Surrey Botanical Society

Analyses of Records and Taxa and Interactive Maps

Analyses of Records and Taxa by Monad and Date Class

The bi-annual analyses of MapMate records and taxa by Monad and Date Class was undertaken on 12th March, 2018. The number of records of Vascular Plants and Charophytes recorded by the SBS in MapMate stood at 714,610 and 10,872 records had a less precise OS Grid Ref than a 1km square.

A list of monads and the percentage of each 1km square in Surrey was copied from the Biological Records Centre (BRC) and imported into a MS Access table for use in the analysis. Surrey covers 2,105 monads, including 1,822 complete monads, 145 with 50% to 99.9% coverage and 138 with 0.1% to 49.9% coverage.

The analyses of records and taxa for each Date Class and all years were carried out in MS Access using queries developed for the purpose (see Appendix 2 for records & Appendix 3 for taxa) with the list of BRC Surrey monads and SBS MapMate data. Records where the Taxon was recorded as 'Not present' (i.e. Quantity = -7) were excluded from the analysis.

A total of 127 records where the OS GridRef was null, 2,520 hectad records and 8,225 tetrad records were not included in the analyses by monad (Table 1).  The analyses also revealed 11 monads without any records or taxa and an additional 10 monads with fewer than 20 taxa (1666-2019).

 

Length of OS GridRefOS GridRef TypeNo. of OS GridRefs% of OS GridRefs
0Blank1270.02
4Hectads - 10km Square2,5200.35
5Tetrads - 2km Square8,2261.15
Subtotal (not mapped)10,8731.52
6Monads - 1km Square149,36120.90
8100m Square544,94076.26
1010m Square9,3481.30
121m Square880.01
Subtotal (mapped)703,73798.47
Total records 714,610

Table 1. Length, type, number and percentage of Grid references

The majority of the records (703,737 or 98.47%) are at a sufficient precision to enable analyses at the 1km Square level.

A total of 127 where the OSGridRef was null, 2,520 hectad records and 8,226 tetrad records were not included in the analyses by monad (Table 1).  The analyses also revealed 11 monads without any records or taxa and an additional 10 monads with fewer than 20 taxa (1666-2019).

The results, as a crosstab query for each Date Class were copied and pasted into Excel spreadsheets and subsequently conditionally formatted. See Records Analysis Spread Sheets  and  Taxa Analysis Spread Sheets

Interactive Maps of Numbers of Records and Taxa

The data were also used to populate Interactive Google and OS Maps. These were developed by Robin Day expressly for the purpose and enable users to search for a grid reference or place name and select whether to display the number of records or taxa in every Surrey monad by date classes / date range against a Google Satellite or OS Map background

Interactive Taxa Distribution Maps

Distribution maps for all Surrey taxa, based on the same MapMate data, have also been updated on the website (accessed via the main menu at Members / Taxa Maps). Other than the most 30 widespread taxa, these are restricted to SBS Members only so you will be prompted to login if you have not done so this session. These were also developed by Robin Day expressly for the purpose. For any taxon you can select any or all Date Classes to display a map of the distribution in Surrey by monad against a Satellite or OS Map background.

Acknowledgements

I am extremely grateful to David Williams, Robin Day and Peter Wakeham for invaluable assistance and Bill Chadwick who provided the code for SBS use which Robin adapted.

The analyses would not have been possible without the massive input of the original records from SBS members, recorders and MapMate users.

Brian Pitkin