Flora of Ashdown Forest - Botanical Society of the British Isles

25Similarly, environmental variables can be correlated with species, as shown below:ENVIRONMENTALVARIABLEAncient woodlandCar parksChurchyard/cemeteryDisused railwayHeathlandMain urban areasMarsh/bogPlantationPond/lakeSemi-natural woodlandStream/riverAlluviumTunbridge Wells SandsWadhurst ClayCurtisden soilsPoundgate soilsWickham 1 soilsSPECIES WITH THE FIVE HIGHEST SIMILARITY CO-EFFICIENTS(SIMILARITY CO-EFFICIENTS IN BRACKETS)Wahlenbergia hederaeea (40), Rlbes rubrum (39), Carex laevigata (35),Veronica hederifolia (35), Hypericum tetrapterum (35).Euphrasia attic/naNs agg. (52), Ranunculus bu/bosus (44), Galiurn verum(43), Unum catharticum (42), Agrimonia eupatoria (41).Svmphoricarpos a/bus (65), Hypericum androsaemum (62), Reynoutriajaponica (49), Calvstegia silvatiea (47), Galanthus nivalis (45).Callitriche platycarpa (100), Chaenorhinum minus (99), Linaria vulgaris(99), Spiranthes spiralis (99), Rosa eanina x obtusifolius (99).Festuea filiformis (63), Juneus squarrosus (61), Erica tetralix (59), Ulexminor (58), Nardus strieta (53).Symphoricarpos rivu/aris (66), Equisetum arvense (51), Me/ica unit/ora(50), Reynoutria japonica (46), Veronica hederifolia (45).Salix rep ens (34), Carex eehinata (32), Salix aurita (29), Trichophorumeespitosum (28), Carex nigra (28).Senecio sy/vaticus (32), Mentha arvensis (31), Stellaria a/sine (30),Senecio vul9aris (27), Ca/litriche stagnalis (26).Lotus u/iginosus (52), Iris pseudacorus (52), Ma/us domestica (52), Carexsvlvatiea (50), Galium palustre (47).Fagus svlvatiea (100), Castanea sativa (99), Bleehnum spieant (97),Holeus mollis (97), Ajuga rep tans (96).Epilobium obscurum (66), Alnus glutinosa (63), Prunus avium (60), Carexsylvatiea (59), Glyeeria fluitans (59).Filipendula ulmaria (50), Scirpus svlvatieus (55), Festuea gigantea (49),Lycopus europaeus (47), Chrysosp/enium oppositifo/ium (46).Carpinus be tu/us (74), Me/ica unit/ora (69), Acer campestre (66), Luzulaforster! (64/, Atriplex patula (62).Acer campestre (57), Crataegus /aevigata (55), Carpinus betu/us (55),Chrvsosplenium oppositifolium (49), Meliea uniflora (49).Carex sv/vatica (51), Rosa arvensis (50), Lvchnis flos-cuculi (46), Prunusdomestiea (46), Arum maeulatum (45).Juncus squarrosus (61), Carex panicea (44), Carex echinata (43), Ribesni9rum (39/, Polvgala serpv//ifolia (38).Acer eampestre (82), Crataegus laevigata (81), Polyp odium agg. (81),Oenanthe crocata (75), Luzu/a forsteri (71).5. Comparison with Sussex Plant AtlasThe Sussex Plant Atlas was recorded using tetrads between 1966 and 1978 (Hall 1980). It wasrecorded on an ad hoc basis with no standardisation in the recording, and thus provides a usefulcomparison with our data. For the comparison we have summarised our 1-km square data into the 14tetrads which directly correspond to the Sussex Plant At/as but also including tetrads 43A and 43V forwhich we have only recorded three of the four 1-km squares.When the number of records for each tetrad were compared the results shown in the table belowwere obtained, We have recorded on average nearly half as many species again as the Sussex PlantAtlas, indicating that the Sussex Plant At/as was under-recorded. About 6.5% of the species recordedin the Sussex Plant At/as were not recorded for our flora, indicating that more species could be found inour squares, Application of Dony's (1963, 1976) species-area relationship for Hertfordshire to our datasuggests that a mean of 223 species would be expected for each l-km square; we have recorded anaverage of 241 species per l-km square (excluding critical species) which suggests that Dony'sequation needs revising based on Sussex data.