Wyniki wyszukiwania - BazTech

1

Ecology of testate amoebae (Protists) in a Sphagnum-dominated peat bog and the relationship between species assemblages and environmental parameters

Niedźwiecki M., Mieczan T., Adamczuk M.

Oceanological and Hydrobiological Studies

|

2016

|

Vol. 45, No. 3

344--352

EN

Despite its ecological importance, little information is available regarding spatial and seasonal changes in the testate amoebae community in peat bogs. The objectives of this study were to examine the structure of communities and horizontal distribution of testate amoebae fauna, to improve the understanding of factors affecting the distribution of moss testate amoebae communities and to analyze the seasonal changes in testate amoebae communities in a Sphagnum-dominated peat bog (eastern Poland). A total of 45 testate amoebae species were identified in the samples. The highest species richness occurred in hollows dominated by Sphagnum angustifolium, much lower numbers of taxa were observed in hummocks dominated by Sphagnum magellanicum and Polytrichum. The Monte Carlo permutation test showed the significance of Ntot, temperature, pH, and the depth to the water table for the variability of testate amoebae in all microhabitats. Species found in spring samples were associated with the increased Ntot content. Species occurring in summer samples were associated with the increasing pH gradient and species developing in late spring and autumn preferred a greater depth to the water table.

2

Composition and seasonal changes in filamentous algae in floating mats

Pikosz M., Messyasz B.

Oceanological and Hydrobiological Studies

|

2015

|

Vol. 44, No. 2

273--281

EN

The occurrence of algal-cyanobacterial metaphyton mats in field (Konojad village) and artificial ponds (Poznań city) was investigated in the Wielkopolska region. The surface area of algal mats ranged between ca. 45% (natural pond) and 10% (artificial pond) of the total water surface, and the mats occurred from the water surface to the bottom; the algal diversity was similar in both types of ponds, i.e. about 10 taxa. The most frequently recorded and dominant taxa in small water bodies were: Spirogyra spp., Cladophora fracta in the artificial pond and Oedogonium spp., Cladophora rivularis in the natural pond. The dynamics of macroalgae demonstrated a pattern comprising different phases of taxa dominance. For example, April regarded as the first phase was characterized by a small amount of metaphyton, represented by Tribonema and Ulothrix taxa. In May, these species disappeared and were replaced by: Oedogonium spp. and Cladophora spp. which formed large aggregations in the field pond, and Spirogyra spp. which abundantly proliferated in the artificial pond. From June, however, Oedogonium and/or Cladophora significantly dominated in the mat structure and at the same time covered a large area of the water surface. The algal community was dominated by common algal taxa, among which single filaments of other taxa could also occur.

3

First report of endosymbionts in Dreissena polymorpha from the brackish Curonian Lagoon, SE Baltic Sea

Chuševe R., Mastitsky S. E., Zaiko A.

Oceanologia

|

2012

|

No. 54 (4)

701-713

EN

We report the first results of a parasitological study of Dreissena polymorpha (zebra mussels) from the brackish Curonian Lagoon, SE Baltic Sea. Zebra mussels were collected monthly from May to October 2011 from a site near the mouth of the River Nemunas. Three types of endosymbionts were found in the mantle cavity and visceral mass of the molluscs during dissections, i.e. the commensal ciliate Conchophthirus acuminatus and parasitic ciliate Ophryoglena sp., and rarely encountered, unidentified nematodes. The abundances of C. cuminatus and Ophryoglena sp. were positively associated with host shell length and water temperature, but no effect of water salinity was detected. As the endosymbionts are either highly host-specific to zebra mussels (C. acuminatus and Ophryoglena sp.) or are probably free-living organisms that inadvertently infect the molluscs (nematodes), we conclude that the presence of D. polymorpha in the Curonian Lagoon does not pose any serious parasitological risk to native biota. We emphasize, however, that this conclusion should be treated with caution as it is based on a study conducted only at a single location. Our work extends the currently scarce records of D. polymorpha parasites and commensals from brackish waters, and adds to a better understanding of the ecological impact this highly invasive mollusc causes in the areas it has invaded.

4

Sezonowa dynamika aktywności nicieni owadobójczych Steinernematidae i Heterorhabditidae w glebie w wybranych zieleńcach Szczecina

Dzięgielewska M., Myśków B., Adamska I., Czerniawska B.

Proceedings of ECOpole

|

2010

|

Vol. 4, No. 2

351--356

PL

Sezonową dynamikę aktywności nicieni owadobójczych z rodziny Steinernematidae i Heterorhabditidae badano od kwietnia do października 2008 roku w czterech zieleńcach Szczecina. Analizowano zagęszczenie nicieni w glebie oraz występowanie potencjalnych żywicieli na poszczególnych stanowiskach. Z badanych miejsc wyizolowano cztery gatunki nicieni: Steinernema feltiae, S. affine, S. bicornutum i Heterorhabditis megidis. Najpospolitszy okazał się S. feltiae, który wystąpił we wszystkich czterech zieleńcach. Największe zagęszczenie nicieni zanotowano jesienią, od 7000 do 50 000 os./m2, co może mieć związek ze zwiększoną dostępnością żywicieli w glebie w tym okresie. Stwierdzono wyraźną zależność między występowaniem nicieni H. megidis i obecnością słonika żołędziowca w zadrzewieniach z dębem. Największe zagęszczenie (ponad 25 000 os./m2) tego gatunku zaobserwowano jesienią. Wśród owadów, które dominowały w badanych środowiskach były chrząszcze, z wyjątkiem zadrzewień z kasztanowcem białym, gdzie żerował szrotówek kasztanowcowiaczek należący do Lepidoptera.

EN

The seasonal dynamics of entomopathogenic nematodes (EPNs) of Steinernematidae and Heterorhabditidae were studied from April to December 2008 in four green areas of Szczecin. The abundance of suitable hosts and entomopathogenic nematodes were investigated. A total of four EPN species were found from all sites: Steinernema feltiae, S. affine, S. bicornutum and Heterorhabditis megidis. The most common of them was S. feltiae, which was found in all habitats. The highest abundance of EPN in all green areas was reported in autumn from 7000 ind./m2 to 50,000 ind./m2 which can correlate with the abundance of suitable host in the soil. Significantly positively correlation between occurrence of H. megidis nematodes and Curculio glandium host in oak wood was observed. The highest abundance of this species (approximately 25,000 ind./m2) was reported in autumn. The dominant hosts, in three habitats (oak wood and green area with Ligustrum vulgare), belonged to Coleoptera except green area with Cameraria ohridella belonged to Lepidoptera.

5

Response of microbial communities to biomanipulation of the numbers of epigean macroarthropods in a field experiment in meadow

Stefaniak O., Dziedzic T., Gorlach K.

Polish Journal of Ecology

|

2000

|

Vol. 48, nr 4

311-326

EN

The objective of our investigations was to analyse if experimental exclusion ofmacroarthropods patrolling soil surface affects numbers, composition and enzymatic activity of microbial communities. The experiments were carried out in mesocosms containing soil cores taken from the meadow or filled with sand (100 cm^2, 15 cm deep), inserted into the soil profile in Arrhenatheretalia mown meadow. Two types of mesocosms have been compared: open (O) - accessible for macrofauna, with openings cut in netting in soil/litter interface, or closed (C), made from the same nylon material (mesh size 0,24 mm), but without openings. In the mesocosms, litter bags containing 9,5 g dry wt of above ground parts of Dactylis glomerata were placed on the soil or sand surface. The experiments have been repeated in the two successive growing seasons (1992, 1993) and lasted from spring, (time of exposure) till autumn. The abundance of microbes in the litter increased gradually from very low initial numbers till the peak (higher by 4-6 orders of magnitude) in autumn, in the period of high moisture content of the habitat (18 or 23 weeks after the exposure, respectively in two experiments). In this last period only, significant differences were recorded between microbial numbers in litter exposed in open and closed mesocosms. The numbers of total bacteria and Actinomycetes were in the most analysed cases (6 per 8 analyses) significantly higher in closed mesocosms. Fungi were more abundant in open ones (3 per 4 cases). Differences between enzymatic activity in the litter placed in these two series of mesocosms were not significant. Highly significant positive correlation was found between litter decomposition rate and the estimated number of microbes in it (P,0,05). The dynamics of microbes in the sand followed a similar trend of gradual increase from springm till autumn, as in the litter. Seasonal dynamics in the soil was different and variable. On the contrary to the litter, in soil and sand higher microbial numbers and higher enzymatic activity were found, in most analysed cases, inmesocosms accessible for macrofauna (O) (higher - 20, lower - 5 cases). It was the consequence of higher input of invertebrate ejecta and higher organic matter content in these mesocosms.

6

Seasonal changes in macrofaunal feeding groups associated with Nuphar lutea (L.) Sm. leaves in a small eutrophic lake

Kornijów R., Ścibior R.

Polish Journal of Ecology

|

1999

|

Vol. 47, no 2

135-143

EN

The epiphytic invertebrates associated with leaves of Nuphar lutea in a shallow small eutrophic Lake G?ębokie (Łęczna-W?odawa Lake istrict, eastern Poland) were pooled into one of three feeding groups: 1. algae-detritus feeders (25 taxa, average density 111 ind.x 100 cm^2), 2. vascular plant feeders (3 taxa, average density 64 ind. x 100 cm^-2), 3. predators (10 taxa, 4 ind. x 100 cm ^-2). The faunal feeding assemblages underwent clearly marked seasonal changes in their relative abundance, dominance structure and densities. The discussed mechanisms responsible for these changes included trophic conditions (development of peryphytic and planktonic algae, nutritive value of the macrophytic tissue, amount of detritus originating from decomposing leaves), so called "dilution effect" (caused by fast increase in the colonizable leaf surface during summer), and the interactions between algae-detritus feeders and predatory invertebrates.

7

The carabid communities of natural and drained peatlands in the Biebrza Valley, NE Poland

Olejniczak I.

Polish Journal of Ecology

|

1998

|

Vol. 46, no 3

243-260

EN

Comparisons between the carabid communities of natural and drained fens in the Biebrza Valley (NE Poland) were made on the basis of trapped material. Fen drainage appears to result in a restructuring of species composition as there is only a limited (20-40%) similarity between the communities in natural and drained areas. The lowest species diversity was noted for a drained meadow on alder peat. Agonum moestum was dominant on natural fens, and in the one not cultivated and periodically flooded site on drained fens and Carabus granulatus or Pterostichus nigrita on drained ones. Tropic structure also differed, with hemizoophages of the genera Amara and Harpalus associated with agrocoenosesbeing present on drained fens but absent from natural ones. Chlaenius costulatus, a species now rare in Poland, is typical of peatlands, but was not present on drained sites. The number of sites accesible for it have declined as a result of wetland drainage.