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. Post-hurricane clone libraries were dominated by sequences that had been rare in pre-hurricane communities. In spite of this dominance shift, re-colonizing mat communities performed nitrogen fixation and photosynthesis at rates within the normal range of variation measured in the mat at similar salinities. There was a tendency for nitrogen fixation rates from mats re-colonizing sites with hurricane-related sand deposition to be higher than those from mats re-colonizing sites without significant sand deposition. This suggests that the altered communities responded to a carbon : nitrogen imbalance that was particularly pronounced in areas subjected to disturbance by sand burial. The post-hurricane dominance of organisms that had been previously rare suggests that pre-hurricane diversity and functional redundancy contributed to the rapid recovery of ecosystem function in the post-disturbance environment.
Yannarell
Anthony C
AC
Institute of Marine Sciences, University of North Carolina at Chapel Hill, 3431 Arendell Street, Morehead City, NC 28557, USA. acyann@email.unc.edu
Steppe
Timothy F
TF
Paerl
Hans W
HW
D000458:Cyanobacteria / Q000254:growth & development*; D004190:Disasters; D017753:Ecosystem; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry / Q000382:microbiology*; D008969:Molecular Sequence Data; D009586:Nitrogen Fixation; D010088:Oxidoreductases / Q000235:genetics; D010802:Phylogeny; D011157:Population Dynamics; D012335:RNA, Ribosomal / Q000235:genetics; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride
D012335:RNA, Ribosomal; D012965:Sodium Chloride; D010088:Oxidoreductases; C029130:nitrogenase reductase