Cyanobacteria and other microbes are important moderators of biogeochemical processes in semi-arid floodplain wetlands with varying inundation regimes. Inundation is a key environmental driver for floodplain biological communities. Little is known about the effect of historical inundation frequency on the spatial abundance of floodplain-wetland Cyanobacteria and other microbes. In this study, soil samples were collected at two locations with a gradient of low-to-high inundation frequency in the Macquarie Marshes, south-east Australia. We used high-throughput sequencing to estimate the proportional abundance of the soil Cyanobacteria and other dominant microbes, targeting the bacterial 16S rRNA gene. Of the microbes recovered, Cyanobacteria constituted proportionally a minor component, relative to other dominant phyla like Proteobacteria and Actinobacteria. Linear regression (generalised least-squares) models accounting for spatial autocorrelation showed that historical inundation frequency had no significant effect on the proportional abundance of Cyanobacteria at both wetlands studied. However, inundation frequency had a significant positive effect on the proportional abundance of Proteobacteria and a significant negative effect on the proportional abundance of Actinobacteria. Cyanobacteria seem to occupy a different hydrological niche from Proteobacteria and Actinobacteria in semi-arid floodplain wetlands, suggesting taxon-dependent response of floodplain microbial communities to varying inundation regimes and associated soil conditions in those environments.
- inundation gradient
- wetlands in drylands
Wetlands in Drylands: conservation through environmental research, citizen science and global engagement
Tim Ralph (Participant)
Impact: Science impacts, Environment impacts, Policy impacts, Society impacts