Thursday 12 February
No science EVAs for us today but we worked on the samples we collected yesterday. We had rocks with seemingly 4 different colourations, or chromotypes, of lichens:
- Yellow lichens, which are the majority on the sites we have found. The create huge circular-like growth area with sometimes inner ÒholesÓ
- Green lichens, mostly close to the yellow ones, and they have a slightly different shape (more conical, and with a little hole inside) and are not often seen
- Grey lichens, most probably are senescent lichens, we do see large colonies of those
- Black lichens, more rare and sparse without really following a pattern
We scrapped each chromotype delicately off the rocks with a flame-sterilized metal knife or a metal scoop.
We brought and put them in petri dishes with distilled water to rehydrate them.
A few uses we will do with them are:
- Staining them with various staining solutions available here to observe them at the microscope in order to describe each of them
- Try to culture some in a temperature-controlled incubator at 30 degree C (started today, but might change incubator for higher temperature)
- Try to separate more clearly the lichens from the rock and sample them in tubes for bringing back to our labs and analyze them further (alongside the dry sample we took during the EVA).
We also sampled another vegetation sample, which we are not too sure if it’s a lichen or moss, but maybe our analysis here and back in our labs will inform us more. If possible we will try to upload pictures alongside this report to clarify the statements.
One conclusion so far we can state about the lichens are that they apparently grow on older rocks that have not been exposed to too much erosion/weathering, and they grow on the protected side of the rock from wind. Here in the MDRS site, there are a lot of wind-holed (wind-bored) rocks, and wind-bored surfaces are orienting about a 200 degree (SWS, south-west-south) direction. This implies that rocky surfaces orienting NEN (north-east-north) are favourable for lichen colonization, which is testable by more detailed studies, too.
In addition, see below for the size measurements of the lichens colonies. They vary a lot, so no conclusion is drawn from the sizes this at this point; however, these should be regarded as basic information for planning subsequent EVAs and post-Crew studies.