Soil Carbon Storage: The Headache of Grazing

[This is a guest post by Thomas Ross, a 3rd year Biology student at The University of Manchester – he is currently doing a Science Media Project on the effects of grazing on soil C storage, which I am supervising. This blog post is part of his portfolio, and he has to reflect on its impact in his final submission. So don’t hesitate to leave your comment!]

The carbon stored in soil amounts to double that in the atmosphere and biomass combined and soil has the potential to sequester more. As atmospheric levels of carbon dioxide have been on the rise there has been an increase in global temperatures and climate change (here, the processes involved in soil carbon storage explained in more detail). The potential of the soil carbon reservoir to sequester this carbon from the atmosphere, and potentially ease the speed of climate change, can be influenced by our actions and the way in which we manage land. One such way is through the grazing of domestic livestock.

Grazing has the potential to modify ecosystems drastically and thus affect soil carbon storage. But how much is too much? Unfortunately, I cannot give you a definitive answer as the effects of grazing on soil carbon storage vary greatly. Some studies showing increases in soil carbon due to grazing, others decreases and some no changes at all. This causes a tricky problem when deciding how to manage livestock to ensure maximum soil carbon storage and withholding the interests of all stakeholders. Continue reading

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Drought belowground

There is a heat wave in the UK, and at least in the north, where I live, not a single drop of rain has fallen for at least three weeks. I quite like it, especially since last year was basically one long, wet, windy autumn and I was craving for a real summer. But, with temperatures this high, and with this little rainfall, many plants are starting to look a bit poorly. Grass is turning brown, and forbs are hanging their heads. Especially in the north of England, where normally everything is lush and green around this time, this is an unusual sight.

I know this all too well, because I am running a drought experiment – our drought pots have been tortured to the max and we wouldn’t have needed the sturdy roofs, while we had to water our control pots.

Does this look dire? Then take a look at what's happening belowground! Pots from my on-going drought experiment.

Does this look dire? Then take a look at what’s happening belowground! Pots from my on-going drought experiment.

So, plants are having a hard time, and I can imagine farmers are becoming worried. Because summer droughts are expected to increase in the UK, and when crops are stressed to their limit, this will lead to yield reductions. Modern agricultural crops have evolved to be adapted to high-resource, low risk environments, and have very different properties than their wild ancestors (read this great paper by García-Palacios et al.) – properties that are not much good for resisting drought conditions.

However, if you think that carnage is going on aboveground, then take a look belowground. Continue reading

To share or not to share?

Big data is great. I don’t think anyone can argue against the benefits of making datasets, whether they are from independent, controlled experiments, or from large-scale projects such as the Earth microbiome, publicly available. Depositing your data in one of the databases available, such as figshare or MG-RAST, can only ever help science. It progresses science by preventing fraud, making the process more transparent, and allowing for crosschecking of results. Sharing facilitates discussion. I have never heard of unethical use of shared data.

Nothing new there. In fact, sharing data might prevent masses and masses of unpublished data from getting lost forever, and thus has the potential to save millions of pounds of public money being spent on experiments that have already been done, but that no one knows about. Think about all those PhD thesis chapters, all analysed and written up, that never get published, and are therefore potentially lost for science forever. Similar to their open access strategy, research councils and funding agencies should perhaps set up a system that obliges PhD students to deposit their data before they can get their doctorate. Continue reading