Disturbance and recovery of microbial community structure and function following Hurricane Frances.

Disturbance and recovery influence microbial community structure and ecosystem functions in most natural environments. This study from a hypersaline Bahamian lagoon details the response of a benthic cyanobacterial mat to disturbance by Hurricane Frances, a category-4 storm. Clone libraries of cyanobacterial small subunit r-RNA genes and nitrogenase genes revealed significant shifts in cyanobacterial and diazotroph community composition following the hurricane.

Genetic variance in the composition of two functional groups (diazotrophs and cyanobacteria) from a hypersaline microbial mat.

Examination of variation in ecological communities can lead to an understanding of the forces that structure communities, the consequences of change at the ecosystem level, and the relevant scales involved. This study details spatial and seasonal variability in the composition of nitrogen-fixing and cyanobacterial (i.e.

Scaling up: the next challenge in environmental microbiology.

Great strides have recently been made in identifying and characterizing the staggering diversity of microorganisms conducting primary and secondary production, nutrient transformation and mineralization processes that underlie ecosystem and regional biogeochemical, trophodynamic and ecological change. We are now faced with the challenge of assigning and coupling function to structure in highly complex and interactive microbial communities mediating such change. Previous and ongoing ecophysiological work has shown that microbial processes controlled by environmental variables and limiting resources are highly specific in terms of what, when, where and why they are active, not to mention how they impact ecosystem dynamics.

Microbial indicators of aquatic ecosystem change: current applications to eutrophication studies.

Human encroachment on aquatic ecosystems is increasing at an unprecedented rate. The impacts of human pollution and habitat alteration are most evident and of greatest concern at the microbial level, where a bulk of production and nutrient cycling takes place. Aquatic ecosystems are additionally affected by natural perturbations, including droughts, storms, and floods, the frequency and extent of which may be increasing.

Hypersaline cyanobacterial mats as indicators of elevated tropical hurricane activity and associated climate change.

The Atlantic hurricanes of 1999 caused widespread environmental damage throughout the Caribbean and US mid-Atlantic coastal regions. However, these storms also proved beneficial to certain microbial habitats; specifically, cyanobacteria-dominated mats. Modern mats represent the oldest known biological communities on earth, stromatolites.