Journal of Ecology 2000, BIOLOGICAL FLORA OF THE BRITISH ISLES* No. 212 List Br. Vasc. Pl. (1958) no. 689, 1 Koeleria macrantha (Ledeb.) Schultes (K. alpigena Domin, K. cristata (L.) Pers. pro parte, K. gracilis Pers., K. albescens auct. non DC.) J.M. DIXON Department of Environmental Science, University of Bradford, Bradford BD7 1DP, UK A compactly tufted perennial; tufts sti and spiky or more rarely soft and gently spreading, 4±60 (70) cm high. Culms slender, 1±3-noded, erect or sometimes slightly curved, downy towards the panicle or hairless. Leaves light grey-green to mid-green on the adaxial and mid-green to dark green on the abaxial surface. Blades curving abruptly to a hooded tip, up to 25 cm long and 1±3.5 mm wide, sti or soft, usually at in unstressed plants when fully expanded, ridged on adaxial surface. Both surfaces extremely variable in degree of hairiness, ranging from glabrous to densely hairy (hairs on margins up to 1.5 mm long). Abaxial surface generally more hairy than adaxial, lower sheaths sparsely to densely hairy. Ligules up to 1 mm long, membraneous, usually surrounded by hairs to 2 mm long. Culm leaves usually 2, upper to 7.5 cm long. Panicles spike-like, very dense and often interrupted in the lower part, narrowly oblong, sometimes tapering towards the top; branches spreading during owering; 1±12 cm long and 2±10 mm wide, silvery-green or purplish, glistening; rhachillas short, usually densely hairy, but sometimes sparsely so; rhachis sparsely to densely hairy. Spikelets 3±6 mm long, 2±3 owered; densely clustered on short pedicels, to 4 mm long on lower branches; spikelets oblong or wedge-shaped, compressed, breaking up at maturity beneath the lemmas; many remain undispersed on the culm until this falls. Spikelet number variable from around 20 to 200. Glumes persistent, pointed, sometimes with a short awn, and thin membraneous margins; silvery-green or purplish, glabrous to densely hairy; lower usually rather shorter than, but sometimes equal to the upper glume; upper glume oblong or elliptic-oblong, 4±5.5 mm long, 3-nerved; lower narrowly oblong, 1-nerved, 3±4.5 mm long. Lemmas pointed, keeled upwards, sometimes with a short awn, silvery-green or purplish, 3±5.5 mm long; Correspondence: Dr Jean Dixon (fax 44 1274 234231; e-mail j.m.dixon@bradford.ac.uk). *Abbreviated references are used for standard works, see Journal of Ecology (1975), 63, 335±344. Nomenclature of vascular plants follows Flora Europaea. glabrous to minutely hairy on keels and near tips, 3- nerved. Paleas as long as or slightly shorter than the lemmas, 3±5 mm long, 2-keeled, colourless and translucent; lodicules to 1 mm long and 2-toothed. Grain 2.5±3 mm, enclosed within the hardened lemma and palea. Mean caryopsis oven-dry weight 0.32 mg. Root system is a dense mat of gingery-brown brous roots, largely unbranched in the upper parts, more strongly branched in the lower; lateral roots often very crinkly. Short wiry rhizomes 1±1.5 mm diameter and to 7 cm long are sometimes present. Native. This is a complex taxon with much variation as a result of polyploidy, and with many ecotypes. The division of the macrantha group in Flora Europaea into nine or more species is based entirely on morphology, and it is considered that these may represent only minor taxa. The species macrantha at the present time is not further subdivided. Grime et al. (1988) noted that in Britain Koeleria glauca had been separated from K. macrantha and some Floras produced since then have listed the two species for Britain. Work currently being undertaken by the present author questions this distinction. I. Geographical and altitudinal distribution The distribution of Koeleria macrantha in the British Isles is shown in Fig. 1. The species is widely distributed on Carboniferous, Magnesian and Jurassic limestones, and on chalk, extending from the north of Scotland, including the Orkney Isles, the Outer and Inner Hebrides, and the Isles of Skye, Mull and Arran, through northern Britain and Wales, the Isle of Man and Anglesey to the south of England. It is also recorded from the Isle of Wight, Jersey, Guernsey and Alderney. In Wales it is abundant on the Lias of south Dyfed and on the calcareous substrata of Clwyd and Anglesey, and less abundantly on calcareous substrata elsewhere (Hyde & Wade 1957). In the north of Britain it is more common in coastal regions. The species is well distributed in the west of Ireland, less so in the east.
710 Koeleria macrantha (Ledeb.) Schultes Fig. 1 The distribution of Koeleria macrantha in the British Isles. (O) Pre-1950; (W) 1950 onwards. Each dot represents at least one record in a 10-km square of the National Grid. Mapped by Mrs J.M. Croft, Biological Records Centre, Institute of Terrestrial Ecology, mainly from records made by members of the Botanical Society of the British Isles. Koeleria macrantha is recorded throughout western, central and eastern Europe, but is noted only as a casual in Fennoscandia (Flora Europaea) although K. glauca occurs in Sweden (SkaÊ ne, OÈ land and Gotland) and Denmark. K. macrantha is absent from the Mediterranean islands of Sardinia, Sicily and Corsica, and the Azores; the species is present in Spain but not in Portugal. It occurs in the Baltic, Central, South-West, South-East and the Crimean divisions of Russia, being recorded from all regions in the Caucasus, Upper and Lower Volga, central and southern Urals, Carpathians, Moldavia, Black Sea, Lower Don and western and eastern Siberia to 128 E, in the Tien Shan, Altai and Pamir mountains of the Central Asian states and in the southern parts of the Aral-Caspian area (Tsvelev 1984). Preston & Hill (1997) refer K. macrantha to the Eurosiberian Temperate oristic element. In Asia K. macrantha is recorded from Afghanistan, Iran, Lebanon, Syria, Turkey and Yemen, and in the Himalayan range from India, Kashmir, Nepal, Pakistan and Tibet. It is also
711 J. M. Dixon recorded from the western Chinese provinces of Kansu, Shantung, Kiangsu and Hopeh, from the northern Chinese province of Shansi, from Japan, Korea, Manchuria and Mongolia. Koeleria macrantha is widespread in North America and is recorded from Arizona, Colorado, Kansas, Nebraska, North Dakota, Oregon, Utah, Washington and Wyoming (Domin 1907); Louisiana, New Mexico and Mexico (Hitchcock 1971); California, Delaware, Indiana, Missouri, Ohio and Texas, and in Canada from Quebec to British Columbia (Steyermark 1963). The species extends to 60 N in Europe, to 62 N in Asia and to 55 N in North America. Koeleria macrantha is also recorded from central Africa ± Ethiopia, Eritrea, Guinea and Cameroon, from the Transvaal and Natal areas of South Africa and from Swaziland (Vergl. Chor.). In England K. macrantha has an altitudinal range from sea level to 550 m (North Yorkshire), from sea level to 412 m in Scotland (eastern Highlands), from sea level to 457 m in Ireland (Donegal) (Alt. Range Brit. Pl.), and from sea level to around 185 m in Wales. It is found to 2700 m in the Alps (Domin 1907), to 2200 m in the Pyrenees (Braun-Blanquet 1939), to 2300 m in Turkey, to 2100 m in Afghanistan, to 3200 m in China and to 4400 m in Nepal. In North America the species is found to 3400 m and in Africa to 3700 m on Mount Kilimanjaro (Vergl. Chor.). II. Habitat ( A ) CLIMATIC AND TOPOGRAPHICAL LIMITATIONS Koeleria macrantha is exposed to average monthly maximum temperatures to around 39 C in August in Spain, to around 50 C average monthly minimum temperatures in January in Siberia and to 30 C in January in European Russia (Meteorological O ce 1972), and to annual precipitation of around 2000 mm on the west coast of Scotland and in the Alps, and to conditions with no precipitation being recorded during July, August and September at Pagham in Afghanistan. No evidence in Britain of wind or insolation damage has been noted, nor from seaspray other than to make the leaves more glaucous. The species is subject to strong gales on northern coasts, such as on the islands of Canna and Sanday, Scotland (Asprey 1947) and to FoÈ hn-swept slopes in Germany, and is found on steep dry slopes in the Jura Alps subject to strong insolation (Braun-Blanquet 1939). Koeleria macrantha is found on both at ground and steep slopes; it is common on slopes of 20±50 (Ecol. Atl.). In the British Isles the species shows no aspect preferences. In Europe it occurs rather less frequently on east-facing, and in Asia rather less frequently on west-facing slopes. It is a component of dry, semi-natural pastures, scree slopes, rock outcrops, old lead mines, limestone and quarry spoil (Grime et al. 1988) and also of limestone pavements. It occurs on sea cli s and sand dunes, shelly or otherwise, particularly on partially xed dunes, but is also present in the later successional closed turf, in both very short and tall vegetation to c. 60 cm; it is found frequently on coastal golf links and in the machair of the Outer Hebrides and Iona. The species is also found on pebble strands and shingle banks, on rocks present at the tops of beaches, and on sandy beaches where limestone runs into the sea, as in the Burren, Co. Clare; it is also recorded from limestone heaths here (Ivimey-Cook & Proctor 1966). The species has been recorded from heathy pastures in the Isle of Man, from peaty soil overlying limestone in Ireland (Bot. Irl.), from tall chalk heath at Lullington Heath, Sussex (Grubb et al. 1969), from limestone heath in Somerset and Wales (Etherington 1981), and from sandy heath near Branderburg, near Lossiemouth, Scotland, where tufts of K. macrantha were growing up through the middle of mats of Calluna vulgaris and Empetrum nigrum. Koeleria macrantha is recorded from ungrazed, partially shaded moist soil overlying Magnesian limestone in Derbyshire (Lloyd 1972), from dry woodland in Pakistan, under Juniper scrub in Nepal, in deep shaded ravines in Nepal, and from wet marshy land in Kashmir. It is also recorded from open woods in North America, and extensively from prairies (Hitchcock 1971). ( B ) SUBSTRATUM Koeleria macrantha is widespread on calcareous brown earths, brown earths and rendzinas overlying chalk and limestone in England, and is less widespread in Wales and Scotland. It is recorded from moderately base-rich brown forest soils in Scotland (Gauld & Robertson 1985), from partially stabilized aeolian deposits in Scotland (Birse 1980) and on almost pure sand, with few shell fragments, at many places around the coast of the British Isles. It is reported from gleys of moderate to high base status in Scotland (Birse & Robertson 1976), and from incipient podzols in England (Balme 1953). The species is recorded from peaty or sandy peat substrata along the coasts of western Ireland (White 1982), and from dry eskers in O alay and Galway (Ir. P.). It is found on soils derived from basalt, dolerite (Asprey 1947), serpentine (Proctor & Woodell 1971), slate, hornfels and phyllite in Scotland, and has been observed by the author on a granite cli, north of Aberdeen. It is found over serpentine in Cornwall, and on `sandstone cli s' in Hampshire (Townsend 1904).
712 Koeleria macrantha (Ledeb.) Schultes Soil analyses (methods according to Chem. Anal.) for sites supporting K. macrantha gave a range for exchangeable calcium and magnesium, extracted with M ammonium acetate (ph 9.0), from 130 to 6500 mg kg 1 and from 560 to 3880 mg kg 1, respectively, while potassium ranged from 110 to 540 mg kg 1. Phosphate phosphorus, extracted with 0.5 M sodium bicarbonate (ph 8.5), ranged from 1.2 to 32 mg kg 1, and total nitrogen from 0.028 to 1.10%, to a high 1.8% from a site on basalt. The low values for all elements were from sand dune sites. Koeleria macrantha is recorded as occurring in soils of ph between 4.5 and 8.0 and very rarely between ph 3.0 and 4.5 (Ecol. Atl.). On chalk it is found at ph values up to 8.4 (Braun-Blanquet 1939). The species grows well in minimal soil depths on tops of walls, in limestone pavement hollows and in rock crevices, with only 2± 5 cm soil, but it is also found on much deeper soils (to 60 cm ), particularly on sand dunes. In Continental Europe, in addition to soils overlying calcareous rocks, K. macrantha occurs in gritty sandy soil over porphyr (Kiem 1974) and over gypsum (Meusel 1940) in Germany, in soils over serpentine in Greece, with very high nickel and chromium contents ± 4400 and 880 mg g 1, respectively (Karataglis et al. 1982), and over schists in the Czech Republic (PivnicÏ kovaâ 1970). The species is recorded from dry, acid soils in Germany (Ellenberg 1988), on sand dunes in Holland and north-west Germany, and in chalk-free, humus-rich surface soils over chalk also in north-west Germany (Braun- Blanquet 1939). It is further recorded from zinc-rich soils, containing between 0.5% and 8.7% zinc, in the neighbourhood of Aachen, Germany and also from Belgium (Braun-Blanquet 1939). Koeleria macrantha is recorded from gneiss and biotite muscovite in the Karakorum Mountains of north Pakistan (Hartmann 1972). The leaf sheaths of K. macrantha are white, papery and moderately persistent, as are the leaves, decomposing slowly, and so adding to the litter layer. III. Communities Koeleria macrantha is predominantly a species of calcareous grasslands and occurs with a high constancy in the following communities de ned by the National Vegetation Classi cation (Rodwell 1991, 1992). CG1 Festuca ovina±carlina vulgaris grassland is found on freely (often excessively) draining rendzina soils with a high base status, on steep and rocky, but stable, slopes on hard limestones, usually with a southerly to westerly aspect and so with a tendency to summer droughting. Often heavily grazed by sheep and rabbits, this community is con ned to Devonian limestone in Devon and to Carboniferous limestone in Wales and the Mendips. Koeleria macrantha has an overall constancy of III in CG1 but attains a constancy of V in the subcommunities of Helianthemum canum and Festuca rubra±scilla verna and a constancy of IV in the K. macrantha subcommunity. Constant species, as de ned by the NVC, for CG1 and the following communities are given in Table 1. CG2 Festuca ovina±avenula pratensis grassland consists of a rich mixture of grasses and dicotyledons in a closed sward and is traditionally grazed by sheep and rabbits. It occurs most frequently in relatively dry and warm lowland climates on free-draining calcareous soils derived from calcareous bedrocks; often prone to summer droughting. Koeleria macrantha has a constancy of V in this community. CG3 Bromus erectus grassland achieves maximum extent on lightly grazed or ungrazed grasslands over chalk and oolite in the south-eastern areas of Britain, and K. macrantha has a constancy of III in this community. CG4 Brachypodium pinnatum grassland is also mainly associated with lightly or ungrazed calcareous swards in south-eastern Britain, but is more generally found on the cooler and damper areas of the chalk and oolite than is the Bromus erectus grassland, which is more Continental in character. Koeleria macrantha has an overall constancy of only I in this community, but of III in the Avenula pratensis±thymus praecox subcommunity. CG5 Bromus erectus±brachypodium pinnatum grassland occurs where B. pinnatum is favoured by amelioration of extreme Continental conditions, but not so greatly as to exclude Bromus erectus. The community is most characteristic on the calcareous, base-rich soils of the oolite on the north-western fringe of southern, lowland limestone. Koeleria macrantha achieves a frequency of III in the typical subcommunity, but an overall frequency of II. CG6 Avenula pubescens grasslands are found on a variety of gently sloping lowland limestones, mainly in the south of England. The soils are deep and moist, though mostly free-draining alluvial rendzinas, or calcareous brown earths, and in some cases more mesophytic soils occur on at limestones. This community is lightly grazed by cattle; on sloping limestones it is grazed by rabbits. Koeleria macrantha has a constancy of III in CG6. CG7 Festuca ovina±hieracium pilosella±thymus praecox/pulegioides grassland is the characteristic vegetation type of thin, stony soils over chalk, or less frequently on south-facing gentle slopes of Carboniferous limestone. The soils are dry and impoverished; this is re ected in the species composition, with grasses generally exhibiting reduced vigour and herbaceous dicotyledons playing a predominant role. The short, open nature of the vegetation is maintained by heavy grazing, mainly
713 J. M. Dixon Table 1 Constant species of the calcareous grassland communities (see text) containing Koeleria macrantha Calcareous grassland community Species CG1 CG2 CG3 CG5 CG6 CG7 CG8 CG9 Avenula pratensis ± IV ± ± IV ± IV ± Avenula pubescens ± ± ± ± IV ± ± ± Brachypodium pinnatum ± ± ± V ± ± ± ± Briza media ± IV ± IV ± ± IV IV Bromus erectus ± ± V V ± ± ± ± Campanula rotundifolia ± ± ± ± ± ± ± IV Carex acca ± V IV V ± ± V IV Carlina vulgaris IV ± ± ± ± ± ± ± Centaurea nigra ± ± ± ± ± ± IV ± Cirsium acaule ± ± ± IV ± ± ± ± Ctenidium molluscum ± ± ± ± ± ± ± IV Dactylis glomerata IV ± ± ± ± ± ± ± Festuca ovina V V IV IV ± V IV IV Festuca rubra ± ± ± ± V ± ± ± Galium sterneri ± ± ± ± ± ± ± IV Galium verum ± ± ± ± ± ± IV ± Helianthemum nummularium ± ± ± IV ± ± IV IV Hieracium pilosella IV IV ± IV ± V ± ± Hypnum cupressiforme ± ± ± ± ± IV ± ± Leontodon hispidus ± IV ± ± IV ± ± IV Linum catharticum IV V IV Lotus corniculatus IV IV IV IV IV ± IV ± Pimpinella saxifraga ± ± ± ± ± ± IV ± Plantago lanceolata IV IV IV ± ± ± IV ± Pseudoscleropodium purum ± ± ± ± IV ± ± ± Sanguisorba minor V V V IV ± ± V ± Scabiosa columbaria ± IV ± ± ± ± IV IV Sesleria albicans ± ± ± ± ± ± V IV Taraxacum o cinale agg. ± ± ± ± IV ± ± ± Thymus praecox V IV ± IV ± ± IV V Thymus praecox/pulegioides ± ± ± ± ± IV ± ± Viola riviniana ± ± ± ± ± ± ± IV by rabbits. Koeleria macrantha has an overall constancy of III, a constancy of IV in the K. macrantha subcommunity and V in the Cladonia spp. subcommunity. CG8 Sesleria albicans±scabiosa columbaria grassland is found only on free-draining calcareous, steep slopes of Magnesian limestone in Durham, principally on rendzinas rich in calcium and magnesium carbonates. The climate is cool and dry, and the community is a plagioclimax vegetation maintained by grazing of domestic animals and rabbits. Koeleria macrantha has a constancy of IV in this community. CG9 Sesleria albicans±galium sterneri grassland is found in the northern Pennine submontane or montane climate, over shallow, freely draining but moist, calcareous lithomorphic soils on drift-free Carbonifeous limestone exposures. It forms an important part of upland farm hill-pasture and as such is frequently grazed, mainly by sheep. In CG9 K. macrantha achieves a constancy of IV. CG13 Dryas octopetala±carex acca heath occurs in the cool oceanic lowlands of north-west Scotland, on shallow rendzinas over the calcareous rocks of the Durness limestone, and on calcareous shell sand blown from the shore. The community is mainly ungrazed on the mainland but is quite heavily grazed by sheep and rabbits on Skye. Koeleria macrantha has a constancy of III in the Salix repens±empetrum nigrum subcommunity and an overall constancy of II in CG13. Koeleria macrantha occurs with a lower constancy in the calcareous grassland community of Festuca ovina±agrostis capillaris (CG10). The species is also found at a low constancy in the mesotrophic grassland community of Cynosurus cristatus±centaurea nigra (MG5) and in the calcifuge sward of Festuca ovina±agrostis capillaris±rumex acetosella grassland (U1). Koeleria macrantha is also present with low constancy in the heathland community of Calluna vulgaris±scilla verna (H7), and occurs with a higher constancy in: H6 Erica vagans±ulex europaeus heath, a subshrub vegetation con ned to the Lizard in Cornwall, on freely draining brown earth poor in calcium, but usually base-rich. The community survives most
714 Koeleria macrantha (Ledeb.) Schultes extensively over serpentine. Constant species are: Agrostis canina ssp. montana (V), Carex acca (III), Erica cinerea (V), E. vagans (V), Filipendula vulgaris (IV), Ulex europaeus (V), U. galli (IV) and Viola riviniana (IV). Koeleria macrantha achieves a constancy of V in the Festuca ovina subcommunity and an overall constancy of II. The species is also recorded from several maritime communities. It is found with a constancy of IV in the Arenaria serpyllifolia±sedum acre subcommunity and an overall constancy of III in the OV39 Asplenium trichomanes±asplenium ruta-muraria crevice community, on limestone. Constant species for this community are Asplenium trichomanes (V), Asplenium ruta-muraria (V), Porella platyphilla (IV) and Homalothecium sericeum (IV). Koeleria macrantha occurs at low frequency in the following communities: OV 34 Allium schoenoprasum± Plantago maritima community, restricted to areas of seasonally damp soils over serpentine on the Lizard cli margins; OV37 Festuca ovina±minuartia verna in limestone areas contaminated with heavy metal spoil; MC5 Armeria maritima±cerastium di usum maritime therophyte community; MC9 Festuca rubra±holcus lanatus cli grassland; MC10 Festuca rubra±plantago species maritime grassland; MC11 Festuca rubra±daucus carota maritime grassland. Koeleria macrantha is also found at low constancy in the following dune communities: SD8 Festuca rubra±galium verum xed dune community; SD9 Ammophila arenaria±arrhenatherum elatius dune grassland; SD10 Carex arenaria dune community and SD12 Carex arenaria±festuca ovina±agrostis capillaris dune grassland. Koeleria macrantha has also been recorded by the author from an extensive area of shingle mixed with sand (c. 2 m O.D.) in Su olk. Accompanying species were Achillea millefolium, Artemisia maritima, Bromus hordeaceus ssp. hordeaceus, Catapodium marinum, Hordeum marinum, Lolium perenne, Lotus corniculatus, Ononis repens, Papaver rhoeas, Plantago coronopus, Puccinellia maritima and Reseda lutea. Koeleria macrantha occurred frequently in this community, and also in a community recorded from a raised beach (c. 3 m O.D.) also in Su olk, with sparse, very short vegetation over almost pure sand, with very few shell fragments. The accompanying species here were: Agrostis capillaris, Dactylis glomerata, Elymus pycnanthus, Festuca ovina, Hordeum marinum, Hypochaeris radicata, Lolium perenne, Lotus corniculatus, Medicago lupulina, Plantago coronopus, P. lanceolata, P. maritima and Sedum acre. In Scotland, Birse (1980) recorded K. macrantha with a high constancy from two coastal dune communities. The Euphrasio±Festucetum arenariae association occurs on immature, brown calcareous soils over xed dunes, with gentle to moderate slopes, particularly on the Caithness coast; the differential species are Bellis perennis, Euphrasia spp., Gentianella campestris, Ranunculus acris and Viola tricolor ssp. curtisii. The Astragalo±Festucetum association also occurs on xed dunes with gentle to moderate slopes on the drier eastern coast of Scotland; the di erential species are Astragalus danicus, Festuca ovina, F. rubra, Galium verum and Tortula ruralis. Koeleria macrantha has a constancy of IV in both these dune associations. Birse (1980) also described K. macrantha from an ultra-basic grassland community in Ayrshire. The Plantago maritima±sieglingia decumbens community is found on freely drained, brown forest soils with a high magnesium content, derived from ultra-basic rocks. Species with a high constancy are Achillea millefolium, Festuca ovina, Trifolium repens, Viola riviniana and K. macrantha, with a constancy of IV. The species has been recorded by the author from a at, sandy foreshore at Auchenmalg Bay, Galloway, in a tall (60 cm ), open community dominated by Raphanus maritimus. Koeleria macrantha occurred frequently in this community, which also included Anthyllis vulneraria, Arrhenatherum elatius, Cochlearia o cinalis, Hieracium pilosella, Plantago lanceolata, Poa pratensis, Rumex acetosella, Tripleurospermum maritimum and Vicia hirsuta. In Ireland, White (1982) lists K. macrantha as a component of the Plantaginetum coronopo±maritima association. This dwarf coastal community, which is subject to frequent strong winds and seaspray, is found on peaty or sandy-peat substrata on at or not very steep cli tops in western Ireland. The vegetation is heavily and persistently grazed by sheep and rabbits. On Malahide Island, north of Dublin, K. macrantha was recorded by NõÂ Lamhna (1982) from the Festuco±Galietum maritimi association, which is found on middle dunes of grass-dominated, ungrazed or very lightly grazed, vegetation. Di erential species are Anthoxanthum odoratum, Briza media, Dicranum scoparium, Euphrasia occidentalis, Koeleria macrantha, Potentilla sterilis, Pteridium aquilinum, Rosa pimpinellifolia, Thymus praecox and Trifolium repens. Koeleria macrantha is a component of the association Camptothecium±Asperuletum, characterized by Asperula cynanchica, Neotinea maculata and Gentiana verna, and described from stable, landward dunes in Galway (Ir. P.) and also from Co. Clare by Ivimey-Cook & Proctor (1966). The association Violo curtisii ± Tortuletum ruraliformis occurs on dry stabilized coastal dunes and is characterized by Centaurium erythraea, Cerastium di usum, Koeleria macrantha and Phleum arenarium. Originally described from Kerry and Co. Mayo (Ir. P.) it has also been recorded from Co. Clare (Ivimey-Cook & Proctor 1966). Koeleria macrantha occurs in the Antennarietum hibernicae association (Ir. P.) found in hollows between dunes on the coast of Co.
715 J. M. Dixon Clare and also in dry eskers in O alay and Galway. The soils have a high humus content and are not very calcium-rich. Characteristic species are Antennaria hibernica, Anthyllis vulneraria, Asperula cynanchica, Carex arenaria, C. caryophyllea, Carlina vulgaris, Danthonia decumbens, Festuca rubra, Gentiana campestris, Lotus corniculatus, Plantago lanceolata, Polygala vulgaris, Ranunculus bulbosus and Thymus pulegioides. This association was also recorded from Co. Clare by Shimwell (1971). Ivimey-Cook & Proctor (1966) described K. macrantha from the Hyperico±Dryadetum association from the Burren, Co. Clare. This is a shrubdominated community found on leached organic soil over bare limestone. Characteristic species are Calluna vulgaris, Danthonia decumbens, Dryas octopetala, Empetrum nigrum, Hylocomium splendens, Hypericum pulchrum, Hypnum cupressiforme var. ericetorum, Neckera crispa, Polygala vulgaris and Rosa pimpinellifolia. Koeleria macrantha is also found in the mesotrophic grassland Cynosurus cristatus±centaurea nigra (MG5) which is the typical grassland of welldrained pastures over limestone, usually grazed by cattle in Ireland. In Continental Europe, K. macrantha is an order character of the Brometalia erecti and occurs in a number of associations belonging to this order throughout western Europe; these occur on dry steep slopes throughout the Alpine range, in dry rocky places in France and Belgium, the deeper moister soils of the Danube and Rhine valleys, and also on north-facing, more humid slopes of the Alps. Koeleria macrantha is also a component of some of the associations of the order Festucetalia valesiacae in various parts of Central Europe, including the Jura, Nahe Valley, Rheinhesse and the Bohemian Mountains. The species is also found in some associations of the class Arrhenatheretalia in the driest parts of the range. A range of communities containing K. macrantha, with a frequency of II and above, is given in Tables 2 and 3 to illustrate its geographical and ecological range. IV. Response to biotic factors Campbell et al. (1992) measured shoot thrust in various herbaceous species and found that those species which were dominants in their usual habitats generated the greatest thrust. Koeleria macrantha with ne shoots demonstrated less thrust and much of this was directed horizontally through the canopy. They concluded that its ne aerial shoots might confer a high ability for ` ne-scale' foraging for light between the dominant species, a strategy in keeping with its usual intermediate status in lightly grazed or Table 2 A selection of the communities in which Koeleria macrantha occurs in Continental Europe Habitat and community Region Reference Group 1. Moderately dry pastures and river valleys Arrhenatheretum elatioris Danube valley Eskuche (1955) Mesobrometum erecti subass. Silene cucubalus-medicago falcata Danube valley Eskuche (1955) Xerobrometum rhenanum Rhine valley Braun-Blanquet (1939) Group 2. Montane, subalpine and alpine Avena amethystina-koeleria gracilis Pyrenees Braun-Blanquet (1939) Festuca duriuscula-sesleria coerulea Jura and Central France, Switzerland Braun-Blanquet (1939) Mesobrometum collinum France Willems (1973)) Mesobrometum Seslerietosum coeruleae Jura and Swabian Alps Braun-Blanquet (1939) Xerobrometum rhaeticum Austria, Germany, Switzerland Braun-Blanquet (1939) Group 3. Chalk slopes Mesobrometum Seslerio-Polygaletosum France, Germany Braun-Blanquet (1939); Stott (1971) Group 4. Coastal dunes Anthyllis maritima-silene otites Germany, Holland Braun-Blanquet (1939) Silene otites-koeleria gracilis Germany, Holland Oberdorfer (1978)) Group 5. Zinc-rich soils Violetum calaminariae Belgium, Germany Braun-Blanquet (1939) Group 6. Short dry turf on at ground, steppe grassland Allio-Stipetum capillatae Germany Oberdorfer (1978) Armerico-Festucetum Germany Oberdorfer (1978) Carex humilis-trinia glauca Germany Braun-Blanquet (1939) Caricetum-Stipetum Germany Meusel (1940) Koelerieto-Festucetum sulcatae Poland Kornas (1949) Koelerio macranthae-stipetum joannis Czech Republic Kolbek (1983)
716 Koeleria macrantha (Ledeb.) Schultes Table 3 Species associated with the groups given in Table 2 Groups 1 2 3 4 5 6 Table 3 continued Groups 1 2 3 4 5 6 Achillea millefolium ± ± ± Adonis vernalis ± ± ± ± ± Agrostis capillaris ± ± ± ± ± Allium sphaerocephalum ± ± ± ± ± Alyssum alyssoides ± ± ± ± ± Andropogon ischaemum ± ± ± ± ± Anthoxanthum odoratum ± ± ± ± ± Anthyllis vulneraria ± ± Arabis hirsuta ± ± ± ± ± Arenaria serpyllifolia ± ± ± ± ± Armeria maritima ssp. elongata ± ± ± ± Arrhenatherum elatius ± ± ± ± ± Artemisia campestris ± ± ± Asparagus o cinalis ± ± ± ± Asperula cynanchica ± ± ± Aster bellidiastrum ± ± ± ± ± Aster linosyris ± ± ± ± ± Avena amethystina ± ± ± ± ± Avenula pratensis ± ± ± ± Avenula pubescens ± Brachypodium pinnatum ± ± ± ± Briza media ± ± ± Bromus erectus ± ± ± Buphthalmum salicifolium ± ± ± ± ± Campanula glomerata ± ± ± ± ± Campanula rotundifolia ± ± ± ± ± Carex arenaria ± ± ± ± ± Carex caryophyllea ± ± ± ± ± Carex acca ± ± ± ± Carex humilis ± ± ± Carex ornithopoda ± ± ± ± ± Carlina acaulis ± ± ± ± ± Centaurea scabiosa ± ± ± ± Cerastium arvense ± ± ± ± Cerastium semidecandrum ± ± ± ± Cirsium acaule ± ± ± Cochlearia danica ± ± ± ± ± Coeloglossum viride ± ± ± ± ± Coronilla minima ± ± ± ± ± Corynephorus canescens ± ± ± ± ± Dactylis glomerata ± ± ± ± ± Daucus carota ± ± ± ± Dianthus carthusianorum ± ± ± ± Dianthus caryophyllus ± ± ± ± ± Dianthus deltoides ± ± ± ± ± Eryngium campestre ± ± ± Euphorbia cyparissias ± Euphrasia rostkoviana ± ± ± ± ± Festuca lemanii ± ± ± ± Festuca ovina ± ± Festuca rubra ± ± Festuca rupicola ± ± ± ± ± Festuca valesiaca ± ± ± ± ± Filipendula vulgaris ± ± ± ± ± Fragaria viridis ± ± ± ± ± Galium glaucum ± ± ± ± ± Galium mollugo ± ± ± Galium verum ± ± ± ± Globularia punctata ± ± ± ± Helianthemum canum ± ± ± ± ± Helianthemum nummularium ± ± ± ± ± Helianthemum ovatum ± ± ± ± Heracleum sphondylium ± ± ± ± ± Hieracium murorum ± ± ± ± ± Hieracium pilosella ± ± Hieracium vulgatum group ± ± ± ± ± Hippocrepis comosa ± ± ± Holcus lanatus ± ± ± ± ± Hypochaeris radicata ± ± ± ± ± Iris aphylla ± ± ± ± ± Knautia arvensis ± ± ± ± ± Lathyrus pratensis ± ± ± ± ± Leontodon hispidus ± ± ± ± Ligustrum vulgare ± ± ± ± ± Linum catharticum ± ± ± ± ± Linum tenuifolium ± ± ± ± Lolium multi orum ± ± ± ± ± Lotus corniculatus ± ± ± Luzula campestris ± ± ± ± ± Luzula campestris ssp. vulgaris ± ± ± ± ± Medicago lupulina ± ± ± ± ± Medicago minima ± ± ± ± Medicago sativa ssp. falcata ± ± ± ± ± Minuartia verna ± ± ± ± ± Onobrychis arenaria ± ± ± ± ± Ononis pusilla ± ± ± ± ± Ononis repens ± ± Phleum phleoides ± ± ± ± Picris hieracioides ± ± ± ± ± Pimpinella saxifraga ± Plantago lanceolata ± ± ± ± Plantago media ± ± ± ± Poa angustifolia ± ± ± ± ± Poa pratensis ± ± ± ± Polygala amara ± ± ± ± ± Polygala amarella ± ± ± ± ± Polygala calcarea ± ± ± ± ± Polygala comosa ± ± ± ± ± Polygala vulgaris ± ± ± ± ± Potentilla argentea ± ± ± ± ± Potentilla cinerea ± ± ± ± Potentilla crantzii ± ± ± Potentilla pusilla ± ± ± ± ± Potentilla tabernaemontani ± ± ± Primula veris ± ± ± ± ± Prunella grandi ora ± ± ± ± Prunella vulgaris ± ± ± ± ± Pulsatilla montana ± ± ± ± ± Pulsatilla vulgaris ± ± ± ± Ranunculus acris ± ± ± ± ± Ranunculus bulbosus ± Rubus caesius ± ± ± ± ± Rumex acetosa ± ± ± ± ± Rumex acetosella ± ± ± ± ± Salvia pratensis ± ± ± ± Sanguisorba minor ± ± ± Saxifraga tridactylites ± ± ± ± ± Scabiosa canescens ± ± ± ± ± Scabiosa columbaria ± ± ± ± Sedum acre ± ± ± ± ± Sedum re exum ± ± ± ± ± Seseli montanum ± ± ± ± ±
717 J. M. Dixon Table 3 continued Groups 1 2 3 4 5 6 Sesleria albicans ± ± ± ± Senecio jacobaea ± ± ± ± ± Silene otites ± ± ± ± Silene vulgaris ± ± ± Stachys recta ± ± ± ± ± Stipa joannis ± ± ± ± ± Taraxacum o cinale agg. ± ± ± ± Tetragonolobus maritimus ± ± ± ± ± Teucrium chamaedrys ± ± ± Teucrium montanum ± ± ± ± Thesium humifusum ± ± ± ± ± Thesium linophyllon ± ± ± ± ± Thlaspi alpestre var. calaminarea ± ± ± ± ± Thymus praecox ssp. ± ± ± ± ± polytrichus Thymus pulegioides ± ± ± Thymus serpyllum ± ± ± Tragopogon pratensis ssp. orientalis ± ± ± ± ± Trifolium arvense ± ± ± ± ± Trifolium dubium ± ± ± ± ± Trifolium pratense ± ± ± ± ± Trinia glauca ± ± ± ± ± Trisetum avescens ± ± ± ± ± Verbascum lychnitis ± ± ± ± ± Veronica prostrata ± ± ± ± ± Veronica spicata ± ± ± ± ± Vicia cracca ± ± ± ± ± Vicia lathyroides ± ± ± ± ± Vicia sativa ssp. nigra ± ± ± ± ± Vincetoxicum hirundinaria ± ± ± ± ± Viola tricolor ssp. subalpina ± ± ± ± ± ungrazed grasslands. Koeleria macrantha also occupies an intermediate status in the prairies of the North American Midwest, and although its rapid recovery after severe droughts initially results in a monoculture, it is not a good competitor and is gradually relegated to its intermediate role by more vigorous species such as Andropogon spp., Poa pratensis and Stipa spp. (Albertson & Weaver 1944). Koeleria macrantha exhibits a more dominant role in its coastal habitats on cli tops, shingle and sand dunes where vegetation is often shorter, though often ungrazed; its attened, tufted habit is an advantage here. Grime et al. (1988) recorded K. macrantha as being notably absent from heavily disturbed situations and where there is intense competition, and Balme (1953) noted that it was rather less frequent on steep slopes in Derbyshire with very shallow soil and loose limestone fragments, where the dominant species was Festuca ovina, than on slopes with greater stability and less loose material and with Festuca ovina and F. rubra as co-dominants. Table 4 Mean ( SE) morphological measurements for Koeleria macrantha from di erent habitats Habitat* Variable Unmown golf links Grazed xed dune Sandy heath Coastal cli Shingle Sandy track Grazed grassland Ungrazed grassland Limestone outcrop Panicle length (cm) 2.5 0.2 3.9 0.2 2.8 0.3 2.7 o.2 3.1 0.2 2.2 0.1 2.8 0.1 2.6 0.1 5.6 0.3 Panicle width (mm) 3.6 0.2 3.8 0.2 4.2 0.2 4.8 0.2 3.3 0.3 2.9 0.2 2.9 0.1 4.4 0.2 4.1 0.3 Leaf length (cm) 6.3 0.7 10.4 1.1 4.4 0.2 4.6 0.2 12.7 0.7 2.7 0.2 5.0 0.3 3.9 0.2 9.2 0.6 Leaf width (mm) 1.8 2.2 2.2 0.1 1.7 0.06 2.0 0.09 1.8 0.1 1.5 0.08 2.0 0.08 1.8 0.08 2.7 0.1 Culm length (cm) 10.2 1.1 17.5 2.3 8.5 0.8 12.3 1.2 17.4 1.7 8.2 0.8 12.0 0.9 11.4 0.7 28.1 0.9 Upper culm leaf length (cm) 1.2 0.1 1.9 0.1 1.1 0.1 1.6 0.2 1.3 0.2 1.0 0.06 1.2 0.1 0.9 0.08 2.8 0.2 *Limestone outcrop: Wormhill, Derbyshire; Ungrazed grassland: Bishopdale, North Yorkshire; Grazed grassland: Little Orme, Gwynedd; Sandy track: Auchenmalg Bay, Galloway; Sandy heath: Branderburgh, Grampian; Coastal cli : Brean Down, Somerset; Shingle: Aldburgh, Su olk; Grazed xed dune: Druridge Bay, Northumberland; Unmown golf links: Camber, East Sussex.
718 Koeleria macrantha (Ledeb.) Schultes Koeleria macrantha is classed as a good forage grass in North America (Hitchcock 1971), but SÏ ikula (1978) comments that it is considered of little agricultural value in Europe because it develops few leaves and these soon become tough. However, in long vegetation on deeper soils it tends to have longer, softer leaves than when growing on, for example, rock outcrops over shallow soils. Watt (1974) observed that K. macrantha increased in a sward over a period of 34 years, after being enclosed against domestic animals and rabbits. Other abundant species in the enclosure were Festuca ovina and Avenula pratensis which also increased; these are species also frequently found with K. macrantha in grazed calcareous grassland. Watt commented that these three species were much more vigorous inside, than outside, the enclosure. Nevertheless, K. macrantha is recorded as a component of a woodland replacement plagioclimax community in central Perthshire, Scotland, which is maintained principally by sheep grazing, but is also grazed by cattle, red deer, rabbits and hares (Gauld & Robertson 1985), and the species has a high constancy (IV) in the NVC plagioclimax community of CG8 (Sesleria albicans±scabiosa columbaria grassland) also maintained by the grazing of domestic animals and rabbits. However, K. macrantha does not seem able to withstand continual heavy grazing. Clarke et al. (1943) reported that the e ects of overgrazing were to produce a decline in its abundance, vigour and productivity, and a simulated grazing experiment by the author, in which clipping was carried out at three height regimes, every 2 weeks for 10 weeks, resulted in the greatest production of shoot material when the plants were only lightly clipped (at 15 cm above soil level). An experiment carried out by Biswell & Weaver (1933) extending for 4 months during the summer with clipping every 14 days showed that K. macrantha increased the diameter of its root mass and stele as a result of the clipping, to a greater degree than Bromus inermis and Poa pratensis. Lloyd (1968) observed that burning stimulated in orescence production in K. macrantha in the summer of the year following a spring burn, but by the following year no signi cant stimulus to owering remained, while Clarke et al. (1943) noted that burning led to reduced yield of K. macrantha for a period of 3±5 years in Canadian prairies subject to moderate grazing. However, Albertson & Weaver (1944) reported that where re was used as a means of weed control in the prairies of Nebraska, K. macrantha became temporarily widespread. Koeleria macrantha is very tolerant of trampling and has been noted, for example, at one site as being the only species present, providing almost 100% cover, apart from a small amount of Festuca rubra and Poa annua. It has been observed on many paths and tracks, particularly at coastal sites, but also on inland limestones, as very attened, sti little tufts, owering on very short culms (see V (B)). V. Response to environment ( A ) GREGARIOUSNESS Koeleria macrantha forms small tufts in cli faces, on walls and in limestone pavement hollows. It is usually found as scattered individuals or more rarely with a number of tillers joined by short rhizomes, in short grazed and ungrazed turf, but on paths and tracks which are not too heavily trampled it often forms almost a monoculture, as it does sometimes on steep roadside banks, especially on sandy soils. In moderately tall vegetation to around 60 cm it is again usually found as scattered individuals of straggling appearance, rather than as tufts. Koeleria macrantha never produces very large tussocks and plants cultivated in a fertile garden soil produced clonal tussocks of not more than 12 cm in diameter after 3 years' growth. ( B ) PERFORMANCE IN VARIOUS HABITATS Sand dune populations of K. macrantha often have very sti, spiky leaves and are generally more glaucous than inland populations. In short dune vegetation, leaves are usually up to 7 cm long, but in longer dune vegetation leaves are much less spiky and longer, to c. 14 cm. When trampled, K. macrantha grows as a prostrate form with attened spiky leaves, almost forming a rosette, and it owers on short sturdy culms, with short, wide panicles. Leaves of trampled plants are usually either glabrous or only sparsely hairy. In tall and ungrazed grassy vegetation, K. macrantha produces longer leaves, culms and panicles than in short or grazed vegetation, but its leaf width is not very variable in any habitat. It is sometimes found in shallow grikes, partially shaded in summer until midday, but leaves, culms and panicles are not particularly elongated here. Koeleria macrantha does not produce in orescences where the irradiance is less than 50% of full sun (see VI (E)). The species sets seed throughout its range. A comparison of morphological characteristics of K. macrantha from various habitats is given in Table 4. ( C ) EFFECT OF FROST, DROUGHT AND WATERLOGGING As K. macrantha is found in Siberia and to 4400 m in the Himalayan Range it is presumably very frost tolerant, and cultivated plants in Britain showed no evidence of frost damage. Koeleria macrantha responds to water de cits by folding or inrolling its leaves. Continued water shortage leads to the leaves going grey, before
719 J. M. Dixon becoming straw-coloured and dying. Pot-grown plants of K. macrantha had 28.5 mg dm 2 cuticular wax. The species appears to be principally a drought avoider, as most of its leaves have been produced by the end of April before the onset of periods of drought is likely. The species also possesses a very plastic root system. Barnes & Harrison (1982) investigated plants growing on prairie dunes where the water table was well below the surface, and where water is obtained from light showers, dew or fog. They noted that K. macrantha growing on the dunes had a shallow, ne, dense root mass which absorbed the sparse moisture rapidly, and that it had higher water potentials than other more deeply rooting species, and Newbauer et al. (1980) reported that K. macrantha responded with rapid growth to periods of above average rainfall where growing on sandy or shallow soils. An alternative strategy shown by K. macrantha is to develop more deeply penetrating roots, if the water table is not too far below the surface. Mueller-Dombois & Sims (1966) grew K. macrantha together with two other grass species on both a sand and a loamy-sand. The maximum reduction in shoot length on the sand, compared with the loamy-sand, was 22% for K. macrantha, and 50% and 80%, respectively, for the other two species. Mueller- Dombois & Sims suggested that K. macrantha suffered the least reduction in growth because of the ability of its roots to extend more deeply than those of the other two species, thus negating the e ects of the greater water de cit in the sand. Koeleria macrantha is not found in waterlogged soil, and more often grows on dry than on moist ground. Baker (1937) surveyed grazed and mown alluvial meadows and noted that K. macrantha occurred only in the driest parts. In a pot experiment, in which K. macrantha was either watered normally or waterlogged to onethird, two-thirds or to the total depth of the pot, for a period of one year, the normally watered plants had the longest leaves, the highest dry weight of living shoots and the lowest weight of dead shoot material at the end of the period; these plants also owered normally. There was no signi cant di erence between plants cultivated under the three waterlogging treatments; these all had a much greater weight of dead shoot material at the end of the year and none owered. VI. Structure and physiology ( A ) MORPHOLOGY The dense brous rootstock is shortly creeping with very short rhizomes; these are rather longer (to c. 7 cm) where the plant is in sandy soils. The root system is plastic and this appears to be a response to the soil-water status (see V (c)). In light soils with a very low water table the rooting strategy seems to be to produce a dense, ne network in the upper layers of the soil. Coupland & Johnson (1965) found that in Nebraska, Colorado and Idaho K. macrantha had an optimum rooting depth of around 30±35 cm, with roots decreasing rapidly below this, while in the less dry brown soils of Saskatchewan it developed roots between 60 and 75 cm long. They noted that the mean number of roots per shoot ranged from 4.8 (on loam) to 7.2 (on sand) and that the mean number of lateral roots per decimetre of main root varied between 32 (on loam) and 55 (on sand), but mostly around the lower value. Lateral spread was found to be 15±20 cm near the surface. Weaver (1920) recorded K. macrantha from true prairie, with abundant rainfall, as having a maximum rooting depth of 50 cm and a lateral spread of about 20 cm. In solitary plants, shoot growth produces small dense tussocks which increase mainly by the production of intravaginal tillers from existing ones and by shoots arising from the short rhizomes. Occasionally, a looser form with a more prostrate creeping habit is produced in short, ungrazed grasslands. In longer vegetation, K. macrantha grows as small groups of tillers supporting several in orescences. Stomatal counts from a shallow, grazed limestone grassland in North Yorkshire gave a mean of 92 3.1 mm 2 for the adaxial surface; no stomata were found on the abaxial surface; the counts were made at three positions along the length of 25 leaves. The stomata occur in rows between the veins with the edges having a slightly higher number of stomata than the middle. Counts from populations from Kent, the island of Barra, Scotland, and from Su olk gave means of 80 3.5, 89 5.5 and 80 1.9 mm 2 for the adaxial surface: no stomata were found on the abaxial surface. ( B ) MYCORRHIZA Koeleria macrantha is listed as being vesicular-arbuscular mycorrhizal by Harley & Harley (1987). However, it does not appear to be mycorrhizadependent, and Wilson & Hartnett (1997) reported that chemical suppression of the symbiosis in tallgrass prairie increased the relative contribution of the non-mycorrhiza-dependent species, including K. macrantha, through competitive release. Hartnett et al. (1994) observed that mycorrhizas generally suppressed owering in K. macrantha. They suggested that as K. macrantha has brous roots it is less dependent on mycorrhizal symbiosis than grasses with less dense root systems, and the cost of maintaining a symbiotic relationship, in the form of reduced owering, may exceed the bene t. However they did record that seedling emergence of K.
720 Koeleria macrantha (Ledeb.) Schultes macrantha was signi cantly reduced in fungicide (Benomyl) treated plots, suggesting that mycorrhizas have a positive e ect on germination. Na aa et al. (1998) isolated a new endophyte from K. macrantha and ascribed this to the genus EpichloeÈ (e-endophyte). ( C ) PERENNATION: REPRODUCTION Koeleria macrantha is a protohemicryptophyte. Its leaves die back gradually during the autumn and winter once owering is completed, but the plant remains green throughout the winter until early spring growth commences. Vegetative growth is very slow and the species does not usually produce very large tussocks. It owers in the rst summer after autumn germination and the number of in orescences at this time is quite low: in cultivation in a good loam this was between 30 and 40, but by the end of 2 years some tussocks had over 200 in orescences (range 30±291, mean 101.4 13.5). Koeleria macrantha produces a transient seed bank during the summer, when the caryopses are shed; these germinate nearly synchronously in the autumn: there is a complete absence of germinable seeds during spring and early summer (Thompson & Grime 1979). ( D ) CHROMOSOMES The basic chromosome number is seven. Diploids, with 2n ˆ 14, have been recorded from France and Switzerland (Bajon 1985), from North America (Robertson 1974), from Hungary (Ujhelyi 1961) and from Poland (Frey et al. 1977). Tetraploids with 2n ˆ 28 have been recorded from Poland (Frey et al. 1977), from North America (Arnow 1994), from South Africa (DeWet 1960) and from Heslington Barrows, Cumbria (Hedberg & Hedberg 1961): counts by the author of 2n ˆ 28, from 50 sites throughout Britain, including inland and coastal sites, suggest consistency here. Higher degrees of polyploidy with 2n ˆ 42 and 2n ˆ 70 have been recorded from Hungary (Ujhelyi 1962). Nuclear DNA ˆ 9.3 pg nucleus 1 (Grime et al. 1988) ( E ) PHYSIOLOGICAL DATA Seedling relative growth rate is given by Grime et al. (1988) as 0.5±0.9 week 1. Koeleria macrantha invests heavily in both roots and in orescences and much less so in leaves. Twenty young plants (consisting of 2±3 tillers) cultivated for just over a year in a fertile loam in West Yorkshire gave a mean dry weight yield ( SE) of 15.4 2.4 g roots, 7.4 0.7 g shoots (living and dead) and 17.5 2.4 g in orescences (culms plus panicles). Thus the roots comprised 38.9%, in orescences 43.6% and leaves only 17.7% of the total dry weight. During the rst year of growth it invests more resources in its root system than either Sesleria albicans (25%) or Avenula pratensis (18%), both species with which it frequently occurs. At the time of harvesting the cultivated plants (mid-july), approximately equal quantities of dead and living shoot material were obtained. Rather surprisingly, K. macrantha was considered by Clarke et al. (1943) to be the most important species in shortgrass prairie vegetation in terms of basal area occupied, and the third most important species in terms of forage production. Ellenberg (1988) reported that K. macrantha is generally found in well-lit places, but also occurs in partial shade. Although the species will survive considerable shading it does not form in orescences where the incident light is less than c. 50% ambient. Koeleria macrantha grown under arti cial neutral shades, with reductions in light ux of 43%, 33% and 26%, produced much longer leaves (means of 60.0 4.4, 42.4 1.5 and 33.9 1.6 cm, respectively, compared with 17.0 1.1 cm for unshaded leaves). Leaf width was not signi cantly di erent, nor was the dry weight yield of shoot material harvested after 1 year. However, there was a signi cant progressive decrease in root dry weight (8.8 2.9, 13.7 2.4 and 32.7 4.8 g, compared with 47.9 11.9 g for unshaded plants). The SLA increased from 12.8 in unshaded plants to 15.1, 18.3 and 21.4 for the above percentage light ux reductions: these plastic reponses enable K. macrantha to survive but not to complete its life cycle in shaded environments. Although K. macrantha is generally considered to be a species of dry places (Ellenberg 1988), Newbauer et al. (1980) commented that K. macrantha appeared to be the least drought tolerant of four species of silty, sandy and thin hill soils. They did, however, record that K. macrantha can show rapid recovery and increase during periods of above average rainfall. Milnes et al. (1998) compared the responses of K. macrantha and Briza media to drought and noted that while both species showed similar sensitivity to drought with respect to duration of soil drying and water content, K. macrantha responded with renewed growth to rewatering after periods of 20 days' drought, unlike B. media which died. In a similar pot experiment carried out by the author, with K. macrantha initially watered to runthrough, and then droughted for 6 weeks, all plants had folded their leaves and were beginning to wilt after 13 days of drought. After 4 weeks much of the shoot material was dead but re-watering of the pots produced new growth in each. After 6 weeks two out of the ve replicates failed to persist but the other three produced new growth. When K. macrantha and Sesleria albicans were grown under the above conditions, 93% of the shoot material of the former was dead after the 6 weeks of drought