Old Grid System

The grid of Atlas Florae Europaeae volumes 1 - 12, with its 4419 grid cells, was modified from the Military Grid Reference System (MGRS). The MGRS itself is an alphanumeric version of a numerical UTM (Universal Transverse Mercator) or UPS (Universal Polar Stereographic) grid coordinate.

AFE 1 - 12 used the 50 x 50 km quadrants of the MGRS 100 x 100 km squares as mapping units. The MGRS pattern was modified in AFE as follows:

Unused shore and island squares
Black squares in the picture above indicate grid cells which were not used. The records from them were moved to adjacent squares, or to grid cells in non-standard position. Iceland, Svalbard and Azores not illustrated (there are plenty of similar cases in those areas, too).

An asterisk (*) indicates symbols of squares the circles of which deviate from the actual position of the UTM squares.

British Isles

The entire S. Part of the Isle of Lewis is in PE2.
All of North Uist (etc.) is in *ND3.
All of S. South Uist (Barra, etc.) is in *ND4.
Dunvegan Head is in PD3.
All of the Isle of Man is in *UF4.
All of the Scilly Isles are in PR4.
UA2 is included in *UA1.
UA4 is included in UA3.
Guernsey and Sark are in WV1.
Alderney and Jersey are in WV3.


All of Laesö is in *PJ1.
All of Bornholm is in *VB4.
Faeröerne are in *FaeN and *FaeS, the limit between them follows Skopen Fjord.


Helgoland is in ME1.
VA2 contains only E. Rügen.


The scheme from AFE vol. 3 (1976):

AFE grid in Greece


All of Snaefellsnes is in *AN4.


NP4 is included in PP2.
*PN2 contains: all of Elba, Capraia, Pianosa, Montecristo, and islands W. Of it. (Mainland on PN2 is included in PN4).
UF2 also contains islands of UF4.
All of Isole Eolie o Lipari are in *VC3.
All of Pantelleria is in *QF3.
All of Isole Pelagie are in *TV1.
(All of Malta is in *VV1).


All of Vlieland is in FU1.
All of Terschelling is in FV4.


Kjelmesöy and the peninsula E. Of it are in VC2.
*Björnöya and *Jan Mayen form a square of their own.
Kvitöya is in *NK4.
Kongsöya is in *NH1.
Svensköya is in *MH4.
Hopen is in *MF4.


Each island of the *Azores forms a square of its own.


All of Poluostrov Rybachiy is in VC4.
NW. Kanin is in *MB4.
Ostrov Matveyev is in EB3, the rest of EC4 is included in EC3.
All of Sur Sari is in NG1.
Ostrov Malyy Tyutyarsari is in NG2.
Kolka is in EJ3.
Ostrov Dzharylgach is in VS4, Rybnoye in VR4.


BD2 is included in *BC1.
All of Isla of Ibiza is in *CD4.
The entire W. part of Isla de Mallorca is in *DD3, the E. part in *ED1.
All of Isla de Menorca is in *EE4.
I. Alboran is in *VE3.


All of Gotska Sandön is in *CK3.
All of Central Gotland is in *CJ1.
W. edge of XD1 is in WD3, N. Öland is in XD2.

Turkey (European part)

All of Imroz Ada is in ME2.
PF4 is included in *PF3.

AFE grid pattern

AFE grid pattern (not the actual grid; grid deviations omitted from this picture). Pale green = central seam square (two MGRS squares of different UTM zones merged, base width of the squares between 20-30 km); pale blue = seam square, widened for 10 km (base width 30-40 km); yellow = seam square with base width over 40 km; purple = narrow seam square (base width < 10 km merged with adjacent square in the same zone); red = seam square, narrowed 10 km; grey = rectanangular square, width 60 km; dark violet = rectangular square, base width 40 km; blue gridlines = MGRS grid in the UTM zone 34

Eastern border of the UTM zone 34 in Estonia and Finland.

  • GREY = Parts of squares on the different sides of the zone boundary are merged if 40 <= x + x <= 60 km. This means for the squares to be merged, x must be between 20 and 30 km. Standard 10-km UTM lines are followed here, and the merging has no effect on the width of the adjacent standard squares.
  • CYAN (DENSE BLUE DIAGONAL GRID SHOWS HOW THE WIDTH OF THE ADJACENT SQUARE IS CHANGED). If x is less than 20 km, the squares on different sides of the zone boundary are not merged, but the small parts of seam squares are joined the adjacent standard square. In cases where this would result in squares wider than 60 km, the width of the adjacent standard square is adjusted by narrowing its western or eastern edge (the edge farther from the zone border) to the next full 10-km UTM easting. In these cases x + 50 <= 60 which means if x is between 10 and 20, this longitudinal shift affecting the width of adjacent standard squares is done. Thus the width of the next standard square also grows to 60 km.
  • YELLOW = If x is below 10 km, then slices are joined to the adjacent square without additionally reducing its width by 10 kilometers (and thus the next square remains as 50 km x 50 km square). Thus the width of the adjacent standard squares becomes something between 50 and 60 km.
  • PURPLE (PURPLE HORIZONTAL GRID SHOWS HOW THE WIDTH OF THE ADJACENT SQUARE IS CHANGED). If x is more than 30 km, but less than 40 km, the partial square are not joined to the adjacent standard square, they would become too wide. Instead the edge outwards of the zone is extended to the next full 10-km UTM easting. Thus the grid cells become at least 40 km wide. Simultaneously the adjacent standard squares become 10 km narrower.
  • RED = If x is more than 40 km, the square is treated as an independent grid cell.

AFE grid in N Europe

AFE old grid pattern in N Europe (deviations from the general pattern not shown!).