Northern Deergrass habitats at some known sites in northern England and Scotland
(habitats of the other two taxa - click the ‘Habitats’ buttons on their own pages)
Calcareous springs and flushes
e.g. Widdybank Pasture, Teesdale (4-500 m)
e.g. Glen Fender Meadows, Blair Atholl (330 m)
~ A remarkably similar suite of species in these sites, with many ‘arctic-alpine relicts’ in common. Northern Deergrass fits comfortably into such communities.
e.g. Blackheugh End, north of Bellingham (one of the original four sites discovered in Northumberland by G.A. Swan).
~ In a wide flushed area in rather unprepossessing blanket-bog plateau, Northern Deergrass grew abundantly in a delightfully compact form, with a range of sedge species – Tawny, Carnation, Flea, Bottle and Yellow (Carex hostiana, panicea, pulicaris, rostrata, viridula ssp. oedocarpa), Few-flowered Spikerush (Eleocharis quinqueflora), abundant Broad-leaved Cottongrass (Eriophorum latifolium), and a variety of other plants such as Butterwort (Pinguicula vulgaris) and Cranberry (Vaccinium oxycoccus) – remarkable diversity for what appeared to be a less-than-promising area, presumably reflecting some calcareous substrate below.
Mineral-rich seepage areas around basin mires
e.g. Muckle Moss NNR, Northumberland: a valley mire close to Grindon Loch and the Roman Wall
~ Northern Deergrass occurs sparsely along a short stretch of runnel and nearby seepages in a small area indicating some slight mineral enrichment – more-demanding plants such as Flea Sedge (Carex pulicaris) were associated with the deergrass here, but closely surrounded by typical acid peat species such as Heather (Calluna vulgaris) and Cross-leaved Heath (Erica tetralix). There were also many more plants of the deergrass hybrid.
e.g. Muckle Moss NNR
~ Some distance out onto the quaking bog two plants of Northern Deergrass were found with only four associates, Heather, Cross-leaved Heath, and the two cottongrasses, Common and Hare’s-tail (Eriophorum angustifolium and E. vaginatum). This may not be a typical habitat, though see next...
Deep peat on blanket mires
e.g. Butterburn Flow, Gilsland, Cumbria
~ Although apparently classed as 'blanket mire', this huge area (several square kilometres) has accumulations of deep peat and several distinct 'domes' which approach raised mire in appearance and vegetation. Hybrid deergrass is very abundant all over the Flow, and locally the dominant plant.
At the western lobe of the Flow, the uniform mire surface starts to slope down to the west into a series of seepages and runnels. Northern Deergrass frequent and very widespread in these seepage areas. The densest populations found were at NY6593.7604 and for about 75 metres eastwards along the south side of the main eroding runnel.
Further east towards the head of the seepages, Few-flowered and Tall Bog Sedges (Carex pauciflora and C. magellanica) occur with Northern Deergrass, here around sphagnum-filled hollows and seepages of acidic water.
A walk around the western end of this very large site revealed Northern Deergrass to be frequent, with the denser patches being in and by seepage areas and around small Sphagnum-filled pools. Typical associates were only the most frequent species of wet peat 'domes', such as Heather, Cross-leaved Heath, Bog Asphodel (Narthecium ossifragum) and the two cottongrasses Eriophorum angustifolium and E. vaginatum. There is very little evidence of groundwater movement here, and the ombrogenous origins of the water regime at this site seems clear.
At the furthest point reached, the Northern Deergrass occurred in small pockets on flat areas without the hybrid - looking very much 'relict' here. Further investigation out onto the even more remote parts of this site is needed!
Only two plants of Common Deergrass were spotted in a walk of over 3 km (although sterile examples may have been overlooked), against an estimated minimum population of Northern Deergrass of 80,000 plants, and a hybrid population perhaps into millions. This raises interesting questions about the history of the three species, and the development and spread of the hybrid.
e.g. Abernethy Forest, Speyside
~ See A. Amphlett's note (BSBI News, No. 119 (January 2012), in which he states, from his experience on Speyside, “… I am confident that the primary habitat for this species in Abernethy Forest is M18 bog”. Many of the bogs with this species “are partially wooded, carrying an open canopy of low-growing native Pinus sylvestris ssp scotica”.
Comments welcome on deergrass habitats!
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