Lichenometry
Definition
The use of lichen thallus diameter to estimate the minimum age of a surface. Based on the known or measured radial growth rate of a species at a specific location, the current diameter implies a minimum colonisation age.
- Field
- Surface dating using lichen growth
- Measured
- Lichen thallus diameter
- Basis
- Known radial growth rate for a species and location
- Output
- Minimum age estimate of colonised surface
Common questions
Why does lichenometry give only a minimum age?+
The technique estimates when the lichen began growing on the surface, but colonisation itself does not necessarily start the moment a surface is exposed, so the true age of the surface could be somewhat older than the lichen's apparent colonisation age.
What limits lichenometry's use as a PMI indicator?+
Growth rates vary by species, microclimate, and substrate, so an examiner needs a locally calibrated growth curve for the specific lichen species and site conditions, and results are generally treated as a coarse, long-timescale estimate rather than a precise dating method.
Related terms
- Biological Soil Crust (Biocrust)
- A community of cyanobacteria, algae, mosses, fungi, and lichens that colonises bare soil surfaces and forms a thin coherent mat. Relevant to...
- Crustose Lichen
- A lichen growth form in which the thallus grows flat against and into the substrate (bone, stone, wood) and cannot be removed...
- Epilithic / Epixylous Colonisation
- Growth of organisms on rock or stone surfaces (epilithic) or on dead wood (epixylous). In forensic contexts, colonisation of bone surfaces by...
- Succession
- The predictable sequence of different insect species colonising remains as decomposition progresses. Early stages attract blow flies; later stages attract beetles, moths,...
- Thallus
- The body of a lichen, consisting of fungal hyphae housing algal or cyanobacterial cells. The thallus diameter or area is the measurement...