https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 Will daytime community calcification reflect reef accretion on future, degraded coral reefs? https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51298 20%) during a reef-wide bleaching event in February 2020 at Heron Island on the Great Barrier Reef. We found that during this bleaching event, rates of NEP and NEC across replicate transects remained positive and did not change in response to bleaching. Repeated benthic surveys over a period of 20d indicated an increase in the percent area of bleached coral tissue, corroborated by relatively low Symbiodiniaceae densities (1/40.6×106cm-2) and dark-adapted photosynthetic yields in photosystem II of corals (1/40.5) sampled along each transect over this period. Given that a clear decline in coral health was not reflected in the overall NEC estimates, it is possible that elevated temperatures in the water column that compromise coral health enhanced the thermodynamic favorability for calcification in other ahermatypic benthic calcifiers. These data suggest that positive NEC on degraded reefs may not equate to the net positive accretion of a complex, three-dimensional reef structure in a future, warmer ocean. Critically, our study highlights that if coral cover continues to decline as predicted, NEC may no longer be an appropriate proxy for reef growth as the proportion of the NEC signal owed to ahermatypic calcification increases and coral dominance on the reef decreases.]]> Wed 30 Aug 2023 15:01:01 AEST ]]> Microbial biobanking - cyanobacteria-rich topsoil facilitates mine rehabilitation https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45002 Symploca, Scytonema, Porphyrosiphon, Brasilonema, Nostoc, and Gloeocapsa comprised more than 50 % of the species richness at each site and 61 % of the total community richness. In the first study of its kind, we have described the response of cyanobacteria to topsoil stockpiling at various depths and ages. Cyanobacteria are moderately resilient to stockpiling at depth and over time, with average species richness greatest in the top 10 cm of the stockpiles of all ages and more viable within the first 6 weeks, indicating potential for biocrust re-establishment. In general, the resilience of cyanobacteria to burial in topsoil stockpiles in both the short and long term was significant; however, in an arid environment recolonisation and community diversity could be impeded by drought. Biocrust re-establishment during mine rehabilitation relies on the role of cyanobacteria as a means of early soil stabilisation. At J–A mine operations do not threaten the survival of any of the organisms we studied. Increased cyanobacterial biomass is likely to be a good indicator and reliable metric for the re-establishment of soil microprocesses.]]> Wed 26 Oct 2022 15:14:50 AEDT ]]>