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Variability of Morphological Traits of the Rare Plant Species Angelica palustris (Apiaceae) in Managed and Abandoned Meadows : Effect of Mowing

Kostrakiewicz-Gierałt K., Stachurska-Swakoń A., Towpasz K.

Polish Journal of Ecology

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2018

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Vol. 66, nr 1

36--47

EN

The effect of meadow management type on selected population traits of the rare plant Angelica palustris was examined. The study was carried out in a regularly mown meadow (Plot I), an abandoned meadow with medium high plants (Plot II) and an abandoned meadow with high plants (Plot III) situated in southern Poland (Proszowice Plateau). Observations conducted in the years 2010 and 2011 showed greater abundance of A. palustris in Plot I than in Plots II and III. This pointed to the significance of disturbance caused by mowing, which creates gaps in the plant cover and litter layer that become safe sites for A. palustris seedling recruitment and their subsequent growth. In the abandoned meadows a diminishing share of vegetative individuals and a reduction in the number of flowering stems in generative individuals were found. The height of generative stems in the abandoned meadows was higher than in the mown one as a response to the height of neighbouring plants. The number of umbels per stem and number of umbellets per umbel were positively correlated with the height of the stem. In light of our investigations, it can be stated that regular mowing has a beneficial effect on the state of populations of A. palustris. On the other hand, the formation of highly productive generative stems with substantial numbers of inflorescences and infructescences in abandoned meadows may promote successful seed dispersal and an escape from an unfavourable site.

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The Influence of Vegetation Structure on the Composition of the Seed Rain and Seedling Pool in Abandoned Molinion caeruleae Meadows

Kostrakiewicz-Gierałt K.

Polish Journal of Ecology

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2017

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Vol. 65, nr 2

269--284

EN

The investigations of the effect of different habitat conditions on the composition of the seed rain and seedling pool were conducted in the years 2014 and 2015 in abandoned patches of Molinion caeruleae dominated by small-stature meadow taxa (patch I), tall-growing grasses (patch II), as well as shrubs and trees (patch III). Observations showed that along the successional gradient the seed rain and seedling pool diminishes. The prevalence of perennials and native taxa in the seed rain and seedling pool occurred in all the study sites. Moreover, in the propagule and seedling pools of all the patches hemicryptophytes and meadow taxa prevailed but their number decreased in successional sites. Also, the abundance of ruderal and grassland taxa decreased gradually, at expense of number of forest species. Zoochorous species prevailed in the seed rain and seedling pool of all patches. Number of hydrohorous species decreased in successional patches, while the abundance of species with other dispersal modes were similar. Irrespective of patch character, the species producing propagules with medium size dominated in the seed rain and seedling pools, whereas a significant decrease of number of small-seeded species was noticed only in the seedling pool. Despite the diminishing of the seed rain and seedling pool along the successional gradient, the gap creation might be a very effective way of active protection of Molinion caeruleae meadows. However, the gap colonisation requires permanent monitoring to avoid further spreading of undesired taxa.

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The Impact of Extensive Sheep Grazing on the Population and Individual Traits of Trollius altissimus Crantz

Kostrakiewicz-Gierałt K., Kozak M., Kozłowska-Kozak K.

Polish Journal of Ecology

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2015

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Vol. 63, nr 4

523--533

EN

The montane glades in the Polish Carpathians were created centuries ago and have lasted mainly as a result of mowing and grazing. The observed abandonment of traditional methods of tillage in the last century led to adverse changes in vegetation cover, including a decrease in floristic diversity and the disappearance of many plant species and associations. One of a rare mountain taxa in Poland is the alpine globeflower Trollius altissimus Crantz. The investigations were carried out between June and September 2014 in the Hala Długa glade (Gorce Mts.) at two 36 m2 plots: extensively grazed (P1) and unmanaged (P2). Light intensity, abundance and density of individuals and ramet clusters were significantly greater in the extensively grazed plot, whereas height of plant canopy, length of basal leaf petioles, width of leaf lamina, number and length of generative stems, number of flowers and follicles achieved higher values in the unmanaged plot. The structure of developmental stages and number of basal leaves did not differ remarkably between the studied sites. Also, the soil properties in both plots were very similar. The studies show that extensive sheep grazing has a positive influence on Trollius altissimus. In the studied locality such management contributes to the gradual spreading of this species. However, too intensive pasturage might eliminate this species as it has never been observed in any of the permanently grazed patches in the vicinity.

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The variability of selected features of Gladiolus imbricatus L. in relation to successive stages of meadow communities following the mowing cessation

Kostrakiewicz-Gierałt K.

Polish Journal of Ecology

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2014

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Vol. 62, nr 2

307--321

EN

Molinietum caeruleae meadows belong to the most endangered plant communities in Central Europe, nowadays suffering due to the lack of management. The land abandonment promotes strong secondary expansion of macroforbs, sedges or willows, contributing to decrease of the species diversity. In light of these findings very interesting seems to be the evaluation of the variability of features of populations of rare meadow species. In Poland one of strictly protected plant is Gladiolus imbricatus L. It is a tuberous, clonal plant with sword-like leaves and tall stalks bearing purple flowers collected in one-sided inflorescence. The studies of spatio-temporal variability of selected features of subpopoulations of Gladiolus imbricatus were carried out in the years 2009-2011 in Kraków-Kostrze (Southern Poland) in patches of Molinietum caeruleae with different species composition. In Patch I chiefly occurred small meadow species, Patch II was prevailed by shrub willow, Patch III was dominated by tallgrowing macroforbs, Patch IV was characterized by substantial share of large-tussock grasses, while Patch V was overgrown by tall rhizomatous grass Phragmites communis. The plant canopy height and ground moisture raised from Patch I, via Patches II, III and IV, to Patch V. Moreover, in all sites the above mentioned parameters increased moderately in consecutive seasons. The decline of abundance of subpopulations observed in the consecutive years and in the successive patches might be caused by a mortality of individuals, a physical damage of tubers, as well as a prolonged dormancy of genets. The structure of developmental stages were similar in consecutive years but differed significantly among Patches. The increasing trend toward senility noted in successive sites could be an effect of lack of microsites suitable for seedling recruitment or absence of vegetative regeneration. The dimensions of leaf blades, flowering stalks and inflorescences remained similar in the subsequent seasons, but they augmented significantly in the successive patches. The length and the width of capsules did not change significantly between seasons and sites. Concluding, it might be assumed, that the perspectives for survivability of subpopulations diminish gradually from Patch I, via Patches II, III and IV to Patch V. Simultaneously, it should be pointed out that prospects for persistence in each place steadily decrease in effect of continuous deterioration of site conditions.

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The influence of standing vegetation height on the reproductive allocation In populations of Serratula tinctoria L. (Asteraceae)

Kostrakiewicz-Gierałt K., Bąba W.

Polish Journal of Ecology

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2014

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Vol. 62, nr 1

89--99

EN

The advantage of the clonal plants over the nonclonal species in colonization of all biomes and biogeographical regions primarily is due to occurrence of two modes of reproduction. The creating of vegetative propagules with high vitality and survivability, enables the spread in the newly colonized site, while seed production increases the chances for successful recruitment of seedlings, ensuring the genetic diversity of the population. The differences in allocation into vegetative reproduction and generative propagation in relation to rising height of adjacent plants was investigated in populations of Serratula tinctoria L., occurring in Molinietum caeruleae meadows localized in Southern Poland. Each locality was represented by randomly established three permanent study plots: dominated by small meadow species (LOW), prevailed by large-tussock grasses (INTER) and overgrown by shrubs and trees (HIGH). In the years 2009–2011 the number of leaf rosettes and length of the longest leaf in rosette (as a measure of allocation in vegetative propagation), as well as height of generative stems, number of capitula per stem and number of seeds per capitulum (as indicators of investment in generative reproduction) were observed. The allocation in vegetative reproduction decreased along the gradient of vegetation height. The gradually decline of number of rosettes might be caused by lack of free space suitable for establishment of new ramets, whereas the small leaf size could be due to drastically augmentation of shading. The allocation in generative reproduction increased along the gradient of vegetation height. The placement of structures necessary for generative propagation in higher layers of herbaceous canopy, as well as considerable number of capitula and seed production might increase the chances for successful recruitment of seedlings. On the basis of obtained results combining with published data it should be assumed, that the substantial allocation in vegetative reproduction and the slight investment in generative propagation seems to be sufficient for persistence of Serratula tinctoria populations in patches dominated by small meadow species, while the considerable allocation in generative reproduction could be crucial for maintenance of population viability under competitive conditions.

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The effect of neighboring plant height, disturbance level and gap size on spontaneous recruitment of large-seeded and small-seeded species in Molinietum caeruleae meadows

Kostrakiewicz-Gierałt K.

Polish Journal of Ecology

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2014

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Vol. 62, nr 2

289--306

EN

The seed size is considered as a key feature, which effects both: colonizing and competitive abilities of species. The disturbance dependent small-seeded taxa are regarded as superior colonists, whereas the large-seeded taxa are considered as best competitors able to survive the competition from adjacent plants and negative effect of litter. The impact of character of standing vegetation, disturbance level and size of gaps on spontaneous recruitment of seedlings of selected light-seeded species (Gentiana pneumonanthe L., Dianthus superbus L.) and heavy-seeded taxa (Serratula tinctoria L., Gladiolus imbricatus L.) were conducted. The investigations were carried out in two areas (A and B). Both of them were consisted of three adjacent patches of Molinietum caeruleae: dominated by small meadow species (labeled MC), prevailed by large-tussocks grasses (labeled GR), and overgrown by willows (labeled SA). In the year 2007, in all patches, ten permanent experimental plots were randomly arranged. In Area A, plots were divided in four square-shaped, neighboring subplots subjected to: no treatment; the removal of litter and moss layers; the removal of litter, bryophytes, and above-ground parts of plants; the removal of litter, moss and the plants, as well as top soil stripping. In the Area B, plots were divided into four subplots measuring from 0.16 m2 to 0.01 m2. In each of them the litter and above-ground part of plant biomass were clipped and removed. The recruitment of seedlings was monitored from 2007 through 2010. In both studied areas, regardless of seed mass, the greatest abundance of seedlings were found in patches MC, and decreased gradually in sites GR and SA. Irrespective of seed size, in subplots where plant cover and litter stayed intact no new genets was noted, moderate appearance of seedlings was observed in subplots without plant necromass, whereas the greatest number of generative progeny was found in subplots without necromass and aboveground parts of plants. The lower abundance of seedlings in subplots without litter, plants and topsoil might have been caused by depletion of seed bank reserves. Moreover, in all patches the number of seedlings of small- and large-seeded taxa increased significantly with augmentation of gap size. In light of performed studies it might be concluded, that the disturbances might play very important role in active protection of studied taxa. The positive impact of disruption diminishes with increasing of plant canopy height. The removal of plant cover and litter contributes to the greatest seedling recruitment but its beneficial effect diminishes with decreasing of opening size.

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Are Deschampsia caespitosa (L.) Beauv. tussocks safe for seedling recruitment in the succession of wet meadows?

Kostrakiewicz-Gierałt K.

Polish Journal of Ecology

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2014

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Vol. 62, nr 4

707--721

EN

In stressful and harsh environments, safe sites for seedling recruitment may be created by nurse plants, which accumulate propagules and subsequently facilitate the establishment of individuals. The main goal of the presented studies focused on observations of seedling recruitment in small and large tussocks of Deschampsia caespitosa derived from patches of unmanaged Molinietum caeruleae meadows situated along the successional gradient and dominated by small meadow species (Patch I), by macroforbs (Patch II), or overgrown by trees and shrubs (Patch III). The studies showed that, irrespective of patch character, Serratula tinctoria, Selinum carvifolia, Lysimachia vulgaris and Filipendula ulmaria are among the best colonizers of Deschampsia caespitosa tussocks. The gradual decrease in number of species and offspring abundance along the successional gradient may be connected with a prolonged period of water stagnation accelerating the development of fungal pathogens, a major cause of mortality for buried diaspores. The growing frequency of species present in standing vegetation and the gradually rising contribution of swamp and forest taxa in consecutive patches may be due to the production of non-persistent diaspores by early successional species, as well as reduced seed immigration from neighboring sites. The obtained results included evidence that, regardless of patch character, the percentage of seedlings representing species present in and absent from existing vegetation as well as taxa with various vegetation types is similar in small and large tussocks. Furthermore, in small tussocks, regardless of patch character, anemochorous and hydrochorous taxa dominated, the frequency of endo- and epizoochorous taxa was much lower, while the percentage of species characterized by other modes of diaspore dispersal attained the lowest rates. In large tussocks, anemochorous and epizoochorous species prevailed, the share of endozoochorous and hydrochorous taxa was lower, and the contribution of species characterized by other modes of dissemination was very scarce. On the basis of these studies it might be concluded that, despite the successive decrease of species and seedling abundance, and along with the increase in the recruitment of taxa resident in standing vegetation, especially woody species, the tussocks of Deschampsia caespitosa are reservoirs of meadow species even in advanced successional stages and may play a significant role in the process of long-term species turnover.

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The impact of disturbance gradient on recruitment of clonal plant species in Molinietum caeruleae meadows

Kostrakiewicz-Gierałt K.

Polish Journal of Ecology

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2013

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Vol. 61, nr 3

519--531

EN

The investigations of the impact of disturbance severity on recruitment of clonal plant species were preformed in three Molinietum caeruleae patches dominated by small meadow species (MC), or prevailed by tall grasses (GR) or overgrown by willows (SA). The meadows were located in Vistula valley close to Kraków agglomeration, southern Poland. In above menntionned patches ten permanent experimental plots were randomly arranged. Each plot was divided in four subplots measured 900 cm2 represented undisturbed control, low level of disturbance (the litter and the moss layer removal), intermediate level of disturbance (the litter, moss and above-ground vegetation removal), high level of disturbance (the litter, moss and the plants removal as well as top soil raking). The colonization of gaps was observed in the years 2008–2010. Irrespective of patch character, the greatest species richness and seedling abundance were observed in gaps, which occurred in result of intermediate disturbances. Weaker recruitment rates were recorded in openings left after disturbances of low- and high severity, while in fully compact herb layer no seedlings were found. In MC patch, regardless of treatment in all openings similar spectra of life history traits were observed. In seedling pool of all subplots appeared taxa creating below ground organs of clonal growth. In all subplots dominated species with intermediate values of lateral spread, numerous vegetative descendants, short-lasting stems and no persistent genet integration. In sites GR and SA in openings left after weak disturbances appeared species with below- and aboveground organs of clonal growth. The majority of them characterized by slight lateral spread, low number of vegetative offsprings, long lifespan of shoots and persistent genet integration. The abundance of taxa creating underground clonal growth organs, with considerable vegetative spread, high production of daughter ramets, short lifespan of shoots and not enduring genet integration increased gradually and significantly with disturbance gradient. Although the greatest recruitment rates were found in gaps left after removal of litter, moss and above-ground parts of plants, the most effective way for conservation of Molinietum caeruleae meadows appeared to be creation of different severity disturbances. Such treatment contributes to maintenance of heterogeneity of clonal species composition, especially in patches in advanced successional stages

9

The effect of vegetation character on abundance and structure of subpopulations of rare herb species Gentiana pneumonanthe L.

Kostrakiewicz-Gierałt K.

Polish Journal of Ecology

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2013

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Vol. 61, nr 1

35--46

EN

During the 20th century in Central and Eastern Europe, traditional agricultural management was either heavily intensified or abandoned due to socio-economic reasons. The land abandonment led to subsequent secondary succession reverted many wet meadows into Phragmites swamps, Salix or Alnus thickets, as well as woodlands. Therefore, the understanding of changes in abundance and structure of populations in the process of succession has become very important especially for rare and endangered species. In Poland one of strictly protected plant is Gentiana pneumonanthe L. It is a nonclonal, long-lived, iteroparous plant consisted of numerous vegetative and generative stems, bearing 1–25 flowers per year. The investigations of abundance and structure of subpopulations of Gentiana pneumonanthe were conducted in the years 2009–2011 in abandoned Molinietum caeruleae meadows dominated by low-stature species (Patch I), prevailed by tall grasses (Patch II), willows (Patch III), as well as partly overgrown by shrubs and trees (Patch IV). The average height of vegetation cover achieved from 65.3 cm (Patch I), via 85.8 cm (Patch II) and 94.0 cm (Patch III), to 142.7 cm (Patch IV). The gradually decline of abundance of Gentiana pneumonathe subpopulations and increased trend toward their senilization along the gradient of vegetation height might be due to successional closure of plant cover, preventing seedling recruitment. The total number of stems per individual and length of vegetative stems decreased with augmentation of neighbouring plants dimensions, whereas the height of generative stems, as well as flower and fruit production presented inversed trend. The greatest dimensions of capsules found in patch dominated by small meadow species might be due to greater availability of solar radiation. The conditions of studied subpopulations decrease gradually from patch dominated by small meadow species, via sites prevailed by grasses and willows, to place overgrown by shrubs and trees. Although obvious differences in abundance and structure of individuals, the prospects of all observed populations are poor, especially that patches are not subjected active protection.