lichenometry

Knowledge graph centered on lichenometry with 13 nodes and 34 connections. Top connected: Atriplex canescens, Rock glaciers in Central Colorado, U.S.A., as indi, cottonwood, Pinus aristata, Bristlecone Pines.

Method synopsis

Dating of rock glacier surfaces using measurements of lichen thalli diameters of Rhizocarpon species, applying established growth curves to estimate surface exposure ages.

Synthesized from method descriptions across 1 paper using this protocol.

Procedure from a recent peer-reviewed implementation

Steps below were extracted from the most recent peer-reviewed implementation of this protocol in the corpus — Rock glaciers in Central Colorado, U.S.A., as indicators of Holocene climate change (2007), Arctic, Antarctic and Alpine Research. Implementations in other papers (listed below) may differ.

1. Site selection and characterization
   Selected 48 lobes on 18 rock glaciers or rock glacier complexes distributed across the Elk Mountains and Sawatch Range. Rock substrates were mostly of granitic lithologies, but some lichens were measured on gneissic and quartzitic boulders. Sites ranged in elevation from 3005 to 3755 m with various aspects and frontal slope angles.
   Quantities: 48 lobes, 18 rock glacier sites, elevation range 3005-3755 mDuration: Not specifiedConditions: High elevation alpine settings, various aspects (NW, N, NNW, etc.), frontal slopes ranging from 22-48 degrees
   Equipment: GPS for location recording, clinometer for slope measurement
2. Establish sampling sites
   At each lobe, established a circular sampling site with a radius of 5 m. Sites were located just above the break in slope above the lobe terminus. Most lobes were sampled in two locations, and larger lobes and those with more variable lichen sizes were sampled in three areas.
   Quantities: 5 m radius circular sites, 2-3 sampling areas per lobeDuration: Not specifiedConditions: Located above break in slope above lobe terminus
   Equipment: measuring tape for 5 m radius
3. Lichen measurement
   Within each sampling site, measured the largest 25 Rhizocarpon subgenus Rhizocarpon thalli. Measurements were taken along the longest axis of each thallus, including the black prothallus rim. Avoided sampling thalli with irregular shapes and those that appeared to have grown together. Excluded any areas that appeared to have suffered from snowkill.

Typical Equipment

• GPS for location recording
• clinometer for slope measurement
• measuring tape for 5 m radius
• calipers or ruler for measuring thalli diameters

Output Measurements

• thalli diameter measurements
• surface exposure ages

Papers Using This Protocol (1)

Species Studied With This Protocol