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Impact of Invasive Aster lanceolatus Populations on Soil and Flora in Urban Sites

Obratov-Petković D., Bjedov I., Nešić M., Belanović Simić S., Đunisijević-Bojović D., Skočajić D.

Polish Journal of Ecology

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2016

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Vol. 64, nr 2

289--295

EN

Invasive plants are one of the major treat to local communities and ecosystems in urban habitats. Aster lanceolatus Willd. is one of the most spreading invasive plant species in Serbia and to examine its impact on soil, flora and aboveground biomass in urban habitats we investigated the pH, electrical conductivity and concentration of trace elements (Zn, Cu, Ni, Mn) in four invaded and four uninvaded plots in urban habitats. We also studied floristic composition and floristic richness regarding these invasive plant populations. These parameters were assessed along transects arranged in the cross shape, running from the centre of the invaded area towards the peripheral uninvaded area. Trace elements were analysed using atomic absorption spectrophotometer. Statistical differences were analysed using ANOVA and post-hoc LSD-tests. The results showed an important decrease of the number of species and herbaceous cover under A. lanceolatus populations. There were no statistically significant differences between invaded and uninvaded patches when soil pH and electrical conductivity were considered. The concentration of Zn, Mn and Ni in the soil was higher in invaded areas. The content of Zn in aboveground biomass collected from invaded compare to uninvaded areas was higher. This study raises the possibility that invasive species changes soil characteristics and create conditions for their spreading.

2

Rotifer invasion? On appearance and abundance of tropical species in lakes of North-Eastern Poland

Ejsmont-Karabin J.

Polish Journal of Ecology

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2014

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Vol. 62, nr 4

821--827

EN

Trichocerca simoneae De Smet described in 1989 has since been found in tropical and subtropical areas, but was not recorded in Poland before World War II. A bibliography of Polish rotifers by Wiszniewski (1953), although very comprehensive, does not refer to T. simoneae. However, in the studies of plankton of the dystrophic lake, i.e. humic one with water rich in humic acids, acidic pH and brown coloured, carried out in the years 1998–2000, the species dominated. Here, studies in 39 small, inter-forest lakes of north-eastern Poland revealed T. simoneae in 15 of them, often at high densities, up to ca 6000 ind L-1. The possible reasons for this ‘invasion’ are: (1) zooplankton communities in dystrophic lakes are unsaturated with biotic interactions too weak to exclude invaders; CCA and RDA analyses showed that T. simoneae preferred habitats with low number of zooplankton species of low density and dystrophic lakes seem to offer such habitats; (2) long-term deposition of rotifer resting eggs is probably more successful in sediments decaying at low rates. The latter possibility seems to be confirmed by observed in the littoral zone of dystrophic lakes appearance from time to time, of rare, mostly tropical species of Rotifera (e.g., Lecane hornemnni, L. monostyla, L. sola).

3

Predicting current and future invasion of Solidago canadensis; a study from China

Xu Z., Peng H., Feng Z., Abdulsalih N.

Polish Journal of Ecology

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2014

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Vol. 62, nr 2

263--271

EN

Solidago canadensis, which is native to North America, is considered to be the most widespread invasive alien plant. The invasion of Solidago canadensis in China has resulted in serious environmental problems. Therefore, understanding the relationship between the geographical distribution of S. canadensis and bioclimatic variables, and then predicting the potential distribution of this species is essential for management actions and practices. Although several studies have delineated the potential distribution of S. canadensis in China, how this species would respond to variations in future climatic conditions remains unclear. In the present study, we predicted the potential distribution of S. canadensis under current and future climatic conditions using species distribution models. We also analyzed range shifting of this species under current and future climatic conditions. We arrived at several conclusions. First, the potential distribution of S. canadensis may expand 40% under future climatic condition compare with that of under current condition. Second, mean diurnal range, isothermality, mean temperature of the wettest quarter, mean temperature of the warmest quarter, precipitation of the driest month, and precipitation seasonality (coefficient of variation) are key bioclimatic variables in determine the potential distribution of S. canadensis. Third, expansion of S. canadensis can be partly attributed to the relatively warmer and wetter future bioclimatic condition than current one.

4

Para zagrożeniowo-ochronna jako element szacowania bezpieczeństwa obiektu i ryzyka

Szczepański P.

Biuletyn Wojskowej Akademii Technicznej

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2014

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Vol. 63, nr 4

233-257

PL

W pracy parami zagrożeniowo-ochronnymi są wirtualne elementy obiektu, rzutujące na jego zdolności ochronne przed konkretnymi zagrożeniami. Skutkiem ukierunkowanej inwazji każdej z tych par jest spowodowanie jakiejś niezdatności. Neutralność pary osiąga się w sytuacji pełnego spokoju lub pełnej ochrony przed przypisanym tej ochronie zagrożeniem. Naruszenia neutralności (charakteryzowane prawdopodobieństwami) są przyczynkami do określenia: bezpieczeństwa obiektu, ryzyka serwisowania i ryzyka rekompensat za czas postoju. Zauważa się, że wyniki pracy mogą służyć także wielu innym zagadnieniom, np. optymalizacji pełnych warunkowych programów diagnozowania.

EN

The paper presents a concept of threat protection pairs as virtual elements of a structure of an object, to indicate its potential capacity to safeguard against specific risks. Neutrality of the pair occurs in a situation of full calm or full protection against the threat assigned to this situation. Degrees of the neutrality violation (defined by the probabilities) are the inputs to determine: the object security and the risk of servicing and risk of compensation for the downtime. It can be noted that the results of the work may be used for many other issues, e.g. to optimize the full conditional programs for diagnosing.

5

Does invasion of Vallisneria spiralis L. promote appearance of rare and new rotifer (Rotifera) species in littoral of the lakes heated by power station (Konin lakes, W. Poland)?

Ejsmont-Karabin J.

Polish Journal of Ecology

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2011

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Vol. 59, nr 1

201-207

EN

Large-scale human-caused ecosystem disturbances may create new habitats. A good example may be long-lasting disturbances in five lakes (area from 148 to 379 ha, max. depth from 3 to 38 m) integrated into the cooling system of the power plants near Konin (52[degrees]17.8'-52[degrees]23.3N, 18[degrees]14.4'-18[degrees]20.7'E, West Poland). In the middle of the 1990s Vallisneria spiralis began to colonize littoral zone of three of lakes and in 2002 it appeared also in fourth one. This species formed dense patches and almost completely displaced other submerged macrophytes. An aim of the study was to test a hypothesis that the appearance of rare and new for Polish fauna rotifer species might be a result of changes in littoral habitats of these lakes particularly caused by the invasion by Vallisneria spiralis. Studies were carried out in the years 2004-2006 on 3-6 littoral stations in each lake. Five-liter samples of water with macrophytes were collected from a center of macrophyte beds. Plankton (free-swimming) and epiphytic (connected with macrophyte surface) samples were elaborated separately. As many as 167 monogonont species were recorded during the three-years. studies. From among them 6 species were new in Polish fauna. These were: Asplanchnopus hyalinus Harring, Beauchampia crucigera (Dutrochet). Lecane inopinata Harring & Myers, Lecane shieli Segers et Sanoamuang, Lecane undulata Hauer and Lepadella apsida Harring. The species are eurythermic or warm-stenothermic. Species new to the rotifer fauna of Poland were not numerous as they usually constituted less than 2% of the total density of rotifers. Thus, although the hypothesis that rare and new for Polish fauna rotifer species may appear in the littoral habitats of the heated Konin lakes was confirmed, it was also clear that the colonization of the habitats by rotifer invaders did not lead to their domination in the rotifer communities.