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This study examined a non-soil seed bank deposited inside the tussock cores of Carex cespitosa, a perennial plant with a tussock growth form. Based on the vertical structure of the seed bank in 20 tussock cores, the history of changes in plant species composition during succession in an unmowed grassland in the Bialowieza National Park was reconstructed. Three horizontal layers were distinguished in each tussock core: upper (corresponding to the initial forest stage), middle (transitory stage—forb and swamp communities) and bottom (early successional stage—grassland). The results showed that seeds of both the parental species and other species were stored inside the C. cespitosa tussock cores. More than 50,000 seedlings were found, representing 42 vascular plant species. The highest number of seedlings was recorded in the middle layer. Seedlings of swamp species were dominant in the upper layer, whereas seedlings of grassland species were dominant in the other layers. The highest number of C. cespitosa seedlings was observed in the upper layer. The most common seedlings in the middle layer belonged to the species Epilobium palustre, Lythrum salicaria and Cirsium palustre. In the bottom layer, the most common species of seedlings were grassland species, e.g. Lychnis flos-cuculi and Ranunculus repens. The protected seed bank inside this tussock species reflected recorded changes in species composition of these grasslands through time. Seed banks in this and other tussock-forming species represent a potentially useful tool for reconstructing recent developmental history of plant communities.

The objective of the study was to describe the life-history pattern of the biennial species Cirsium palustre. It has been demonstrated that under optimum conditions in the greenhouse individuals live 1.5 to 2 years, in a mown meadow 2 to 3 years, and during the plant succession in abandoned meadows they prolong their life to several years. This is accompanied by a gradual decrease of C. palustre population size. A relationship between the life-history pattern differences during a plant succession and the population abundance dynamics has been found. Reproductive-phase age is correlated with the rosette size. In spite of the occurrence of many limiting factors during a succession (closed plant cover, shading by macroforbs, willows) C. palustre survives until the formation of forest communities. Its persistence is favoured by: protracted life history, attainment the reproductive phase at different ages (not only in the second year), formation of a permanent seed bank, air-borne seeds and the emergence and survival of seedlings under the canopy of several-year old rosettes during a strong competition. The arresting of juvenile individuals under the rosettes for several years has been termed the "rosette mechanism". Cirsium palustre can be included among facultative biennials. In every conditions a proportion of individuals in a population attain the flowering phase in life year 2. During a succession the proportions of "triennial" and "quadriennial" forms, and at the terminal stage - of perennial monocarpic forms increase.

The addition of a novel host plant to a phytophagous insect's diet may result in subsequent host-plant specialisation, and is believed to be a key cause for speciation in this trophic group. In northern Britain, the tephritid fly Tephritis conura has experienced a unique host-plant expansion, from the melancholy thistle Cirsium heterophyllum to the marsh thistle C. palustre. Here, we examine whether the incorporation of C. palustre in the repertoire of British T. conura flies has caused genetic divergence between populations infesting the old host and the novel host, and how British populations differ from populations infesting C. heterophyllum in continental Europe where C. palustre is not infested. No evidence for restricted gene flow among British C. palustre and C. heterophyllum flies was found. Significant differentiation between British and continental T. conura was found at only one allozyme locus, hexokinase, and caused by a new allele, Hex_95. Hexokinase is related to host-race formation in continental European flies infesting C. heterophyllum and C. oleraceum, and might be linked to loci determining host choice. Based on morphological and phenological data from previous studies, we suggest that T. conura in Britain has adapted to the novel host but that host-race formation is impeded by similar plant phenologies.

In the hexane extract of C. palustre and C. rivulare fruits, fatty acids, sterols, triterpenes, and volatile compounds were analyzed by the GC-MS-FID method. In the methanolic extracts, total phenol content was estimated. The antioxidant activity of both extracts was measured with DPPH assay and expressed in % scavenged DPPH.

Crude aqueous extracts from leaves of Cirsium arvense, C. oleraceum, C. palustre, C. rivulare and C. vulgare were investigated. The content of tannins in mentioned sources, determined by the weight method with hide powder, varied between 1 and 7.63%. Total phenolic content, analysed by using Folin-Ciocalteau's method, ranged between 54 and 96 mg g(-1), was expressed as milligrams of gallic acid per gram of dry extract. Phenolic acids were identified by HPLC method. Antimicrobial activity of those extracts was examined. Cirsium palustre extract was the most active against investigated microorganisms. It was observed that the content of small-molecular phenolic compounds had greater influence on the activity of extracts than tannins. The total antioxidant activity indicated by radical cation 2,2'-azini-di-(3-ethylbenzthiazoline sulphonate) ABTS(*+), expressed as total antioxidant status (TAS) ranged from 2.31 to 2.78 mM L(-1).

The composition of the essential oils of Cirsium palustre and C. rivulare and their antiproliferative activity against breast adenocarcinoma cells (MCF-7 and MDA-MBA-231) were investigated. The essential oils obtained by hydro-distillation from the roots (yield 0.2 and 0.1% v/w, respectively), leaves and inflorescences (yield below 0.01%), were analyzed by gas chromatography coupled with mass spectrometry (GC-MS). The composition of the essential oils in the respective organs of each plant differed considerably. On the other hand, similarities were observed in the composition of root and leaf oils. In C. palustre and C. rivulare root oil, 50 and 39 constituents were identified, accounting for 95.3% and 92.4% of the total content. The main components were aplotaxene and its derivatives, representing 78.6% and 46.6% of the total content. In leaf oils of both species, 59 and 49 compounds, respectively, were identified, representing 67.4% and 78.3% of the total content. The major constituents were β-damascenone (4.1% and 13.4%, respectively) and β-ionone (6.7% and 5.3%, respectively). Short-chain saturated and unsaturated aliphatic alcohols and aldehydes constituted another important group of compounds (17.7% and 9.0%, respectively). The essential oils of the roots have moderate anti-proliferative activity, with IC50 values ranging from 110 to 140 μg/mL. These concentrations were below the level able to inhibit the proliferation of healthy cells.

SUMMARY Growth and CO2-exchange were measured on two species in the field layer of ash coppice. Two independent methods for the measurements of photosynthesis were used: the 14CO2-method and the URAS-method. Before coppicing the woodland plant Geum urbanum showed its adaptation to the deciduous woodland environment: a high rate of growth and photosynthesis in the spring light phase, and an adaptation to the shade conditions in summer. The first year after coppicing, Geum showed stunted growth and partly disappeared. Cirsium palustre, on the other hand, germinated after coppicing and demonstrated a high assimilation rate and rapid vegetative growth, which led to abundant blooming in the second year of the coppice cycle.

It is demonstrated that after the feelling of ash coppice Cirsium palustre becomes established from seed that was produced during the previous coppice cycle and has lain underground for several years. These seeds are light-requiring and it is probable that their germination is triggered by exposure to light during coppicing in winter. It is assumed that the seeds become light-requiring because phytochrome in the far-red absorbing form high. This facilitates their incorporation in the seed bank in summer. However, the disappearance of Pfr is inhibited at low temperatures; this means that the seeds can store the light stimulus in winter and will not germinate until they experience higher temperatures in spring. The significance of the inhibition of seed germination under a leaf canopy is that it enhances the seeds chance of being incorporated in the soil seed bank.

SUMMARY The adaptability of Cirsium palustre, a shade avoiding species, and Geum urbanum, a species avoiding exposed conditions in the ash coppice cycle, to a change from a high to a low light intensity was studied, in order to simulate the changes taking place in the light climate in a deciduous woodland in spring. Both the vegetative rosette phase and the generative phase were considered. In the rosette phase a rapid adaptation to the low light intensity took place in both species in a similar way. In the generative phase Geum adapted much better after the plants had been transferred from a high to a low light intensity. The dry weight increase of Cirsium ceased after the transfer, whereas Geum continued to grow. The leaf area ratio was much higher after the transfer, giving better assimilation in limiting light conditions. Cirsium when continuously grown in a low light intensity also had a high leaf area ratio, but the stems were too weak to support themselves, in contrast with Geum. So in the vegetative phase both species can be considered shade tolerant, but Cirsium palustre is not shade tolerant in the generative phase.

SUMMARY The influence of different light intensities on the vegetative growth and CO2-exchange characteristics of Cirsium palustre and Geum urbanum were studied in order to give a possible explanation for the different behaviour of the two species in the ash coppice cycle. The shade avoiding species C. palustre showed shade tolerant characteristics, whereas the species which avoids exposed conditions, G. urbanum, grew well in full daylight. Although there were some minor differences between the two species, the influence of light intensity on vegetative growth gives no sufficient explanation for the observed phenomena in the coppice cycle.

(1) Cirsium palustre, Galeobdolon luteum and Sanicula europaea were used in factorial experiments to investigate the effects of two features of vegetational shade: shade density, measured as the percentage transmission of photosynthetically active radiation (PAR), and shade type, measured as the ratio of red to far-red radiation (R/FR ratio). Neutral shade has an unaltered R/FR ratio, filtered shade a low R/FR ratio as under a deciduous tree canopy in summer. (2) The growth of all species was reduced in shade but not proportionately to shade density, partly because of compensatory increases in specific leaf area. Shade type had little or no effect. Plants died under 1 % PAR: Cirsium quickly, Galeobdolon more slowly and Sanicula most slowly of all, but in all cases more rapidly in filtered than in neutral shade. All grew well at 20% PAR and above. (3) Cirsium leaves and Sanicula petioles were longer the less dense the shade and tended to be longer in filtered shade. The lengths of Galeobdolon internodes and petioles were greater in denser shade and in filtered shade. (4) The flowering of Galeobdolon was reduced in filtered shade as well as in dense shade and independently of plant size. The flowering of Sanicula was not affected by shade type but was related to shade density and plant size. (5) Herbaceous woodland plants respond to filtered shade although increased height growth to overtop the shading plants would not be appropriate. Leaf display responses and increases in leaf and petiole lengths help to optimize PAR interception among the ground vegetation.