The FSEs (the UK's GM crops trials) 1999-2005

All seedbank measurements in the FSEs were carried out by SCRI using the emergence method applied to soil sampled from the 250 or so sites used in the experiment by field staff from CEH, Rothamsted Research and SCRI.

The method was developed in 1999 on three spring and four winter oilseed rape sites. On the basis of these initial measurements, the group estimated that differences of 1.5- to 2- fold in seedbank density between treatments would be detected from around ten samples of each one litre of soil from each treatment (half field). In the event, the estimates proved correct.

From 2000 onwards, a baseline sample was taken before the treatments were applied at each of the 250 sites, and repeat samples from the same locations 12 and 24 months later. At the height of activity in 2001, thousands of trays containing soil were spread throughout several large cubicles in glasshouses equipped with temperature control and shading. In all, SCRI's seedbank records in the FSE comprise the largest arable seedbank survey in the UK.

Most comparisons in the FSE's used only the 'first flush', the seedlings that emerged in the three months immediately after the soil was sieved and put out in trays. Up to two other flushes were observed for a selection of the sites, leading in total to an emergence period of 18 months for each soil sample. The general seedbank measures were also used as context for later work on the persistence of GM seed. More than 250 plant species were identified in the FSE seedbanks. The group acquired rare expertise in recognising seedlings and also seeds or arable species. The FSE seedbank database continues to be a source of information on the arable flora.

Contact: Geoff Squire, Cathy Hawes

Papers and reports

Many of the refereed papers on the FSEs included seedbank measurements made at SCRI. In addition, the baseline measurements were used to examine the occurrence of volunteer oilseed rape in a data-mining study (Debeljak et al. 2008). The seedbank records from the FSEs are still being analysed. Further refereed papers on seedbank composition are in preparation.

Debeljak, M., Squire, G.R., Demsar, D., Young, M.W., Dzeroski, S. 2008 Relations between the oilseed rape volunteer seedbank, and soil factors, weed functional groups and geographical location in the UK. Ecological Modelling 212, 138-146 (doi:10.1016/j.ecolmodel.2007.10.019).