Maps Scheme The BSBI Maps Scheme produces 10km
square, or hectad, dot maps showing the distribution of vascular
plants and charophytes in the British Isles, updated at weekly
intervals. It was launched in 1950 and is now based on a ten-year
cycle of recording, so the black dots at any point in time show
only the records that have come in so far this decade.
The BSBI Maps Scheme database was commissioned by David Pearman,
designed by Alex Lockton and constructed by Alan Hale and Bob
Ellis. Quentin Groom & Alex Lockton manage the data and maintain
the maps. The project is funded by the BSBI.
next step will be to change the resolution of the dots from 10km
to 2km - a 25 fold increase in recording. Many counties have done
this already, but coverage is far from complete. For the rarer
species the tetrad maps are quite comprehensive, but for commoner
plants they simply show the counties that record at tetrad scale.
you would like to see how the Tetrad Maps Scheme is developing,
have a look at the maps, but be aware of the limitations of the
data so far.