A networking resource devoted to biological soil crusts and the researchers who study them. We will provide a means for international scientists to communicate, share their research, share important news and announcements, ask questions and find collaborators. We will also provide a space for informal writing on research, opinion, and ideas (now seeking posters!).

Sunday, October 28, 2012

Julius Csotonyi's mashup of arts & sciences

Every morning as I'm drinking enough coffee to kill a lesser man (but just enough to get me to the office), I read all the science news I can find. That includes a perusal of research blogging, wired science blogs, whatever NPR has posted, and an obsessive compulsive daily search for "Mars Curiosity". So, I read about our neanderthal and denisovan ancestry, psychology, and dinosaurs, among many other things. So naturally, this illustration caught my eye in a story about a new feathered dinosaur fossil, and the possible role of bright plumage in dino-sexiness.

Not only is it a cool illustration, I saw that it was credited to Julius Csotonyi. Why am i posting cool dinosaur art on this biocrust blog? Well, in addition to being an illustrator, he's a scientist with very diverse interests and an occasional biocrust researcher to boot. Once upon a time, I was an art student, but I find all my creative energy goes elsewhere now. So, it's always interesting to see people that balance and mix art and science. In looking for additional biocrust papers that he'd written, I learned about his "other" career a while ago. Now I realize that we see his work pretty frequently. He seems to be getting pretty famous for his paleo-illustration; there are quite a few blog posts about the dinosaur work including this recent scientific american piece, which calls him a "paleoart rockstar".  He also writes a truly excellent blog, Evolutionary Routes, which is a model of how to communicate science to non-scientists (also added to the blogroll on the left).

He has a dissertation and a couple papers on the biocrusts of Canada:
Csotonyi JT, Swiderski J, Stackebrant E, Yurkov V. 2010. A new extreme environment for aerobic and oxygenic phototrophs: biological soil crusts. Pages 3-14 In: Cohen IR, Lajtha A, Lambris JD, Paoletti R (eds),  Recent Advances in Phototrophic Prokaryotes. Springer, Berlin.

- Here, the authors document the existence of autotrophic bacteria in biocrusts that do not use the oxygenic photosynthesis that was all the rage when cyanobacteria came around (and still is about the coolest thing happening on Earth). So, crust communities may have multiple unique approaches to photosynthesis.

Csotonyi JT, Addicott JF. 2004. Influence of trampling-induced microtopography on growth of the soil crust bryophyte Ceratodon purpureus in Jasper National Park. Canadian Journal of Botany 82:138-1392.

- This one caught my eye years ago because I was working on the influence of bumpy crust micro-topography on the generation of favorable microsites for biocrust growth. Julius shows the same phenomenon in depressions initially created by elk footprints.

I end with one comment and one question for Dr. Csotonyi:
1. Colonization of land by biota was a significant event in the history of Earth. Some think the first organisms to do so were cyanobacteria, and we know that cryptogams such as mosses pre-dated the vascular plants. This age of the crusts could be some nice material for a paleoartist (perhaps not paying the bills like dinosaurs, but interesting nonetheless).

2. Since I was 7, and not a bad dinosaur artist, I have seen Allosaurus (lifelong personal favorite dinosaur predator) interpreted as some shade of tan with tiger-like stripes. Where did this come from and why does it persist, even in your work?

Sunday, October 14, 2012

Scooped! - Through The Sandglass

Scooped! - Through The Sandglass

Nice summary of the Curiosity rover's soil sampling activity thus far at the linked blog.  Lots of fun surprising news from Mars lately: Ancient streambed, well-above freezing temperatures in Gale Crater, previously unobserved igneous rock types (which like others suggest presence of water). Gale Crater sounds more and more like cyanobacteria habitat every day.

Monday, October 8, 2012

Theme Issue 'Impacts of global environmental change on drylands: from ecosystem structure and functioning to poverty alleviation'

Out today, a special issue of Philosophical Transactions "Impacts of global environmental chang on drylands: from ecosystem structure and functioning to poverty alleviation" edited by Fernando Maestre and Roberto Salguero-Gómez.

Below are the 2 most biocrust focused abstracts, but I recommend the whole issue as it contains submission by the editors, Andrew Dougill, and Elisabeth Huber-Sannwald. Happy reading.

  • Andrew D. Thomas
Research article: Impact of grazing intensity on seasonal variations in soil organic carbon and soil CO2 efflux in two semiarid grasslands in southern Botswana Phil. Trans. R. Soc. B November 19, 2012 367 1606 3076-3086; doi:10.1098/rstb.2012.0102 1471-2970 

 Biological soil crusts (BSCs) are an important source of organic carbon, and affect a range of ecosystem functions in arid and semiarid environments. Yet the impact of grazing disturbance on crust properties and soil CO2 efflux remain poorly studied, particularly in African ecosystems. The effects of burial under wind-blown sand, disaggregation and removal of BSCs on seasonal variations in soil CO2 efflux, soil organic carbon, chlorophyll a and scytonemin were investigated at two sites in the Kalahari of southern Botswana. Field experiments were employed to isolate CO2 efflux originating from BSCs in order to estimate the C exchange within the crust. Organic carbon was not evenly distributed through the soil profile but concentrated in the BSC. Soil CO2 efflux was higher in Kalahari Sand than in calcrete soils, but rates varied significantly with seasonal changes in moisture and temperature. BSCs at both sites were a small net sink of C to the soil. Soil CO2 efflux was significantly higher in sand soils where the BSC was removed, and on calcrete where the BSC was buried under sand. The BSC removal and burial under sand also significantly reduced chlorophyll a, organic carbon and scytonemin. Disaggregation of the soil crust, however, led to increases in chlorophyll a and organic carbon. The data confirm the importance of BSCs for C cycling in drylands and indicate intensive grazing, which destroys BSCs through trampling and burial, will adversely affect C sequestration and storage. Managed grazing, where soil surfaces are only lightly disturbed, would help maintain a positive carbon balance in African drylands. 

  • Cristina Escolar,
  • Isabel Martínez,
  • Matthew A. Bowker,
  • and Fernando T. Maestre
Research article: Warming reduces the growth and diversity of biological soil crusts in a semi-arid environment: implications for ecosystem structure and functioning Phil. Trans. R. Soc. B November 19, 2012 367 1606 3087-3099; doi:10.1098/rstb.2011.0344 1471-2970 

Biological soil crusts (BSCs) are key biotic components of dryland ecosystems worldwide that control many functional processes, including carbon and nitrogen cycling, soil stabilization and infiltration. Regardless of their ecological importance and prevalence in drylands, very few studies have explicitly evaluated how climate change will affect the structure and composition of BSCs, and the functioning of their constituents. Using a manipulative experiment conducted over 3 years in a semi-arid site from central Spain, we evaluated how the composition, structure and performance of lichen-dominated BSCs respond to a 2.4°C increase in temperature, and to an approximately 30 per cent reduction of total annual rainfall. In areas with well-developed BSCs, warming promoted a significant decrease in the richness and diversity of the whole BSC community. This was accompanied by important compositional changes, as the cover of lichens suffered a substantial decrease with warming (from 70 to 40% on average), while that of mosses increased slightly (from 0.3 to 7% on average). The physiological performance of the BSC community, evaluated using chlorophyll fluorescence, increased with warming during the first year of the experiment, but did not respond to rainfall reduction. Our results indicate that ongoing climate change will strongly affect the diversity and composition of BSC communities, as well as their recovery after disturbances. The expected changes in richness and composition under warming could reduce or even reverse the positive effects of BSCs on important soil processes. Thus, these changes are likely to promote an overall reduction in ecosystem processes that sustain and control nutrient cycling, soil stabilization and water dynamics.