@inbook {4187, title = {Complex Structure but Simple Function in Microbial Mats from Antarctic Lakes}, booktitle = {The Structure and Function of Aquatic Microbial Communities}, year = {2019}, pages = {91 - 120}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, address = {Cham}, abstract = {

Microbial mats growing under the permanent ice cover of Antarctic lakes occupy an exceptionally low-disturbance regime. Constant temperature, the absence of bioturbation or physical disturbance from wind action or ice formation allow mats to accumulate, as annual growth layers, over many decades or even centuries. In so doing they often assume decimetre scale, three-dimensional morphologies such as elaborate pinnacle structures and conical mounds. Here we combine existing and new information to describe microbial structures in three Antarctic lakes\—simple prostrate mats in Lake Hoare, emergent cones in Lake Untersee and elaborate pinnacles in Lake Vanda. We attempt to determine whether structures emerge simply from uncoordinated organism-environment interactions or whether they represent an example of \“emergent complexity\”, within which some degree of self-organisation occurs to confer a holistic functional advantage to component organisms. While some holistic advantages were evident from the structures\—the increase in surface area allows greater biomass and overall productivity and nutrient exchange with overlying water\—the structures could also be understood in terms of potential interactions between individuals, their orientation and their environment. The data lack strong evidence of coordinated behaviour directed towards holistic advantages to the structure, though hints of coordinated behaviour are present as non-random distributions of structural elements. The great size of microbial structures in Antarctic lakes, and their relatively simple community composition, makes them excellent models for more focused research on microbial cooperation.

}, keywords = {LTER-MCM, biofilm, microbial ecology, microbial structures, self-organising structures, stromatolite}, isbn = {978-3-030-16775-2}, doi = {10.1007/978-3-030-16775-2_4}, url = {https://link.springer.com/chapter/10.1007/978-3-030-16775-2_4}, author = {Ian Hawes and Sumner, Dawn Y. and Jungblut, Anne D.}, editor = {Hurst, Christon J.} } @article {3254, title = {Cyanobacterial diversity in benthic mats of the McMurdo Dry Valley lakes, Antarctica}, journal = {Polar Biology}, volume = {38}, year = {2015}, month = {01/2015}, pages = {1097 - 1110}, abstract = {
Perennially ice-covered, meromictic lakes in\ the McMurdo Dry Valleys, Antarctica, are useful models to\ study the relationship between cyanobacterial and environmental\ variables. They have rich benthic cyanobacterial\ mat accumulations and stable stratification of physical and\ chemical conditions. Here, we evaluated cyanobacteria\ from benthic mats from multiple depths in three geographically\ separated ice-covered lakes, Lakes Vanda,\ Hoare and Joyce, using 16S rRNA gene clone libraries. We\ identified 19 ribotypes, mostly Oscillatoriales and several
Chroococcales, as well as potentially novel cyanobacterial\ ribotypes. The majority of ribotype diversity was shared\ between lakes, and only a weak relationship between ribotype\ community structure and environmental variables\ was evident. Multivariate analysis of all lake\–depth combinations\ implied that photosynthetically active radiation,\ dissolved reactive phosphorus and conductivity were\ potentially important for shaping benthic communities in\ McMurdo Dry Valley lakes. Cyanobacterial-specific pigment\ signature analysis by high-performance liquid chromatography
showed that the cyanobacterial communities\ responded to light conditions similarly, irrespective of\ community composition. The results imply a capability\ within a suite of cyanobacteria to colonise, adapt and grow\ across broad environmental ranges and geographic space,\ and such adaptability may provide a high degree of community\ resistance and resilience to future climate-driven\ environmental change in Antarctic terrestrial aquatic
ecosystems.
}, keywords = {LTER-MCM}, issn = {0722-4060}, doi = {10.1007/s00300-015-1669-0}, url = {http://link.springer.com/10.1007/s00300-015-1669-0http://link.springer.com/content/pdf/10.1007/s00300-015-1669-0}, author = {Zhang, L. and Jungblut, Anne D. and Ian Hawes and Dale T. Andersen and Sumner, Dawn Y. and Mackey, Tyler J.} }