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1

Soil properties and light availability determine species richness and vegetation diversity in an overgrown coppice oak stand

Szymura T., Szymura M.

Polish Journal of Ecology

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2011

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Vol. 59, nr 3

523-533

EN

Coppicing is uncommon in Poland; however, some remnants of a previously coppiced oak forest persist in the foothills of the Sudety Mountains (southern Poland). Some of these forests are considered as a kind of thermophilous oak forest, classified as habitat 91I0 in the European programme Natura 2000. As an example of previously coppiced sessile oak (Quercus petraea (Matt.) Liebl.) forest in Poland, the vegetation and environmental factors in the "Wąwóz Lipa" reserve (area 101 ha, altitude ca. 400 m a.s.l.) were surveyed. Canonical correspondence analysis showed a basic compositional gradient of vegetation related to the content of coarse fragments in the soil, light availability and soil pH. The number of species per plot was not correlated with any particular environmental variable; in general, the plant species number and cover decreased in the most exposed sites, where the heat load was highest. We hypothesize that the higher number of species in some plots was the results of an edge effect: this occurred in transitional zones between the most exposed sites, which work as refuges for light-demanding, drought-tolerant species, and less exposed sites, with vegetation typical of acidophilous oak forests. The land relief also allowed the spread of species typical of mesophilous forests, which found refuge in the shaded, wet gorges. Thus, the specific land relief, along with previous coppice management, allowed the coexistence, probably temporally, of species of plants considered typical of different habitats.

2

Effect of the colony edge on the clutch size and fledging success in the Little Egret Egretta garzetta (L.)

Uzun A., Kopij G.

Polish Journal of Ecology

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2010

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Vol. 58, nr 2

393-396

EN

The term "edge effect' can be defined as an abrupt and local change in the abundance, diversity, composition etc. at the edge of any distinct, spatial patches (structure(s). It usually refers to forest/field, meadow/shrub and other ecotone environments. This effect in relation to breeding densities and success in birds has been the focus of considerable debate (Manolis et al. 2002). The edge of bird colony is expected to affect similarly on avian population (Krebs 1974). Although such studies can be very useful for management and conservation strategies, they are scarce in the Mediterranean.

3

Modelling of edge effects taking account diffusion phenomenon

Rajkowski B., Nowak P.

Optica Applicata

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2001

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Vol. 31, nr 2

489-498

EN

The results of simulation model examination of the occurrence intensity of edge effects show that they are dependent on time, reaction rate constant, substrate and product concentration, layer thickness and exposure intensity. For this purpose, a model development process was applied, taking account of the kinetic reaction equation as well as the diffusion equation. The results obtained are represented in the form of three-dimensional plots where the intensity of edge effect occurrence is shown as a function of two variables.

4

Semiperiodicity of end effects in linear induction motors

Mikulik J., Sobczyk T.

Zeszyty Naukowe. Elektryka / Politechnika Łódzka

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1998

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z. 91

113--118

EN

Very often in electrical machines the runs of the physical quantities are described by the semiperiodical functions. In fact electrical excitations on the one hand and mechanical motion on the other decide the nature of the phenomena. They are independent of each other. The suitable structure of the mathematical model of LIMs allows to show that random phenomena are subjected to rules of semi-periodicity.

PL

Bardzo często w maszynach elektrycznych występują przebiegi wielkości fizycznych, które można opisać przy pomocy funkcji prawie okresowych. Dzieje się tak dlatego, iż o naturze tych zjawisk decydują: z jednej strony pobudzenia elektryczne a z drugiej ruch mechaniczny, które są od siebie niezależne. Pojęcie prawie okresowości zjawisk dotyczy stanów ustalonych w silnikach liniowych, w tym kontekście w pierwszym przybliżeniu zjawiska brzegowe wydają się nie podlegać regułom prawie okresowości, gdyż trudno jest mówić o stanie ustalonym w przypadku , gdy elementy przewodzącej części wtórnej wchodzą w strefę głównego pola magnetycznego pod induktorem, przebywają w tej strefie przez pewien czas a następnie opuszczają tę strefę. Okazuje się, że odpowiednia budowa modelu matematycznego silnika liniowego pozwala wykazać, że z pozoru przypadkowe zjawiska podlegają regułom prawie okresowości. Pozwala to opisać zjawiska całkowicie niepowtarzalne przy pomocy szeregu Fouriera o skończonej liczbie elementów.