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1

Soil nematodes in organic and conventional farming system: a comparison of the taxonomic and functional diversity

100%
Ilieva-Makulec K., Tyburski J., Makulec G.
Polish Journal of Ecology
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2016
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tom 64
|
nr 4
Agricultural practices in organic farming theoretically are supposed to lead to higher diversity and activity of soil organisms, which correlates with the stability or resilience of the soil system. In a 3-year study, we tested that hypothesis by comparing the nematode abundance, genera composition and community structure in the soil of winter wheat crop under organic and conventional management. We found the soil type to be a stronger predictor for the total nematodes abundance than the farming system itself. In both systems nematode densities were higher in the sandy than in the clayey soil. Total abundance of nematodes was significantly higher in the organic than conventional farm only in sandy soil and only in the autumn. Significantly more plant feeders was observed in organic than in the conventional crops regardless the soil type. In the clayey soil more bacterial feeders were found in the conventional farm, while in the sandy soil — in the organic one. Nematode generic richness was higher in the organic (a range of 15–35 genera) than in the conventional crops (a range of 15–29) on most sampling dates. Higher generic diversity (H') in the organic crop than in conventional was found for total nematodes in the clayey soil, and for hyphal feeders in sandy soil. H' for plant feeders were higher under organic than conventional system in both types of soil. In both farming systems bacterial feeding genera (Rhabditis, Panagrolaimus, Cephalobus and Acrobeloides) dominated in the communities. Plant feeders and omnivores were found among dominant genera only in the clayey soil, first under both systems, the latter only in the organic crops. The evaluation based on the ecological indices such as Maturity Index, Plant Parasite Index, Enrichment and Structure Index, and ratios between nematode trophic groups, showed that nematode communities under both farming systems most of the time were low matured and the soil food webs strongly disturbed.
2

Nematode abundance, diversity and trophic structure in relation to spatial heterogeneity of a natural fen

100%
Ilieva-Makulec K.
Polish Journal of Ecology
|
2004
|
tom 52
|
nr 3
Spatial distribution of nematode fauna was studied in relation to horizontal heterogeneity of a natural tall-sedge fen in north-eastern Poland. Due to vegetation patchiness at scale of several tens centimetres two distinct habitats can be distinguished – “tussocks” and sites “between tussocks”. Nematode fauna in the soil “between tussocks” was different from that of the adjacent “tussocks” sites with respect to total abundance, generic composition and community trophic structure. On the two sampling dates (in spring and summer) significant more nematodes were found in the “tussocks” than “between tussocks”. Nematode communities were more diverse in the “tussocks” than “between the tussocks”, however the differences between two sites were significant only in spring. Each site had its own dominant genera different from the dominant genera of the adjacent site. Spatial pattern of nematodes was dynamic over time and seemed to be highly influenced by seasonal fluctuations of floods, which make the sites “between tussocks” available for nematodes only when floods recede.
3

Physiological properties and taxonomy of epiphytic bacteria in Chelmzynskie Lake in Poland

100%
Lalke-Porczyk E., Donderski W., Malecka M.
Polish Journal of Environmental Studies
|
2004
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tom 13
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nr 5
Research was carried out on the number of heterotrophic bacteria inhabiting the surface of macrophytes submerged in water that are dominant in the littoral zone of Chełmżyńskie Lake: common reed, cattail and hornwort. Bacteria were identified and their ability to decompose certain biopolimers was determined. It was found that the number of bacteria growing on helophytes, i.e. common reed and bulrush, increased from spring to summer, and then decreased in autumn. On the surface of hornwort the number of heterotrophic bacteria increased throughout the whole vegetative season, reaching its maximum in autumn. From among all of the isolated strains, lipo-, cellulo- and proteolytic bacteria were dominant. Strains isolated from the surface of cattail were characterized by the potentially highest physiological activity. The generic composition of the isolated strains changed with the development of the macrophytes (season) and depended on the species of plant.
4

Occurrence and physiological properties of bacterioplankton of Lake Chelmzynskie [Poland]

100%
Donderski W., Kalwasinska A.
Polish Journal of Environmental Studies
|
2003
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tom 12
|
nr 3
This paper presents the results of research on the numbers of planktonic bacteria in Lake Chełmżyńskie, their developmental dynamics and their physiological properties. It was found that the total number of planktonic bacteria (TNB) was between 0.01 to 34.90 x 10⁷ cells . ml⁻¹ while the number of heterotrophic bacteria (TVC 22°C) in the water of the research sites in the lake varied between 0.17 to 42.06 x 10² cells . ml⁻¹. The maximum number of bacteria was found in summer, and the minimum in autumn. In the part of the lake near the town (sites I-VI) a distinctly greater number of planktonic bacteria was found in spring and autumn than in the part far from the town (sites VII- IX). Based on Korsh’s bacteriological “Q” index (Q > 1000) the water of Lake Chełmżyńskie is rated as clean. Among the planktonic bacteria of Lake Chełmżyńskie, Gram-negative rods were dominant, and the majority were slowly growing strains. The most numerous among planktonic bacteria were strains that hydrolyse fat, protein, deoxyribonucleic acid and starch. The least numerous were chitinolytic, nitrifying and ureolytic bacteria. Bacteria belonged to genera Flavobacterium, Aeromonas and Alcaligenes dominated in all examined periods.
5

Epiphytic bacteria inhabiting the yellow waterlily [Nuphar luteum L.]

80%
Donderski W., Kalwasinska A.
Polish Journal of Environmental Studies
|
2002
|
tom 11
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nr 5
Studies on the development dynamics and the physiological properties of heterotrophic bacteria growing on the surface of the yellow waterlily (Nuphar luteum L.) during the plants’ development cycle were carried out. It was stated that the number of the epiphytic bacteria is different in the examined sections of the plant. The number is higher on bottom parts of petioles and rhizomes but lower on the surface of leaf blades and petioles beneath the leaf blade. The number of the epiphytic bacteria oscillated between 0.54 x 106 and 37.85 x 106 cells per 1g of wet weight of the plant. The gram negative rods dominated among the epiphytic bacteria, the majority of which was slowly growing strains. Among the epiphytic bacteria the most numerous strains were those hydrolyzing fat, starch, and protein; the least numerous were the chitinolytic bacteria.
6

Redescription of Diporotaenia colymbi Spasskaya, Spassky et Borgarenko, 1971 [Cestoda, Cyclophyllidea, Schistotaeniidae] and amended diagnoses of Diporotaenia Spasskaya, Spassky et Borgarenko, 1971 and Diporotaeniinae Ryzhikov et Tolkacheva, 1975

71%
Gulyaev V. D., Vasileva G. P., Konyaev S. V.
Acta Parasitologica
|
2010
|
tom 55
|
nr 4
340-348
Diporotaenia colymbi Spasskaya, Spassky et Borgarenko, 1971 (Cestoda, Cyclophyllidea, Schistotaeniidae) is redescribed from Tachybaptus ruficollis (L.) in Turkmenistan. An amended generic diagnosis of Diporotaenia Spasskaya, Spassky et Borgarenko, 1971 is proposed. The taxonomy of Schistotaeniidae Johri, 1959 and the generic composition of its subfamilies, Schistotaeniinae Johri, 1959 and Diporotaeniinae Ryzhikov et Tolkacheva, 1975, are discussed. The genera Ryjikovilepis Gulyaev et Tolkacheva, 1987, Isezhia Gulyaev et Konyaev, 2004, Mircia Konyaev et Gulyaev, 2006 and Decarabia Konyaev et Gulyaev, 2005 are considered as members of the subfamily Diporotaeniinae. An amended diagnosis of the latter subfamily is proposed.
7

Generic composition and metabolic activity of bacteria inhabiting surface seawater layers

70%
Mudryk Z.
Oceanological Studies
|
1998
|
tom 27
|
nr 3
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