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Soil Nematodes in Organic and Conventional Farming System : A Comparison of the Taxonomic and Functional Diversity

Ilieva-Makulec K., Tyburski J., Makulec G.

Polish Journal of Ecology

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2016

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Vol. 64, nr 4

547--563

EN

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.

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Changes in soil nematode community structure following warming and drought manipulations in a grassland mesocosm experiment

Ilieva-Makulec K., De Boeck H. J.

Polish Journal of Ecology

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2013

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Vol. 61, nr 1

157--163

EN

The response of soil nematodes to simulated in spring, summer and autumn periods of warming and drought were studied in a grassland mesocosm experiment. The abundance, diversity and some community parameters of nematodes were analysed at different times after the end of the extreme events – 170 days after the spring treatment, 90 days after the summer treatment and 22 days after the autumn treatment. Among studied parameters the abundance of nematode trophic groups, taxonomic richness and diversity were found to be sensitive to changes in the soil system caused by extremes. Our results showed that warming and drought did not cause predictable shifts in nematode communities. Moreover the extremes’ after-effect was not unidirectional with time. The periods of warming and drought induced a positive or negative long lasting influence on nematodes, and the outcome seems to depend on season, the nematode trophic group or even the nematode taxon.

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Response of soil nematodes to climate-induced melting of antarctic glaciers

Ilieva-Makulec K., Gryziak G.

Polish Journal of Ecology

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2009

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Vol. 57, nr 4

811-816

EN

Nematode colonization and establishment of nematode communities on icefree areas created by the recession of Antarctic glaciers were studied on the Antarctic Specially Protected Area (ASPA) No. 128 (Western coast of Admiralty Bay, King George Island, South Shetlands Islands). Soil samples were taken along three transects marked between sea shore and Ecology Glacier, Baranowski Glacier and Windy Glacier and assigned to four age-class intervals: 0-7, >7-29, >29-52 and >52 years after the retreat of the glaciers. Changes in nematode communities, in terms of abundance, diversity and trophic structure were related to the duration of the ice-free period. The abundance of nematodes increased with the age of ice-free areas. The highest numbers of nematodes were found on the sites free of ice for more than 52 years. Taxonomic and trophic diversity of nematodes on these sites was also significantly higher in comparison to the rest sites. Nematode communities on the sites from the first three age-class intervals were poor in genera (up to 6 genera) while on the oldest sites in total 16 genera of nematodes were found. A trend of increasing the number of nematode trophic groups along the age classes was also apparent - from community of nematodes belonging to only two trophic groups (bacterial and fungal feeders) on younger ice-free sites to more complex community of nematodes (belonging to five trophic groups), at the oldest sites.

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

Ilieva-Makulec K.

Polish Journal of Ecology

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2004

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Vol. 52, nr 3

359-362

EN

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 centimeters two distinct habitats can be distinguished - "tussocks" and sites "between tussocks". Nematode fauna in the soil "between tussocks" was different ffrom 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 werre 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.

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A comparative study of the life strategies of two bacterial-feeding nematodes under laboratory conditions. 3, Influence on the initial nematode density on the interactions of Arobeloides nanus (de Man 1880) Anderson and Dolichorhabditis dolichura (Schnei

Ilieva-Makulec K.

Polish Journal of Ecology

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2001

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Vol. 49, nr 2

137-144

EN

Population development and interactions between two bacterial-feeding nematodes Acrobeloides nanus and Dolichorhabditis dolichura were studied in mixed cultures at different initial density of nematodes. Population dynamics of the two studied species differed significantly in both competition experiments, with the initial numerical advantage of A. nanus as well as with the initial numerical advantage of D. dolichura. In all experimental variants population peak of D. dolichura occured always earlier than that of A. nanus. Population dynamics of A. nanus and D. dolichura depended significantly on the initial density of the second species in the mixed cultures. The higher initial density of D. dolichura the less abundant populations of A. nanus were noticed. However, no consistent trend in the influence of the A. nanus initial density on the abundance of D. dolichura was found. Numerical advantage of D. dolichura never led to the extinction of A. nanus and in the opposite, numerical prevalence of A. nanus in two cases resulted in a complete elimination of D. dolichura. Population dynamics of A. nanus and D. dolichura in mixed cultures showed a distinct difference in the way of food utilisation by these two species. As food resources become scarce with time, D. dolichura density decreased but A. nanus density started to increase. It appears therefore that, under the present laboratory conditions, A. nanus was the better competitor. That species maintained a positive growth rate even at low food concentrations at which its competitor could no longer sustained.

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A comparative study of the life strategies of two bacterial-feeding nematodes under laboratory conditions. 2, Influence of the initial food level on the population dynamics of Acrobeloides nanus (de Man 1880) Anderson 1968 and Dolichorhabditis dolichura

Ilieva-Makulec K.

Polish Journal of Ecology

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2001

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Vol. 49, nr 2

123-135

EN

Population dynamics of two bacterial-feeding nematodes Acrobeloides nanus and Dolichorhabditis dolichura in relation to the initial food level was studied under laboratory conditions. Population density, age structure and selected productivity parameters of the two nematodes were compared in single and mixed species cultures. Initial food (bacteria Sporosarcina sp.) level significantly affected population dynamics of A. nanus and D. dolichura in the laboratory cultures. While A. nanus grew well at the three food levels, D. dolichura developed only at the highest initial density of food. There were significant differences in population dynamics of both studied species at the highest initial density of the bacterial food. In single species cultures population peak of D. dolichura occured earlier than that of A. nanus and maximal density of D. dolichura was significantly higher than maximal density of A. nanus. In mixed cultures population maximum was observed at the same time in both species and their peak densities were similar. Population maximum of A. nanus in mixed cultures was observed earlier than in its single cultures but the peak density of that species in single cultures was significantly higher than in mixed ones. Population peak of D. dolichura at the highest food level occurred at the same time irrespective of the type of culture, while peak abundance of that species in mixed cultures was almost 50% lower than in single cultures. The differences observed in population dynamics of the two nematode species were discussed with respect to the differences in the food supply of their natural habitats and the role they play in the processes of decomposition and mineralisation in soil.

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A comparative study of the life strategies of two bacterial-feeding nematodes under laboratory conditions. 1, Influence of culture conditions on selected life-history parameters of Acrobeloides nanus (de Man 1880) Anderson 1968 and Dolichorhabditis dolic

Ilieva-Makulec K.

Polish Journal of Ecology

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2001

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Vol. 49, nr 1

29-43

EN

Selected life-history parameters like age of maturity, fecundity, egg development time, pattern of growth and reproduction, longevity and intrinsic rate of natural increase (r) were compared for two bacterial-feeding nematode species in xenic (with a several bacterial species as food) and monoxenic (with a bacteria Sporosarcina sp. as a food organism) agar cultures at 20 stopni C. There were pronounced differences in the life-history patterns of the two species in both types of culture conditions. D. dilichura showed a higher growth and development rate than A. nanus. D. dolichura had a shorter pre-reproductive period, a shorter reproductive period but more intensive pattern of reproduction, a shorter total life span and a considerably greater r than A. nanus. The differences in life-history traits of the two nematode species were discussed with reference to their adaptive significance for habitat properties. While D. dolichura represents short-lived habitats with temporarily high food supply, A. nanus can be found in habitats of various food abundance.

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Wpływ metali ciężkich zawartych w odpadach z huty ołowiu na zespoły nicieni glebowych

Ilieva-Makulec K., Dmowska E.

Chemia i Inżynieria Ekologiczna

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1998

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Vol. 5, nr 8-9

707-711

PL

Badano działanie następcze metali ciężkich Cd, Zn i Pb na nicienie glebowe po wapnowaniu. Badania prowadzono na poletkach doświadczalnych wapnowanych trzykrotnie wapnem z kopalni węgla brunatnego w dawce dwa razy większej niż hydrolityczna kwasowość gleby (2Hh), wapnowanych dwukrotnie i trzykrotnie odpadami z huty ołowiu (2h) oraz niewapnowanych. Analiza gleby przeprowadzona w roku pobierania prób, tj. wiosną 1996 r., wykazała różnice w zawartości metali ciężkich w glebie badanych poletek. W glebie wapnowanej trzykrotnie odpadami z huty ołowiu, najbardziej skażonej metalami ciężkimi, zawartość Cd i Zn po czterech latach po wapnowaniu była bliska ilości przewidzianej dla gleb o podwyższonym stopniu skażenia. W glebie tej stwierdzono istotnie niższą liczebność nicieni bakteriożernych, grzybożernych i roślinożernych oraz mniejszą różnorodność rodzajową nicieni niż w pozostałych glebach.

EN

The effect of heavy metals Cd, Zn and Pb on soil nematodes was investigated after liming. Some of the experimental fields were treated three times with lime (2Hh) from the brown coal mine or twice or three times treated with lime waste (2Hh) from lead-works and other were untreated. Chemical analysis of soil from the test fields in the year of sampling, spring 1996 showed some differences in heavy metal contains. In soil with the highest content of Cd, Pb and Zn (three times repeated usage of lime waste from lead-works) the abundance of bacterial-feeding, fungal-feeding and plant-feeding and also genera diversity were significant lower then in the other soils.