Collections in Lichenology

Scientific Collections, Herbarium, and Fungarium in Lichenology: Importance, Structure, and Categories

Scientific collections, including herbaria and fungaria, are central to the study and conservation of biological diversity. In the field of lichenology, these collections serve as vital repositories of both historical and contemporary specimens, offering a wealth of data for taxonomic, ecological, and evolutionary research. The systematic study of lichens relies heavily on these collections, which house physical evidence of species diversity, distribution, and variation.

These collections are particularly important in lichenology due to the complexity of the organisms—formed from the symbiosis of fungi and photosynthetic partners—and their significant ecological roles. Understanding the diversity and evolutionary relationships within the lichenized fungi is inherently linked to the availability and proper management of herbarium and fungarium specimens.

1. The Role of Scientific Collections in Lichenology

Scientific collections—whether housed in herbaria, fungaria, or other specialized research centers—serve as fundamental tools for lichenological research. These collections provide:

• Voucher Specimens: Essential physical references to support species identification and taxonomic revisions.
  
  

• Type Specimens: The foundation of nomenclature, these are the designated specimens upon which species names are based.
  
  

• Historical Data: Collections provide a temporal record of lichen species distributions, aiding studies in climate change, biogeography, and conservation.
  
  

• Genetic Resources: Many collections now include DNA extracts, enabling molecular studies and advances in phylogenetics and systematics.
  
  

2. Herbaria in Lichenology

Herbaria are specialized institutions that house dried and pressed plant specimens, but lichen herbaria also play a critical role in the study of lichens. The primary function of a lichen herbarium is to preserve physical specimens in a way that allows for continued study and identification. These collections are often accessible to researchers, taxonomists, and curators, offering specimens for comparison, research, and publication.

Key Features of Lichen Herbaria:

• Physical Specimens: These are typically pressed, dried, and mounted on herbarium sheets, with detailed labeling that includes locality, habitat, collector, date, and other relevant ecological data.
  
  

• Storage and Preservation: The preservation of lichens involves specific techniques to prevent degradation by pests, moisture, and light. The use of climate-controlled storage and pest management systems is crucial.
  
  

• Taxonomic Significance: Herbarium collections serve as repositories for type specimens, which are the definitive examples of species names. These specimens are crucial for resolving taxonomic uncertainties and providing evidence for species identity.
  
  

• Accessibility and Exchange: Lichen herbaria are central to the global exchange of specimens for identification, taxonomic revision, and comparative research. Many herbaria participate in international networks for specimen loans and data sharing.
  
  

Examples:

• The Field Museum Herbarium (USA)
  
  

• The Royal Botanic Gardens Kew Herbarium (UK)
  
  

• The Lichen Herbarium at the University of Helsinki (Finland)
  
  

3. Fungariums in Lichenology

Fungaria, while often associated with fungal collections broadly, are integral to lichenological studies as they house preserved fungal specimens, including those of lichen-forming fungi (mycobionts). While herbariums focus on lichenized organisms as a whole, fungaria specifically store the fungal components of lichens, and sometimes the independent fungal or algal components of lichen symbioses.

Key Features of Fungaria in Lichenology:

• Fungal Cultures and Specimens: Fungaria house fungal isolates, including those of lichen-forming fungi, which can be studied for morphological, ecological, and genetic characteristics. These collections are invaluable for molecular systematics, taxonomy, and experimental research.
  
  

• Ecological Studies: Lichen fungi stored in fungaria provide insights into their environmental preferences, growth habits, and interactions with photobionts.
  
  

• Experimental Research: Living cultures of fungal components from lichens can be used in laboratory settings to explore symbiotic relationships, genetic diversity, and even the effects of environmental stressors.
  
  

Examples:

• The National Fungus Collection (USA)
  
  

• The Finnish Museum of Natural History Fungarium (Finland)
  
  

• The Royal Botanic Gardens Kew Fungarium (UK)
  
  

4. Categories of Lichen Collections

Scientific collections in lichenology can be categorized based on their focus, structure, and role in research. The main categories include:

a. Taxonomic Collections

• Focus on preserving specimens for species identification, revision, and comparison.
  
  

• Organized by taxonomic categories such as genera, families, and orders.
  
  

• Crucial for resolving taxonomic debates and revising existing classifications.
  
  

b. Ecological Collections

• Focus on preserving specimens tied to specific ecological studies.
  
  

• Include data on habitat, substrate, environmental conditions, and geographical location.
  
  

• Important for monitoring biodiversity and understanding species-environment interactions.
  
  

c. Molecular Collections

• Contain DNA extracts and preserved fungal tissues for genetic studies.
  
  

• Facilitates molecular barcoding, phylogenetic analysis, and genomic research in lichenology.
  
  

• Used in molecular taxonomic studies, including the identification of cryptic species.
  
  

d. Type Collections

• Consist of holotypes, isotypes, lectotypes, and paratypes.
  
  

• Central to the scientific naming and definition of species.
  
  

• Preserved specimens that anchor species to their names in accordance with the International Code of Nomenclature for algae, fungi, and plants (ICNafp).
  
  

e. Regional and Biogeographic Collections

• Collections focused on specific geographical regions or biogeographical zones.
  
  

• Often used in the study of endemism, biogeography, and the distribution of lichen species in relation to climate and habitat.
  
  

• Serve as reference points for conservation efforts in biodiversity hotspots.
  
  

5. The Role of Digital Lichen Collections

The rise of digital technologies has transformed how lichen collections are curated, accessed, and shared. Digital herbarium records, including high-resolution images and specimen data, have expanded access to rare or delicate specimens that are housed in remote or international collections. Additionally, genomic data linked to these specimens further supports remote studies and collaboration.

Key Advances:

• Virtual Herbariums: Digitalization of specimens allows for worldwide access to lichen collections. For example, the Global Biodiversity Information Facility (GBIF) includes digitized records for many lichen species.
  
  

• Online Databases: Many institutions now offer searchable databases that include specimen images, collection data, and references to published studies.
  
  

• Integrated Molecular Data: DNA sequences, extracted from preserved specimens, are integrated into databases such as GenBank, facilitating cross-disciplinary research in genomics and biodiversity informatics.
  
  

Herbaria and fungaria are indispensable resources for the advancement of lichenology. As repositories of biodiversity, they support taxonomic, ecological, genetic, and conservation-related studies. Their structured organization, along with the growing role of digital technologies in their management, ensures that scientific collections remain pivotal in the ongoing exploration and preservation of lichen diversity.