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1

Significance of Stump-Sprouting for the Population Size Structure and Spatial Distribution Patterns of Endangered Species, Magnolia cylindrical

Li J., Wu Y., Wu T., Cao L., Chen J., Qiu Z., Zhang Y., Xu G., Zhang J., Liu P.

Polish Journal of Ecology

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2017

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Vol. 65, nr 2

247--257

EN

Magnolia cylindrica Wils. is one of the third most-protected wild plants in China. To describe the size structure and dynamics of its population, field data were obtained from eight newly established sites, using a contiguous grid quadrate method in Jiulong Mountain of East China. The population size structure and spatial distribution pattern were discussed based on a theoretical distribution model and assembling intensity index. The population size structure showed a declining trend because of the lack of seedlings. The number of stump-sprouting, size class III (sapling trees) individuals was large enough to make up for the shortage of small seedlings and the complete regeneration of populations through sprouting. The distributions of M. cylindrica, both seedling populations (Group A) and overall populations (Group B), were mostly clumped. The spatial pattern intensities of the populations at different stages (mainly small trees, middle trees, and big trees) were higher for Group A than those for Group B. The two groups have the same tendency in that the pattern intensity declined from small trees to the larger ones. Group A and Group B differed in spatial pattern: small and middle trees were randomly distributed in seedling populations, but aggregated in overall populations. The populations of M. cylindrica (both group A and B) were characterized by the pattern scale between 16 to 32 m2, measured by Greig-Smith and Kershaw methods. These results suggest that sprouting should be seriously considered in population rehabilitation and forest tending management and the area of forest tending management should be close to the maximum intensity.

2

Impact of magnetized water on germination energy of seeds and weight of garden savory (Satureja hortensis L.), buckwheat (Fagopyrum esculentum L.), yellow lupine (Lupinus luteus L.) and winter rape (Brassica napus L.) seedlings

Podsiadło C., Skorupa B.

Infrastruktura i Ekologia Terenów Wiejskich

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2017

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nr III/2

1241--1250

EN

The laboratory experiment was carried out in 2008-2009. It consisted of several series of measurements, which were designed to evaluate the effect of magnetized water on seeding value and growth of seedlings and the weight of selected plant species. The results confirmed a diverse reaction of assessed species seeds towards the type of water used. Mag¬netized water stimulated the seed germination of garden savory and rape, while had no effect on the seeds of yellow lupine. In case of the seeds of buckwheat, this parameter decreased under the influence of magnetized water in the first six days of the experiment. A beneficial effect of bio-stim¬ulation with magnetized water on the rate of growth of the aboveground parts of seedlings was recorded. The positive effect related to all species. The greatest stimulation was observed in buckwheat and garden savory. The use of magnetized water reduced the growth rate of roots at garden savory and buckwheat, while it increased the growth of winter rape roots. It had no effect in yellow lupine. The type of water exerted a significant influence on the fresh weight and roots of seedlings. Regardless of the assessed species, the use of magnetized water resulted in a significant increase in fresh weight and roots by 6% and 9%. No significant influence of the water type on dry matter of seedlings of analysed plant was assessed.

3

Modelling of beetroot seedlings with modified generalized logistic functions

Szparaga A., Czerwińska E.

Agricultural Engineering

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2017

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Vol. 21, No. 3

107--117

EN

Modified generalized logistic functions (also known as Koya-Goshu functions) were used for mathematical description of germination. These functions constitute natural modification of traditionally used Richards' function for description of plants germination that introduces a non-linear time increase in exponent and an element related to time shift. Curves were adjusted to experimental data based on minimization of the square sum of difference between experimental data and a mathematical model (the smallest squares method). Results of simulation research show that the determined parameters of curves (e.g., values of the growth parameter, time shift or upper limit of population) describing the number of seedlings as a time function stay compliant to interpretation with regard to biology of the investigated processes. Based on the research, it was stated that for control and application of plant extracts to soil, Koyu-Gosha model has better adjustment to experimental data in comparison to the generalized logistic model.

PL

Do opisu matematycznego wschodów wykorzystano zmodyfikowane uogólnione funkcje logistyczne (znane również jako funkcje Koya-Goshu). Funkcje te stanowią naturalną modyfikację klasycznie stosowanych funkcji Richardsa w opisie wzrostu roślin, wprowadzającą nieliniowy przyrost czasu w wykładniku exponenty oraz człon związany z przesunięciem czasowym. Dopasowanie krzywych do danych eksperymentalnych przeprowadzono w oparciu o minimalizacje sumy kwadratów różnic pomiędzy danymi eksperymentalnymi, a modelem matematycznym (metoda najmniejszych kwadratów). Rezultaty badań symulacyjnych pokazują, iż wyznaczone parametry krzywych (np. wartości parametru wzrostu, przesunięcia czasowego czy górnej granicy populacji) opisujących ilość wschodów w funkcji czasu pozostają w dobrej zgodności z interpretacją na gruncie biologicznym badanych procesów. Na podstawie przeprowadzonych badań stwierdzono, iż dla kontroli oraz aplikacji do gleby wyciągów roślinnych model Koya-Goshu posiada lepsze dopasowanie do wyników eksperymentalnych w stosunku do uogólnionego modelu logistycznego.

4

The effect of gaps size on colonization process in Molinietum caeruleae meadows with different habitat conditions

Kostrakiewicz K.

Polish Journal of Ecology

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2011

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Vol. 59, nr 4

677-686

EN

The disturbances defined as an external factor causing biomass removal are a key component of all ecosystems. In phytocenoses with a continuous vegetation cover and a large proportion of perennial plants the fine-scale disturbances create gaps, which are the temporary competitor-free microsites suitable for plant recruitment. The investigations of natural colonization of different size gaps in Molinietum caeruleae meadows were carried out in patches dominated by small species creating delicate, erect or procumbent stems (MC), prevailed by large-tussock grasses (GR), and overgrown by willows (SA). Each patch was represented by ten plots, divided into four square subplots of 0.16 m2, 0.09 m2, 0.04 m2 and 0.01 m2. In each of them the aboveground parts of plants were clipped and removed with the litter. the seedlings recruitment was observed in 2007.2009. The highest species richness in gaps was observed in the MC patch and might be caused by week competition for light from neighbouring plants with delicate, procumbent stems and narrow leaves. The smaller rate of recruitment in SA and GR patches could be caused by overshading willows as well as by the competition from large and dense tussocks of Deschampsia caespitosa and Molinia caerulea. At all patches species richness declined with the decreasing gap size. The developed seedling pool represented both species occurring in the surrounding canopy and such which were not found there. However, their contribution varied between particular patches. Regardless gap size, the MC seedling pool was dominated by species which did not occur in the established vegetation, whereas in GR gaps both groups were represented by similar numbers of taxa and the SA gaps become dominated by species present in the surrounding canopy. Irrespective of patch character, in each subplot the medium-seeded species were represented most abundantly. The recruitment of genets of large-seeded species decreased, while the abundance of individuals ofsmall-seeded taxa increased with the increasing gap size. In the light of the performed study, one might suggest that extent-controlled disturbances can be used as an effective way of the conservation of Molinietum caeruleae patches dominated by small meadow species being outcompeted by large-tussock grasses and over-shaded by willows.