Calamagrostis Epigejos Research Articles

Biological method for the detoxification of spent monoethanolamine solutions

Monoethanolamine (MEA) solutions are widely used in for gas cleaning from carbon dioxidefor many industrial purposes. Spent MEA solutions should be properly decontaminated andsafely disposed. As these processes proceed at high temperature, the MEA solutions produceand accumulate tars and other degradation products as well as heavy metals from thecorroding equipment.This report presents a biological method for the detoxification of spent MEA solutions. Asolution is mixed with soil in order to inoculate aerobic microorganisms decomposing organicsubstances; and the obtained substrate is spread on a flat and properly hydro-isolated ground.To strengthen the vitality and increase activity of the microorganisms, the substrate is aerated,humidified, fertilized and its pH is monitored and controlled. When the MEA concentration isreduced, vascular plants (Calamagrostis epigejos, Secale cereale, Salix viminalis) areimplanted in the substrate, and their growth concludes the detoxification.

Soil water status influences plant nitrogen use: a case study

We studied differences in nitrogen use efficiency (NUE) among six species [Calamagrostis epigejos (L.) Roth., Carex duriuscula C.A. Mey., Phragmites communis (L.) Trin., Salix gordejevii Y.L. Chang, Salix cheilophila Schneid., and Typha minima Funk.] growing in two contrasting habitat types, i.e., a riverine wetland with high water supply and a riparian zone with low water supply. The two sites were different in soil water supply, but not in nitrogen supply. Here, NUE was defined as the total net primary production per unit nitrogen absorbed. There was no significant difference in NUE between the species growing in the riverine wetland (Carex duriuscula, P. communis, S. cheilophila, T. minima) and the species growing in the river bank (Carex duriuscula, Calamagrostis epigejos, P. communis, S. gordejevii). We further analyzed NUE as the product of the nitrogen productivity (A, the rate of dry matter production per unit of nitrogen in the plant) and the mean residence time of nitrogen (MRT, the period of time a unit of nitrogen is present in the plant). The species growing in the riverine wetland had larger A but lower MRT than the species growing in the river bank. There was an inverse relationship between A and MRT. Consequently, NUE was similar among species and habitats. These results suggested that environmental factors, such as soil water supply, can influence N use by plants.

Dynamics of ground vegetation after surface fires in hemiboreal Pinus sylvestris forests

The aim of this work was to investigate the changes of ground vegetation (field layer: mosses, lichens; ground layer: herbs, shrubs, tree seedlings and saplings) and regeneration of tree species in pine forests after surface fires. The study area was located in Southern part of Lithuania in hemiboreal zone of Europe. The field and ground vegetation was recorded in forest stands burned in 1992 and 1994–2002 and compared with the nearby control fire untouched areas. We selected five burned areas for each year (total 50 burned stands). Vegetation sampling was conducted during July and August 2003. For vegetation description in each stand we systematically placed twenty 1 m × 1 m plots. Mann–Whitney nonparametric test was used to identify significant differences in vegetation between burned and untouched areas. It was determined that species richness increased after fire. Early successional species such as Agrostis capillaris L., Calamagrostis epigejos (L.) Roth, Chamerion angustifolium (L.) Holub, Festuca ovina L. and Melampyrum pratense L. invaded in burned areas immediately after fire. Abundance of dominant species ( Vaccinium myrtillus L. and Vaccinium vitis-idaea L.) recovered after 5 years. Pioneer moss species ( Polytrichum piliferum Hedw. and Polytrichum juniperinum Hedw.) replaced late successional mosses ( Dicranum polysetum Sw., Dicranum scoparium Hedw., Hylocomium splendens (Hedw.) Schimp. and Pleurozium schreberi (Brit.) Mitt.). Species number in the shrub layer decreased. Juniperus communis L. was killed by fire. Amount of undergrowth decreased first 4 years after fire. Saplings of Picea abies (L.) Karst., disappeared at all. Fire stimulated regeneration of Pinus sylvestris L., especially first 4 years after fire. Herbaceous and dwarf shrubs recovered 5–6 years after fire, moss cover—9 years after fire. Differences in moss species composition still remained 11 years after fire. Main finding suggest that fire is favourable to biodiversity of pine forest ecosystems. Fires induce regeneration of pine trees and can be used for restoration of pine forest.

RELATIONSHIP BETWEEN PLANT COMMUNITY AND SOIL ON THE INTER_DUNE LOWLAND IN THE MIDDLE OF OTINGDAG SAND LAND

Aims Vegetation and soil surveys were conducted in the summer of 2004 to study the relationship between vegetation types and soil of inter-dune lowland of Otindag sand land. Of 102 vegetation samples collected, 99 were herb-dominated, the others shrub-dominated. We analyzed soils for total nitrogen, soil organic matter, soluble sodium, soluble potassium and pH. Vegetation samples were classified based on species composition and species functional groups. We used detrended canonical correspondence analysis (DCCA) to determine the main environmental factors related to the distribution of plant communities. Methods The 102 samples were classified into twenty-eight groups dominated by Artemisia annua, A. intramongolica, Bromus ircutensis, Chenopodium acuminatum, A. sieversiana, Oxytropis gracilima, Setaria viridis, A. scoparia, A. frigida, Carex duriuscula, Cleistogenes squarrosa, Agropyron cristatum, Stipa krylovii, Leymus chinensis, L. secalinus, Bromus inermis, Saussurea amara, Potentilla tanacetifolia, Achnatherum splendens, Iris lactea, Salix microstachya, Phragmites australis, Calamagrostis epigejos, Potentilla anserine, Halerpestes ruthenica, Puccinellia tenuiflora, Scirpus tabernaemontani and Suaeda glauca. Importunt findings The Artemisia annua, A. intramongolica, Bromus ircutensis, Chenopodium acuminatum, A. sieversiana, Oxytropis gracilima, Setaria viridis and A. scoparia associations are mostly distributed on sites often covered by quicksand. The level of the groundwater is low, the lixivium of the soil is neutral and the average soluble K+, Na+, total nitrogen and organic matter are low. Artemisia frigida, Cleistogenes squarrosa, Agropyron cristatum, Stipa krylovii, Potentilla tanacetifolia, Leymus secalinus, Carex duriuscula and L. chinensis associations are rooted mostly in stable sand, where soil water, organic matter and total nitrogen are high. Bromus inermis, Saussurea amara, Puccinellia tenuiflora, Phragmites australis and Potentilla anserine associations grow in wet sites, where organic matter and total nitrogen are relatively high. Achnatherum splendens, Iris lacteal, Calamagrostis epigejos, Salix microstachya and Halerpestes ruthenica associations are on saline sites that have high groundwater and alkalinity. The Suaeda glauca association occurs in a highly saline lake, where water and salinity levels are very high. The Scirpus tabernaemontani association occurs in a marsh. The first DCCA axis denoted gradients in ground water level (GWL) and factors related to ground water level such as pH, soluble sodium and soluble potassium. The second axis reflected gradients of total nitrogen and soil organic matter. The third axis reflected a pH gradient. Ground water level, pH, soluble sodium, soluble potassium, total nitrogen and soil organic matter significantly correlated with the distribution of plant communities.

Skład gatunkowy populacji drobnych ssaków na ekstensywnie wykorzystywanych łąkach Basenu Czarnocińskiego nad Zalewem Szczecińskim

Czarnocin and the surroundings meadows are located in the Skoszewskie Meadows district. These permanent grasslands, very abundant in the past, are now dominated by the sedges, reeds and phytocenosis with Reed Canary-grass, Wood Small-reed and Common Couch. These areas are still very valuable, and were included into the Nature 2000. The main aim of the protection is to increase biodiversity of flora and fauna in these areas. Till now the research has included mostly flora and avifauna. There are no records about other vertebrates’ species. In the present paper the authors tried to estimate the composition of the small mammals’ species living on this tract. The bone material, skeletonized from the pellets of the Barn Owl (Tyto alba) was used. Research results show 12 species of small mammals, including 5 protected species. A big percentage of Soricidae and Arvicolidae families are connected with environmental conditions (mostly high soil moisture) and extensive forms of grasslands management.

The influence of different vegetation patches on the spatial distribution of nests and the epigeic activity of ants ( Lasius niger) on a spoil dump after brown coal mining (Czech Republic)

A study was carried out during 2001 on mine tailings in NW Bohemia aimed at describing the spatial patterns of nests distribution and epigeic activity of ants in relation to the vegetation mosaic. Lasius niger was the most abundant species of ant and its nest mounds were significantly more numerous in patches with sparse vegetation than inside dense Calamagrostis epigejos vegetation; this was particularly true for small and medium-sized nests. Small and medium nests also occurred more frequently near the edges of a given patch than in the center. Large and medium nests were randomly distributed in the area, whereas small nests had an aggregated distribution. Pitfall trapping reveal significantly higher activity of L. niger workers in tall and dense vegetation stands in comparison with low and sparse vegetation. This pattern was particularly pronounced during the peak of foraging activity in summer and was not so significant in spring or autumn. We expect that ant preferentially forage in shaded habitats during the summer months when bare soil may be too hot. The results indicated that nesting and foraging may differ in their microclimatic requirements and the formation of vegetation mosaics may be important to changes in the ant population during succession.

Phenolic Acids as Bioindicators of Fly Ash Deposit Revegetation

The floristic composition, the abundance, and the cover of pioneer plant species of spontaneously formed plant communities and the content of total phenolics and phenolic acids, as humus constituents, of an ash deposit after 7 years of recultivation were studied. The restoration of both the soil and the vegetation on the ash deposits of the "Nikola Tesla-A" thermoelectric power plant in Obrenovac (Serbia) is an extremely slow process. Unfavorable physical and chemical characteristics, the toxicity of fly ash, and extreme microclimatic conditions prevented the development of compact plant cover. The abundance and cover of plants increased from the central part of the deposit towards its edges (ranging from 1-80%). Festuca rubra L., Crepis setosa Hall., Erigeron canadensis L., Cirsium arvense (L.) Scop., Calamagrostis epigeios (L.) Roth., and Tamarix gallica L. were the most abundant species, thus giving the highest cover. Humus generated during the decomposition process of plant remains represents a completely new product absent in the ash as the starting material. The amount of total phenolics and phenolic acids (38.07-185.16 microg/g of total phenolics and 4.12-27.28 microg/g of phenolic acids) in fly ash increased from the center of the deposit towards its edges in correlation with the increase in plant abundance and cover. Ash samples contained high amounts of ferulic, vanillic, and p-coumaric acid, while the content of both p-hydroxybenzoic and syringic acid was relatively low. The presence of phenolic acids indicates the ongoing process of humus formation in the ash, in which the most abundant pioneer plants of spontaneously formed plant communities play the main role. Phenolic compounds can serve as reliable bioindicators in an assessment of the success of the recultivation process of thermoelectric power plants' ash deposits.

Pathogenicity and host range of Heterodera arenaria in coastal foredunes

AbstractIn coastal foredunes, the cyst nematode Heterodera arenaria has been supposed to play a role in degeneration of the pioneer grass Ammophila arenaria (marram grass). However, recent field surveys and field inoculation experiments suggested that the abundance of this cyst nematode is controlled by the host plant. Here, we test pathogenicity of H. arenaria by inoculating a range of densities of second-stage juveniles (J2) onto A. arenaria in sterilised soil. Plant root biomass was reduced after 6 weeks of growth, but not after 13 weeks, when cyst formation was completed. Shoot biomass was not influenced. In the field, H. arenaria occurred in sand and on roots of Elymus farctus and A. arenaria in mobile dunes, but not on A. arenaria in stable dunes. Although we observed Heterodera cysts and juveniles in later succession stages, this cyst nematode appeared to be H. hordecalis. In a host suitability test, H. arenaria produced cysts on E. farctus and A. arenaria, while there were almost no cysts produced when J2 had been added to the later succession species Festuca rubra ssp. arenaria, Carex arenaria, Elymus athericus and Calamagrostis epigejos. Heterodera arenaria did not negatively affect its natural host plants. However, H. arenaria reduced root growth of one later succession plant species, E. athericus, which was a poor host for H. arenaria. The effects of H. arenaria inoculation on plant biomass production did not differ when J2 were added to plants growing in non-sterilised soil. We conclude that H. arenaria is specialised on the pioneer grasses E. farctus and A. arenaria, and also on mobile dunes as a habitat. Our results confirm recent suggestions that H. arenaria may cause little direct growth reduction to its natural host plants.

Effects of nitrogen enrichment on coastal dune grassland: A mesocosm study

Mesocosms filled with dune sand were planted with graminoid ( Calamagrostis epigejos, Carex arenaria) and herbaceous species ( Carlina vulgaris, Galium verum). Strong effects of nitrogen addition on the vegetation were found within two to three years. The above-ground biomass of C. epigejos and C. arenaria increased at deposition rates between 10 and 80 kg N ha −1 yr −1. Both grasses were limited by N. In latter stages P limitation was suggested for C. arenaria. At high N-levels, C. epigejos dominated the vegetation within two years. C. vulgaris and G. verum declined drastically as a result of increased competition for light by the highly competitive grass C. epigejos. It is concluded that increased (ambient) N inputs are of major importance for the increased dominance of tall grasses in stable dune grasslands.

Enhanced nitrogen loss may explain alternative stable states in dune slack succession

Ecological theory emphasizes competitive interactions between plant species when explaining primary succession in plants. Ecosystem processes, such as nutrient accumulation, are often regarded as independent, steering successional changes without being affected by the interacting plant species. We present experimental evidence that plant species in wet dune slack systems are able to affect ecosystem processes in their favor by reducing the rate of nitrogen accumulation by coupled nitrification–denitrification, promoting their competitive position. We compared denitrification rates of two early successional species having radial oxygen loss (ROL) with two non‐ROL late successional species in a mesocosm experiment. The denitrification rates were significantly higher in mesocosms planted with early successional species Littorella uniflora (P<0.001) and Schoenus nigricans (P<0.05), relative to the rates found in the presence of non‐ROL species, Carex nigra and Calamagrostis epigejos. We analyzed the consequences of enhanced nitrogen loss on the competition between an early and a late successional species by means of a simple theoretical model. Our analysis revealed that early successional species capable of ROL might retard successional changes and lock the ecosystem in an unproductive state for an extended period of time. We emphasize that understanding of ecosystem processes is crucial in successful conservation of high biodiversity vegetation in wet dune slacks.

The Use of Internal Nitrogen Stores in the Rhizomatous Grass Calamagrostis epigejos During Regrowth After Defoliation

The regrowth dynamics after defoliation of the invasive grass Calamagrostis epigejos were studied. As nitrogen (N) reserves have been shown to play an important role during plant regrowth, the identity, location and relative importance for regrowth of N stores were determined in this rhizomatous grass. Plant growth, nitrate uptake and root respiration were followed during recovery from defoliation. Water soluble carbohydrates, nitrate, free amino acids and soluble proteins were analysed in the remaining organs. Nitrate uptake and root respiration were severely reduced during the first days of regrowth. Roots were the main net source of mobilized N. The quantitatively dominant N storage compounds were free amino acids. Free amino acids and soluble proteins in the roots decreased by 55 and 50%, respectively, and a substantial (approximately 38%) decrease in stubble protein was also observed. Although the relative abundance of several soluble proteins in roots decreased during the initial recovery from defoliation, no evidence was found for vegetative storage protein (VSP). Furthermore, rhizomes did not act as a N storage compartment. Production of new leaf area was entirely reliant, during the first week after defoliation, on N stores present in the plant. Mobilized N originated mainly from free amino acids and soluble proteins located in roots, and less so from proteins in stubble. Presence of VSP in the roots was not confirmed. The data suggest that rhizomes played an important role in N transport but not in N storage.

Plant functional types and their ecological responses to salinization in saline grasslands, Northeastern China

Photosynthetic pathways (C3, C4, and CAM) and morphological functional types (e.g. shrubs, high perennial grasses, short perennial graminaceous plants, annual grasses, annual forbs, perennial forbs, halophytes, and hydrophytes) were identified for the species from salinity grasslands in Northeastern China, using the data from both stable carbon isotope ratios (δ13C) and from the references published between 1993 and 2002. 150 species, in 99 genera and 37 families, were found with C3 photosynthesis, and most of these species are dominants [e.g. Leymus chinensis (Trin.) Tzvel., Calamagrostis epigeios (L.), Suaeda corniculata (C.A. Mey.) Bunge]. 40 species in 25 genera and 8 families were identified with C4 photosynthesis [e.g. Chloris virgata Sw., Aeluropus littoralis (Gouan) Parlat] and 1 species with CAM photosynthesis. Gramineae is the leading family with C4 photosynthesis (27 species), Chenopodiaceae ranks the second (5 species). The significant increase of C4 proportions with intense salinity suggested this type plant is remarkable response to the grassland salinization in the region. 191 species were classified into eight morphological functional types and the changes of most of these types (e.g. PEF, HAL, and HPG) were consistent with habitats and vegetation dynamics in the saline grassland. My findings suggest that the photosynthetic pathways, combined with morphological functional types, are efficient means for studying the linkage between species and ecosystems in this type of saline grassland in Northeastern China.

Distribution and habitat use by red and roe deer following a large forest fire in South-western Poland

Although well documented in North America, the relations between deer and large burnt areas have not been studied in Europe. In the early spring of 1997–2000, deer pellet groups were counted following a large (ca. 5000 ha) forest fire in 1992, along 2 m wide transects in the burnt area (total length of transects 23 km) and in unburnt forest (32 km). Throughout the study, the density of roe deer ( Capreolus capreolus) pellets in the burnt area was only around half that in the unburnt forest. A similar trend was noted for red deer ( Cervus elaphus), but only in the first year of the study. The limited use made of the burnt area by roe deer most probably reflected unfavourable food conditions (a prevalence of wood small-reed Calamagrostis epigeios among herbaceous species, and pine ( Pinus silvestris) as well as birch ( Betula pendula) among woody species. For red deer, cover also was important, such that when pine trees were short (most of them below 1.5 m), red deer made less overall use of the burnt area than of the unburnt forest. When trees were taller, red deer use of both areas became similar. The distributions of pellet groups for two deer species across the burnt area were unrelated to distance from the unburnt forest. In the first two years of the study, red deer preferred patches dominated by birch to those with pine. However, later when pines became tall enough to offer adequate cover this difference in use disappeared. In contrast, roe deer used both kinds of patches to a similar degree throughout the study. The use of pine patches by red deer was dependent on tree height, but habitat use by roe deer was not. It was concluded that deer made little use of burnt areas dominated by Calamagrostis sp. and with no forest regeneration of preferred browse species. In the presence of the fast-growing tree species like birch that rapidly provide deer with cover after a fire, tree protection against damage by deer should not be limited to the zone near unburnt forest. Results of the study also suggest that cover may be more important as a determinant of habitat use in large than in smaller deer species.

Elevated UV‐B radiation has no effect on litter quality and decomposition of two dune grassland species: evidence from a long‐term field experiment

AbstractFrom studies on living plant tissues it has been inferred that elevated UV‐B radiation could negatively affect litter quality and subsequent decomposition. However, in general, the effects of UV‐B radiation on litter chemistry and decomposition reported in the literature are variable and are often only marginally (if at all) significant. This might be due to the ecologically unrealistic conditions under which these experiments were performed.We investigated the effects of elevated UV‐B radiation on litter quality and subsequent decomposition on initial litter chemistry and long‐term (2 years) decomposition of freshly senesced Carex arenaria and Calamagrostis epigejos leaf litter under ecologically realistic conditions. This material was collected from a dune grassland that had received UV‐B radiation treatments for three growing seasons. It was then used in a 2‐year decomposition study using litter bags.We found no significant effects of elevated UV‐B radiation on any of the litter chemistry parameters in either of the two species, nor did we find significant effects on litter decomposition. However, we did find significant differences in litter decomposition between the species. These differences were related to the interspecific differences in litter chemistry, particularly the litter phenolics concentration. These results show that litter quality and decomposition in dune grasslands are, also under ecologically realistic conditions, not affected by UV‐B radiation. Instead, litter decomposition is determined by constitutive interspecific differences in litter chemistry.In conclusion, with our results added to the already existing literature, the preponderance of evidence now clearly suggests that elevated UV‐B radiation has very little, if any, impact on litter quality and subsequent decomposition in real ecosystems.

Seasonal Changes of Nitrogen Storage Compounds in a Rhizomatous Grass Calamagrostis epigeios

The seasonal dynamics in content and distribution of N-rich compounds between overwintering organs of Calamagrostis epigeios were examined. Samples were taken both from plants grown in natural conditions and in containers with controlled nutrient supply. There were significant changes in content of nitrate, free amino acids and soluble protein in all investigated plant parts during the course of a year. Amino acids showed both the highest maximum and seasonal fluctuation among the all N compounds observed and, therefore, appear to have a central role in N storage. Their content rises in the autumn, remains stable during winter and declines quickly at the beginning of spring. The most abundant amino acids in the end of winter storage period - asparagine, arginine and glutamine - constituted about 90 % of N in fraction of free amino acids. The portion of N stored in soluble proteins, however, was considerably smaller compare to both amino acids and nitrate. The amount of N stored in rhizomes of C. epigeios was smaller than in roots and stubble base before the onset of spring re-growth. This indicates that roots and stubble base are particularly important for winter N storage in this species.

Développement végétal dans le lit endigué de l’Isère en amont de Grenoble : du diagnostic à l’évaluation des pratiques de gestion

In a channelized 50 km reach of the Isère river, studies of changes in bedforms and vegetation were undertaken from a series of vertical aerial photographs between 1948 and 1996 and from field measurements of geomorphological and ecological parameters. Results showed a radical change of channel landscape and geomorphological activity during the last decades. Two different periods have been identified. During the first period (pre-1 970), geomorphological activity of Isère channel was intense, bedforms were continually removed, and pioneer vegetation uprooted during frequent floods. During the second period (post-1970), geomorphological activity slowed down, leading to the stabilisation of bedforms (lateral gravel bars) and development of vegetation. Vegetation rate which was less than 5% in 1970 is presently by 20% and new successional mature stages with hardwood species (Fraxinus excelsior, Robinia pseudacacia, Ulmus minor) have progressively replaced pioneer communities and softwood woodlands. Several causes explain this change. The main cause was the drastic decrease in the gravel bedload supply (from 150,000 m3 before 1950 to 40,000 m3 in 1960 and 5,000 m3 in 2000) which resulted in lateral bars pavement processes and narrowing of the active bedload band. Secondary causes such as gravel extraction (responsible for 1-3 meters deep channel incision) and absence of large floods over the last decades have added their effects, favouring establishment of mature plant communities. The vegetation inside the dykes infers new risks for riverside residents : increase of roughness and elevation of flood water levels by promoting denser growth of woody floodplain species within the dykes, and logjams formation in the downstream reach in Grenoble in case of a very large flood. In an effort to reduce the risk of these vegetated bars, river managers propose two types of maintenance. The first one consists in a simple clear cutting of the vegetation. Fine sediments which recover the gravel bars (the thickness is 1 to 3 meters) are left in place as well as tree stumps and roots. In the second type, clear-cutting is followed by additional disturbances such as burning of branches, scraping of the ground, and scouring of fine sediment deposits. First records of species richness and distribution of community diversity and geomorphological changes permitted comparisons between the both techniques. The first one (clear cutting) encouraged bed-forms stabilisation, rapid and denser coppice regrowth, increase of channel roughness, increase of fine sediment deposits during floods, decrease in plant diversity and invasion by exotic species such as Faloppia japonica. As a consequence, this type of operation needs to be systematically repeated with a 3-year rotation. The second technique (clear cutting and scouring of fine sediment deposits) is particularly effective because it favoured the restoration of geomorphological processes (erosion-deposit). Gravel bars are regularly eroded during frequent floods and migrate downstream. The reactivation of geomorphological processes led to the restoration of favourable conditions for regeneration of vegetation in the active channel. Biodiversity is enriched with presence of pioneer species, typical of the alpine rivers with high geomorphological activity (Typha minima, Calamagrostis epigejos, Salix, Populus, Alnus).

The role of UV-B radiation in aquatic and terrestrial ecosystems—an experimental and functional analysis of the evolution of UV-absorbing compounds

The role of UV-B radiation in aquatic and terrestrial ecosystems—an experimental and functional analysis of the evolution of UV-absorbing compounds

Concentrations of heavy metals and plant nutrients in water, sediments and aquatic macrophytes of anthropogenic lakes (former open cut brown coal mines) differing in stage of acidification

Concentration of heavy metals (Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V and Zn) as well as macronutrients (N, P, K, Ca, Mg, S) were measured in water, bottom sediments and plants from anthropogenic lakes in West Poland. The collected plants were: Phragmites australis, Potamogeton natans, Iris pseudoacorus, Juncus effusus, Drepanocladus aduncus, Juncus bulbosus, Phalaris arundinacea, Carex remota and Calamagrostis epigeios. Two reference lakes were sampled for Nymphaea alba, Phragmites australis, Schoenoplectus lacustris, Typha angustifolia and Polygonum hydropiper. These plants contained elevated levels of Cd, Co, Cr, Cu and Mn, and part of the plants contained in addition elevated levels of Mn, Fe, Pb, Ni and Zn. Analyses of water indicated pollution with sulfates, Cd, Co, Ni, Zn, Pb and Cu, and bottom sediments indicated that some of the examined lakes were polluted with Cd, Co and Cr. Strong positive correlations were found between concentrations of Co in water and in plants and between Zn in sediments and plants, indicating the potential of plants for pollution monitoring for this metal. Heavy metal accumulation seemed to be directly associated with the exclusion of Ca and Mg.

The effects of mowing and fertilization on carbohydrate reserves and regrowth of grasses: do they promote plant coexistence in species-rich meadows?

After the cessation of regular management and after fertilization a single clonal species tends to dominate in many types of grasslands, whereas in regularly managed meadows these potential dominants usually attain a low cover. It has been hypothesized that plants reaching a high dominance in abandoned and fertilized meadows are selectively suppressed by mowing so that a balanced competition is maintained and competitive exclusion is postponed. We compared regeneration capacity and carbohydrate reserves accumulated by three species of clonal grasses, which markedly increase their dominance in irregularly mown, un-mown or fertilized meadows. Above-ground biomass and the amount of storage carbohydrates of the two largest species, (Molinia arundinacea, Calamagrostis epigejos) were reduced in a mown meadow. This effect was weaker in Bromus erectus, which produces smaller shoots. Shoots of Molinia were most impacted by mowing but their regeneration was efficient due to the large carbohydrate reserves in the shoot bases. Fertilization did not affect Bromus and Calamagrostis. In contrast, fertilized plants of Molinia produced larger storage organs and accumulated more carbohydrates. We conclude that plant size and growth form are important features promoting the ability of potential dominants to tolerate mowing and regenerate after it. Our results confirm that taller plants are selectively suppressed by this type of disturbance, thereby potentially promoting plant coexistence.

Associations of dominant plant species with arbuscular mycorrhizal fungi during vegetation development on coal mine spoil banks

Among plants colonizing mine spoil banks in Northern Bohemia the first colonizers, mainly ruderal annuals fromChenopodiaceae andBrassicaceae were found not to be associated with arbuscular mycorrhizal fungi (AMF). These species cultivated in pots with soil from four sites in different succession stages of the spoil bank did not respond to the presence of native or non-native AMF. All grass species studied (Elytrigia repens, Calamagrostis epigejos andArrhenatherum elatius) were found moderately colonized in the field and they seemed to be facultative mycotrophs, because their response to mycorrhiza in the experiment was negligible.Carduus acanthoides was found to be highly colonized in the field, however, it did not show growth response to AMF in the pot experiment. The AMF native in four sites on the spoil banks showed high infectivity but low effectiveness in association with colonizing plants compared to the non-native isolateG. fistulosum BEG23. In general, dependence on AMF in the cultivation experiment was rather low, regardless of the fact that plants were found to be associated with AMF either in the field or in pots. Occurrence and effectiveness of mycorrhizal associations might relate primarily to the mycotrophic status of each plant species rather than to the age of the spoil bank sites studied.