Top Streams & Viral Hits in Lichenology

Top Streams and Viral Hits in Lichenology: An Academic Perspective

Lichenology, once a niche discipline within cryptogamic botany and mycology, has experienced a renaissance in recent decades, propelled by technological advances, environmental concerns, and integrative research frameworks. The term "streams" refers to dominant research directions and conceptual frameworks currently shaping the field, while "viral hits" are defined as highly influential discoveries, datasets, or studies that have catalyzed widespread attention, redefined hypotheses, or opened new subdisciplines.

This review categorizes and analyzes these focal points, offering insight into how lichenology is evolving in response to both academic and societal challenges.

1. Molecular and Genomic Advances

1.1. Stream: Phylogenomics and DNA Barcoding

• The adoption of multilocus and whole-genome sequencing approaches has led to major taxonomic revisions and the resolution of complex species boundaries.
  
  

• Key initiatives include the UNITE database for fungal ITS sequences and multi-gene matrices for resolving deep phylogenies in families such as Parmeliaceae and Megasporaceae.
  
  

1.2. Viral Hit: Discovery of Cryptic Species Complexes

• Examples include the reclassification of the Cladonia and Lecanora groups, where morphologically identical lichens were found to comprise multiple distinct genetic lineages.
  
  

• These findings reshaped ecological and biogeographical interpretations of lichen diversity.
  
  

2. Symbiotic Complexity and Microbiome Research

2.1. Stream: Holobiont Theory in Lichenology

• Moving beyond the classical mycobiont-photobiont paradigm, lichens are now studied as multispecies consortia, incorporating bacterial, algal, and fungal endosymbionts.
  
  

• This approach intersects with microbiome science and systems ecology.
  
  

2.2. Viral Hit: Discovery of Basidiomycete Yeasts in Cortex Layers

• The work of Spribille et al. (2016) demonstrated that basidiomycete yeasts form a regular part of some lichen cortices, profoundly impacting our understanding of lichen symbiosis and evolution.
  
  

3. Conservation Biology and Environmental Monitoring

3.1. Stream: Lichens as Bioindicators

• Long-standing but increasingly refined, this field includes epiphytic lichens for air pollution monitoring, soil crust lichens in desertification studies, and marine lichens in climate change research.
  
  

• Standardized protocols have elevated lichen bioindication to a policy-relevant science.
  
  

3.2. Viral Hit: Red-Listing and IUCN Frameworks

• Numerous countries now maintain national red lists for lichens, and species like Pseudocyphellaria crocata have gained international attention due to their habitat sensitivity.
  
  

• These assessments directly influence forest management and conservation policies.
  
  

4. Lichen Secondary Metabolites and Applied Research

4.1. Stream: Bioprospecting and Chemical Ecology

• Lichens produce over 1,000 unique secondary compounds with antifungal, antiviral, and anti-cancer potential.
  
  

• Interdisciplinary collaborations have linked lichen chemistry to pharmaceutical and biomaterial research.
  
  

4.2. Viral Hit: Identification of Usnic Acid’s Antimicrobial Properties

• Though known for decades, renewed interest in usnic acid has led to its use in nanotechnology, antibiotic resistance research, and biodegradable coatings.
  
  

5. Digital Infrastructure and Data Mobilization

5.1. Stream: Open Data and Citizen Science

• Platforms like GBIF, iNaturalist, and MycoPortal are integrating lichen data from herbaria, field surveys, and non-specialists.
  
  

• The resulting datasets support macroecological studies and real-time biodiversity monitoring.
  
  

5.2. Viral Hit: Digitization of Historical Lichen Collections

• Projects such as Digitarium and the Consortium of North American Lichen Herbaria (CNALH) have unlocked thousands of type specimens and locality records for computational research and conservation assessment.
  
  

6. Lichen Biogeography and Climate Modeling

6.1. Stream: Predictive Niche Modeling

• GIS and ecological niche modeling (ENM) are being used to forecast species range shifts, especially for Arctic, alpine, and maritime lichens under climate change scenarios.
  
  

6.2. Viral Hit: Rediscovery of Supposedly Extinct Lichen Taxa

• Technological and field advances have enabled the rediscovery of species such as Lobaria pulmonaria in previously degraded areas, overturning assumptions about local extinctions and highlighting microrefugia.
  
  

7. Lichenology in Cultural and Heritage Contexts

7.1. Stream: Lichens and Stone Conservation

• Interdisciplinary efforts in biodeterioration studies have highlighted the role of endolithic lichens in degrading monuments and cultural heritage.
  
  

• Research spans from SEM imaging of colonization to enzymatic biofilm analysis.
  
  

7.2. Viral Hit: Lichen Biodeterioration of UNESCO Sites

• Studies of Circinaria species on Persepolis or Caloplaca on European cathedrals have elevated lichenology's visibility in heritage science and policy circles.
  
  

The streams and viral hits of lichenology demonstrate a vibrant, multi-faceted discipline integrating taxonomy, genomics, conservation, chemical biology, and cultural heritage. These rapidly advancing fields are increasingly collaborative, data-rich, and socially relevant. Understanding these trends is essential for shaping the future of lichenological research and its applications across scientific, environmental, and cultural domains.