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 last undertaken on 11th September, 2018. The number of records of Vascular Plants and Charophytes recorded by the SBS in MapMate stood at 743,032, of which 10,898 records (1.467%) 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 128 records where the OS GridRef was null, 2,523 hectad records and 8,246 tetrad records were not included in the analyses by monad (Table 1). The analyses also revealed 9 monads or partial monads, mainly on the county border, without any records or taxa and an additional 6 monads with fewer than 20 taxa (1760-2019).
|Length of OS GridRef||OS GridRef Type||No. of OS GridRefs||% of OS GridRefs|
|4||Hectads - 10km Square||2,523||0.34|
|5||Tetrads - 2km Square||8,246||1.11|
|Subtotal (not mapped)||10,898||1.47|
|6||Monads - 1km Square||157,649||21.21|
Table 1. Length, type, number and percentage of Grid references
The majority of the records (732,404 or 98.57%) are at a sufficient precision to enable analyses at the 1km Square level.
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.
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.