Lichenometry is a dating technique based on the predictable, radially symmetrical growth rates of crustose lichen species, such as Rhizocarpon geographicum, colonizing freshly exposed rock surfaces. Because these organisms require direct exposure to sunlight and atmospheric moisture while remaining intolerant of rapid substrate erosion, successful colonization occurs almost exclusively on stable rock faces immediately following glacial retreat or landslide events. However, because lichen growth rates vary inversely with altitude and depend heavily on microclimatic humidity, researchers cannot establish universal growth curves; instead, calibration curves must be constructed independently for each specific geographic microregion using substrates of historically documented ages.
Which of the following can be most reasonably inferred from the passage regarding the application of lichenometry?
- ACrustose lichens colonize rapidly eroding rock surfaces more effectively than stable substrates due to higher nutrient availability.
- BA single universal growth curve can accurately determine the exposure age of rock surfaces across varying elevations worldwide.
- Accurately dating rock surfaces in a particular valley requires comparing lichen measurements against baseline growth data calibrated specifically for that local environment.Cevap
- DLichenometry can be reliably performed only on rock formations that are completely sheltered from sunlight and precipitation.
- ECrustose lichens were historically cultivated by human populations to stabilize unstable moraines after glacial retreat.