Five well-recorded tetrads (2km × 2km squares) per hectad (10km × 10km) are required to give adequate statistical coverage for the BSBI ‘Atlas 2020’ project.
To count as ‘well-recorded’ a tetrad should have at least 75% of its known species recorded within the period 2000 to 2019.
The percentage target is flexible, however, and may be adjusted to meet local circumstances. The thorough work done for A Flora of Cumbria, published shortly before the Atlas period, means that in vice-counties 69 (i.e. Westmorland) and 70 (Cumberland) it is harder to reach the 75% target than it would be in a previously poorly-recorded vice-county (*). Also until recently the emphasis was on getting hectads well-recorded, so many records at tetrad level are missing. For now the target percentage has been reduced to 60%. If we have a good season this year it may be possible to raise this.
We have many tetrads recorded in the 2020 date-class that only narrowly fail to meet the 60% target. These are to be our ‘target tetrads’. It makes sense to target these fairly well-recorded tetrads where one visit may raise a tetrad to “well-recorded” rather than to work on poorly-recorded tetrads where several visits each could be needed.
To complete the task of five tetrads per hectad we have a list of 171 tetrads that need to be targeted, or 57 per year for the next three years.
We have at least twenty active recorders in Cumbria who spend at least ten days in the field in a typical season. If each of these were to divert three days’ effort per year to the target tetrads the goal may be achievable.
It is certainly not necessary for everyone to abandon their normal recording activities: all these endeavors produce useful records. Also it may not have escaped your notice that we have significant areas where there are few or no records (see below); it would be very useful to devote a little time to these. An hour or two in an un-recorded tetrad could easily yield fifty species, which would ‘put a new dot on the map’.
NB: Although we are here discussing tetrads rather than monads (1km × 1km squares), we still prefer recording at the level of monad (or better), and indeed last year the vast majority of records submitted were at monad level. However, for the foreseeable future analyses of botanical data nationwide will necessarily be at tetrad level; there are not enough previous monad records to allow much analysis at this resolution.
Where are the Target Tetrads?
The link … Atlas 2020 recording … will open a folder that contains the following:
A file called Target Tetrads contains the list of target tetrads as outlined above. When you have recorded in one of these tetrads you can add in your name, the recording date and the number of records made. This will indicate to others which tetrads have been worked. [Before putting in your details you may need to click on “EDIT IN EXCEL” in the middle of the bar above the worksheet.]
Then please send the records to PLB as soon as possible! If, when the records are entered, the tetrad becomes ‘Well Recorded’ the tetrad will be marked as such so others can see that there is no further need to record there.
When you look at this spreadsheet you will notice that several have already become “Well Recorded”, either as a result of a recording visit or because of entering past records to the database.
You will also notice that some tetrads are marked as “MEETING PLANNED”; these have a FoC meeting planned this year so you may wish not to choose them for a visit.
The situation could be quite fluid with hopefully more and more tetrads becoming “well recorded” as old and new records are added, so do keep checking to see which tetrads still need attention.
If you feel that looking at spreadsheets is far too irksome feel free to phone or email PLB for information on which tetrads you could attack.
A file called Target Tetrads Information contains some additional information about each tetrad for those who may be interested.
A folder called Desiderata contains two folders, one for VC69 and one for VC70, that have desiderata lists for all 171 target tetrads.
A file called Target Tetrads Map (updated 05-04-2017) shows the location of all the target tetrads.
A file called Tetrad Records Map (updated 14-08-2017) shows the present state of post-1999 records in VC69/70, and may be used to locate ‘where the holes are’ if you should fancy filling them.
PLB, 14 August 2017
[* what is a vice-county ?]
See also: What plants should we record?
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