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The Influence of Vegetation Structure on the Composition of the Seed Rain and Seedling Pool in Abandoned Molinion caeruleae Meadows

Kostrakiewicz-Gierałt K.

Polish Journal of Ecology

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2017

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Vol. 65, nr 2

269--284

EN

The investigations of the effect of different habitat conditions on the composition of the seed rain and seedling pool were conducted in the years 2014 and 2015 in abandoned patches of Molinion caeruleae dominated by small-stature meadow taxa (patch I), tall-growing grasses (patch II), as well as shrubs and trees (patch III). Observations showed that along the successional gradient the seed rain and seedling pool diminishes. The prevalence of perennials and native taxa in the seed rain and seedling pool occurred in all the study sites. Moreover, in the propagule and seedling pools of all the patches hemicryptophytes and meadow taxa prevailed but their number decreased in successional sites. Also, the abundance of ruderal and grassland taxa decreased gradually, at expense of number of forest species. Zoochorous species prevailed in the seed rain and seedling pool of all patches. Number of hydrohorous species decreased in successional patches, while the abundance of species with other dispersal modes were similar. Irrespective of patch character, the species producing propagules with medium size dominated in the seed rain and seedling pools, whereas a significant decrease of number of small-seeded species was noticed only in the seedling pool. Despite the diminishing of the seed rain and seedling pool along the successional gradient, the gap creation might be a very effective way of active protection of Molinion caeruleae meadows. However, the gap colonisation requires permanent monitoring to avoid further spreading of undesired taxa.

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Microcrustacean (Cladocera, Copepoda) source-sink dynamics in a lowland river ecosystem with a dam reservoir

Karpowicz M.

Oceanological and Hydrobiological Studies

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2016

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Vol. 45, No. 3

297--303

EN

Dispersal of crustacean zooplankton from a reservoir in a lowland river was observed over a relatively long distance. Zooplankton samples were collected by a unique technique from “the same water”. Large Cladocera (Daphnia cucullata and Diaphanosoma brachyurum) showed the greatest reduction in a river, but they were common over a distance of up to 130 km below a dam. These two planktonic species revealed a low potential for colonizing oxbow lakes. Eurytopic Chydorus sphaericus and Mesocyclops leuckarti transferred from the Siemianówka Reservoir had a great dispersal capacity in the Narew River and could effectively support local populations in oxbow lakes over a distance of 180 km. Similarity between the crustacean communities in the river and the reservoir significantly decreased with the increasing distance from the dam. At the same time, crustacean communities in oxbow lakes were not affected by the distance from the source. Dispersal from the large source of zooplankton to local communities is a very important process but the local environmental factors such as habitat heterogeneity, aquatic vegetation and the hydrological connectivity can be strong enough to affect the structure of local crustacean communities in oxbow lakes.

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Demography of a common butterfly on humid grasslands : Argynnis aglaja (Lepidoptera: Nymphalidae) studied by mark-recapture

Zimmermann K., Konvicka M., Fric Z., Cihakova V.

Polish Journal of Ecology

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2009

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Vol. 57, nr 4

715-727

EN

Much of the research into the demography of butterflies conducted in Europe during the last few decades focused on rapidly declining or, on the other hand, expanding species, whereas species with stable trend tend to be neglected by researchers. Argynnis aglaja, a widely distributed inhabitant of semi-natural grasslands, represents a suitable model for studying patterns of landscape persistence of not-yet-threatened grassland insects. Using mark-recapture method conducted for one season on humid meadows in Western Bohemia, Czech Republic, we show that this large-bodied species is capable to form large and dense populations, reaching densities of over 250 individuals per hectare. The adults were relatively long-living, an average female longevity (11.8 d) was over twice as high as an average male longevity (4.6 d), with maxima being 22 (a male) and 30 (a female) days. The prolonged female lifespan is beneficial for a species that do not emerge with fully-matured eggs and oviposits singly over large areas. Modelling mobility, well-approximated by an inverse-power function, predicted that about one individual in a thousand would cross the distance of 1000 meters. We conclude that the satisfactory conservation status of A. aglaja stems from its capability to reach high local densities combined with a good dispersal power.

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Collembola (Insecta) disperse the arbuscular mycorrhizal fungi in soil: pot experiment

Seres A., Bakonyi G., Posta K.

Polish Journal of Ecology

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2007

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Vol. 55, nr 2

395-399

EN

Collembola often play an important controlling role in the interrelationship between arbuscular mycorrhizal fungi (AMF) and host plants. However there are little data to prove AMF dispersing ability of Collembola. In our experiment Folsomia candida (Willem) did not consume the spores of Glomus mossea (Nicol. and Gerd.) and G. intraradices )Schenck and Smith), but Sinella coeca (Schott) consumed 45% of the G. mossea spores and 71% of G. intraradices spores. Both species were able to disperse mycorrhiza in the soil, but the efficiency of dispersal was different. F. candida carried the infection more effectively than S. coeca, in spite of the fact that F. candida did not consume the spores in the food choice experiment. The total plant biomass was 23% higher in the presence of F. candida and 8.5% higher in the presence of S. coeca then in the control treatment without Collembola. The water content of the plants was also a little higher in the presence of both Collembola species (about 10%) than that of the control plants, but this difference was not statistically significant. Collembola improved the dispersion of the AM fungi, therefore enhanced the nutrient and water uptake of the plant.

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The fate of the ephippia - Daphnia dispersal in time and space

Pietrzak Barbara, Slusarczyk Miroslaw

Polish Journal of Ecology

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2006

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Vol. 54, nr 4

709-714

EN

When conditions deteriorate, freshwater cladocerans from the genus Daphnia switch to production of diapausing eggs encased in chitinous shells called ephippia. Ephippia may serve for temporal escape and recolonisation of the habitat or for geographical dispersal and colonization of other habitats. While dormancy and dispersal of ephippia have been well studied, initial factors determining the fate of the ephippia have remained unknown. We first consider the fate of an ephippium that sinks to the bottom of the water body, where it enriches the egg bank present in the sediments. We then discuss the potential and evidence for dispersal of ephippia, which is probably facilitated by their flotation on the water surface. Finally, we concentrate on the moment of the release of the ephippium showing a likely mechanism that determines its further fate - temporal or spatial dispersal - and we demonstrate it to be accomplished through maternal behaviour.

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A home away from home: a meiobenthic assemblage in a ship's ballast water tank sediment

Radziejewska T., Gruszka P., Rokicka-Praxmajer J.

Oceanologia

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2006

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No. 48 (S)

259-265

EN

The world-wide research on ship-aided dispersal of marine organisms and invasions of non-indigenous species focuses primarily on the plankters, which show the greatest potential for invading new areas and establishing viable populations in them, either in the water column (holoplankton) or on the bottom (meroplanktonic larvae of benthic species settling on the sea floor). As meiobenthic animals usually lack a pelagic larval stage in their life cycle, no biological invasion study has, to our knowledge, ever specifically targeted marine transport as a means of meiofaunal dispersal. Here we present a set of data showing that the sediment deposited in a ship's ballast water tank does support a viable meiobenthic assemblage. We examined 0.015-dm3 aliquots of a 1 dm3 sample from a c. 1.5-cm thick layer of sediment residue in the ballast tank of MS Donnington, brought to the "Gryfia" Repair Shipyard in Szczecin (Poland). The samples were found to contain representatives of calcareous Foraminifera, hydrozoans, nematodes, turbellarians, harpacticoid copepods and their nauplii, and cladocerans, as well as meiobenthic-sized bivalves and gastropods. Nematodes proved to be the most constant and most numerous component of the assemblage. The sediment portions examined revealed the presence of 1-11 individuals representing 11 marine nematode genera. The viability of the meiobenthic assemblage was evidenced by the presence of ovigerous females of both nematodes and harpacticoids. Survival of the meiobenthos in shipborne ballast tank sediment residues may provide at least a partial explanation for the cosmopolitan distribution of meiobenthic taxa and may underlie the successful colonisation of new habitats by invasive meiofaunal species.

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Rozpraszanie gazu w wodnym roztworze gliceryny metodą ciągłego zderzania się strumieni faz

Pawełczyk R., Kiszka K., Pindur K.

Przemysł Chemiczny

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2001

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T. 80, nr 5

197-201