Spartina anglica

The smooth cord-grass Spartina alterniflora was introduced from the east coast of North America to Southampton Water prior to 1870 and was first found on mudflats near Hythe (Stapf 1913). Its subsequent crossing with the native small cord-grass S. maritima resulted in the appearance of a fertile amphidiploid, the common cord-grass S. anglica (and in the sterile hybrid S. townsendii which preceded it). Their identification is covered by Marchant (1967).

 

It is thought that Spartina alterniflora was originally introduced in ships' ballast water.

 

Following its formation through hybridisation and tetraploidy, Spartina anglica was successful through having a rapid rate of growth, high fecundity and aggressive colonisation (Benham 1990).

 

Following the appearance of Spartina anglica, it was extensively planted throughout Britain to stablise soft sediments (Hubbard & Stebbings 1967) and in Europe, China and eastern USA. Spartina has also spread naturally. At many sites it remained dormant as seeds for a number of years then showed a considerable expansion over a relatively short period. This expansion appears to be correlated with a year in which early seed development takes place and seedling establishment is extensive. Thereafter, clumps of Spartina arise by vegetative growth from seedlings and these gradually coalesce to form monospecific swards (Doody 1984).

 

In Britain Spartina anglica is widespread around the east and west coasts and is still expanding in the west. However, on the south coast, having initially spread extensively, it died back (Doody, 1984). It is generally found in sheltered, estuarine conditions where mud flats are present. Elsewhere in Europe it is found in estuaries in the west (P. Doody pers. comm.).

 

The availability of mud flats for colonisation, change in sediment patterns, tidal regimes and climate (it appears less able to set viable seed in colder climates) have influenced its spread.

 

The rapid colonisation of Spartina over extensive flats in sites with large wintering populations of waders and wildfowl is a major concern because of the birds' loss of habitat for feeding and roosting (Davidson et al. 1991). It is believed that Spartina anglica may have helped the die back of the native S. maritima as the latter is much less widely spread than formerly (Perring & Walters 1976). In addition, by taking over the mantle of the native pioneer species, S. anglica has altered the course of succession. It usually produces a monoculture which has much less intrinsic value to wildlife than the naturally species-diverse marsh (Davidson et al. 1991).

 

Amenity interests may be affected, though it has been used in the past as an aid to saltmarsh enclosure.

 

Before World War II, copper sulphate was sprayed on Spartina as a treatment (Hardy 1968). More recently there have been several attempts to control Spartina anglica where it has invaded nature reserves (Doody 1984) by spraying it with the herbicides Dalapon and Feneron, and attempts have also been made to dig up seedlings. Dalapon is reported to have been up to 80% successful, but is generally considered to be not very effective. Pesticide trials have been carried out at Lindisfarne National Nature Reserve off the Northumberland coast and at several other sites.

 

The ability of Spartina to colonise open mudflats at a faster rate, and further seaward, than its competitors has been seen as of potential benefit to man. As a consequence it was extensively planted throughout Britain (Hubbard & Stebbings 1967), in Europe, and even as far as China, as an aid to stabilisation of coastlines and a stimulus to enclosure and land-claim (Davidson et al. 1991).

 

Spartina anglica is now the main species of cord-grass found throughout Great Britain.

 

Burd, F. 1994. Guide to the identification of British saltmarsh plants. National Rivers Authority, on behalf of the Institute of Estuarine and Coastal Studies, University of Hull.

 

Benham, P.E.M. 1990. Spartina anglica - a research review. Huntingdon, Institute of Terrestrial Ecology. (ITE Research Publication No. 2.)

 

Davidson, N.C., Laffoley, D.d'A., Doody, J.P., Way, L.S., Gordon, J., Key, R., Drake, C.M., Pienkowski, M.W., Mitchell, R., & Duff, K.L. 1991. Nature conservation and estuaries in Great Britain. Peterborough, Nature Conservancy Council.

 

Doody, J.P., ed. 1984. Spartina anglica in Great Britain. A report of a meeting held at Liverpool University on 10th November 1982. Huntingdon, Nature Conservancy Council. (Focus on nature conservation, No. 5.)

 

Hardy, E. 1968. The control of Spartina townsendii in a tidal estuary. Dock Harbour Authority, 41: 269-270.

 

Hubbard, J.C.E., & Stebbings, R.E. 1967. Distribution, date of origin and acreage of Spartina townsendii (s.l.) marshes in Great Britain. Proceedings of the Botanical Society of the British Isles, 7: 1-7.

 

Marchant, C.J. 1967. Evolution of Spartina (Gramineae). I. The history and morphology of the genus in Britain. Journal of the Linnean Society (Botany), 60: 1-24.

 

Perring, F.H., & Walters, S.M. 1976. Atlas of the British flora. Botanical Society of the British Isles.

 

Stapf, O. 1913. Townsend's grass or ricegrass. Proceedings of the Bournemouth Natural Science Society, 5: 76-82.

Dr J.P. Doody, Joint Nature Conservation Committee.