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1

Resistance of riverine macroinvertebrate assemblages to hydrological extremes

100%
Szczerkowska-Majchrzak E., Lik J., Leszczynska J.
Oceanological and Hydrobiological Studies
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2014
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tom 43
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nr 4
2

Effects of hydrological disturbance of different magnitude on riverine habitats and benthic invertebrates

84%
Szczerkowska-Majchrzak E., Grzybkowska M.
Polish Journal of Ecology
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2015
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tom 63
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nr 1
Spates of different magnitude in a four order section of the lowland Drzewiczka River (central Poland) downstream from a dam reservoir and a wild-water slalom canoeing track (abbr. WCT) located just below the dam were studied. For over 20 years daily fluctuations enabling the training of canoeists induced a patchy mosaic of the riverbed, with five dominant habitats: pool, stagnant with emergent plants, submersed macrophyte, bank and riffle. Artificial floods, in September 2000, March 2001 and February 2002, were other flow events of this reach, thus the main aim of this paper is to assess the resistance of macroinvertebrates, measured as the relative lack of loss in density after floods. The three- (September) and five-fold (March) increased discharge in relation to the median affected the riverine environmental variables and caused the entrance into the water column and/or washing away of Ephemeroptera, Trichoptera and Simuliidae. In turn the highest-flow event (February, 16-fold flow increase) induced the instability of all bed patches. Oligochaeta, one of the dominant, inbenthic groups of passive drifters, were dragged along the bottom and then stopped by macrophytes. Meanwhile, chironomids, the second dominant benthic group, showed two kinds of behaviour patterns. Orthocladiinae, organisms prone to drift, were washed away after each flood; consequently the riffle and submersed macrophytes became partly depleted of them. Other midges, inbenthic Chironomini (Chironominae) with worse propensities to drift, were also washed out, except from deeper sediment layers, between the roots of macrophytes and in the bank habitat. Thus the macroinvertebrate assemblages in the Drzewiczka River have adapted to the moderate pulse disturbances, but their response to high flow events depends on the species' traits.
3

Factors shaping European rabbit abundance in continuous and fragmented populations of central Spain

84%
Virgos E., Cabezas-Diaz S., Malo A., Lozano J., Lopez-Huertas D.
Acta Theriologica
|
2003
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tom 48
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nr 1
This study analyses differences in European rabbitOryctolagus cuniculus (Linnaeus, 1758) abundance between fragmented and continuous populations and the relative importance of habitat structure (micro- and macrohabitat) and isolation in determining the abundance pattern in fragmented and continuous areas of central Spain. The species was mainly restricted to mediterranean vegetation habitat. In fragmented areas, rabbit abundance was linked to scrubland cover but was not correlated to pasture/cropland cover. The model explained very little of the observed variance. Distance to continuous populations did not improve the model. Stochastic phenomena or unmeasured factors (predation level, soil type) could be acting in this context. Rabbits were more abundant in continuous areas than in fragmented ones. In continuous areas, rabbit abundance was associated with mosaics of pastures, scrublands, and croplands. These habitat features are linked to shelter and feeding requirements of rabbits. The model explained an important part of the observed variance. This supports that management and conservation strategies should be based on the landscape pattern in each situation.
4

Local diversity versus geographical distribution of arthropods occurring in sandstone rock labyrinth

67%
Ruzicka V., Mlejnek R., Smilauer P.
Polish Journal of Ecology
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2010
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tom 58
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nr 3
Rocks have been overlooked as subjects for ecological study. However, the system of narrow and deep vertical spaces (gorges, crevices, abysses) in sandstone rocks supports a highly diverse mosaic of habitats. The patterns of air temperatures and the assemblages of arthropods were studied along the environmental gradient in the Poseidon Sandstone Labyrinth within the Adršpašsko-Teplické Skály National Nature Reserve, NE Bohemia, Czech Republic. The labyrinth, developed in Cretaceous sandsones at an altitude of about 600 m, is approximately 740 m long and 550 m wide. It consists of a broken, interconnected network of deep vertical crevices, crevice caves, and talus caves in extensive block accumulations. The total length of the human-accessible underground spaces is estimated to be at least 27 km, the vertical range is 105 m. The annual course of air temperature was monitored on the sun-exposed upper rock margin (max. 26.5°C, min. –7.3°C, mean 6.1°C), as well as in the cold and dark crevice cave (max. 9.6°C, min. –1.9°C, mean 3.7°C). Due to the climatic inversion in the deep vertical spaces, mountain bryophytes and vascular plants occur here. A total of 2285 arthropods belonging to eight taxonomic groups were evaluated; spiders and beetles were the most numerous. We registered 304 species, which colonize the totality of habitats in the labyrinth: cold bottom parts, dark caves, shady rock walls, as well as the sun-exposed upper rock margins. The cold parts of the labyrinth harbour populations of sixteen species of mountain arthropods (beetles, spiders and a harvestman) and five species of arthropods with distributions in tundra or boreal forests, and similar disjunctive habitats in the temperate zone in central Europe (spiders and a mite). The first record of the Arctic predatory mite Rhagidia gelida in central Europe was in the Poseidon Labyrinth in 1986; this species proved to be a bio-indicator of the long-lasting periglacial microclimate in central Europe. Prior to discovery of the spider Sisicus apertus in the Poseidon Labyrinth, it had been recorded in central Europe in the Alps and in the High Tatra Mountains at altitudes of 1150 to 2300 m. At the present time, we consider the Poseidon Sandstone Labyrinth to be a paleorefugium of cold-adapted arthropods.
5

Badger Meles meles sett site selection in low density Mediterranean areas of central Spain

67%
Virgos E., Casanovas J. G.
Acta Theriologica
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1999
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tom 44
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nr 2
We studied the habitat selection of badgers Meles meles (Linnaeus, 1758) in a mountainous area of central Spain through badger sett location, in relation to a series of variables related to the micro and macrohabitat structure considered potentially important for habitat requirements (food and shelter) were choosen. The analysis was carried out using the Savage index (W) for use/availability data, Badgers in this area prefer mid-elevation mountain areas, where both dehesas (open woods with pastures) and pine forests prevail. Lower elevation areas were avoided, Badgers are associated with watercourses, but we found, no significant differences for distance to villages or for roughness. Badgers preferred trees and rock covered areas, which provided shelter places. Badger conservation in Mediterranean mountains requires mosaic habitats (dehesas). The low density that has been found could be due both to human factors (eg persecution and habitat loss) and to a probable low suitability value of Mediterranean environ­ments for the badger. Department of Animal Biology I (Vertebrate Zoology), Faculty of Biological Sciences.
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