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Accelerated steppe demutation (ecological restoration) as an effective method for restoration of the Crimean steppe landscapes

Wakhrusheva L., Wakhrushev B.

Prace Komisji Krajobrazu Kulturowego

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2013

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nr 20

45--50

EN

Accelerated steppe demutation (ecological restoration) is an effective method for restoration of the Crimean steppe landscapes. Critical state of steppe type of vegetation is analyzed, the slow rate of natural demutation is assessed, the urgency of measures for accelerated restoration of steppe habitats is argued for. Data on flora of steppe areas of the Kerch peninsula steppe used as the bank for seed material are provided, as well as the data of the vegetation at the areas chosen for accelerated restoration. The experiment on accelerated demutation has been conducted following the method by D.S. Dzybov with the author’s modifications.

PL

Artykuł omawia stan krytyczny roślinności naturalnej krymskich stepów, wskazuje na wolny przebieg naturalnej demutacji i uzasadnia konieczność prowadzenia prac przyśpieszających odradzanie się stepowych fitocenozów. Scharakteryzowano florę obszarów stepowych Półwyspu Kerczeńskiego służących za obszary źródłowe materiału nasiennego oraz stan roślinności w obrębie obszarów, wytypowanych do demutacji roślinności stepowej. Eksperymentalne prace demutacyjne wykonano wg zmodyfikowanej przez autorów metody D.S. Dzybowa.

2

Test research on the resistance performance of high-speed trimaran planing hull

Ma W., Sun H., Zou J., Yang H.

Polish Maritime Research

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2013

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nr 4

45--51

EN

In order to identify high-speed navigation ability of trimaran planing hull, as well as investigate the characteristics of its resistance and hull form, ship model tests were conducted to measure resistance, trim and heaving under different displacements and gravity centre locations. The test results were then used to study the influence of spray strips on resistance and sea-keeping qualities. Moreover, different planning surfaces were compared in the model tests which helped to look into influence of steps on hull resistance and its moving position. Also, the resistance features of monohull and trimaran planing hulls, both with and without steps, were compared to each other. From the tests it can be concluded that: the two auxiliary side hulls increase aerodynamic lift at high-speed motion, which improves the hydrodynamic performance; the trimaran planing hull has also excellent longitudinal stability and low wave-making action; when Fr∇> 8, its motion is still stable and two distinct resistance peaks and two changes of sailing state (the second change is smaller) appear; spray strips are favourable for sea-keeping qualities at high speed. The change trends before the second resistance peak as to the resistance and sailing behaviour of trimaran planing hull without steps are the same as for monohull planing hull without steps. but when steps in both hulls exist the change trends are different; more specifically: trimaran planing hull with steps has only one resistance peak and its resistance increases along with its speed increasing, and the resistance is improved at the increasing speed as the number of steps increases.

3

Impact of the invasive species Elaeagnus angustifolia L. on vegetation in Pontic desert steppe zone (Southern Ukraine)

Sudnik-Wójcikowska B., Moysiyenko I., Slim P., Moraczewski I.

Polish Journal of Ecology

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2009

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Vol. 57, nr 2

269-281

EN

The Irano-Turanian species - Russian olive (Elaeagnus angustifolia L.) - is one of most commonly planted tree in the shelterbelts in southern Ukraine. The consequences of introduction of the species from windbreaks, into areas of different land use in west and central Pontic desert steppe zone are evaluated. The above steppe is unique on a European scale and exists only in some parts of the Black and Azovian Sea coasts. In recent years, the socio-economical crisis in Ukraine (less intensively cultivation, as well as limited grazing) has been responsible for the intensification of the spread of alien tree species outside the windbreaks. Studies were conducted in Kherson Region, in the immediate vicinity of the Black Sea Biosphere Reserve, where the presence of aliens is undesirable. The analysis of phytosociological material (48 releves with and without Russian olive) collected from areas of different land use type and limited human pressure (as abandoned field, former intensively grazed solonetz and extensively grazed desert steppe vegetation) show that E. angustifolia can impede the regeneration of the desert steppe. The species creates favourable conditions for the growth of geographically and ecologically alien nithrophilous weeds.