Influence of anthropogenic factors on microhabitats inhabited by riverine hydrobionts - assessment with MRT method

This study concerns the influence of urban area on vegetation and invertebrates inhabiting the Słupia River (northern Poland). Altogether, 10 plant communities and 37 macrozoobenthos taxa were determined during four seasonal samplings (October 2005, January, April and August 2006). In order to reveal how the city of Słupsk affects the vegetation and fauna, MRT (multivariate regression tree) models were created. On their basis the most important factors were determined from the following set of variables: season, water temperature, salinity, distance, water depth, bottom type, location in the river bed and degree of river bed transformations. Performed analyses showed that vegetation in the urban area was primarily influenced by distance (correlated with anthropogenic pressure), while for invertebrates season and temperature were the most important factors

Geochemistry of deposits from spring-fed fens in West Pomerania (Poland) and its significance for palaeoenvironmental reconstruction

The cupolas of the spring-fed fens at Bobolice and Ogartowo (West Pomerania, Northern Poland) are composed of alternating peat and calcareous tufa layers. The geology of those two fens, together with the geochemistry of their deposits and radiocarbon dating results, made it possible: (1) to determine the source of water and mineral matter, and (2) to reconstruct the main stages in their development. The distinguished five main stages of development of the fens (four at Ogartowo) reflected varying depositional environments resulting, among other things, from the proportion of groundwater supply and its physico-chemical properties. On the basis of principal components analysis, the sources supplying elements of the peat-tufa rhythmite were found to be chemical denudation and sedentation of peat deposits, while mechanical denudation and atmospheric supply were considerably less important. The geochemistry of deposits was also influenced by local conditions of the geochemical environment, such as its pH, redox potential, CO2 content in water, and the occurrence of organic matter.Les dômes formés par les tourbières de source de Bobolice et d'Ogartowo (Ouest de la Poméranie, Pologne du nord), sont composés de niveaux alternés de tourbes et de tuf calcaires. L'étude géologique de deux d'entre elles, à laquelle s'ajoute une analyse géochimique des sédiments et des datations radiocarbone, a permis d'identifier (1) les sources de l'approvisionnement en eau et en matière minérale, (2) les phases principales du développement des tourbières. On a identifié cinq phases principales de développement (quatre à Ogartowo) qui reflètent différents milieux de sédimentation résultant, entre autres, de l'importance des apports en eaux souterraines et de leurs propriétés physico-chimiques. Sur la base d'une analyse factorielle (ACP), l'étude montre que les sources d'approvisionnement des séquences tourbe/tuf résultent de processus d'altération chimique et du dépôt des sédiments tourbeux, et, dans une moindre mesure, de la dénudation mécanique et des apports atmosphériques. La géochimie des sédiments dépend également de l'influence des conditions locales de l'environnement chimique, comme le pH, le potentiel d'oxydo-réduction, le contenu de l'eau en CO2 et la présence de matière organique

Spergulo-Chrysanthemetum segeti (Br.-Bl. et de Leeuw 1936) R. Tx. 1937 in the Drawsko Lakeland (Western Pomerania)

The species richness and structure of Spergulo-Chrysanthemetum segeti have been assessed on the basis of 25 phytosociological relevés made by the Braun-Blanquet method in the Drawsko Lakeland (Poland). Two variants have been distinguished, Spergulo-Chrysanthemetum segeti chamomilletosum typicum and Spergulo-Chrysanthemetum segeti chamomilletosum with Plantago intermedia. The paper presents the distribution and analytical characteristics of this subatlantic association against the background of habitat conditions

In vitro antimicrobial activity of ethanolic extracts obtained from Ficus spp. leaves against the fish pathogen Aeromonas hydrophila

The main goal of this study was to determine in vitro antimicrobial activity of ethanolic extracts obtained from the leaves of various Ficus species against Aeromonas hydrophila isolated locally from infected rainbow trout (Oncorhynchus mykiss Walbaum) with the aim of providing scientific rationale for the use of the plant in the treatment of bacterial infections induced by Aeromonas spp. in fish. Antimicrobial susceptibility testing was done on Muller-Hinton agar with the disc diffusion method. In the present study, most ethanolic extracts proved effective against the A. hydrophila tested, with 10-12 mm inhibition zones observed. A. hydrophila demonstrated the highest susceptibility to F. pumila. Among various species of Ficus with moderate activity against A. hydrophila, the highest antibacterial activities were noted for F. benghalensis, F. benjamina, F. deltoidea, F. hispida, and F. lyrata. Thus, Ficus can be used as a natural antiseptic and antimicrobial agent in veterinary practice. Further investigations need to be conducted to isolate and identify the bioactive compounds that can then be subjected to detailed pharmacological studies and the development of clinical applications. The alarming rate of increasing resistance in bacterial pathogens in aquaculture environments means that medicinal plants with antibacterial properties are very important as natural resources of new active compounds