Microbial mat communities in response to recent changes in the physiochemical environment of the meltwater ponds on the McMurdo Ice Shelf, Antarctica

In spite of their dominance in meltwater environments in the Polar Regions, little is known about conditions that control community structure and production in microbial mats. Microbial mats were sampled at 13 recently separated ponds on the McMurdo Ice Shelf, Antarctica, with the aim to determine microbial mat community response to shifts in deterministic processes. Community structure in ponds of different size classes responded to different environmental variables, with conductivity as a common theme. Biomass and net oxygen exchange did not vary across the pond conditions and may reflect the very slow turnover rates characteristic of Antarctic microbial communities. Microbial mat communities on the MIS appear unresponsive to large intra-annual variability, while the long-term inter-annual physiochemical environment of the overlying appears to be influencing the community dynamics.