The diversity of arable plants - past, present and some futures

There is much current concern about declines in the biodiversity associated with changes in the diversity of arable plants. Sources of data on the cur rent status and trends in the flora of arable fields are reviewed. Forthcom ing national data sources are reviewed, and a proposal for a synoptic arabl e plant survey is presented. There have been reductions in and in the range of some species, reductions in species diversity at the field level, and s hifts from broad-leaved species to assemblages dominated by grasses. It is suggested that present conservation measures may be enough to ensure the su rvival of scarce species, but that the decline in conservation value of ara ble fields in general will continue, unless there is an increased awareness that weed management and arable plant conservation are not incompatible.