Hampshire 10km distribution maps
Compiled by John Norton. Last updated 8 May 2025.
Introduction
These maps show the distribution of bryophyte taxa recorded in Hampshire (VC11 & 12) plotted at 10km square (hectad) resolution. The taxon names (species, subspecies and varieties) correspond with those used in the latest British checklist and vice-county census catalogue, both published in 2021. All well-defined infraspecific taxa that occur in the county and are listed in the census catalogue have been mapped. As at May 2025 there are 513 taxa recorded in Hampshire as a whole, corresponding to 501 full species. Hectad maps are shown for all of these and quadrant maps for 498 (see the introductory page to the quadrant maps for details). There are currently 483 taxa recorded in VC11 and 433 in VC12. Note that a small number of taxa mapped on this website are not listed for either VC11 or VC12 in the census catalogue because although identification was certain no voucher specimen was submitted to the national recorders for mosses and liverworts.
The maps were generated from records in the British Bryological Society (BBS) database (administered by the Biological Records Centre, BRC), together with those submitted but not yet incorporated into the the database and those compiled but not yet submitted by the Hampshire recorders (up to December 2024 for VC12 and April 2025 for VC11). Totals of 38,870 records were available for mapping at hectad resolution and 25,184 at quadrant resolution, though many of these were duplicates (a large number of Hampshire records were only input at hectad precision). The maps were produced using the Tom.bio plugin for QGIS, developed for the Field Studies Council. Note that the captions on the maps are automatically generated from the taxon list used, and the plugin removes hyphens and punctuation.
The format of the taxon names, with or without qualifiers (s.str., s.l.), follows a master BRC list (s.str. sensu stricto = in the strict sense; s.l. sensu lato = in the broad sense). Many taxon definitions have changed over the years as former species have been split into more than one species or where subspecies have been promoted to full species. Some notes on a few examples are given below (and see the table of name changes), but the variety of different combinations of names and qualifiers can be very confusing and made the production of the species maps quite complicated. To avoid confusion only currently recognised taxa are now mapped (see above), so for example old records of Leucobryum glaucum are excluded since this taxon was found to include L. albidum. Recently checked specimens of L. glaucum s.str. and L. albidum have been mapped, but there are no records of L. glaucum yet for VC12. In some cases older species defitions have been mapped according to the newer defition if it is certain that most or all the older records from the county belong to one of the more recently defined taxa. One purpose of showing these maps is to encourage more recording of recently split taxa so that gaps in distribution can be filled.
The coloured shading on the maps shows the date class in which the taxon was most recently recorded in each hectad. The first three date classes follow those used in The Atlas of British and Irish Bryophytes, published in 2014, except that the first class (grey shade) indicates records made before 1970 rather than before 1950 (1970 is now the cut-off date for vice-county records becoming bracketed in the census catalogue). Records added after the publication of the atlas (i.e. 2014 onwards) are indicated by the yellow shade. The brown background colour on the base map shows the New Forest SSSI. There are still some problems to be resolved concerning date classes for Hampshire records, because a great many were entered for date ranges rather than a specific year (past recorders kept lists of species on record cards covering several years). Usually the start date has been used for mapping purposes but some records only have an end date which has been used instead. Therefore this may have caused some records to be mapped with the wrong colour.
I would like to thank all the people who have sent in records and Oli Pescott for supplying the datasets on behalf of the BRC and BBS. The atlas records and some subsequent records (up to at least 2021) are on the NBN Atlas but newer records may not have been uploaded (the BBS database will be integrated with iRecord in 2025, after which all the more recently submitted records will be added). Please contact me (John Norton) if you notice any errors or can fill gaps by submitting records, or if you need help with mapping records for your own recording area. Simple and full versions of the Hampshire bryophyte recording sheets are available here.
Notes on some of the mapped taxa
Old records for the following taxa (now denoted by the s.l. qualifier due to a subsequent taxonomic revision) have not been mapped in addition to their component taxa: Campylium stellatum, Ditrichum flexicaule, Fissidens pusillus, Fossombronia pusilla, Hypnum cupressiforme, Marchantia polymorpha, Metzgeria fruticulosa, Palustriella commutata, Racomitrium canescens, Scorpidium revolvens, Sphagnum capillifolium, Sphagnum denticulatum, Sphagnum recurvum, Sphagnum subsecundum, Streblotrichum convolutum and Syntrichia ruralis. Old records of Racomitrium canescens mainly refer to what is now R. elongatum, which is widespread in the New Forest and well recorded.
Records of Aloina aloides s.l. have been grouped with s.str. records as no doubt the majority of records do relate to this taxon. The same has been done for Chiloscyphus polyanthos s.l., which may include some records of C. pallescens. Similarly, all records of Polytrichum commune s.l. have been mapped as Polytrichum commune s.str. – there is currently only a single record of P. perigionale.
Microbryum davallianum as previously defined now comprises var. davallianum and the readmitted var. conicum. A small number of specimens were checked for each vice-county by the national moss recorder so that the census catalogue could be updated. In Hampshire both varieties are common but currently there are likely to be only single accepted records for VC11 and VC12. The VC11 record is prior to 1970. For now, maps of this taxon have not been included until the details and locations of these records is known.
Records of Ulota crispa s.l. and Ulota crispa sensu Smith (2004) have not been mapped, to encourage gaps to be filled for the more recently defined species: U. crispa s.str., U. crispula and U. intermedia.
Records of Weissia brachycarpa var. brachycarpa (apparently rare in the county) and W.b. var. obliqua (common on chalk) have been mapped separately and old records recorded only as W. brachycarpa have not been mapped, even though most are likely to refer to var. obliqua. The same applies to records of Weissia controversa var. controversa and var. crispata.
Analysis
Recording coverage
The map below shows the recording coverage for Hampshire and the Isle of Wight compiled for all records where a 1km grid reference was available. Many Hampshire records have, however, been entered at quadrant precision (5km squares) so these are mapped for the SW corner 1km square for that quadrant – hence some squares appear to fall outside the VC boundaries or in the sea. Note that there are no bryophyte records for tiny areas of Hampshire within SU01 and SU02, so these squares are blank. It is possible that there are some records recorded to tetrad level which will not be shown on this map. The map clearly shows that the Isle of Wight, the greater New Forest and the coastal area of the eastern Solent have received good coverage, but recording in VC12 has generally been much thinner. Contains OS data © Crown Copyright and database right 2025.
Species richness
This map plots the total number of mapped taxa recorded in each 10km square for the two Hampshire vice-counties (out of total 518). Unsurprisingly the richest squares are located in the New Forest, with the highest count of 325 in the south-eastern part (SU30). Elsewhere, the richest square is SU73 with 301 taxa; this includes chalk downland and wooded hangers around Selborne as well as part of the Woolmer Forest heathland; areas which have been well covered in the past. SU72 to the south, which takes in part of Butser Hill, is also relatively rich (275 taxa). Other squares exceeding 250 taxa are SU42 (269 taxa) which includes most of Winchester and SU51 which includes some important woodland areas, including part of Botley Wood and most of West Walk, both near Wickham. As would be expected the squares lying on the county boundary have lower counts, especially where only a small portion lies within VC11 or VC12 and two squares with a very small Hampshire land area have no bryophtye records at all (SU01 and SU02). Contains OS data © Crown Copyright and database right 2025.
Under-recorded taxa
This map shows the counts of ‘common’ taxa which are presently unrecorded in each hectad (based on 150 taxa which are more widely distributed in the county, occur in commonplace habitats or are likely to be common but under-recorded for various reasons). This analysis obviously highlights some squares around the county boundary where land area is small or suitable habitats may not be present, but also reflects the fact that much of the central, southern part of the county (within VC11) is better recorded than the west and north. Contains OS data © Crown Copyright and database right 2025.
