It’s been a while since I’ve touched base about the TeaComposition H2O initiative. To recap, this global initiative aims to understand long-term aquatic decomposition and carbon cycling in seagrass meadows, mangrove forests, tidal marshes, all types of freshwater wetlands as well as lakes, ponds and streams. In using household tea as pseudo-plant litter, we can standardised the starting material, which gives us the power to tease apart the larger-scale drivers that influence decomposition, like climate, inundation and habitat type.
The optional, but incredibly important, variable that is being measured by a subset of participants is the MICROBIAL COMMUNITIES associated with the decomposing tea. Why microbes? A powerful analogy I like to use when answering the ‘why bother’ questions is that the microbes are the gatekeepers of the global carbon cycle (see Arnosti 2011). In other words, microbes and their ability to break down carbon compounds will determine the portion of carbon being sequestered as well as the carbon being emitted as greenhouse gases.
One of the big questions at the moment is whether or not microbes can be managed in a way to benefit humans. We can see this type of work in gut microbiome research as well as pollution bioremediation. For TeaComposition H2O, our ultimate goal is a multi-faceted approach to link decomposition chemistry with the environmental conditions and with the microbial functional capacity. We hope that these results will allow us begin hypothesising on how these wetland microbes may be managed to benefit carbon sequestration.
To do this, we are sampling the microbes directly on the tea as well as microbes in the bulk sediment. One way to sample for microbes at specific depths in muddy sediments/soils is using a cut-off syringe core. While we missed the first port in panel A, we can typically get down to ~10 cm. The ports fit a smaller cut-off syringe for subsampling the depths (panel B). These bulk sediment/soil samples will act as a reference for the attached soil within the tea bag (panel C).
Until next time!
Stacey Trevathan-Tackett Blue Carbon Lab, Melbourne, Australia