Natural Grasslands (natural + grassland)

Distribution by Scientific Domains


Selected Abstracts


Mechanisms linking plant species richness to foraging of a large herbivore

JOURNAL OF APPLIED ECOLOGY, Issue 4 2010
Ling Wang
Summary 1.,There is general concern that local loss of plant diversity will adversely impact net primary productivity and other ecosystem properties. However, mechanisms linking plant diversity with other trophic levels, especially for large herbivores, are poorly understood. 2.,We examine the responses of foraging sheep to changes in plant species richness in an indoor cafeteria experiment involving six plant species richness levels (1, 2, 4, 6, 8 and 11 species) and three plant functional group compositions within each level, and in a field experiment involving three plant species richness levels (1, 4,6 or >8 species). 3.,Sheep preferred a diverse diet over a single diet even when palatable species were in the diet. Voluntary daily intake steadily rose with increases in plant species richness in both cafeteria and field experiments. The overall nutrient intake (i.e. daily energy and protein intakes) of sheep in the cafeteria also rose significantly with increased plant species richness until it reached a plateau at eight species. The quality of the diet selected by sheep was also significantly affected by plant species richness, but the variation of dietary quality was small and variable. 4.,High nutrient acquisition by the sheep depended on selecting those palatable species with high nutrient content from the plant forage on offer together with the complementary effects of plant species richness, especially for plant functional group richness. 5.,Synthesis and applications. Our experiments demonstrate an asymptotic relationship between plant species richness and voluntary intake by sheep. Increases in plant species richness from a low level led to increased daily nutrient intake, and presumably performance of the sheep. Natural grasslands are generally low in nutritional quality and so plant species richness will critically influence herbivore food intake and nutrition. The asymptotic relationship indicates that the maintenance of plant species richness in rangelands will benefit both domestic herbivore production and the conservation of biodiversity. [source]


Economic-technological appraisal of grassland resources in Northern China by a fuzzy model

GRASSLAND SCIENCE, Issue 2 2005
Hua Wang
Abstract After briefly reviewing an appraisal of natural grassland of the Northern China, we made an attempt to apply a new mathematical method to grassland utilization and management. We turned our attention to those factors that can play an important part in an appraisal of grassland resources. A fuzzy mathematical model of multifactorial tri-stage appraisal of grassland resources is proposed in this paper. This is the first report in which such a mathematical model is applied to the appraisal of natural grasslands. To verify the practical value of the model, we appraised three types of grassland as examples and the description of the computing process is given in detail. The present study proves that the model was highly accurate and is suitable for economic-technological appraisals for natural grassland. [source]


Prediction of butterfly diversity hotspots in Belgium: a comparison of statistically focused and land use-focused models

JOURNAL OF BIOGEOGRAPHY, Issue 12 2003
Dirk Maes
Abstract Aim, We evaluate differences between and the applicability of three linear predictive models to determine butterfly hotspots in Belgium for nature conservation purposes. Location, The study is carried out in Belgium for records located to Universal Transverse Mercator (UTM) grid cells of 5 × 5 km. Methods, We first determine the relationship between factors correlated to butterfly diversity by means of modified t -tests and principal components analysis; subsequently, we predict hotspots using linear models based on land use, climate and topographical variables of well-surveyed UTM grid cells (n = 197). The well-surveyed squares are divided into a training set and an evaluation set to test the model predictions. We apply three different models: (1) a ,statistically focused' model where variables are entered in descending order of statistical significance, (2) a ,land use-focused' model where land use variables known to be related to butterfly diversity are forced into the model and (3) a ,hybrid' model where the variables of the ,land use-focused model' are entered first and subsequently complemented by the remaining variables entered in descending order of statistical significance. Results, A principal components analyses reveals that climate, and to a large extent, land use are locked into topography, and that topography and climate are the variables most strongly correlated with butterfly diversity in Belgium. In the statistically focused model, biogeographical region alone explains 65% of the variability; other variables entering the statistically focused model are the area of coniferous and deciduous woodland, elevation and the number of frost days; the statistically focused model explains 77% of the variability in the training set and 66% in the evaluation set. In the land use-focused model, biogeographical region, deciduous and mixed woodland, natural grassland, heathland and bog, woodland edge, urban and agricultural area and biotope diversity are forced into the model; the land use-focused model explains 68% of the variability in the training set and 57% in the evaluation set. In the hybrid model, all variables from the land use-focused model are entered first and the covariates elevation, number of frost days and natural grassland area are added on statistical grounds; the hybrid model explains 78% of the variability in the training set and 67% in the evaluation set. Applying the different models to determine butterfly diversity hotspots resulted in the delimitation of spatially different areas. Main conclusions, The best predictions of butterfly diversity in Belgium are obtained by the hybrid model in which land use variables relevant to butterfly richness are entered first after which climatic and topographic variables were added on strictly statistical grounds. The land use-focused model does not predict butterfly diversity in a satisfactory manner. When using predictive models to determine butterfly diversity, conservation biologists need to be aware of the consequences of applying such models. Although, in conservation biology, land use-focused models are preferable to statistically focused models, one should always check whether the applied model makes sense on the ground. Predictive models can target mapping efforts towards potentially species-rich sites and permits the incorporation of un-surveyed sites into nature conservancy policies. Species richness distribution maps produced by predictive modelling should therefore be used as pro-active conservation tools. [source]


Ecosystem properties determined by plant functional group identity

JOURNAL OF ECOLOGY, Issue 2 2010
Jennie R. McLaren
Summary 1.,Ecosystem properties may be determined by the number of different species or groups of species in a community, the identity of those groups, and their relative abundance. The mass ratio theory predicts that the effect of species or groups of species on ecosystem properties will be dependent on their proportional abundance in a community. 2.,Single plant functional groups (graminoids, legumes, non-leguminous forbs) were removed from a natural grassland in northern Canada to examine the role of group identity in determining both ecosystem properties and biomass compensation by remaining species. Removals were conducted across two different environmental treatments (fertilization and fungicide) to examine the context dependency of functional group identity effects. 3.,The degree of biomass compensation in the first 4 years after removal was influenced by the identity of the functional group removed and also of those remaining. When graminoids were removed, none of the remaining functional groups compensated for the loss of biomass. Graminoids partially compensated for the removal of forbs or legumes, with the degree of compensation depending on environmental treatments. 4.,Light interception, soil moisture and soil nutrients were all influenced by functional group identity, with graminoids having a greater impact than expected based on their biomass contribution to the community. Legumes, in contrast, had very little effect on any of the ecosystem properties measured. 5.,For most ecosystem properties measured, the role of plant functional groups was not context dependent; functional groups had the same effect on ecosystem properties regardless of fertilization or fungicide treatments. 6.,Synthesis. We have shown that the effects of losing a functional group do not solely depend on the group's dominance. In this northern grassland, there are greater effects of losing graminoids than one would predict based on their biomass contributions to the community, and functional group identity plays a critical role in determining the effects of diversity loss. [source]


Flooding and grazing promote germination and seedling establishment in the perennial grass Paspalum dilatatum

AUSTRAL ECOLOGY, Issue 3 2009
PATRICIA S. CORNAGLIA
Abstract Seed germination and seedling emergence are key processes for population recruitment. Flooding and grazing are disturbances forming gaps that may strongly influence recruitment patterns in space and time, but their combined effects and action mechanisms have rarely been addressed. In this study we analysed the effects of microhabitat conditions associated with winter flooding and spring-summer defoliation on seed germination and seedling establishment of Paspalum dilatatum, a dominant perennial C4 grass in native grasslands of the Flooding Pampa, Argentina. The dynamics of seedling emergence from natural seed banks and buried seeds was studied in a factorial experiment with flooding and defoliation treatments applied to soil monoliths (mesocosms) collected from natural grassland. Additional laboratory experiments were applied to investigate seed germination under different combinations of temperature, light quality and simulated flooding. Seed germination and seedling emergence of P. dilatatum were promoted by flooding and high intensity defoliation. Gaps generated by flooding were maintained by high intensity defoliation exercising a synergistic effect on survival seedlings. Flooding resulted in the breaking of seed dormancy and higher germination rates associated with alternating temperature and the activation of the phytochrome system. Our results indicate that microhabitat conditions associated with the disturbances forming gaps, such as flooding and heavy grazing, synergistically promote the recruitment process of this dominant grass species. [source]


Forest landscape pattern in the KwaZulu,Natal midlands, South Africa: 50 years of change or stasis?

AUSTRAL ECOLOGY, Issue 6 2004
MICHAEL J. LAWES
Abstract Understanding patterns and processes of habitat change is essential for managing and conserving forest fragments in anthropogenically altered landscapes. Digitized aerial photographs from 1944 and 1996 were examined for changes to the indigenous forest landscape in the Karkloof-Balgowan archipelago in KwaZulu,Natal, South Africa. Attributes relating to proximate land-use, patch shape, isolation and position in the landscape were used to determine putative causes of forest change. The total change in forest area was ,5.7% (forest covered 6739 ha in 1996). This is contrasted with previous reports for the period 1880,1940 that estimated change in total forest area of up to ,80%. Attrition was the predominant process of forest transformation between 1944 and 1996. Despite little overall change in forest area, 786 mostly small (<0.5 ha) forest patches were lost from the landscape, leaving 1277 forest patches in 1996. An increase in patch isolation, but no change in patch cohesion accompanied the changes in forest area. Ignoring patches that were eliminated, 514 patches decreased in area. This was partly a function of patch size, but the conversion of natural grassland to commercial plantation forestry in the matrix also influenced forest decline. Their small size and irregular shape caused forest patches in the region to be vulnerable to edge effects. Core area declined in a negative exponential way with increasing edge width and the total area of edge habitat exceeded that of core habitat at an edge width of only 50 m. Nevertheless, total core area decreased by only 2% (65 ha) between 1944 and 1996 because most of the eliminated patches were small and contained no core area. The large Karkloof forest (1649 ha) is a conservation priority for forest interior species, but the ecological role and biodiversity value of small forest patches should not be overlooked. [source]


Size traits and site conditions determine changes in seed bank structure caused by grazing exclusion in semiarid annual plant communities

ECOGRAPHY, Issue 1 2006
Yagil Osem
1. Contrasting patterns of change in the seed bank of natural grasslands are frequently found in response to grazing by domestic herbivores. Here, we studied the hypotheses that a) patterns of change in seed bank density and composition in response to grazing depend on spatial variation in resource availability and productivity, and b) that variation among species in patterns of seed bank response to grazing is linked to differences in species size traits (i.e. size of plant, dispersal unit and seed). 2. Effects of sheep grazing exclusion on the seed bank were followed during five years in a semiarid Mediterranean annual plant community in Israel. Seed bank density and composition were measured in autumn, before the rainy season, inside and outside fenced exclosures in four neighboring topographic sites differing in vegetation characteristics, soil resources and primary productivity: Wadi (dry stream terraces, high productive site), Hilltop, South- and North-facing slopes (less productive sites). 3. Topographic sites differed in seed density (range ca 2500,18000 seed m,2) and in seed bank response to grazing exclusion. Fencing increased seed density by 78, 51 and 18% in the Wadi, South- and North-facing slopes, respectively, but had no effect in the Hilltop. At the species level, grazing exclusion interacted with site conditions in determining species seed bank density, with larger or opposite changes in the high productive Wadi compared to the other less productive sites. 4. Changes in seed bank structure after grazing exclusion were strongly related to species size traits. Grazing exclusion favored species with large size traits in all sites, while seed density of tiny species decreased strongly in the high productive Wadi. Species with medium and small size traits showed lesser or no responses. 5. The size of plants, dispersal units and seeds were strongly correlated to each other, thus confounding the evaluation of the relative importance of each trait in the response of species to grazing and site conditions. We propose that the relative importance of plant size vs seed size in the response to grazing changes with productivity level. [source]


The impact of grassland management on archaeal community structure in upland pasture rhizosphere soil

ENVIRONMENTAL MICROBIOLOGY, Issue 3 2003
Graeme W. Nicol
Summary The community structure of rhizosphere soil Archaea from three grassland types, associated with different management practices, was examined at a site in the Borders region of Scotland, by analysis of 16S rRNA gene fragments amplified from 16S rDNA and from rRNA. Denaturing gradient gel electrophoresis (DGGE) and sequence analysis of amplified products indicated high relative abundance within the archaeal community of two distinct lineages of non-thermophilic (group 1) Crenarchaeota. Grassland management practices influenced archaeal community structure, as characterized by both 16S rRNA- and 16S rDNA-derived DGGE profiles. One band dominated DGGE profiles in all three grassland types examined, and reproducible differences in the presence and intensity of bands were observed between profiles from managed and natural grassland sites. Analysis of 16S rRNA-derived amplicons from managed and natural grasslands at sites in the north of England and the north of Wales also indicated high relative abundance of non-thermophilic crenarchaeotes within the archaeal community. The band dominating the Scottish grassland site also dominated DGGE profiles from the English and Welsh sites, and similar differences were seen between profiles derived from soils subjected to different management regimes. The study indicates that grassland archaeal communities are dominated by Crenarchaeota, with closely related members of this lineage ubiquitous in distribution in UK upland pasture, and indicate that management practices influence the nature of the crenarchaeotal community. [source]


Argentine rangeland quality influences reproduction of yearling pregnant heifers?

GRASSLAND SCIENCE, Issue 2 2009
Liliana G. Hidalgo
Abstract The Flooding Pampa natural grasslands are gradually being transformed into croplands to increase the economic returns of ranches. It is therefore becoming necessary for stockmen to increase beef cattle efficiency to compete with crops and to maintain the native grassland and its associated fauna. However, natural grasslands during winter have the lowest content of nutrients of the year. We intend to demonstrate that, with breeding weights of over 65% of cow mature weight, low forage quality of rangelands during winter does not have a negative effect on reproduction. These higher breeding weights were obtained by selecting early born female calves and by grazing annual and cultivated pastures. Pregnant Aberdeen Angus yearling heifers (n = 90) were evaluated using a pregnancy test (May 2005) until the second calving (July 2006). At the beginning of the experiment, yearling heifers with live weight ranging 360,514 kg (mean, 425 kg ± 3.5 SE) were used. Cattle grazed native grasslands (humid mesophytic meadows and humid prairie grasslands) and old mixed pastures. The second pregnancy was high (100%), with the same mean calving date as in the first pregnancy (227 Julian days). Heifers which calved later in the first calving year were early calvers in the second year, resulting in the relatively constant average calving dates across the animals. [source]


Phytosociological study on steppe vegetation in the vicinity of Kharkiv, Ukraine

GRASSLAND SCIENCE, Issue 2 2006
Yunxiang Cheng
Abstract To classify the steppe vegetation of the natural grasslands in the Ukraine from a viewpoint of phytosociology, vegetation investigation was carried out in three relatively homogeneous sites in Kharkiv Province. Plant communities were classified by their characteristic species and differential species on the basis of the floristic composition into two communities, Stipa capillata,Festuca sulcata community and Poa angustifolia,F. sulcata community, and below four lower units. Using the data of three phases of soil in each of the three sites and the detrended correspondence analysis ordination technique, the score of axis 1 correlated most closely with geographical gradient which reflected the soil water condition. This result shows that the S. capillata,F. sulcata community is more tolerant to a dry habitat of the steppe vegetation of the Ukraine. [source]


Economic-technological appraisal of grassland resources in Northern China by a fuzzy model

GRASSLAND SCIENCE, Issue 2 2005
Hua Wang
Abstract After briefly reviewing an appraisal of natural grassland of the Northern China, we made an attempt to apply a new mathematical method to grassland utilization and management. We turned our attention to those factors that can play an important part in an appraisal of grassland resources. A fuzzy mathematical model of multifactorial tri-stage appraisal of grassland resources is proposed in this paper. This is the first report in which such a mathematical model is applied to the appraisal of natural grasslands. To verify the practical value of the model, we appraised three types of grassland as examples and the description of the computing process is given in detail. The present study proves that the model was highly accurate and is suitable for economic-technological appraisals for natural grassland. [source]


The impact of land-cover modification on the June meteorology of China since 1700, simulated using a regional climate model

INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 5 2003
H. Wang
Abstract A series of simulations was conducted using a regional climate model with a domain covering mainland China. Simulations were conducted for a single June using estimated land cover for 1700, 1750, 1800, 1850, 1900, 1950, 1970 and 1990. The conversion of land cover between these periods was extensive over mainland China, where large areas were altered from natural forests to either grass or crops, or from natural grasslands to crops. These land-cover modifications affect various characteristics of the land surface, which lead to changes in the way available energy and water are partitioned. Over areas where land cover was modified, substantial changes are simulated. The conversion from forests to grasses or crops leads to warming and to reductions in root zone soil moisture and latent heat fluxes. Regionally, the conversion from forest to grasses and crops leads to significant warming over large areas of China, but there is an area of cooling present that is coincident with the main location of a land-use change from short grass to crops. The changes in temperature propagate to about 1500 m above the surface and affect specific humidity throughout this part of the atmosphere. An analysis of daily average results shows a consistent impact of land-cover modification on temperature, latent heat flux and soil moisture. Therefore, we find large and consistent impacts over China resulting from historical land-cover modification that are sufficiently important to the regional-scale climate to warrant inclusion in future modelling efforts. Our results suggest that efforts to attribute warming patterns over China to any particular cause need to take into account the conversion of the land cover that has taken place over China over the last 300 years. Copyright © 2003 Royal Meteorological Society [source]


Virus infection and grazing exert counteracting influences on survivorship of native bunchgrass seedlings competing with invasive exotics

JOURNAL OF ECOLOGY, Issue 2 2006
C. M. MALMSTROM
Summary 1,Invasive annual grasses introduced by European settlers have largely displaced native grassland vegetation in California and now form dense stands that constrain the establishment of native perennial bunchgrass seedlings. Bunchgrass seedlings face additional pressures from both livestock grazing and barley and cereal yellow dwarf viruses (B/CYDVs), which infect both young and established grasses throughout the state. 2,Previous work suggested that B/CYDVs could mediate apparent competition between invasive exotic grasses and native bunchgrasses in California. 3,To investigate the potential significance of virus-mediated mortality for early survivorship of bunchgrass seedlings, we compared the separate and combined effects of virus infection, competition and simulated grazing in a field experiment. We infected two species of young bunchgrasses that show different sensitivity to B/CYDV infection, subjected them to competition with three different densities of exotic annuals crossed with two clipping treatments, and monitored their growth and first-year survivorship. 4,Although virus infection alone did not reduce first-year survivorship, it halved the survivorship of bunchgrasses competing with exotics. Within an environment in which competition strongly reduces seedling survivorship (as in natural grasslands), virus infection therefore has the power to cause additional seedling mortality and alter patterns of establishment. 5,Surprisingly, clipping did not reduce bunchgrass survivorship further, but rather doubled it and disproportionately increased survivorship of infected bunchgrasses. 6,Together with previous work, these findings show that B/CYDVs can be potentially powerful elements influencing species interactions in natural grasslands. 7,More generally, our findings demonstrate the potential significance of multitrophic interactions in virus ecology. Although sometimes treated collectively as plant ,predators', viruses and herbivores may exert influences that are distinctly different, even counteracting. [source]


Variation in leaf traits through seasons and N-availability levels and its consequences for ranking grassland species

JOURNAL OF VEGETATION SCIENCE, Issue 4 2005
Raouda Al Haj Khaled
Abstract Question: Are leaf dry matter content, specific leaf area and leaf life span relevant plant traits to discriminate the fertility gradient in species-rich natural grasslands? In other words, is species ranking conserved when nitrogen availability or growing periods change? Location: Toulouse Research Centre, France; 150 m a.s.l. Methods: Fifteen grasses and nine dicotyledons were sown in pure stands in a random block design with three replicates. Each species was cultivated at two levels of nitrogen supply, limiting and non-limiting for growth, with three replications per nitrogen level. Leaf traits were measured across both levels of nitrogen supply and growing periods over the year. Results: Leaf dry matter content values separated the species into three life-form classes (grasses, rosette forbs and upright forbs, P < 0.001). This was not the case for specific leaf area and leaf life span. The three leaf traits were variable across growing periods and nitrogen levels, but the ranking of species was conserved over N-levels and growth periods. Furthermore leaf dry matter content was always less variable than the other leaf traits. Conclusion: We conclude that leaf dry matter content measured only on grasses could be used as an indicator to describe the N-richness of the habitat where native herbaceous vegetation develops. [source]


Temporal trends in species composition and plant traits in natural grasslands of Uruguay

JOURNAL OF VEGETATION SCIENCE, Issue 3 2003
Claudia Rodríguez
Cabrera (1970) Abstract. We report the successional trends of the major life-forms (graminoids and forbs) in natural grasslands of Uruguay over a 9-yr period after the removal of domestic herbivores. For the whole community, species richness and diversity decreased over the successional period. In graminoids we observed clear temporal trajectories in floristic composition; the rate of floristic change decreased with time and was associated with a shift in plant traits. The exclusion of large herbivores promoted erect and tall grasses with narrow leaves and greater seed length, vegetative growth constrained to the cool season and increased frequency of annual species. Forbs did not show a clear temporal trend in species composition, but there was, nevertheless, a plot-specific species turnover of this functional group that was reflected in their attributes. Species spreading by means of rhizomes, with vegetative growth restricted to the warm season. Species with larger seeds increased under grazing exclusion, as did annual and nitrogen-fixing forbs. The floristic changes induced by cattle exclusion occurred early in the succession. This early high rate of change has practical implications for management and conservation programs of the natural grasslands of Uruguay. Additionally, the shift in plant traits may be helpful in devising simple indicators of grazing impact. [source]


Spatial distributions of multiple plant species affect herbivore foraging selectivity

OIKOS, Issue 2 2010
Ling Wang
Spatial distribution of food resources is an important factor determining herbivore foraging. Previous studies have demonstrated that clumped distribution of preferred species increases its consumption by herbivores in single- or two-species systems. However, the potential impact of distribution pattern of less preferred species on foraging was ignored. In natural grasslands with high species diversity and complexity, the spatial distribution of preferred species impacts on herbivore foraging may be strongly correlated with the distribution of less preferred species. Our aims were to determine the effect of distribution of both preferred and other plant species on herbivore foraging under conditions close to a native, multi-species foraging environment, and conceptualize the relationships between spatial distribution of food resources and herbivore consumption. We hypothesized that random distribution of non-preferred species reduces herbivore consumption of preferred species because the dispersion of less preferred species likely disturbs herbivore foraging. We conducted an experiment using three species with five combinations of clumped and random distribution patterns. Three species Lathyrus quinquenervius, Phragmites australis and Leymus chinensis, were of high, intermediate and low preferences by sheep, respectively. Results showed that distribution of low preferred species, but not that of high preferred one, affected the consumption of preferred species. Sheep obtained higher consumption of high preferred species when low preferred species followed a clumped distribution than a random distribution. Distance between aggregations of high and low preferred species did not affect sheep foraging. It was concluded that the effects of spatial distribution of preferred species on its consumption are dependent on herbivore foraging strategy, and sheep can consume more preferred species when there is a consistent spatial pattern between preferred species and the entire food resource, and that the random dispersion of low preferred species in grassland may reduce herbivore consumption of high preferred species, thus minimizing selective grazing. [source]


Climatic signals in tree-rings of Araucaria angustifolia in the southern Brazilian highlands

AUSTRAL ECOLOGY, Issue 2 2010
JULIANO MORALES OLIVEIRA
Abstract Araucaria angustifolia (Bertol.) O. Kuntze (Araucariaceae) is a Neotropical tree, widely distributed in subtropical mountain rain forests and nearby natural grasslands of Southern Brazil. This species produces annual growth rings, but its dendroclimatic potential is barely known. In the present paper, the long-term growth patterns of A. angustifolia were investigated using annual growth ring time series and association to climate over the last century. Wood cores of A. angustifolia trees growing in forest and grassland habitats were obtained with an increment borer. The cores were surfaced, measured and cross-dated. The dated ring-width time series were standardized and submitted to correlation and principal component analysis to verify growth trends among sites and trees. Growth-climate relationships were investigated using correlation and regression analyses, comparing the ordination axes scores to regional time series of precipitation and temperature. Due to anatomical irregularities, mainly partial rings, only 35 out of 60 trees were cross-dated. The correlation and ordination analyses showed common tree-growth trends within and between sites, indicative of a regional environmental force determining inter-annual cambial activity variation. Despite growing in distinct habitats and disturbance regimes, A. angustifolia trees share a common long-term growth pattern, which is significantly related to thermal conditions during the current and previous growing seasons. Moreover, site-specific characteristics may have influenced opposite growth responses and association to climate conditions between forest and grassland trees. [source]


Fungal endophyte infection changes growth attributes in Lolium multiflorum Lam

AUSTRAL ECOLOGY, Issue 1 2005
Martin M. Vila-Aiub
Abstract Lolium multiflorum is a successful invader of postagricultural succession in the Inland Pampa grasslands in Argentina, becoming a dominant species in the plant community. Individual plants of this annual species are naturally highly infected with fungal endophytes (Neotyphodium sp.) from early successional stages. We assessed the effect of Neotyphodium infection on the biology of L. multiflorum. We evaluated growth attributes between endophyte infected (E+) and uninfected (E,) plants under non-competitive conditions during the normal growing season. E+ plants produced significantly more vegetative tillers and allocated more biomass to roots and seeds. Although seed germination rates were greater in endophyte free plants, the rate of emergence and the final proportion of emerged seedlings were similar between the biotypes. The greater production of vegetative tillers, and the greater resource allocation to roots and seeds are likely to confer an ecological advantage to E+ plants, thus enabling their dominance over the E, individuals in natural grasslands. [source]


Fungal endophyte infection changes growth attributes in Lolium multiflorum Lam

AUSTRAL ECOLOGY, Issue 1 2005
MARTIN M. VILA-AIUB
Abstract Lolium multiflorum is a successful invader of postagricultural succession in the Inland Panipa grasslands in Argentina, becoming a dominant species in the plant community. Individual plants of this annual species are naturally highly infected with fungal endophytes (Neotyphodium sp.) from early successional stages. We assessed the effect of Neotyphodium infection on the biology of L. multiflorum. We evaluated growth attributes between endophyte infected (E+) and uninfected (E-) plants under non-competitive conditions during the normal growing season. En+plants produced significantly more vegetative tillers and allocated more biomass to roots and seeds. Although seed germination rates were greater in endophyte free plants, the rate of emergence and the final proportion of emerged seedlings were similar between the biotypes. The greater production of vegetative tillers, and the greater resource allocation to roots and seeds are likely to confer an ecological advantage to E+ plants, thus enabling their dominance over the E- individuals in natural grasslands. [source]