Saturday, August 11, 2018

It's alive!

I mean this blog (it's been dormant, not dead), and the biocrust in this picture. There are no rocks in this foreground of this photo. The rolling gray micro-hills are the liverwort Anthelia juratzkana. The orange sporophytes are those of a Polytrichum. Then you can see tufts of another moss. Also present are lichens such as Stereocaulon (not visible in this photo, but they are around). This is one of the prevailing community types in the Icelandic highlands, translating to a moss snow bed community. Apparently highland soils dry out quickly and easily, even though the climate is wet, low lying areas with late snow are needed to support this community. Once these crusts occur, the soil N increases strongly, and also importantly, frost heaving caused by needle ice is reduced. Under these conditions, vascular plants may germinate.

Lest you think this community is something like a moss or lichen carpet typical of boreal regions, I've cut away a small piece here revealing that this is really just a superficial layer (about 1 cm or so) directly over mineral soil. It's not so different from biocrusts of semi-arid regions. Generally, alot of dominant biocrust species tend to have massive multicontinental distributions. This Anthelia also fits this pattern, for example it also forms biocrusts on volcanic soils in Alaska.



The photos below will give you a sense of the habitat. This was from a place called Kaldidalur (translates to cold valley...an appropriate name). These are andosols (andisols in USDA system), a type of soil that forms from volcanic ash. You would not be silly to think highlands areas like this one are bare because they were recently glaciated. Actually, they used to support heath vegetation within the last 1000 years. The reason(s) why they are barren now will be the subject of a future post.



I am on sabbatical. I love that phrase. The absolutely wonderful Fulbright Global Scholar program is making it possible for me to spend about the next 3 months here (disclaimer: any views I express in this blog are mine and do not represent the Fulbright Program or the US Government). This is one of the coolest things the Department of State does. Briefly, they support academic exchanges for professors (and students) to spend time in other nations to foster international collaboration and understanding. I am hosted here by the Agricultural University of Iceland. My hosts are Ása Aradóttir, a plant ecologist and restoration ecologist and Ólafur Arnalds, a soil scientist, who were my guides to learning about these highland crusts. My goals for this portion of my sabbatical are to 1. refine the sampling protocol for CrustNet (a global study we are whipping up...more on this in later posts) and conduct the first sampling, 2. learn as much as I can from this unique environment, 3. keep this blog alive. 

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