36 research outputs found

    Post-fire succession on abandoned fields in coniferous forest habitat [Nord-East Poland]

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    In July, 1992, fire swept through the Jelonka Reserve (52o35'33"N; 23o22'10"E). Litter, herbs layer and juniper shrubs were razed and the tree trunks of Pinus sylvestris and Populus tremula damaged, which resulted in their death the following year. Five research plots of 25 m2 each were established in the post-fire area. The species present there and their degrees of coverage were listed on the Londo scale between 1993 and 2002. The calculation of average degrees of coverage for individual populations allowed for the establishing of a chronological pattern of post-fire succession. The following findings have been made: 1) the primary function in colonization belongs to species of guerilla strategy of growth whose dormant buds survived fire underground (Holcus mollis, Calluna vulgaris and Populus tremula) or phalanx strategy of growth (Corynephoms canescens); 2) the dominants of the initial succession stage are perennial grasses, not therophytes; 3) the spatial pattern of succession is influenced by the occurrence of H. mollis or C. canescens in a particular location; 4) the initial stage terminates with the occurrence and further growth of C. vulgaris clumps; the post-fire succession in the Jelonka Reserve attained a brushwood stage faster in comparison to secondary succession, formerly triggered by the cessation of cultivation on arable land

    Flora and habitat of potato pits on kame hills in North-Eastern Poland

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    The research was carried out in north-eastern Poland in the vicinity of the village of Haćki (52°50’00’’N; 23°11’20’’E). This area is distinguished by an exceptionally numerous agglomeration of kames (10). Previous archaeological and soil research showed that kames have been inhabited by man from the iron age, and that the following stages of colonization are reflected in three levels of fossil soils. In modern times local people use the base of kames for the storage of potatoes over the winter. The potato pits are a cultural curiosity found only in this area. They are dug out in the cohesive, fine-grained substratum, which is the building material of kames, down to 1.5-2 m deep. Research plots (16) with a surface area of about 2-5 m2 were established in the potato pits in 1990. In the summer of the same year 16 phytosociological surveys were performed and soil samples taken. The investigated habitats are characterized by very low humidity. The concentration of carbon in the samples from potato pits dug out at the foot of a kame hill (the site of a settlement in the past) results probably from the occurrence of soil from the Roman period. At the present time the pits are covered by poor ruderal flora (approx. 10 species in one phytosociological survey). It is distinguished from other communities of such type by a low participation of species occurring in the xerothermic grasslands

    Conditions of the occurrence of Anemone sylvestris in a kettle hole in North-Eastern Poland

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    The research, in 2004, was focused on the whole population of Anemone sylvestris (Snowdrop Windflower) present in the area of a kettle hole (0.8 km2) in north-eastern Poland (52°50’00’’N; 23°11’20’’E). The location of 56 clumps of generative specimens was surveyed. They numbered from several to approx. 1500 specimens. The number of generative specimens in this population exceeded 10 000. On account of this, it is a unique stand of A. sylvestris in Poland. The relationship between the occurrence of the Snowdrop Windflower and the presence of kame hills and ridges has been proven. Low slopes of kame with an inclination of 10-20o, and a north-eastern or eastern exposition has been found as the local ecological optimum for this species. Research carried out in 1970-2001 on 5 permanent plots (25 m2 each) has shown that: 1) Anemone sylvestris is an essential element of xerothermic grasslands of the order Festucetalia valesiacae; 2) the species suddenly withdraws from the parts of land on which woody species have already reached the shrub layer; 3) the greatest danger for the population of A. sylvestris in this area is the process of secondary succession initiated by the discontinuation of grazing on the kame hills

    The pattern of seed banks during secondary succession on poor soils

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    Studies on the soil seed banks of fallow lands of different ages were carried out on poor soil abandoned fields and in a fresh coniferous forest in north-eastern Poland. The size and diversity of seed banks was studied with the seedling emergence method. Species abundance (i), density (ii), number of species from different biological groups (iii) and distribution and mean LI value (iv) were analysed as the function of fallow land age. It was found that: (i) species diversity, number of species and ln of density are linear declining function of the fallow land age; (ii) for approx. 25 years the share of diaspores of identified species groups has been relatively similar. Seed banks of 40-50-year-old fallow lands are dominated by Calluna vulgaris, while the seed bank of the old fresh coniferous forest is dominated by dicotyledonous perennials and grasses; (iii) within the first 50 years of succession the persistence of seed banks measured by the Longevity Index increases gradually

    The effects of different types of woodstand disturbance on the persistence of soil seed banks

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    The research was conducted on four patches of thermophilous oak wood in Białowieża Primeval Forest: A – with a woodstand: oak + approx. 30-year-old hornbeam + hornbeam brushwood; B – with a hornbeam stand formed by natural seed fall after logging (ca. 1920) oaks; C – after logging oaks and replanted (ca. 1965) with pine and oak; D – with a natural low-density oak stand. Species composition and seed bank density were estimated using the seedling emergence method. Seedling emergence was observed over two vegetation seasons. Research demonstrated that: 1) the species abundance of the seed banks depends on canopy cover (A, B approx. 50 species; C, D approx. 70 species); 2) the floristical similarity (Sørensen’s index) of the seed bank and ground vegetation is higher in the undisturbed patch D (0.50) than in disturbed patches (0.30-0.35); 3) species diversity in plots A, B, C, D (H’=12.5; 13.4; 15.5; 16.9) and seed bank density per m2 (432.5; 958.0; 1486.5; 2268.0) are negatively correlated with the degree of patch shading; 4) the average weight of diaspores in the seed banks of shady plots is lower (A, B approx. 0.003 g) than that of sunny plots (C, D approx. 0.08 g); 5) the share of long-lived diaspores increases in patches after logging

    Effectiveness of a multicenter training programme to teach point-of-care vascular ultrasound for the detection of peripheral arterial disease in people with diabetes

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    Background The primary aim of this study was to evaluate the effectiveness of a training programme to teach a focused bedside ultrasound scan (PAD-scan; Podiatry Ankle Duplex Scan) for the detection of arterial disease in people with diabetes. Methods Five podiatrists and one diabetologist across two hospitals were enrolled in a structured training programme consisting of a training course (1-day), supervised scanning (5-weeks), independent scanning (3-weeks) and a final evaluation of performance (1-day). Time, technical skills (Duplex Ultrasound Objective Structured Assessment of Technical Skills tool (DUOSATS); minimum score = 6, maximum score = 26) and accuracy (level of agreement with vascular scientist PAD-scan assessment) were assessed for every supervised scan and again for the final evaluation of performance. Results A total of 90 PAD-scans in 65 patients were performed during the supervised phase. Participants demonstrated significant improvements in median time (19 min(IQR 13.9–25.5) vs 9.3 min (IQR 7.3–10.5); p = 0.028) and DUOSATS scores (17.5 (IQR 16.8–21) vs 25 (IQR 24–25.3); p = 0.027). At the final evaluation, participants completed scans in 5.4 min (IQR 5.3–5.9), achieved full DUOSAT scores and perfect agreement with the vascular scientist. Conclusion A structured training programme, integrated into diabetic foot clinics, was effective in teaching the PAD-sca
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