I recently took a day off volunteer on fieldwork with the Natural History Museum Soil Biodiversity Group – my first fieldwork with the group since the BESS Earthworm Project, and a nice change from the pollinator and plant surveys I have been doing as part of my work at Reading University. The project I assisted on this time is the National Vegetation Classification (NVC) Project, this is a structured survey of soil and litter invertebrates across UK woodland types which began in 2002 and is now on its third round of sampling. The National Vegetation Classification categorises all UK ecosystems according to major vegetation type (woodland, grasslands etc.) which are then broken down into community types according to plant species composition. Woodlands are given the prefix W and fall into ‘wet woodland’ W1 to W7 and ‘dry woodland’ W8 to W18, this year is the turn of the dry woodlands and the study site I visited was Warburg Nature Reserve in Oxfordshire, an example of W12, a beech (Fagus sylvatica) woodland with plants characteristic of basic soils such as Dog’s Mercury (Mercurialis perennis).
Instead of sampling from random quadrats as in my MSc fieldwork the NVC project uses a transect through the habitat with a 1m square quadrat being sampled at set intervals, alternating each side of the transect line. Other than that the method was similar, fellow volunteer and current MSc student Dan and I took turns scrapping and sieving litter from the quadrat which was then bagged up with a label to take back to the lab. Paul took the environmental readings while Kelly dug a soil pit and collected any invertebrates found into tubes of alcohol. A vegetation survey was also made of each quadrant, although being a beech woodland this was sparse and a lot less effort than my MSc project were the quadrats were often covered in vegetation!
Dan sieves leaf litter while Kelly sorts soil for invertebrates
After the cold wet days sampling in the middle of winter for the BESS Earthworm work the NVC fieldwork on a sunny day was quite a treat, finishing before lunch! Then it was back off to the Natural History Museum to process the leaf litter samples. The sieved leaf litter is placed into mesh bags which are hung inside a Winkler bag, basically a cloth funnel with a pot of alcohol tied to the bottom. These are hung up for three days and as the leaf litter dries the invertebrates move downwards into the pot where they are preserved ready for sorting and identification. Once, the Winkler bags were hung up in one of the towers either side of the main entrance of the Museum, but now they are in a much more convenient location which doesn’t involve carrying bags of leaf litter up narrow Victorian staircases!
Paul puts the sieved leaf litter samples into Winkler bags
After the three days are up the pots can be removed ready to be sorted and counted to order level by volunteers with selected invertebrate groups later identified to species level. The NVC dataset is just one example of long-term data collection by the NHM Soil Biodiversity Group, another being the monthly sampling at Whitley Wood in the New Forest, which I am volunteering on in August. I am very excited to be given the opportunity to analyse these datasets, among others, in my upcoming PhD.