Checklists of lichen-forming, lichenicolous and allied fungi of Iran

The Importance of Checklists in Lichenological Studies

Checklists serve as foundational tools in lichenological research, providing a comprehensive inventory of species occurrence within a defined geographic or ecological region. These records are not merely taxonomic compilations but are critical frameworks for biodiversity assessment, conservation planning, ecological monitoring, and biogeographical analysis. In regions where lichens are underexplored or subject to rapid environmental change, checklists play an especially vital role in establishing baseline data and identifying research priorities.

The value of checklists extends beyond cataloging species. They facilitate the detection of endemism, rare or threatened taxa, and newly recorded or undescribed species, thereby supporting red-list assessments and conservation strategies. Checklists also help in tracking distributional shifts over time, which can be linked to factors such as climate change, habitat degradation, pollution, or land-use change. In this way, lichen checklists contribute to a broader understanding of ecosystem health and resilience.

From a taxonomic and systematic perspective, checklists aid in standardizing nomenclature and clarifying synonymies and misapplied names, often drawing upon herbarium records and revisions of type specimens. Furthermore, they serve as a critical interface between classical morphology-based identification and molecular-based taxonomy, enabling integrative approaches to lichen classification.

In applied contexts, particularly in environmental monitoring and heritage conservation, lichen checklists provide essential references for bioindication studies. The presence or absence of specific lichen taxa can reflect air quality, substrate integrity, or microclimatic conditions. For heritage scientists, knowing which lichen species colonize historical stone and architectural surfaces is crucial for assessing biodeterioration processes and formulating conservation responses.

Types of Checklists in Lichenology

Checklists in lichenology can vary in scope and purpose, and understanding their types enhances their applicability across scientific and conservation contexts:

1. Floristic Checklists:
   These list all known lichen species in a particular geographical area (e.g., a country, region, national park). They are essential for biodiversity surveys and biogeographical comparisons.
   
   

2. Ecological or Habitat-Based Checklists:
   These focus on lichens found within specific ecosystems or habitat types (e.g., epiphytic lichens in old-growth forests, saxicolous lichens on calcareous rocks). They are often used in ecological studies and conservation assessments.
   
   

3. Substrate-Specific Checklists:
   Compiled based on the substrate lichens grow on (e.g., bark, soil, stone, metal), these are particularly useful for understanding niche specialization and in studies of urban environments and heritage conservation.
   
   

4. Temporal or Historical Checklists:
   These record species occurrences across different time periods, helping to track changes in lichen flora due to environmental or anthropogenic pressures.
   
   

5. Red List-Based Checklists:
   These include species of conservation concern, often aligned with IUCN criteria, and are vital for threat assessments and biodiversity policy-making.
   
   

6. Functional or Trait-Based Checklists:
   Emerging in more recent years, these associate species with ecological traits such as photobiont type, growth form, reproductive strategy, or pollution sensitivity, supporting functional biodiversity and ecosystem service evaluations.
   
   

7. Molecular and Genomic Checklists:
   Integrating DNA-based data, these are used to compile barcoded or sequenced species records, aiding in cryptic species recognition and molecular ecology studies.
   
   

Floristic Checklists

Floristic checklists are one of the most fundamental and widely used tools in lichenology. These checklists provide a comprehensive record of all lichen species known to occur within a specific geographic area, such as a country, province, island, mountain range, or protected area. Their primary goal is to document lichen biodiversity and distribution across landscapes, which is essential for understanding regional species richness, endemism, biogeographical patterns, and conservation needs.

The value of floristic checklists lies in their ability to establish baseline biodiversity data, which serves as a reference for future ecological, taxonomic, and conservation work. These lists are particularly important in underexplored or rapidly changing environments, where new species discoveries, range extensions, and changes in community composition are likely. For example, floristic checklists in arid regions, tropical forests, or high-altitude ecosystems often lead to the identification of undescribed species or significant biogeographical disjunctions.

In the context of global change, floristic checklists help track the appearance or disappearance of species over time, offering insights into climate-driven range shifts, habitat loss, pollution impacts, or invasive species encroachment. The repeated compilation of floristic checklists over decades can reveal long-term trends in lichen diversity and abundance, aiding ecological modeling and conservation planning.

Floristic checklists also play a vital role in the development of national and regional red lists of threatened lichens, as they provide the necessary occurrence and distribution data required for IUCN-style assessments. Furthermore, they support the designation of Important Plant Areas (IPAs), Key Biodiversity Areas (KBAs), or other conservation priority sites where rare or specialized lichen taxa are concentrated.

From a taxonomic standpoint, floristic checklists encourage re-examination of herbarium records and often necessitate field-based confirmation of historic records. They also support molecular studies by providing locality-based sampling frameworks and contextualizing phylogenetic findings within broader biodiversity patterns.

In addition to their scientific value, floristic checklists are crucial for public engagement, citizen science, and environmental education. When presented in accessible formats—whether through publications, online databases, or field guides—they foster awareness of lichen diversity and promote community involvement in biodiversity recording and monitoring.

To maximize their utility, high-quality floristic checklists typically include:

• Accepted names and synonyms to reflect current taxonomy.
  
  

• Geographic coordinates or detailed locality information.
  
  

• Habitat or substrate preferences.
  
  

• Collection references or voucher specimens.
  
  

• Notes on abundance, ecology, and distribution.
  
  

• Updates on recently discovered or removed species.
  
  

Modern floristic checklists are increasingly integrated into digital platforms such as the Global Biodiversity Information Facility (GBIF), the Consortium of North American Lichen Herbaria (CNALH), and national biodiversity portals, where they contribute to open-access biodiversity data and facilitate large-scale comparative research.

Conclusion

In summary, lichen checklists are indispensable to both basic and applied sciences. They underpin ecological, taxonomic, and conservation research, foster data comparability across studies, and strengthen the scientific basis for sustainable management of lichen diversity across natural and cultural landscapes. The diversity of checklist types enables their use in a wide range of interdisciplinary studies—from classical floristics and taxonomy to bioindication, genomics, and heritage conservation.