Ramsons carpets

Two recent woodland trips provided the inspiration for this post on ramsons (Alium ursinum). The first trip was an afternoon recce for some uncommon woodland flora when a visually compelling ramsons carpet was chanced upon in less than ideal lighting. Another location identified and added to the seemingly ever lengthening 'to visit under more idealised lighting' list.

To increase the chances of finding ramsons carpets an appreciation of their ecology is useful and a Hungarian research paper provides some useful insight into the habitat requirements amongst other things:

"In spite of its broad distribution across continents, and its occurrence as a weed, the species cannot be considered as a generalist. Several authors have classified it as a habitat specialist, having a rather narrow range of ecological tolerance (Grime et al. 1988, Kevey 1977, Rychnovská and Bednář 1998). A. ursinum is particularly sensitive to the availability of water. It requires a mesic soil, which is well-drained. Both drought and waterlogging are unfavourable (Csiky et al. 1999, Grime et al. 1988, Kevey 1977, Rychnovská and Bednář 1998, Trémolières et al. 2009, Tutin 1957). Sufficient humidity in the air is also crucial for survival (Kevey 1977, Kovács 2007)."

"The species strongly prefers the forest floor; it can rarely be found outside of a forest (Grime et al. 1988), only in some places with high, evenly distributed precipitation (Tutin 1957) or along rivers or streams (Kevey 1977)." 

"The plant requires a nutrient-rich soil (Tutin 1957)"

"A. ursinum is sensitive to the pH, missing from base-poor sands and mor soils (Tutin 1957). Falkengren-Grerup and Tyler (1993) demonstrated experimentally that mor (pH 3.6) inhibited the production of new roots. Tutin (1957) estimated the tolerated pH range from 5.5 to 7.9; Grime et al. (1988) narrowed it to 6–7.5" 

Extracts taken from Oborny, B., Botta-Dukat, Z., Rudolf, K. and Morschhauser, T., 2011. Population ecology of Allium ursinum, a space-monopolizing clonal plant. Acta Botanica Hungarica, 53(3-4), pp.371-388.

Ransoms are an indicator species of ancient woodland and some online detective work cross referencing national ancient woodland inventories e.g. Wales and England, against a relevant geology map will identify candidate sites of ancient woodland overlying calcareous bedrock. It is then a case of recceing the candidate woods.

The second trip was one made specifically to photograph a riparian carpet of ramsons within the Lower Wye Valley AONB on a rare day with overcast skies, the weather in May, thus far, has been mostly clear blue skies and sunshine. The woodland is designated as ancient semi natural and has outsize coppice stools of alder, ash, wych elm and hazel with a ground flora community of ancient woodland indicator species.