Earthworms – the final chapter!

 

With the soil analysis laboratory in York shortly closing for Christmas the race was on to complete enough samples in each field and county for the statistician on the project to work his magic. The result was an epic 400 mile round trip to finish off sampling fields in Leicestershire, Berkshire and Dorset. It was just David and I who set off Sunday evening for Leicester, meaning that I was navigator (oh the pressure!), but on Monday we met up with Jo who is the technician at the University of York undertaking the soil analysis, to finish the final field in Loddington.

Jo and David sorting soil (is David praying for the project to end?)

It was great to meet with Jo and find out about the soil analysis side of the project, at the moment she is working on the samples taken for the measurement of microbial activity since these need to be processed quickly for accurate results, later analysis will be done on particle size, pH, nutrient content and more. The method used by the lab is the fluorescein-diacetate (FDA) hydrolysis assay, enzyme activity from microbes in the soil sample cause the colourless FDA to break down into fluorescein which is a fluorescent yellow-green. The intensity of the colour is measured using spectroscopy and comparison with a standard determines the relative microbial activity of the sample.

Not unlike the earthworms Jo has found the microbial activity to vary greatly both between and within fields, from extremely high in the field in Yorkshire with the longhorn cattle to nearly ‘dead’ in one of the fields in Berkshire. Jo informed me that clayey soils are particularly difficult to process which I could sympathise with as they are also difficult to sort!

We made good progress despite being just the three of us, squeezing in an extra 11th sample which unfortunately had to be sorted in car headlights (again) and I made the tactical error of not taking my waterproofs off so ended up being volunteered to wander around a field in the dark to put the soil back in the hole.

Such dedication!

Loddington finished, Jo returned to York with the soil samples and David and I travelled south to Berkshire, returning to the lovely Dundas Arms, sadly too late for dinner but they did make us some amazing sandwiches. In the morning we were joined by Paul and Kelly and volunteers Cecilia and Alex, as a team of six we made brilliant progress and a super 21 samples were completed.

Kelly and David take the environmental variables while Cecilia prepares to sort

The Soil Biodiversity Group gets stuck into sorting another sample

With still a few left to do in Berkshire next week the rest of the team went their separate ways while David and I travelled to Dorset. Thankfully this time we arrived in time for a pub dinner, nothing like two days of sandwiches for dinner to make me appreciate a hot meal! The next morning we met with the farmer of the final farm to find out about the management history of the fields and decide which would be suitable for the project. After picking up Paul from the train station we began sampling the penultimate field of the project.

The penultimate field, the barn at the back would prove useful later in the week!

On Thursday we were joined by fellow project veterans Sholto and Irfaan to finish off the field in the quarry (no blasting this week sadly) and the other two fields. By Friday the weather was against us, but we maximised the work achieved by sorting in the barn during the heaviest rain and by dusk the required samples had been done!

A very wet and muddy Sholto, Irfaan and Paul sorting in the rain in Dorset

All that remained was to finish the two fields in Berkshire so on Monday David, Paul and I met up again for the final day of sampling, two weeks and a day overdue! The fields were extremely wet, particularly (and not surprisingly) the one by the river, with one soil moisture reading at 100%. In the absence of a tap the stream proved useful for filling the mustard bottles, since they were to be used straight away the issue of bacterial contamination was avoided.

In the absence of a hotel or research centre to fill the mustard bottles, a stream will do

 

And now…

The final pit

And so finally the time had come, after 10 weeks of field work, the final pit was dug!

At last – the final pit!

And Paul had the ‘honour’ of pouring the final bottle of mustard solution

Of course the project is not over, there are still thousands of earthworms to count and identify, soil samples to analyse, numbers to crunch, meetings to attend and papers to write, but my part is done. It has been a fantastic experience for me to be part of such an ambitious project. Being involved has given me a greater understanding of what is involved in research,  including the logistical and political aspects as well as the science. I have been reminded how much I enjoy field work, even in the rain and mud but most of all I reaffirmed my aspiration to be a researcher. I miss being in a muddy field but most of all I miss the interaction with like-minded people (wow, never thought I would say that!) – from discussion on scientific topics to intense debate on the merits of different biscuits. The New Year should bring more financial stability after my student life and so I hope to be able to visit the Museum once a week and continue volunteering with the Soil Biodiversity Group.

And so I offer a big thank you to everyone I worked with on the project, you have been an inspiration.

More earthworm sampling, or the mystery of the farty mustard

Another county, another field… Last Monday and Tuesday I was again away with the Natural History Museum Soil Biodiversity Group, this time heading up to Leicestershire, for more earthworm sampling. Not as scenic as Somerset, we were sampling in a research farm near Loddington, in addition to myself, Sholto was again volunteering, I also met for the first time Salma and we were joined by Irfaan on Tuesday.

Another earthworm is sampled by Irfaan, with Salma and Sholto

Salma is trained in the correct way to retract the tape measure

In the previous week there was a problem with the mustard solution, which had developed a pungent smell of hydrogen sulphide (egg-fart gas). This was a concern because the smell was so strong it could be killing the worms in their burrows before they could emerge. Could the change be because of a faulty batch of mustard powder, or change to the ingredients? This week different batch numbers of mustard powder were purchased to test this.

David checks the bouquet of the mustard solution

Sniffing the mustard solution before pouring was now a necessary step, after the first mixing the smell was promising but by the morning some bottles had deteriorated. A new hypothesis was proposed that some sort of bacterial contamination was causing the smell and then it was realised the problem started after the mustard solution was made up using water from the soil laboratory back at the the Museum. The water in the labs comes from the museum’s own borehole and often has a slightly sulphurous smell, could some sulphur-reducing bacteria dwelling in the supply have caused the problem? It was decided to use fresh water bottles on the next trip.

Tuesday evening we travelled back to London and on Wednesday I spent the afternoon helping in the soil laboratory preparing the kit for Thursday and Friday and changing the alcohol in the earthworm samples. Earthworms have a high water content and this dilutes the alcohol, if the liquid is not replaced with fresh spirit the earthworms can start  to decompose which makes identification difficult (and stinky). Then Wednesday evening we left for Dorset - the final county being sampled in.

That’s a lot of earthworms!

Living in just the next county I have had many family holidays in Dorset and it was a pleasure to be back in beautiful Purbeck. Our site was near a quarry were limestone (Purbeck ‘marble’) is extracted and on Friday we got to view a blasting, which was very exciting.

Quarry manager Simon discusses the site with David

Quarry blasting (guess who made the excited squeal!)

The shallow soil did not yield many big anecic worms but large numbers of smaller species, since earthworms have a preference for areas of high pH. As might be expected there were also large numbers of snail shells which I tried my best not to be distracted by, although I think I may sneak a few specimens when we return next week!

Off for a well-earned meal after a hard day’s earthworm sampling

My first symposium

 

On the 28th and 29th November I attended the British Ecological Society Moving on to a PhD and Mastering Ecology Symposium, for advice on PhDs and the opportunity to present my Masters research. This was the first Symposium I have presented at and although I had to give a presentation of my work during my MSc this was to a much larger group of people I had not met before. I was very anxious, with one half of me saying “why are you putting yourself through this?” and the other half “it’s good for you and will get easier the more you do it”. Thankfully fellow Soil Biodiversity Group volunteer Fez was also at the Symposium presenting a poster of her work on termites in Wallacea which was a confidence boost.

Fez and I with our Soil Biodiversity Group posters at the British Ecological Society Mastering Ecology Symposium

The talk was both the fastest and slowest five minutes of my life! It went by in a blur. Feedback however was not too bad, considering how scared I was, hopefully next time it will get better and maybe one day I will be as confident as my university lecturers etc.