Search

The use of inter-row ground covers has been suggested to reduce soil degradation in raspberry (Rubus idaeus L.) production. The effect after 6 yr of consistent inter-row management of ground covers or roto-tillage in raspberry on soil wet aggregate stability (WAS), bulk density, organic C and total N, and mineralizable nitrogen in the Fraser Valley of British Columbia was studied. Management treatments included no cover crop or cover crops of barley (Hordeum vulgare L.), sheep's fescue (Festuca ovina L.), perennial ryegrass (Lolium perenne L.), and white clover (Trifolium repens L.). A general pattern of perennial grasses > legume and barley > control was observed for soil WAS. Some quantitative and qualitative differences in the organic component of the soil profile to 30 cm were detected among management treatments. The differences were not statistically strong because the changes were small relative to the large pool present, but were relatively consistent overall. The white clover treatment tended to have more organic carbon, particularly in the subsurface, than the other treatments. The four treatments that included inter-row vegetation tended to have a greater amount of total and mineralizable N than the clean-tilled control. Crop vigour, as indicated by cane diameter, was reduced by the perennial grasses, but the inter-row management had only limited effects on berry yield. White clover appears to provide the best compromise between improving soil quality and minimizing competition with the berry crop. Key words: Wet aggregate stability, barley, sheep's fescue, perennial ryegrass, white clover

The grass, Festuca ovina, was grown in a nutrient‐poor medium with three levels of nitrogen (N) fertilization, four of phosphorus (P), and three of potassium (K), in factorial combination. Overall, there were considerable nutrient responses with evidence of toxicity at high levels of all three nutrients. However the nutrients interacted in all possible combinations, such that toxicity effects were seen only when levels of the other nutrients were low. This is the first report of N, P, and K toxicity for a single species, and the first report of N x P x K interactions in macronutrient toxicity. The occurrence of toxicity interactions between all three possible pairs of macronutrients, reported here for the first time from a single species, supports the osmotic theory of macronutrient toxicity.

Occasionally, adult European ground squirrels can be observed to practise a quite complex behavioural technique to obtain seed grains from the top of tall grass plants (e.g. Festuca ovina: 10-70 cm, Poaceae). They bite through the stem of a plant at the basis and, subsequently, know how to handle the fallen stem so as to successfully reach the food. The present field study aimed to analyse the detailed ontogeny which, in growing ground squirrels, leads to this behaviour. Data for 5 juveniles belonging to one litter were collected during an observation period of 38 successive days after the animals' first appearance above ground (video recordings). They show that this behaviour emerges as the final result of a whole series of successive developmental steps involving increasingly more efficient techniques in which simple techniques are gradually elaborated to more sophisticated ones. The underling causal mechanism is supposed to be operant conditioning based on increasingly more complex motor activities involving the animal's paws. Despite frequent social contacts, learning through imitation or even through instruction by the mother turned out to be not an important factor. With regard to cognitive abilities, the observations suggest experiments to verify the hypothesis of a beginning object permanence in ground squirrels.

Background: A horizontal gene transfer has brought an active nuclear gene, PgiC2, from a polyploid Poa species (P. palustris or a close relative) into the common grass sheep’s fescue (Festuca ovina). The donor and the receptor species are strictly reproductively separated, and PgiC2 occurs in a polymorphic state within F. ovina. The active gene copy is normally closely linked to a very similar pseudogene. Methodology/Principal Findings: By genome walking we have obtained the up- and downstream sequences of PgiC2 and of corresponding genes in the donor and recipient species. Comparisons of these sequences show that the complete upstream region necessary for the gene’s expression is included in the transferred segment. About 1 kb upstream of PgiC2 a fragment with transposition associated properties has been found (TAF). It is present in P. palustris and its polyploid relatives, though not at the homologous position, and is absent from many other grasses, including non-transgenic F. ovina plants. It is possible that it is a part of a transposing element involved in getting the gene into a transferring agent and/or into the recipient chromosome. Conclusions/Significance: The close similarity of the up- and downstream regions with the corresponding regions in P. palustris excludes all suggestions that PgiC2 is not a HGT but the result of a duplication within the F. ovina lineage. The small size of the genetic material transferred, the complex nature of the PgiC2 locus, and the associated fragment with transposition associated properties suggest that the horizontal transfer occurred via a vector and not via illegitimate pollination.

Studies of whether plant community structure and ecosystem properties depend on the genetic diversity of component populations have been largely restricted to species monocultures and have involved levels of genetic differentiation that do not necessarily correspond to that exhibited by neighboring mature individuals in the field. We established experimental communities of varying intraspecific genetic diversity, using genotypes of eight species propagated from clonal material of individuals derived from a small (100-m2) limestone grassland community, and tested whether genetic diversity (one, four, and eight genotypes per species) influenced community composition and annual aboveground productivity across communities of one, four, and eight species. Eight-species communities were represented by common grass, sedge, and forb species, and four- and one-species communities were represented by four graminoids and the dominant grass Festuca ovina, respectively. After three years of community development, there was a marginal increase of species diversity with increased genetic diversity in four- and eight-species communities, and genetic diversity altered the performance of genotypes in monospecific communities of F. ovina. However, shifts in composition from genetic diversity were not sufficient to alter patterns of community productivity. Neighborhood models describing pairwise interactions between species indicated that genetic diversity decreased the intensity of competition between species in four-species mixtures, thereby promoting competitive equivalency and enhancing species equitability. In F. ovina monocultures, neighborhood models revealed both synergistic and antagonistic interactions between genotypes that were reduced in intensity on more stressful shallow soils. Although the dependence of F. ovina genotype performance on neighborhood genetic composition did not influence total productivity, such dependence was sufficient to uncouple genotype performance in genetic mixtures and monocultures. Our results point to an important connection between local genetic diversity and species diversity in this species-rich ecosystem but suggest that such community-level dependence on genetic diversity may not feedback to ecosystem productivity.

To assess the extent of progress in breeding for resistance to some typical turfgrass diseases, a field collection of 6 varieties of sheep fescue (Festuca ovina) and 35 varieties of red fescue (Festuca rubra s.l.) was used to assess the incidence of red thread (Laetisaria fuciformis) in the years 2004–2007. Whereas in the first crop years (2004–2005) disease incidence was very low and did not provide enough information about intervarietal differences, in the years 2006–2007 the levels of disease in the collection of red fescue varieties were very high. As sheep fescue varieties generally had high resistance red thread incidence was not recorded. In the collection of F. trichophylla varieties, Barpearl, Baroyal and Viktorka had high resistance (area damaged did not exceed 5%). They differed significantly from other varieties. Among the varieties of F. rubra ssp. rubra there was none with higher resistance (damage was 95%). In the collection of F. nigrescens the varieties Barborka and Citera had high resistance (damage was less than 10%) and differed significantly from other varieties of this species. There was no connection observed between disease incidence and experimental treatments (wear, cutting frequency). A hypothesis was confirmed that with low levels of fertilizer application there is considerable expression of this disease, especially in older stands and the selection of donors of resistance is optimal.

Fine-leaved fescue (Festuca L.) species are valuable breeding material with potential use for marginal land cover. However, the breeding of these species is complicated by morphological similarity among species and high heterogenity within species. Molecular DNA markers are needed to facilitate species identification. Inter simple sequence repeat polymerase chain reaction (ISSR-PCR) was used for the genetic analysis of the five fine-leaved fescue species encountered in Lithuania, namely Festuca sabulosa, Festuca polesica, Festuca ovina, Festuca trachyphylla and Festuca psammophila. Fifty six ISSR markers were scored for 21 fescue accessions. Similarity indicies were calculated and UPGMA dendrogram constructed with NTSYSpc 2.2. Three species (F. ovina, F. trachyphylla and F. psammophila) could be distinguished as separate clusters in the dendrogram. Further analysis revealed two ISSR fragments of 600 and 950 bp to be species-specific for F. psammophila. These fragments are potential targets for more specific SCAR marker development. The remaining two highly related species (F. sabulosa and F. polesica) formed one intermixed cluster and could not be distinguished from each other. The results of this work show the suitability of the ISSR method to investigate genetic diversity of fine-leaved fescue species encountered in Lithuania and provide valuable data for the identification of these species.

1. Currently, there is a debate among plant ecologists on the concepts of the intensity of competition and the importance of competition, which is central to many issues of modern plant population ecology and plant community ecology. 2. It is problematic that the current measures of intensity and importance of competition, typically, are reported as dimensionless indices because they hide the fact that both indices are functions of plant density and the level of the environmental gradient. 3. Here, a new formulation of the concepts is suggested, which explicitly highlights the functional dependencies on plant density and the level of the environmental gradient. The new measures are a generalization of the previous indices and correspond to the previous indices in the case of a simple experimental design. 4. The suggested measures of the intensity and importance of competition are exemplified using data from a response surface competition experiment between Agrostis capillaris and Festuca ovina along a herbicide gradient, where the expected clear effect of plant density was demonstrated. 5. Synthesis. As the suggested measures of the intensity and importance of competition explicitly highlight the functional dependencies on plant density and the level of the environmental gradient, we think that they will help to ensure a closer connection between experimental plant ecology and the attempts to model plant populations and communities.

The use of root / shoot ratios to describe allocation of dry weight to structures for capturing soil resources and light is limited due to other functions of the root and shoot such as support and storage. The ratio of fine-root length to leaf area (RLA) provides a better expression of the relative sizes of above-and below-ground exchange surfaces. Dry matter partitioning, leaf area and root lengths were determined for five species of chalk grassland perennial (Carex flacca, Cirsium acaule, Festuca ovina, Leontodon hispidus and Scabiosa columbaria) by extraction of soil cores from an intact sward. The forb species had a greater proportion of their dry matter below-ground. Interspecific variation in values of RLA was considerable, mean values ranging from 137 m/m2 in Cirsium acaule to ca. 27 000 m/m2 for Festuca ovina. The implications of this interspecific variation in RLA for the competitive interactions in infertile calcareous grasslands are discussed in relation to phenology and internal nutrient cycling.

Extremely high degrees of lead tolerance, measured by comparing rates of root extension in culture solutions, are reported from populations of Festuca ovina growing at two lead-mining sites (Westschacht and Keldenich-II) near Mechernich in the Eifel Mountains, Germany. Other populations from nearby heavy metal-contaminated areas show a considerably smaller degree of lead tolerance. Samples of Festuca ovina collected in the field at Westschacht and Keldenich-II contain higher levels of lead in their aerial organs than do those from other lead-contaminated sites. The main soil factor determining the high degree of lead tolerance is the high Pb/Ca ratio. Populations from soils with a low Pb/Ca ratio display a very low degree of tolerance. It is therefore concluded that in Westschacht and Keldenich-II plants, a genuine intracellular tolerance mechanism is present, allowing the accumulation of lead in aerial organs. Leaf samples of zinc-tolerant Festuca contain higher levels of zinc than do samples of non-tolerant plants. Lead and zinc amounts in leaves are correlated with the soil ratios of Pb/Ca and Zn/Ca, respectively, rather than with the absolute soil-metal levels. In a slightly lead-tolerant, but highly zinc-tolerant clone of Festuca ovina from a site contaminated with large amounts of lead and zinc (Plombieres), lead was found to be the major factor affecting the inhibition of root extension with combined treatments of lead and zinc in culture solutions. In the highly lead-tolerant, zinc-sensitive population from Westschacht, zinc governs the response of root growth to combinations of the two metals. The results are discussed in terms of discriminating distinct types of heavy-metal tolerance.

Suitability of six cool-season turfgrasses, including tall fescue, festuca arundinacea Schreb., infected or not infected by the endophyte Acremonium coenophialum Morgan-Jones & Gams, was studied for root-feeding grubs of the Japanese beetle, Popillia japonica Newman, and the southern masked chafer, Cyclocephala lurida Bland. Larval growth, survival, food use, effects of larval diet on adult weight and fecundity, and natural incidence of grubs were investigated in laboratory, greenhouse, and field assays. Hard fescue, Festuca ovina var. duriuscula L., endophyte-free tall fescue, and perennial ryegrass, Lolium perenne L., were generally more favorable than creeping bentgrass, Agrostis palustris (Huds.), for growth of C. lurida, whereas Kentucky bluegrass, Poa pratensis L., was a relatively poor host for both grub species. Variation in nitrogen content of roots is apparently too small to explain these differences. Roots of endophyte-infected tall fescue contained 93 micrograms/g N-formyl loline, a level previously shown to deter grub feeding on artificial medium. However, this study suggests that antixenosis may not occur in the presence of the stimulus complex in tall fescue roots. Survival or growth or both of neonate first instars were lower on endophyte-infected than on endophyte-free tall fescue. However, response of older instars was variable, and there was no measurable effect of endophyte on density or weight of grubs in field plots or on fecundity of P. japonica adults that emerged from endophyte-infected turf. Variation in susceptibility of cool-season turfgrasses to white grubs is probably affected more by differences in their ability to tolerate the feeding damage than by their inherent suitability as food.

Herbage production and nutrient content are affected by light interception and soil fertility. The objective of this study was to assess the effects of artificial shade and fertilization on herbage production, growth characteristics, and nutrient content of the grass species Dactylis glomerata and Festuca ovina, and the legume species Trifolium subterraneum and Medicago lupulina. Each plant species was placed under three shading treatments of 90% (heavy shade), 50% (moderate shade) and 0% (control). Fertilization (225 kg/ha N, 450 kg/ha P, and 225 kg/ha K) was applied to half of the pots of every species and shading treatment. Reduced light intensity (90% shading) significantly lowered herbage production from 18% for F. ovina to 48% for D. glomerata and decreased the root:shoot (R/S) ratio of all species but the moderate reduction of light intensity (50%) did not affect R/S ratio and herbage production of the grasses and M. lupulina, while it resulted in an increase of the production of T. subterraneum by 10.5%. Reduced light intensity increased by 25% on average, the crude protein concentration of the grass species while moderate shading did not affect the crude protein concentration of T. subterraneum. Fertilization increased herbage production from 16% for F. ovina to 59% for D. glomerata and ameliorated its nutrient content. Among the tested species, D. glomerata and T. subterraneum demonstrated the highest shade tolerance and could be incorporated into silvopastoral systems of the Mediterranean region., La intensidad de luz y la fertilización del suelo pueden afectar a la producción de biomasa y al contenido en nutrientes de los vegetales. El objetivo de este trabajo fue establecer los efectos del sombreado artificial y de la fertilización sobre la producción, las características de crecimiento y el contenido en nutrientes de las gramíneas Dactylis glomerata y Festuca ovina, y de las leguminosas Trifolium subterraneum y Medicago lupulina. Cada una de las especies vegetales se sometió a los siguientes tratamientos: 90% (sombreado intenso), 50% (sombreado moderado) y 0% (control). Se aplicó fertilización (225 kg/ha N, 450 kg/ha P y 225 kg/ha K) a la mitad de las macetas de cada especie y tipo de sombreado. La reducción en la intensidad de luz (90%) disminuyó significativamente la producción (del 18% de F. ovina al 48% de D. glomerata) y la relación raíz:tallo (R/S) de todas las especies. Sin embargo, la reducción moderada de la intensidad de luz (50%) no afectó a la relación R/S ni a la producción de M. lupulina, promoviendo un incremento del 10,5% de la producción de T. subterraneum. La reduccion en la intensidad de luz incrementó en un 25% de media la concentración de proteína cruda de las especies de gramineas, mientras que el sombreado moderado no afectó a la concentración de proteína cruda de T. subterraneum. La fertilización aumentó la producción (del 16% de F. ovina al 59% de D. glomerata) y mejoró el contenido en nutrientes. Entre las especies estudiadas, D. glomerata y T. subterraneum demostratron alta tolerancia al sombreado y podrían ser incorporadas a sistemas silvopastorales de la región mediterránea.

Aim We assessed the relative contribution of ploidy-level variation and adaptive trait diversity to the diversity of taxon realized niches in a plant lineage with several ploidy levels. Location A large number of sites covering a wide range of environmental conditions in France. Methods Our material comprised a collection of populations from several taxa of the ‘fine-leaved fescue’ lineage, namely section Aulaxyper (Festuca rubra s.l.) and subsection Festuca (Festuca ovina s.l.) of the subgenus Festuca. This collection was assessed for several traits related to vegetative growth, investment in seed production, morphology and phenology. Environmental parameters that best differentiate taxon-realized niches were identified by multivariate ordination and logistic regression. Canonical correlation analyses were performed to relate plant traits and ploidy-level variation to these environmental parameters. Taxon differentiation was assessed along the first canonical directions of the plant descriptor (plant-trait and ploidy-level) space. Results The climatic summer water balance, soil texture and land use were identified as the main environmental parameters differentiating taxon realized niches. Canonical correlation analyses revealed associations between plant traits and these environmental parameters, independent of ploidy-level variation. More specifically, the production of long and abundant rhizomes appeared to be an efficient adaptation to poor climatic summer water balance. In contrast, the ploidy level was rather weakly associated with environmental parameters. The marked prevalence of high ploidy levels in the collection suggests that they could have a competitive advantage in the range of environmental conditions investigated. Main conclusions Adaptive trait diversity appears to contribute more than ploidy-level variation to the present diversity of realized niches for fine-leaved fescue taxa, although plant-trait variations were associated to some extent with ploidy-level variation. However, cytotypes with high ploidy levels could have been efficient colonizers and competitors, favouring the expansion of the lineage and leading to their present prevalence. Furthermore, adaptive trait diversification may have been an efficient factor in niche diversification for the present cytotypes with high ploidy levels.

Genetic variation in two commercial varieties, ‘Liwally’ and ‘Barok’, and two Swedish natural populations of sheep's fescue, Festuca ovina s.l., was studied by means of starch gel electrophoresis. Variation in allele frequencies was found at the Dial, Gpi2, Got2, Pgdl, Pgm, Tpil and Tpi2 loci. ‘Liwally’, belonging to ssp. vallesiaca, showed clear differences compared to the other samples which belong to ssp. capillata and ssp. vulgaris. Genetic diversity, as measured by per cent polymorphic loci, number of alleles per locus and frequency of heterozygotes, was high in all samples in agreement with what has been found in other perennial, outcrossing mono-cotyledonous species with a wide distribution. The bred varieties and the wild populations did not statistically differ with respect to frequency of heterozygotes or number of alleles, though the last value was lower in the domesticated lines than in the natural populations. No significant deviation from the expected Hardy-Weinberg proportions was found in any of the samples.

A new taxonomic treatment of the Festuca ovina L. aggregate (Poaceae) in the British Isles. A wide range of morphological, anatomical and cytological characters was collected and analysed by a variety of methods, some taxometric. As a result nine species are recognized in the British Isles, one (F. glauca Vill.) only as a garden plant and two (F. huonii Auquier and F. armoricana Kerguelen) only in the Channel Isles. Two other species sometimes claimed for the British Isles (F. guestfalica Boenn. ex Reichb. and F. indigesta Boiss.) are excluded for various reasons given. One species (F. ovina L.) is divided into three subspecies: the diploid subsp. ovina (commonest in the north); and the tetraploid subsp. hirtula (Hackel ex Travis) M. Wilkinson (the commonest taxon of the aggregate in the British Isles) and subsp. ophioliticola (Kerguelen) M. Wilkinson (scattered throughout the British Isles, but commonest on chalk and limestone and not restricted to serpentine soils as once thought).

summary Two components of root architecture (topology and link lengths) were measured in a group of 13 dicotyledon and eight grass species, under both high and low nutrient supply rates. Predictions were made, based on a simulation analysis, that root systems from plants grown in low nutrient conditions and those from plants characteristic of such conditions should have the more herringbone topology (branching principally on main axis) and longer links. Both these predictions were confirmed for the dicots, but data from grasses agreed with the predictions only in terms of geometry (link lengths) and not topology. The ecological character of the species was assessed on the assumption that species of low inherent relative growth rate were characteristic of infertile soils, Taxonomic patterns were also evident, indicating that some variation in root system architecture may be historical rather than adaptive.

In the Pacific Northwest of the United States, certain cool-season turf grasses grown for seed are colonized by Russian wheat aphid, Diuraphis noxia (Mordvilko). The objectives of our study were to determine which turfgrass species are colonized and damaged by the aphid, to determine if genetic resistance occurs within genotypes of the same species, and to determine if fungal endophytes enhance aphid resistance in turfgrasses. Compared with cereal species and intermediate wheatgrass ( Elytrlgia intermedia (Host) Nevski subsp. intermedia ), turfgrass species were not as susceptible to Russian wheat aphid. Festuca spp. were better hosts than other grass species. Perennial ryegrass ( Lolium perenne L. ‘Repell’ and ‘Regal’) had resistance 6 wk after infestation. Redtop ( Agrostis alba L. ‘Streaker’), sheep fescue ( Festuca ovina L. ‘Azay’), slender creeping red fescue ( F. rubra subsp. litoralis ‘Logro’), and tall fescue ( F. arundinacea Screb. ‘Mustang,’ ‘Apache,’ and ‘Rebel’) had intermediate resistance to Russian wheat aphid feeding. ‘Repell’ and ‘Regal’ were infected with a fungal endophyte, Acremonium lolii Latch, Christenson, & Samuels. ‘Mustang’ was infected with Acremonium coenophialum Morgan-Jones & Cams, and ‘Wrangler’ was infected with an unidentified species of Acremonium . Sheep fescue ‘Bighorn’ and strong creeping fed fescue ( F. rubra L. subsp. rubra , ‘Ruby’) were infected with Epichloe typhina (Pers. ex Fr.) Tul. ‘Repell’ and ‘Regal’ showed the greatest resistance to aphid feeding, suggesting that plant resistance may have been enhanced by the presence of fungal endophytes. Observations suggest that Russian wheat aphid survival was better on isogenic lines of endophyte-free tall fescue and that nymphs were more sensitive to the presence of fungal endophyte than adults. Researchers in the areas of plant resistance and germ plasm screening for genetic resistance to aphids must be cognizant of fungal endophyte and its effect on aphid biology.

BACKGROUND AND AIMS: Previous studies have shown that silica in grass leaves defends them against small herbivores, which avoid high-silica grasses and digest them less efficiently. This study tested the idea that silica can reduce digestibility by preventing the mechanical breakdown of chlorenchyma cells. METHODS: Both the percentage of total chlorophyll liberated from high- and low-silica grass leaves by mechanical grinding and the chlorophyll content of locust faeces were measured. KEY RESULTS: High-silica grasses released less chlorophyll after grinding and retained more after passing through the gut of locusts, showing that silica levels correlated with increased mechanical protection. CONCLUSIONS: These results suggest that silica may defend grasses at least in part by reducing mechanical breakdown of the leaf, and that mechanical protection of resources in chlorenchyma cells is a novel and potentially important mechanism by which silica protects grasses.

This paper discusses interspecific differences and phenotypic responses to nitrogen supply in various root parameters of five perennial grasses from contrasting habitats. The following root parameters were studied: root:shoot ratio, specific root length, specific root area, mean root diameter, frequency of fine roots, and the length and density of root hairs. Significant between-species variation was found in all of these features. Species from fertile sites had higher root:shoot ratios at high nitrogen supply than species from infertile habitats. All species growing at low nitrogen supply showed a significant increase in root:shoot ratio. Specific root length, specific root area, mean root diameter and frequency of fine roots were not affected significantly by nitrogen supply. Species from infertile sites responded to low nitrogen supply by a significant increase in root hair length and root hair density.

Variation in the intensity of competition has been proposed as a mechanism that may control the species diversity and composition of many kinds of communities, including North American prairie. Competition intensity is predicted to increase with soil fertility and decrease with disturbance, causing variation in the abundances of competitively subordinate species. Variation in competition intensity was examined in an experiment in which fire and fertilizer were applied to native mixed—grass prairie. Treatments consisted of annual burns, a single burn, and untreated control, and fertilization (N ≥ 15 replicates) applied to 7 x 5 m plots for two growing seasons. The experiment was repeated at a second site 15 km away. Fire reduced standing crop and litter, and increased the frequency of bare ground. Nutrient addition increased standing crop and decreased bare ground. Species composition and diversity were largely unaffected by fire. Two common species, Bouteloua gracilis and Carex obusata, were significantly more abundant in fertilized vegetation than in controls at both sites; species diversity decreased in fertilized plots. Vegetation responses to the treatments were similar at the two sites. To tests for variation in competition intensity with fire and nutrient availability, removal experiments were performed in each treatment at one site. Two tussocks each of Festuca ovina and Stipa spartea were chosen in each plot. One plant of each pair had all neighbors within 30 cm clipped and removed during two growing seasons. Each species grew larger and faster in the absence of neighbors, but the magnitude of this effect did not vary with fire, fertilizer, or standing crop. Fire and nutrient addition produced significant changes in the community structure of mixed—grass prairie but did not alter competition intensity in the manner predicted.

The phenology of the satyrine butterflies Coenonympha pamphilus L., Lasiommata megera L., Hipparchia semele L. and Maniola jurtina L. was compared under seminatural conditions with Festuca ovina as the food-plant. Coenonympha pamphilus shows striking phenotypic plasticity as revealed by initiating cohorts at successive dates during the whole flight period. Growth rate is finely tuned depending on season, and larvae can hibernate in any of the three first instars, but also aestivate when 'surplus’time is available. Hipparchia semele and M. jurtina have reduced growth rates as last instar larvae at the beginning of summer. Lasiommata megera, which has an obligate bivoltine life cycle, shows the highest overall growth rate of all four species. Results suggest that egg size variation has consequences for the life cycles of these species.

SUMMARY To examine the ecological relevance of slow growth for survival in unproductive environments, responses to nutrient depletion were compared between two ecologically contrasted grasses with reference to their ability to utilize a nutrient flush. Dry weight growth, ability of roots to absorb nitrogen and subsequent distribution between root and shoot were determined for Holcus lanatus L. and Festuca ovina L. before and after subjecting them to nutrient depletion at warm and cool temperatures. Initially, the relative growth rates (RGR) of H. lanatus were much higher than those of F. ovina, but after 21 days of nutrient depletion, F. ovina attained higher RGR. During nutrient depletion, F. ovina maintained higher shoot N concentrations than H. lanatus, mainly due to lower rates of dry matter accumulation in F. ovina. Maintenance of N concentrations in F. ovina may contribute to sustaining of the shoot activity under N-depleted conditions. Nutrient depletion caused an increase in the proportion of N allocated to roots relative to shoots, but F. ovina exhibited less plasticity than H. lanatus. Following nutrient depletion, the ability of roots to absorb nitrate declined markedly in H. lanatus and to a much lesser extent in F. ovina. The ability to absorb ammonium was also reduced at warm temperatures, while at cool temperatures it was unchanged in H. lanatus, but increased in F. ovina. These results suggest that F. ovina has a greater potential to exploit ‘nutrient flushes’ than H. lanatus under unproductive conditions, especially at cool temperatures.

SUMMARY Samples of 8–35 individuals of Agrostis capillaris, A. stolonifera, Anthoxanthum odoratum, Deschampsia cespitosa and Festuca ovina were collected from zinc-contaminated soils beneath electricity pylons erected in North Wales and Lancashire between 1956 and 1970. Their zinc tolerance was assessed, as was that of two individuals of the same species collected from adjacent uncontaminated soils. Five soil samples from beneath each pylon were collected for evaluating total and extractable soil zinc, soil pH, and soil organic matter. Some degree of zinc tolerance was detected in all five species, suggesting that evolution of tolerance has taken place relatively rapidly, particularly in A. capillaris, D. cespitosa, and Anthoxanthum odoratum. However, tolerant individuals of all species were not found beneath all pylons even when the species was present in the surrounding vegetation. This confirms and extends to other species previous findings in A. capillaris, that the gene or genes necessary for the evolution of tolerance are not universally present within species.

Festuca ovina Linnaeus, Species Plantarum 1: 73. 1753. "Habitat in Alpibus Lapponicae, Helvetiae, Scotiae." RCN: 614. Lectotype (Kerguélen in Lejeunia, n.s., 75: 150. 1975): Herb. Linn. No. 92.1; Lapland Herb. No. 55 (LINN; iso- LAPP). Generitype of Festuca Linnaeus (vide Hitchcock, Prop. Brit. Bot.: 120. 1929). Current name: Festuca ovina L. (Poaceae). Note: A detailed account of the original elements is given by Jarvis & al. (in Watsonia 16: 300. 1987) who also illustrated the type (their pl. 2A), though their choice is pre-dated by that of Kerguélen (1975)., Published as part of Jarvis, Charlie, 2007, Chapter 7: Linnaean Plant Names and their Types (part F), pp. 516-528 in Order out of Chaos. Linnaean Plant Types and their Types, London :Linnaean Society of London in association with the Natural History Museum on page 518, DOI: 10.5281/zenodo.291971

1 Competition for nutrients is an important factor structuring plant communities. Plant symbionts such as arbuscular mycorrhizal fungi (AMF) can have considerable influence on nutrient uptake and are therefore likely to influence plant competition. In this study we investigated the influence of different AMF isolates on the competitive relationships between a legume (Lotus corniculatus L.) and a grass (Festuca ovina L.), and between L. corniculatus and a forb (Plantago lanceolata L.). 2 AMF altered the competitive interactions between the investigated plant species. The legume, which was the most AMF-dependent plant species, was favoured in the presence of AMF relative to the non-AMF treatment in seven out of eight cases. Competition between the grass and the legume was the most strongly affected by AMF. The grass and the legume both benefited from AMF when grown alone, but in competition AMF favoured the legume and grass biomass was reduced by 38%. 3 The presence and also the identity of AMF influenced the competitive relationships. The extent to which AMF influenced plant competition and changed the relative abundances of the competitors depended on the specific AMF isolate. 4 This study shows that both presence and identity of AMF can influence plant competition. These results indicate that AMF and the composition of AMF communities regulate plant interactions and determine the structure of plant communities. © 2007 The Authors.

1 We tested the hypothesis that the competitive effect of multi-species mixtures on a single target plant can be described as a simple additive function of the effects of single species. 2 In a controlled field competition experiment on sand, we used four common species of dry acidic grasslands (Hieracium pilosella, Jasione montana, Corynephorus canescens and Festuca ovina) to study the effects of both, single- and multi-species neighbourhoods on the target species H. pilosella. 3 Target plant biomass points at a competitive ranking of neighbour species with F. ovina as the strongest competitor followed by C. canescens and H. pilosella, while J. montana has a lower effect on the target. The analysis of the competitive response gives no indication of competitive release or amplification with increasing number of neighbouring species. 4 Further analysis with yield-density models reveals that the competition intensity of most multi-species mixtures is well predicted by the effect of pairwise interactions. Hence, for the majority of species combinations, our results indicate additive effects of species competition. 5 Specific species combinations, however, significantly deviate from this result. For combinations of C. canescens with either one of the herbs, the models show a significantly better fit if a non-additivity parameter is included. The important missing factor to describe target plant growth is species-specific biomass of neighbouring plants and here root biomass is the most crucial determinant. The addition of each of these factors as non-additive parameters significantly increases the predictive power of the model. 6 Our work adds to the increasing evidence that interactions in diverse plant communities are not simply a sum of their component species interactions. For a better understanding of the effect of competition on the structure and development of diverse plant communities, future studies need to consider both additive and non-additive effects of competing species. [References: 89]

In sheep's fescue, Festuca ovina , genes coding for the cytosolic enzyme phosphoglucose isomerase, PGIC, are not only found at the standard locus, PgiC1 , but also at a segregating second locus, PgiC2 . We have used PCR-based sequencing to characterize the molecular structure and evolution of five PgiC1 and three PgiC2 alleles in F. ovina . The three PgiC2 alleles were complex in that they carried two gene copies: either two active genes or one active and one pseudogene. All the PgiC2 sequences were very similar to each other but highly diverged from the five PgiC1 sequences. We also sequenced PgiC genes from several other grass species. Phylogenetic analysis of these sequences indicates that PgiC2 has introgressed into F. ovina from the distant genus Poa . Such an introgression may, for example, follow from a non-standard fertilization with more than one pollen grain, or a direct horizontal gene transfer mediated by a plant virus.

The inoculum sources of ascospores of Pleospora allii and of conidia of its anamorph Stemphylium vesicarium were investigated in relation to the brown spot disease epidemiology on pear. Dead and living leaves of three pear varieties (Abate Fetel, Conference and William), seven grasses (Poa pratensis, Festuca rubra, Festuca ovina, Lolium perenne, Digitaria sanguinalis and Setaria glauca) and Trifolium repens, which are used in pear orchard lawns, were inoculated with conidia of Stemphylium vesicarium virulent on pear and incubated under controlled-environment. Stemphylium vesicarium was always re-isolated from dead leaves of the considered plants, but not from symptomless green or yellowish living leaves. The fungus was occasionally re-isolated from leaf segments showing unspecific necrosis. Inoculation of pear leaves with isolates from grasses demonstrated that the fungus did not lose pathogenicity. Pseudothecia, ascospores and conidia were produced on all the dead inoculated leaves; differences between specimens were found for phenology of pseudothecia, their density and size, and for the number of conidia produced. Pseudothecia were produced faster in the lawn species than in pear leaves, and their density was higher, especially for S. glauca, L. perenne and P. pratensis. Ascospore maturation and ejection was more concentrated for the pseudothecia developed on pear leaves than for those on F. ovina and S. glauca. All the lawn species produced more conidia than pear leaves.

International audience; We examined whether grass species and soil nitrogen (N) availability could enhance Carbon (C) and N turnover during root litter decay in grassland. Three species with increasing competitiveness (Festuca ovina, Dactylis glomerata and Lolium perenne) were grown at two N fertiliser levels in an undisturbed grassland soil, in which soil organic fractions derived for the last 9 years from Lolium root litter which was C-13-depleted. During the subsequent experimental year, the C turnover was calculated using the respective delta(13)C values of the old and new C in the root phytomass, in two Particulate Organic Matter (POM) fractions above 200 pm and in the lightest part of the aggregated soil fraction between 50 and 200 mu m. Soil N availability was monitored during the regrowth periods with ion exchange resins (IER). The C decay rates of each particle size fraction were calculated with a simple mechanistic model of C dynamics. The N mineralisation immobilisation turnover (MIT) was characterised by dilution of N-15-labelled fertiliser in the N harvest The C:N ratio and the residence time of C in the fractions decreased with particle size. The presence of a grass rhizosphere increased the decay rate of old C. Accumulation of new C in particle size fractions increased with species competitiveness and with N supply. Species competitiveness increased C turnover in the aggregated fraction, as a result of greater accumulation of new C and faster decay of old C. Fertiliser N increased N turnover and C mineralisation in the SOM. Species competitiveness decreased soil NO3--N exchanged with the IER and increased dissolved organic C (DOC) content. The nature of the current rhizosphere is thus an important factor driving C and N transformations of the old root litter, in relation with grass species strategy. Plant competitiveness may stimulate the C and N turnover in the more evolved SOM fractions in a similar way to the mineral N supply.

Summary:1 - Effects of organisms that obtain resources from others (e.g. herbivores) can depend on the location of resource removal with respect to their ‘prey’. We investigated whether such an effect can be seen in hemiparasitic plant–host plant interactions.2 - We conducted rhizotron studies of the interactions between Rhinanthus minor and individuals of two common host species, Festuca rubra and Festuca ovina. Parasites were grown at two distances from the host, and growth characteristics of hosts and parasites measured over time.3 - Parasites close to their host suffered reduced survival as a result of shading. Without shading these parasites attached earlier, produced more haustoria, grew larger and had a greater fecundity than those planted further away. This effect was significant for parasites infecting the fast-growing F. rubra, but not for parasites infecting the less vigorous F. ovina. Effect of parasite position on host biomass was significant only for F. rubra, which showed a greater reduction when infected by more proximal parasites.4 - Differences in the response of hosts to infection, and parasite growth, suggest the effect of the position of R. minor is host-species specific.

Blissus occiduus Barber is an important pest of buffalograss, Buchloedactyloides (Nut- tall) Engelmann, turf. No-choice studies documented the susceptibility of selected turfgrasses, crops, and weeds to B. occiduus feeding. Highly to moderately susceptible grasses included buffalograss; yellow Setaria glauca (L.) and green foxtail Setaria viridis (L.); Kentucky bluegrass, Poa pratensis L.; perennial ryegrass, Lolium perenne L.; brome, Bromus spp. Leyss.; zoysiagrass, Zoysia japonica Steudel; Bermuda grass, Cynodon dactylon (L.) Pers.; sorghum, Sorghum bicolor (L.) Moench; tall fescue, Festuca arundinacea Schreb.; and barley Hordeum vulgare (L.). Slightly to nonsusceptible grasses included Þne fescue, Festuca ovina hirtula L.; rye, Secale cereale L.; crabgrass Digitaria sanguinalis (L.); bentgrass, Agrostis palustris Huds.; wheat, Tritium aestivum L.; corn, Zea mays L.; fall panicum Panicum dichotomiflorum Michx.; and St. Augustinegrass, Stenotaphrum secundatum (Walt.) Kuntze. The reproductive potential of B. occiduus was also investigated on these same grasses. B. occiduus produced offspring on 15 of the 18 turfgrass, crop, and weed species evaluated. No reproduction occurred on either Bermuda grass or St. Augustinegrass, and buffalograss plants were killed by B. occiduus feeding before offspring could be produced.

Festuca ovina is the abundant matrix-forming species and F. rubra a subordinate species in shallow-soil calcareous grasslands. F. pratensis is a transient species, occurring sparsely in this community. We hypothesised that the different abundances of these three species are primarily due to the differential effect of moisture conditions on their germination and early establishment, and that the effect of the pattern of rainfall intensity depends on the presence or absence of a bryophyte layer. We studied the dependence of the germination and establishment of the three fescue species on the moisture conditions both in the laboratory and in the patches of intact grassland community (microcosms). In a laboratory germination experiment, F. pratensis showed the highest, F. rubra , the intermediate and F. ovina, the lowest drought tolerance. In microcosms, the establishment of F. ovina was the highest. At the same time, the annual mortality of seedlings of F. ovina was the lowest. All three species responded positively to an increasing irrigation level. Differently from F. ovina, F. rubra showed a positive response only in plots from which the bryophyte layer had been removed, while F. pratensis responded positively to both irrigation and bryophyte removal. We conclude that moisture conditions have a differential effect on the three fescue species mainly in the seedling establishment, not in the germination phase. For the successful establishment of F. rubra and F. pratensis, the coincidence of high rainfall and local disturbance, removing bryophytes, is required. The presence or absence of bryophytes had no effect on establishment in dry years, while in rainy years the removal of bryophytes has a clear positive effect.

To evaluate the effects of nitrogen, disturbance, mowing and boundary width on the composition of plant communities of field boundaries a spatial plant competition model was developed that incorporates competition for nitrogen and light as well as mineralisation and population dynamical processes. The model was parameterised for four grassland species: Poa annua, Holcus lanatus, Anthoxanthum odoratum and Festuca ovina. To test the model, simulation results were compared with data from a pot and a field experiment. In addition, several long-term simulations were performed to analyse the effect of the various factors on field boundary composition. The results of the simulations were generally in agreement with experimental results. The simulation study indicated that perennial diversity was maximal when nutrient input and degree of disturbance were low, cuttings removed and the boundary wide. The simulations and experimental results indicated that to enhance diversity of the field boundary vegetation the following measures should be taken: (1) preventing nutrient input from the arable field; (2) mowing and removing of the mown material; (3) restricting annual disturbance to less than 20% of the area; (4) keeping the boundary as wide as possible but at least wider than the maximum fertiliser misplacement.

The type of Puccinia festucae-ovinae Tai on leaves of sheep fescue (Festuca ovina L.) contains five previously unreported uredinia. We present an emended description of this species which was originally described from telia (Tai, 1947). Spores and infected host tissue from the type were wetted with 70% ethanol, then mounted in modified Hoyer's medium for bright-field ob? servation (Cunningham, 1972) or prepared for scanning electron microscopy (SEM) as de? scribed previously (Kulik and Dery, 1992). Photographs were taken with a Wild Photoautomat MPS 55 camera apparatus mounted on a Leitz Ortholux microscope.

Active duplicate PgiC genes in sheep's fescue, Festuca ovina, are associated with a PCR marker of specific length (about 370 bp, of which 231 are in an intron). Using this marker, the frequency of plants with duplicate genes is estimated to be about 10% in a population from southern Sweden. The close molecular similarity between the electrophoretically different duplicated genes is in accordance with the conclusion reached earlier that they are indeed alleles at the same locus.

We tested the prediction that the successional replacement of plant species during succession on inland sand dunes results from the effects of an increase in nitrogen mineralization on competitive interactions. The growth and competitive strength of Festuca ovina and Deschampsia flexuosa on soil substrates with different amounts of soil organic matter or nitrogen supply were measured. Small tillers of Festuca ovina and Deschampsia flexuosa were grown in monocultures and 1:1-mixtures on soil columns with undisturbed layers of soil organic matter from different successional age. There was (a) no visible soil organic matter, (b) a thin soil organic layer (0.5 cm) and (c) a thicker soil organic layer (6.0 cm) present on the soil columns. The species were also grown on columns with no visible soil organic matter (bare sand) with two different levels of N fertilization to mimic the increased N mineralization in the older successional stages. In monoculture, Festuca produced more biomass on the substrates with a soil organic layer compared to the unfertilized sand substrate. It also produced more biomass on sand substrates with N fertilization. Deschampsia produced more biomass in treatments with a soil organic layer compared to the bare sand treatments, but did not respond to the ammonium-nitrate addition. In competition, Festuca seemed to be the stronger competitor on the unfertilized sand substrate. Festuca was also the better competitor on the N fertilized sand treatments, while on the treatments with a soil organic layer Deschampsia was the winning species. Our results do not support the hypothesis that an increase in N supply is responsible for the replacement of Festuca by Deschampsia that concur with the accumulation of soil organic matter during succession in inland dunes.

Preemergent herbicide phytotoxicity was evaluated for six species of container-grown ornamental grasses: beach grass (Ammophila breviligulata Fern.), pampas grass [Cortaderia selloana (Schult. & Schult. f.) Asch. & Graebn.], tufted hair grass [Deschampsia caespitosa (L.) Beauvois.], blue fescue [Festuca ovina cv. glauca (Lam.) W.D.J. Koch], fountain grass [Pennisetum setaceum (Forssk.) Chiov.], and ribbon grass (Phalaris arundinacea cv. picta L.). Herbicides included isoxaben, metolachlor, MON 15151, napropamide, oryzalin, oxadiazon, pendimethalin, prodiamine, and trifluralin; the granular combination products of benefin plus trifluralin; and oxyfluorfen plus pendimethalin. Metolachlor, granular or spray, and oryzalin severely injured all species tested, except beachgrass, which was not injured by metolachlor granule. Napropamide injured pampas grass, fountain, grass, blue fescue, and tufted hair grass, but was safe on ribbon grass and beach grass. Pendimethalin, prodiamine, trifluralin; MON 15151, isoxaben, oxyfluorfen plus pendimethalin, and benefin plus trifluralin were safe on all six species. Chemical names used: N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)benzenamine(benefin);N-[3-(1-ethyl-1-methylpropyl)5-isoxazolyl]-2,6-dimethoxybenzamide(isoxaben);2-chloro-N-(2-ethyl-6-methylphenyll-N-(2-methoxy-1-methylethyl)acetamide (metolachlor); S,S-dimethyl 2-(difluoromethyl)-4-(2-methylpropyl)-6-(trifluoromethyl)-3,5-pyridinedicarbothioate(MON 15151);N,N-diethyl-2-(l-naphthalenyloxy)propanamide (napropamide); 4-(dipropylamino)-3,5-dinitro-benzenesulfonamide (oryzalin); 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2-(3H)-one (oxadiazon); 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl) benzene (oxyfluorfen); N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin); N3,N3-di-n-propyl-2,4-dinitro-6-(trifluoromethyl)-m-phenylenediamine (prodiamine); 2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine (trifluralin).

Normally sheep’s fescue (Festuca ovina) carries a single locus encoding the cytosolic enzyme phosphoglucoisomerase (PGI). However, at several localities in southern Sweden plants with more than two different alleles have been found by isozyme studies. Crossing experiments and subsequent progeny analyses revealed two unlinked loci. The additional locus was polymorphic for two alleles with different electrophoretic mobilities. Two of the numerous alleles at the primary locus had the same mobility. A complex gene coding for both electrophoretic types was also found to map to the additional locus, but no such complex gene has been found at the primary locus. The genes at the additional locus can be lacking, or present in hemizygous or homozygous form. Allozymes encoded by the additional locus readily form heterodimers with those encoded by the primary locus, thus giving rise to multibanded isozyme patterns. This segregating, polymorphic gene duplication may well represent a rare case where the initial stage of the evolution of a new gene can be directly studied.

Three perennial grass species, perennial ryegrass (Lolium perenne L.), colonial bentgrass (Agrostis capillaris L.), and sheep fescue (Festuca ovina L.), were grown at two CO{sub 2} concentrations (350 and 700 {micro}L L{sup {minus}1}) and under two N regimes: one with a minor addition of 8 kg N ha{sup {minus}1} and one with an addition of {approximately}278 kg N ha{sup {minus}1}, both labeled with {sup 15}N. The effects of elevated CO{sub 2} on {sup 15}N and N uptake and dynamics in the plant-soil systems were determined after 32 and 55 d, with close attention to the rhizosphere. Total N uptake by the plants was not affected by elevated CO{sub 2}, compared with ambient CO{sub 2}, independent on N treatment and grass species. A clear decrease from 1.77 at ambient CO{sub 2} to 1.25 at elevated CO{sub 2} was observed in the shoot/root (S/R) ratio of N, resulting from a significant decrease of the N concentration in shoots, and an unchanged root N concentration. At 700 {micro}L L{sup {minus}1} CO{sub 2}, N concentration in the shoots decreased from 12.9 to 9.9 g kg{sup {minus}1}, even at the low N supply, whereas the slight decrease in root N concentration for plants grown atmore » elevated CO{sub 2} was not significantly different. The relative increase of {sup 15}N found in the rhizosphere soil microbial biomass (SMB) and the rhizosphere soil residue under elevated CO{sub 2} was too small to affect plant growth, even in the low N treatment. The total amount of {sup 15}N recovered in the plants was not affected by the CO{sub 2} treatment. Although at the second harvest slightly more {sup 15}N was found in the plants than at the first harvest, probably due to turnover of the SMB, no interaction with CO{sub 2} was observed. This shows that the fertilizer {sup 15}N had not been immobilized to a larger extent or for a longer time by the SMB at elevated CO{sub 2} than under ambient CO{sub 2}, even independent of N level and grass species. No evidence was found that under elevated CO{sub 2} substantial amounts of N had been immobilized by the SMB, nor than mineralization of native soil organic matter (SOM) had been stimulated by an increased supply of substrate to the SMB. The authors conclude that elevated CO{sub 2} has the potential to induce significant changes in plant N nutrition, modifying N allocation and tissue quality within perennial grasses, but that these effects appear to be independent of the SMB.« less

A lot of work has been done on the occurrence and role of endophytes in ryegrass and tall fescue in the USA and New Zealand. In Europe some investigations were made on the role of endophyte infested meadow and tall fescue (BUMERL and MIKA 1991, SCHMIDT 1991), but few data are known about the occurrence of endophytes in meadow fescue. The aim was to evaluate European commercial cultivars and also ecotypes from fescue grasses for endophytic fungi.

Six plant species in the family Gramineae were used to investigate the relationship between Cs uptake, nutrient regime and plant growth strategy sensu Grime (1979: Plant Growth Strategies and Vegetation Processes, John Wiley). The roots of 66 day old Elymus repens (L.) Gould., Bromus sterilis L., Agrostis stolonifera L., Anthoxanthum odoratum L., Festuca ovina L. and Nardus stricta L. plants grown in acid-washed sand at high and low nutrient levels were exposed to a 96 h pulse of stable Cs at 0.05 mm, 0.15 mm, 0.3 mm, 1.0 mm and 3.0 mm concentrations. Different nutrient regimes induced large differences in dry wt in E. repens, B. sterilis and A. stolonifera plants but only small differences in N. stricta and F. ovina plants. At high nutrient concentrations, A. stolonifera, A. odoratum, F. ovina and N. stricta shoots showed significantly greater increases in internal Cs concentration with rising external Cs concentrations than did E. repens and B. sterilis shoots. The relationship between increases in shoot and external Cs concentrations was statistically indistinguishable between species in plants grown at the low nutrient concentration. These patterns of Cs uptake ensured that with long-term high K concentrations the more competitive plants (E. repens and B. sterilis) accumulated higher concentrations of Cs from low external concentrations than did non-competitive plants or competitive plants grown at low nutrient levels. It is suggested that the relationship between plant growth strategy sensu Grime (1979) and Cs accumulation patterns may help to explain the different concentrations to which species accumulate radiocaesium from the soil.

Nitrogen losses from plants may occur through a variety of pathways, but so far, most studies have only quantified losses ofnutrient by above-ground litter production. We used 15N pulse labelling to quantify total nitrogen losses from above-and belowground plant parts. Using this method we were able to inelude also pathways other than above-ground litter production. To test the hypothesis that species from nutrientpoor habitats lose less nitrogen than species from more fertile soils six perennial grasses from habitats with a wide range ofnutrient availability were investigated: Lolium perenne, Arrhenatherum elatius, Anthoxanthum odoratum, Festuca rubra" Festuca ovina and Molinia caerulea. The results ofan experiment carried out in pots in a greenhouse at two fertility treatments show that statistically significant losses occur through pathways other than litter production. In the low fertility treatment, most (70010) losses from L. perenne occurred by litter production, but in A. elatius, F. rubra, F. ovina and M. caerulea. more than 50% oflabelled N losses took place by root tumover, leaching or exudation from roots. When nutrient supply increased, the 15N losses in above-ground dead material increased in all species and in A. elatius, A. odoratum and F. rubra the 15N losses vía other pathways decreased. Ranked according to decreasing tumover coefficient the sequence of species was: L. perenne, A. odoratum F. rubra. F. ovina" A. elatius, M. caerulea These results show that species adapted to sites with low availability ofnutrients lose less nitrogen (incIuding above-and belowground losses) than species adapted to more fertile soils., This work was supported by a grant from the Spanish Ministry ofEducation and Science. Thanks are due to JG Heij for technical assistance, to GW Va1kenburg for analysing the labelled samples and to JCM Withagen for statistical help.

Nomenclature follows that of A. R. Clapham, T. G. Tutin and E. F. Warburg’s Excursion Flora of the British Isles (3rd. edn), published by Cambridge University Press in 1981, except for the following species groupings: Betula spp. (includes B. pendula, B. pubescens and their hybrid), Festuca ovina (also includes F. tenuifolia), Festuca rubra (also includes F. nigrescens), Lolium perenne (refers only to ssp. perenne; the monocarpic, and introduced, ssp. multiflorum (Lam.) Husnot is a non-persistent escapee from cultivation), Medicago sativa (excludes ssp. falcata (L.) Arcangeli which is native in East Anglia), Nasturtium officinale agg. (N. microphyllum, N. officinale and their hybrid), Poa pratensis agg. (P. angustifolia, P. pratensis sensu stricto and P. subcaerulea), Quercus agg. (Q. petraea, Q. robur and their hybrid), Rosa spp. (R. canina group, R. rubiginosa group and R. tomentosa group), Salix cinerea agg. (S. aurita L., S. caprea, S. cinerea and hybrids), Salix fragilis agg. (S. alba L., S. fragilis L. and related hybrids) and Taraxacum agg. (Section Erythrosperma, Section Obliqua, Section Palustria, Section Spectabilia and Section Taraxacum).