Viruses in wetland ecosystems

1. We review studies of viruses in natural and constructed wetlands, focusing on the importance of surfaces as viral habitat, and differences in viral ecology between wetlands and other aquatic ecosystems. 2. Viruses in natural wetlands are predominantly associated with sediment, macrophytes and other submerged surfaces. In constructed wetlands, these surfaces are critical to the removal of viral pathogens and indicator organisms from wastewater. 3. Interactions between viruses and other ecosystem components have rarely been examined in wetlands, and the role of viruses in regulating wetland microbial communities is unclear. Environmental factors such as temperature and flooding regime are important abiotic controllers of viral abundances in wetlands but few studies have examined how abiotic or biotic factors affect community structure. Even basic information on wetland viral diversity is lacking. 4. Future research should include broad surveys of different types of wetlands, an emphasis on differences between microhabitats, and an increased use of molecular approaches to examine wetland viral diversity and its relationship to microbial community structure. Such studies should consider wetlands as part of the broader landscape, and emphasize interactions between wetlands and adjacent terrestrial and aquatic ecosystems.