in Late-Seral Pine-Lichen Woodlands?

| Various authors | Canadian Journal of Forest Research | 22 December 2023

Carefully designed partial harvesting may offer ways to maintain lichen forage while managing northern forests, although outcomes depend strongly on disturbance intensity and habitat conditions.

106. Long-Term Dynamics of the Iconic Old-Forest Lichen Usnea longissima in a Protected Landscape

| P.-A. Esseen, J. Rytterstam, A. Atrena and B.G. Jonsson | Forest Ecology and Management | 15 October 2023

A 37-year study documented substantial decline of the exceptionally long beard lichen Usnea longissima even inside a protected landscape.

107. Practical Conservation Action on a Critically Endangered Lichen Species

| Various authors | Journal for Nature Conservation | October 2023

Experimental transplantation of the Critically Endangered Leptogium hibernicum demonstrates that direct intervention can sometimes supplement conventional habitat protection.

108. A Hypervolume Approach to Niche Specialism, Tested for the Old-Growth Indicator Status of Calicioids

| Christopher J. Ellis | The Lichenologist | 13 December 2022

Ecological niche modeling provides a quantitative test of whether calicioid lichens and fungi reliably function as indicators of old-growth forest conditions.

109. Growth Form Matters – Crustose Lichens on Dead Wood Are Sensitive to Forest Management

| Annina Kantelinen et al. | Forest Ecology and Management | 15 November 2022

Crust-forming lichens on deadwood can respond strongly to forestry practices and may be overlooked when conservation assessments focus primarily on conspicuous macrolichens.

110. Conifer Tree Species and Age as Drivers of Epiphytic Lichen Communities in Northern European Production Forests

| Lisa Petersson et al. | The Lichenologist | July 2022

Both the species and age of trees influence the lichen communities occurring in production forests, highlighting the importance of retaining older trees during forestry rotations.

111. Identifying Drivers of Change in Bryophyte and Lichen Species Occupancy in Scotland

| Various authors | Ecological Indicators | June 2022

Long-term distribution records reveal how habitat, climate, pollution, and other environmental changes affect where Scotland's lichens and bryophytes persist.

112. High and Balanced Contribution of Regional Biodiversity Hotspots to Epiphytic and Epixylic Lichen Species Diversity in Great Britain

| Various authors | Biological Conservation | February 2022

Britain's richest lichen landscapes collectively protect complementary groups of species, supporting conservation strategies that maintain multiple geographically separated hotspots.

113. Influence of Canopy Structure and Light on the Three-Dimensional Distribution of the Iconic Lichen Usnea longissima

| Various authors | Forest Ecology and Management | 2022

The vertical and horizontal structure of forest canopies determines where Usnea longissima can obtain suitable combinations of light and moisture.

114. Does Air Pollution Influence the Success of Species Translocation?

| Various authors | Ecological Indicators | October 2020

Transplants of the threatened lung lichen Lobaria pulmonaria show that pollution exposure can affect physiology and potentially reduce the effectiveness of conservation translocations.

115. Epiphytic Lichen Diversity and Sustainable Forest Management Criteria and Indicators in Italian Coppice Forests

| Various authors | Ecological Indicators | August 2020

Lichen diversity provides measurable information about the ecological condition of coppice forests and can contribute to indicators used in sustainable forest management.

116. Using Lichen Communities as Indicators of Forest Stand Age and Conservation Value

| Jesse E. D. Miller et al. | Forest Ecology and Management | 2020

Lichen community composition can help distinguish younger forests from older stands and provide an additional tool for identifying forests with high conservation value.

117. Successful Conservation of the Endangered Forest Lichen Lobaria pulmonaria Requires Knowledge of Fine-Scale Population Structure

| Various authors | Fungal Ecology | 2018

Genetic differences among nearby populations of Lobaria pulmonaria indicate that conservation programs should consider local population structure when moving or restoring lichens.

118. Lichen Communities as Climate Indicators in the U.S. Pacific States

| Robert J. Smith, Sarah Jovan and Bruce McCune | USDA Forest Service | 2017

Large-scale lichen surveys across western forests produced community-based climate indicators capable of tracking ecological responses to temperature and moisture patterns.

119. Lichen Habitat May Be Enhanced by Thinning Treatments

| Heather T. Root and Bruce McCune | USDA Forest Service | 2013

Forest thinning can alter light and microclimate in ways that benefit some lichens, suggesting that carefully designed management may sometimes improve lichen habitat.

120. Historical Patterns in Lichen Communities of Montane Quaking Aspen Forests

| Paul C. Rogers et al. | USDA Forest Service | 2011

Lichen communities associated with aspen forests provide information about long-term stand conditions and the ecological consequences of changing forest structure.

Polar, Alpine, Desert, Biocrust, and Extreme-Environment Lichens

121. Fog, Symbiosis, and Survival: The Ecological Architecture of the Grit Crust From the Atacama Desert

| Various authors | Environmental Microbiology | 2026

Lichen-dominated crusts associated with quartz fragments in the Atacama Desert function as complex holobionts sustained by rare fog moisture in one of Earth's driest environments.

122. Linking Biocrust Architecture and Dispersal: Reproductive Ecology of Lichens of the Grit Crust in the Coastal Atacama Desert

| Various authors | Scientific Research Article | 2026

The study investigates how Atacama lichens reproduce and disperse among quartz grains and shows that free-living algal partners may act as reservoirs for future lichen formation.

123. Desert Lichen Offers New Evidence for the Possibility of Life on Other Planets

| Desert Research Institute | Phys.org | 25 June 2025

The ability of desert lichens to tolerate extreme environmental stress is being studied as an analogue for how symbiotic organisms might survive on harsh extraterrestrial worlds.

124. A Step Towards Life on Mars? Lichens Survive Martian Conditions

| Science news staff | Phys.org | April 2025

Experiments simulating Martian environmental conditions found surprising persistence of lichen fungal metabolism, strengthening interest in lichens within astrobiology.

125. Lichens and Health – Trends and Perspectives for the Study of Biodiversity in the Antarctic Ecosystem

| Various authors | Journal of Fungi | 4 March 2025

A systematic review surveys Antarctic lichen diversity, biology, environmental stress, and potential health-related applications of compounds produced under extreme polar conditions.

126. Study Reveals Effect of Slope Position on Nonstructural Carbohydrates in Biological Soil Crusts

| Science news staff | Phys.org | November 2024

Lichen-dominated biological soil crusts adjust stored carbohydrates according to differences in slope, moisture, and temperature, illustrating fine-scale adaptation to desert conditions.

127. Two New Species of the Genus Lecidella from Maritime Antarctica, Southern South America and North America

| Various authors | The Lichenologist | 7 March 2024

Taxonomic research from Antarctica and the Americas demonstrates that even relatively well-studied lichen genera continue to yield previously unrecognized species.

128. Biological Soil Crusts as an Integral Component of Desert Environments

| Jayne Belnap and Bettina Weber | Ecological Processes | 16 May 2013

This broad synthesis explains how lichens, cyanobacteria, mosses, and other organisms create living soil surfaces that stabilize deserts and influence water, nutrients, and ecosystem productivity.

129. Lichen Species Dominance and the Resulting Photosynthetic Behavior of Sonoran Desert Soil Crust Types

| Various authors | Ecological Processes | 26 March 2013

Different dominant lichen species produce measurable differences in photosynthetic behavior across biological soil crust communities in the Sonoran Desert.

130. Diversity of Free-Living and Lichenized Fungal Communities in Biological Soil Crusts of the Sultanate of Oman

| Various authors | Soil Biology and Biochemistry | February 2013

Research in Oman's deserts documents diverse lichenized and free-living fungi and examines their contribution to soil characteristics in arid ecosystems.

Taxonomy, New Species, and Regional Biodiversity

131. Ontogenetic Development of Pycnidial Conidiomata and Conidium Formation in the Genus Peltigera

| Gernot Vobis and Thorsten Lumbsch | The Lichenologist | 3 June 2026

Detailed microscopic study examines development of fungal reproductive structures in Peltigera and contributes to understanding lichen reproduction and fungal morphology.

132. A First Record of the Genus Canoparmelia in Europe

| Pradeep K. Divakar et al. | The Lichenologist | 21 May 2026

Discovery of Canoparmelia in Europe extends the known geographic distribution of the genus and demonstrates how regional lichen floras continue to change with new collecting and molecular analysis.

133. High Diversity at the Small Scale: An Inventory of Foliicolous Lichens of Brunei Reveals 193 Species, Including 21 New to Science

| Danielle A. Ward et al. | The Lichenologist | 29 April 2026

Intensive sampling of leaf-dwelling lichens in Brunei uncovered remarkable diversity in a small area, including 21 species previously unknown to science.

134. The Cyanolichen Dripzone Hypothesis Revisited

| André Arsenault and Patricia Baines | The Lichenologist | 29 April 2026

Field observations from eastern North America explore why cyanolichens frequently occupy particular positions on tree trunks associated with water flow from branches and crowns.

135. Dynamics of Lobaria pulmonaria Near Its Northern Distribution Boundary in Paanajärvi National Park Old-Growth Forests

| Roman Ignatenko and Anna Ignatenko | The Lichenologist | 28 April 2026

Population studies of the sensitive lung lichen Lobaria pulmonaria examine its persistence in northern old-growth forests near the climatic edge of its distribution.

136. Bound by Ammonia: Pollution Constrains Cetraria sepincola at the Margin of Its Central European Range

| Michael Boxriker et al. | The Lichenologist | 2 March 2026

Atmospheric ammonia appears to restrict the occurrence of a pollution-sensitive lichen near the southern edge of its Central European distribution.

137. Lecanora hybocarpa and Similar European Species

| Ulf Arup, Jiří Malíček, Ulf Schiefelbein and Håkon Holien | The Lichenologist | 29 December 2025

Detailed morphological and molecular comparisons clarify boundaries among several European Lecanora species that have historically been difficult to distinguish.

138. Unveiling Lichen Diversity on Volcanic Substrates: A Comparative Study Across Mainland Spain

| Various authors | Journal of Arid Environments | December 2025

Volcanic landscapes support distinctive lichen assemblages whose composition reflects differences in rock chemistry, climate, and habitat history.

139. Speciation Continuum in Non-Model Organisms: Revisiting the Species-Pair Concept in Lichens

| Various authors | Molecular Phylogenetics and Evolution | November 2025

Genetic analysis of Usnea examines whether morphologically distinct reproductive forms represent separate species or stages within a continuing process of divergence.

140. Lecanora austrocalcicola, a New Species from a Limestone Outcrop in Brazil

| André Aptroot, Lidiane Alves dos Santos and Marcela Cáceres | The Lichenologist | 20 October 2025

A limestone outcrop in Brazil yielded a previously undescribed Lecanora, emphasizing the conservation significance of small and geologically distinctive habitats.

141. Fellhaneropsis sigmoidea, a New Foliicolous Species from China

| Wei-Cheng Wang | The Lichenologist | 20 October 2025

A newly identified leaf-dwelling lichen adds to growing knowledge of China's foliicolous lichen diversity.

142. Little Giants: Lichens in Tropical Dry Forests

| Various authors | Forests | 22 August 2025

Lichens represent an ecologically important but frequently overlooked component of tropical dry-forest biodiversity and respond strongly to habitat structure and environmental conditions.

143. New Species of Chiodecton and Enterographa from India

| Rakesh Adhikari, Sanjeeva Nayaka and Dalip K. Upreti | The Lichenologist | 19 August 2025

New Indian species in the Roccellaceae demonstrate that tropical and subtropical bark surfaces continue to harbor substantial undescribed lichen diversity.

144. A New Lichenicolous Species of Laetisaria from France

| Damien Ertz, Patrick Pinault and Paul Diederich | The Lichenologist | 11 August 2025

Molecular and morphological evidence identifies a new fungus growing in association with the lichen Physcia, adding to the diversity of specialized lichenicolous fungi.

145. Pine Cones in Plantations as Refuge and Substrate of Lichens and Bryophytes in the Tropical Andes

| Ángel Benítez | Diversity | 1 August 2025

Fallen and retained pine cones can function as miniature habitats for lichens and bryophytes, demonstrating the ecological importance of small substrates in plantation landscapes.

146. A New Epiphytic Species of Gyalolechia with a Maritime, Mediterranean-Macaronesian Distribution

| Ulf Arup, Pier Luigi Nimis, Jan Vondrák, Stanislav Svoboda and Ulrik Søchting | The Lichenologist | 31 March 2025

Taxonomic study identifies a distinctive Gyalolechia occurring in coastal Mediterranean and Macaronesian habitats.

147. New Species of Bacidia s.l. from the Azores and the Resurrection of Genus Woessia

| P.P.G. van den Boom and P. Alvarado | Diversity | 6 March 2025

Study of Azorean lichens produces new species descriptions while molecular evidence supports renewed recognition of the genus Woessia.

148. The Epiphytic Leprose Leprocaulon inexpectatum sp. nov. from Italy and Its Photosynthetic Partner Symbiochloris

| Gabriele Gheza et al. | The Lichenologist | 25 February 2025

Researchers describe both a new lichen-forming fungus and its associated green algal partner, illustrating how studying both symbionts can reveal previously hidden biodiversity.

149. Micarea svetlanae, a New Species of the M. prasina Group from the Russian Far East

| Liudmila A. Konoreva, Sergey V. Chesnokov and Ivan V. Frolov | The Lichenologist | 25 February 2025

A newly recognized Micarea species from eastern Russia expands the rapidly developing taxonomy of small crustose forest lichens.

150. Diploicia edulis and Physcia ornamentalis, Two New Species Associated with Invertebrates from the Tropical Dry Forest of Mexico

| Ricardo Miranda-González, Felipe Campos-Cerda and María de los Angeles Herrera-Campos | The Lichenologist | 25 February 2025

Two newly described Mexican lichens have unusual ecological relationships with invertebrates, illustrating previously overlooked connections within tropical dry forests.

151. Porina dolichoepiphylla, a New Species from Mindanao Island and an Updated Checklist of Philippine Porina

| Ermalene C. Taer et al. | The Lichenologist | 25 February 2025

Discovery of a new Philippine Porina species accompanies an updated inventory of the genus and highlights the richness of tropical leaf- and bark-dwelling lichens.

152. Diversity and Elevational Levels of Lichens in Western Tianshan National Nature Reserve in Xinjiang, China

| Anwar Tumur, Reyim Mamut and Mark R.D. Seaward | Diversity | 29 January 2025

Surveys across an elevational gradient document substantial lichen diversity in the western Tianshan Mountains and show how community composition changes with altitude.

153. New Phylogenetic Insights into the Lichen Genus Lecanora s. lat. and Resurrection of Glaucomaria, Straminella and Zeora

| Various authors | The Lichenologist | 2025

Molecular phylogenetics reorganizes parts of the enormous Lecanora complex and restores several genera that better represent evolutionary relationships.

154. A Preliminary Assessment of Lichens in Different Landscapes of Hanoi, Vietnam

| Hoang Ngoc Khac et al. | Diversity | 30 December 2024

Surveys across contrasting Hanoi landscapes reveal how urbanization and habitat type influence tropical lichen richness and composition.

155. Epiphytic Lichens in Salt Flats as Biodiversity Refuges in Reserva Ecológica Arenillas

| Carlos Naranjo et al. | Diversity | 24 October 2024

Lichen communities associated with trees in Ecuadorian salt-flat landscapes highlight the ecological importance of unusual habitats that can function as refuges for epiphytic biodiversity.

156. Forest Disturbance Determines Diversity of Epiphytic Lichens and Bryophytes on Trunk Bases in Tropical Dry Forests

| Ángel Benítez et al. | Forests | 6 September 2024

Disturbance changes the epiphytic communities occurring near the bases of trees, with implications for conservation of cryptogams in threatened tropical dry forests.

157. A New Species and a New Record of Byssoid Arthoniaceae from Southern China

| Lulu Zhang, Junxia Xue and Linlin Liu | Diversity | 10 May 2024

Field and taxonomic research expands knowledge of delicate byssoid lichens in southern China, including a species previously unknown to science.

158. The Taxonomy of Sterile Arthoniaceae from Brazil: White Crusts on Overhanging Tropical Trees Can Be Named

| André Aptroot et al. | The Lichenologist | 28 February 2024

Detailed examination of inconspicuous sterile crustose lichens in Brazil resulted in recognition of numerous species, including multiple taxa new to science.

159. Placopsis craterifera, a New Lichen Species from Alpine Habitats on Mount Meru, Tanzania

| Various authors | The Lichenologist | 2024

Discovery of a previously unknown alpine lichen on Mount Meru demonstrates the distinctive biodiversity of isolated high-elevation African habitats.

160. Neoplaca mirabilis, a New Genus and a New Epigaeic Species

| Ivan Frolov, Mikhail Prokopiev and Lidia Konoreva | The Lichenologist | 28 November 2023

Morphological and molecular investigation establishes a new lichen genus and species, illustrating the continuing expansion of recognized fungal diversity.

161. A New Species and Two New Records of the Lichen Genus Fissurina from China

| Kaijie Shi, Zefeng Jia and Xin Zhao | Diversity | 25 August 2023

Taxonomic surveys continue to expand the known diversity and geographic range of Fissurina lichens in East Asia.

162. High Species Richness in the Lichen Genus Peltigera: 34 Species Including 24 New to Science

| Nicolas Magain, Jolanta Miadlikowska, Bernard Goffinet et al. | Persoonia | 8 August 2023

Molecular species delimitation radically expands recognized diversity within two Peltigera lineages, describing 24 species that had previously been hidden within broadly defined morphospecies.

163. A New Lichenized Fungus, Lendemeriella luteoaurantia, with a Key to the Species of Lendemeriella

| Beeyoung-Gun Lee and Jae-Seoun Hur | Diversity | July 2023

A newly described species adds to the genus Lendemeriella and is accompanied by an identification key useful for distinguishing its known species.

164. Rediscovery of Five Rinodina Species Originally Described from Southwest China and One New Species

| Qiuyi Zhong et al. | Diversity | 25 May 2023

Revisiting historical collecting sites allowed researchers to relocate poorly known Rinodina species and describe an additional member of the genus.

165. A New Species and a New Record of the Genus Squamulea from Pakistan

| Farzana Afshan et al. | The Lichenologist | 20 March 2023

Taxonomic work in Pakistan adds a newly described species and a new regional record to the rapidly developing inventory of Asian lichens.

166. The Lichen Genus Sticta in East African Montane Ecosystems

| Various authors | Journal of Fungi | 12 February 2023

Detailed taxonomic research shows that East African mountain forests contain far more Sticta diversity than previously recognized.

167. Dozens of New Lichen Species Discovered in East African Mountain Forests

| University of Helsinki | University of Helsinki | 2023

Intensive research in African montane forests has revealed numerous previously undescribed lichens, demonstrating how incompletely documented tropical lichen diversity remains.

168. Four Lichen Species New to Science Discovered in Kenyan Cloud Forests

| University of Helsinki | University of Helsinki | 2020

Examination of Kenyan cloud forests uncovered several previously unknown Micarea lichens and emphasized the global conservation importance of African montane forests.

169. Lichen Biodiversity in Southwest Alaska National Parks

| National Park Service | National Park Service | 2018

Large inventories in Katmai and Lake Clark documented hundreds of lichen taxa, including species new to science and numerous previously unreported records.

170. Southwest Alaska Lichen Inventory

| National Park Service | National Park Service | undated

Intensive inventory work across Katmai, Lake Clark, and Kenai Fjords demonstrates the extraordinary lichen richness of Alaska's varied coastal, forest, tundra, and volcanic landscapes.

Biocrusts, Conservation, and Public Science

171. Threats on Lichens and Their Conservation—A Review Based on a Bibliometric Analysis

| Various authors | Diversity | 2026

A broad review identifies habitat destruction, land-use change, pollution, climate change, overharvesting, and inadequate knowledge as major obstacles to global lichen conservation.

172. Lichens as Bioindicators of Global Change Drivers

| Lourdes Morillas et al. | Journal of Fungi | 5 January 2024

Lichens respond not only to conventional pollutants but also to climate, nitrogen deposition, land-use change, and other global-change pressures, making them unusually versatile ecological indicators.

173. More Than You Can See: Unraveling the Ecology and Biodiversity of Lichenized Fungi Associated with Leaves and Needles of 12 Temperate Tree Species

| Various authors | Frontiers in Microbiology | 16 September 2022

DNA sequencing reveals substantial hidden diversity of lichenized fungi living on leaves and needles, including organisms that conventional visual surveys are likely to overlook.

174. A Call to Reconceptualize Lichen Symbioses

| Jessica L. Allen and James C. Lendemer | Trends in Ecology & Evolution | July 2022

The authors argue that lichens should no longer be treated simply as fungus-plus-alga organisms and propose a broader ecological framework for understanding multipartite lichen symbioses.

175. To Gauge Impact of Nitrogen Pollution, Sri Lanka Project Looks to Lichens

| Malaka Rodrigo | Mongabay | 6 May 2022

Scientists in Sri Lanka are using lichen communities to investigate atmospheric nitrogen pollution, demonstrating the growing application of biological monitoring in tropical countries.

176. A Biogeographical Study of Red Listed Lichen Species at Temporal and Spatial Scales Within Protected and Non-Protected Areas

| Various authors | Scientific Reports | 18 January 2022

Comparing threatened lichen distributions inside and outside protected areas helps evaluate whether existing conservation networks are adequately preserving vulnerable species.

177. On the Hunt for Unloved, Unstudied, Yet Super Important Lichen

| Harrison Tasoff | Smithsonian Magazine | 20 August 2018

Scientists and museum collections reveal an enormous reservoir of poorly understood lichen biodiversity whose ecological roles may be substantial despite receiving comparatively little attention.

178. New Lichen Database Takes Big Picture Approach to Forest Monitoring

| Amy McDermott | Mongabay | 22 May 2017

Large lichen datasets assembled from forest surveys allow researchers to examine pollution, climate, and ecological change over geographical scales that individual field studies cannot capture.

179. What Scientists Thought Was a Single Species Is Actually 126-Plus

| Rachel Nuwer | Smithsonian Magazine | 2 July 2014

Genetic studies of apparently similar lichens demonstrate how traditional morphology can conceal extraordinary cryptic species diversity.

180. Lichens Do Not Age

| Rachel Nuwer | Smithsonian Magazine | 2 January 2013

Studies of exceptionally long-lived lichens raise intriguing questions about growth, senescence, stress tolerance, and what biological aging means for slow-growing symbiotic organisms.

Lichens and Other Organisms

181. Mat-Forming Lichens Support Contrasting Micro-Arthropod Density

| Ruben E. Roos, Kristel van Zuijlen, Tone Birkemoe, Stef Bokhorst and Johan Asplund | Fungal Ecology | December 2025

Different mat-forming lichens support markedly different densities of tiny soil and vegetation arthropods, showing that lichen identity can shape animal microhabitats.

182. Lichens and Drones Reveal Dinosaur Bones

| University of Reading | University of Reading | 3 November 2025

Researchers found that distinctive lichens growing preferentially on exposed fossil bone can create color signatures detectable by drones, potentially assisting paleontological surveys.

183. A New Experimental Approach to Investigate Grazing on Epiphytic Lichens by Gastropods

| André Arsenault and Patricia Baines | The Lichenologist | 30 June 2025

Controlled experiments provide a method for measuring how snails and slugs consume epiphytic lichens and potentially influence their abundance and distribution.

184. Endangered Mountain Caribou Possess Unique Gut Microbiome That May Be Important for Recovery Efforts

| University of Alberta | EurekAlert | 5 June 2025

Mountain caribou consuming large quantities of tree lichens possess distinctive gut microorganisms that may help them digest this chemically unusual winter food.

185. High Host Preferences in Epiphytic Lichens Across Diverse Phorophyte Species in the Mediterranean Region

| Various authors | Journal of Fungi | 30 January 2025

Many epiphytic lichens show strong preferences for particular tree species, suggesting that conserving tree diversity also protects specialized lichen communities.

186. Generalism in Species Interactions Is More the Consequence Than the Cause of Ecological Success

| Various authors | Nature Ecology & Evolution | 2024

Analysis of tens of thousands of ecological interactions, including lichen relationships with plants, suggests that broadly distributed organisms may become generalists because ecological success exposes them to more potential partners.

187. Santa's Reindeer and the Quest for Scottish Enlichenment

| University of St Andrews | University of St Andrews | 15 December 2023

Research into reindeer vision suggests their unusual ability to perceive ultraviolet light may help them distinguish lichen forage against snowy landscapes.

188. Effects of Fire on Pyrodiversity of Terricolous Non-Tracheophyte Photoautotrophs in a Páramo of Southern Ecuador

| Erika Yangua-Solano, Vinicio Carrión-Paladines and Ángel Benítez | Diversity | 27 November 2023

Fire history influences ground-dwelling lichens and other cryptogams in high-elevation páramo ecosystems, with different fire regimes producing contrasting community responses.

189. Lichen-Associated Oribatid Mites in the Taiga Zone of Northeast European Russia

| Elena N. Melekhina | Diversity | 27 April 2023

Surveys reveal diverse communities of oribatid mites associated with lichens, illustrating an often overlooked animal component of lichen-dominated microhabitats.

190. Culturable Diversity of Lichen-Associated Yeasts Through Enrichment Strategies

| Daniel B. Raudabaugh and M. Catherine Aime | Ecologies | 2 March 2023

Improved culturing methods reveal diverse yeasts associated with lichens and provide organisms that can be experimentally studied rather than detected only through DNA sequencing.

Applied Lichen Science and Emerging Research

191. Lichen-Derived Secondary Metabolites: Ethnobotanical Insights and Pharmacological Prospects

| Various authors | Plant Science Today | 5 February 2026

The review connects traditional human uses of lichens with modern investigations of their chemically unusual secondary metabolites and possible pharmaceutical applications.

192. Computer Vision Species Identification of Lichens and Bryophytes from Biocrusts in Australian Drylands

| Cécile Gueidan et al. | Applications in Plant Sciences | 6 November 2025

Machine-learning models trained largely on herbarium images demonstrate that automated image recognition may assist identification of difficult lichen and bryophyte species in biological soil crusts.

193. The Lichen Life: Lessons From the Edge

| CUNY Graduate Center | CUNY Graduate Center | 28 May 2025

Researchers discuss lichens as models for understanding symbiosis, survival in extreme environments, and the increasingly blurred boundary between individual organisms and ecological communities.

194. Cracking the Code: Deciphering How Concrete Can Heal Itself

| Jennifer Nichols | Texas A&M Engineering | 7 May 2025

Engineers inspired by the cooperative biology of lichens are developing synthetic microbial partnerships designed to produce minerals that could allow concrete to repair its own cracks.

195. A Comprehensive Review on Chemical Structures and Bioactivities of Ostropomycetidae Lichens

| Yunhui Wang et al. | Journal of Fungi | 2025

Lichens belonging to the Ostropomycetidae produce a diverse collection of compounds with antimicrobial, antioxidant, cytotoxic, and other experimentally observed biological activities.

196. Steep Increase in Red-Listed Lichens of Estonia

| Tiina Randlane et al. | The Lichenologist | 12 December 2024

Updated national assessments reveal a substantial increase in the number of threatened Estonian lichens, demonstrating continuing pressures on specialized species and habitats.

197. Natural History Museum and Royal Botanic Gardens, Kew Announce Groundbreaking Mycological Research Programme

| Natural History Museum and Royal Botanic Gardens, Kew | Natural History Museum | 20 May 2024

A major genomics initiative will sequence fungi and lichens preserved in national collections, opening large historical specimen archives to modern evolutionary and biodiversity research.

198. Red Listing Lichenized Fungi: Best Practices and Future Prospects

| Rebecca Yahr et al. | The Lichenologist | 2024

Conservation specialists outline methods for applying IUCN Red List criteria to lichens and discuss how limited distribution and population data can be handled rigorously.

199. UAB BioBlitz Identifies an Endangered and Protected Lichen

| Universitat Autònoma de Barcelona | UAB | 13 April 2023

A university BioBlitz involving scientists and citizen participants documented a protected lichen, illustrating how community biodiversity surveys can generate meaningful conservation records.

200. Ecology's Next Frontier: Student Researchers Hone In on Rare and Understudied Lichens

| Cal Poly | Cal Poly | 2021

Field research on poorly documented lichens demonstrates how university collections and local surveys can fill major gaps in regional biodiversity knowledge.