Changes in the arable flora of central southern England since the 1960s

In the early 1960s, 156 arable fields scattered across Oxfordshire and Berkshire were surveyed. A full resurvey of all these fields which were still in arable production was carried out in 1997. The results were used to assess the change in status of arable weed species over the past 30 years. Many of the rarer species found in the original survey were found over 30 years later at the same sites, suggesting that the distribution of scarce species may not have contracted as seriously as had been believed. However, although these species persist in the seed bank, their overall abundance has declined markedly and consequently urgent, active conservation measures should be undertaken to prevent further extinctions within this species group. Requirements for conservation of rare arable plants are considered. (C) 2000 Elsevier Science Ltd. All rights reserved.