VICE-COUNTY 104 – RECORDING UNITS AND COMMON PLANTS: TOWARDS ATLAS 2020
VC 104 comprises part of 51 hectads (10 km squares of the British National Grid). It shares eight of these with other vice-counties, three (NG60, NG71, NM47) with VC 97 (West-Inverness-shire), three (NG63, NG64, NG65) with VC 105 (West Ross) and two (NG72, NG82) with both VC 97 and VC 105.
No hectad is 100% land (including freshwater bodies), though four are >98% (NG43: 99.8%, NG42: 99.7%, NG45: 98.1%, NG34: 98.0%).
NG82 has only 0.1% as land in VC 104 and NM19 only 0.4%.
There are 709 tetrads (2 km squares of the British National Grid) in VC104 according to the Biological Records Centre. At least nine of these are likely to contain no vascular plants (with the possible exception of Zostera) as they appear to lie wholly below the High Water Mark.
It shares six tetrads with other vice-counties, three (NG71T, NG72V, NG72W) with VC 97, two (NG72N and NG72T) with VC 105 and one (NG82B) with both VC 97 and VC 105.
At the time of writing (April 2015) there are 20 species that have been recorded in >500 tetrads in VC104:
If one takes records from 1 January 2000 onwards Carex nigra is lost from the top twenty list to be replaced by Angelica sylvestris (and only 13 taxa exceed 500 tetrads).
Taking records from 1 January 2000 onwards, there are 163 plants recorded from >200 tetrads.
Common Plants Missing from Individual Hectads
In 20 of the 51 hectads all 163 common plants, as arbitrarily defined above, have been recorded since 2000.
Eleven hectads are currently missing records for 1-4 common plants and six more are missing 5-10.
The remaining 14 hectads are
missing more – from 18 to 114 taxa. With one exception these are the
smallest hectads, each with <5% of its total area as land in VC 104. The
exception is NG63 which has 9%, mostly in the northeast of Scalpay and is
known to need further work. This is illustrated in the following table
with the smallest 13 hectads having a coloured background:
Missing 114 of 163 common plants might look like serious under-recording but in fact reflects that the only land in NM19 is Hyskeir (Ňigh-sgeir), a low-lying, seriously exposed islet that marks the southern end of The Minch and is composed of hexagonal basalt columns and sandy material formed therefrom.
Details of Hectads Missing 1-4 Common Plants
Almost all of these seem likely to be present. Similar lists for e.g. those hectads missing 5-10 common plants can readily be constructed.
For many years when recording I have taken tetrad lists split into pre- and post-2000 records. Recently I have constructed lists for each hectad of plants recorded there only before the year 2000. The advantage of this is that they show old records for which there is no grid reference better than hectad level.
Constructing these lists is complicated where subspecies are involved as e.g. a pre-2000 record of Luzula multiflora might show up as “Not Re-found” despite Luzula multiflora subsp. multiflora having been recorded frequently from 2000 onwards. By and large this issue has been resolved but the odd false positive may remain. I have left microspecies of Hieracium, Rubus and Taraxacum on these lists but made them pale as in general it is not expected that these will be covered for Atlas 2020.
These “Not Re-found” lists contain many taxa recorded only once or twice, often a long time ago, many of which may be erroneous.
All lists alluded to in this document are freely available to anyone recording in the vice-county.
Of the 709 tetrads in VC104, 146 (20.6%) have fewer than 50 taxa recorded. Forty–two of these tetrads have no records at all, though at least 9 of these probably contain no vascular plants (with the possible exception of Zostera) as they appear to lie wholly below the High Water Mark.
Thirty-eight of the 51 hectads in VC104 contain one or more of these poorly recorded tetrads. The most severe cases are shown in the table:
Stephen J Bungard
Updated 22nd April 2015