Content of the Volume 33.
Pénzes, Zs., Csanádi, Gy., Kovács, M.G. and Beer. Zs.: Molecular markers in ecology
Horváth, R.: The diet of dippers (Cinclus cinclus) in the Aggtelek karst
Dombos, M. (2002): A Tullgren–type extractor for sampling springtails populations from small volume soil cores in high sample size. — Tiscia 33, 3-7.
Abstract. I investigated the accuracy and precision of a Tullgren–type extractor, modified to sample springtails populations from small volume soil cores in high sample size. Efficiency of the extractor was tested in two types of running procedures by putting known number of Folsomia candida (Willem) in the soil cores. The accuracy and precision depended highly on the running procedures, one of the loading types had sufficient reliability, whereas other conditions did make high variance in the efficiency. In the loading methods, when the temperature was slightly increased, both the accuracy and precision of the census technique was higher compared to that one, where temperature was enhanced abruptly. The construction of the extractor is detailed.
Key–words: sampling methods, Tullgren–type
extractor, Collembola
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text)
Pénzes, Zs., Csanádi, Gy., Kovács, M.G. and Beer. Zs. (2002): Molecular markers in ecology. — Tiscia 33, 9-30.
Abstract. The aim of this paper is to encourage reluctant ecologists thinking more on the use of genetic markers. No training in molecular methods is supposed. The resistance may be explained by the confusion of the high number of methods, including laboratory techniques (named by up to four characters) and evaluation. Inevitably, field work needs some extra step to collect DNA source, but sampling strategy is the same or even less restrictive owing to the new, powerful statistical methods. Laboratory techniques develop very fast, many phases can be done automatically and/or many customers provide services on reasonable price.
Despite the financial and technical requirements, genetic markers provide high quality information that can be obtained hardly otherwise, or simply impossible. We try to overview the most important genetic markers and technology used recently. Some examples are given by studies of parentage, population structure (migration, fragmentation) or population history.
Keywords: DNA techniques, DNA markers,
molecular markers
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text)
Vörös, G., Gallé, L. (2002): Ants (Hymenoptera: Formicidae) as primary pests in Hungary: Recent observations. — Tiscia 33, 31-35.
Abstract. During the period between 1994 and 2001 considerable ant damages were observed in several fields, horticultural and medicinal crops in county Tolna, southern Hungary. Ants generally attacked young plants, foraging and thinning their root collars, therefore the plants fell off and then dried. They foraged skin of fruit crops and grapes and consumed fruit flesh, too. In public parks and nurseries of Budapest ants provoked lobed leaves on ornamental shrubs and trees. Majority of ants collected from damaged plants were Tetramorium caespitum and Lasius spp. In apples Camponotus spp. also occurred, while from grapes a Mediterranean species, Prenolepis nitens was identified.
Key words: ants (Formicidae), damage, crops,
Hungary
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text)
Zivic, I., Markovic, Z. and Brajkovic, M. (2002): Macrozoobenthos of three brooks in the southern part of the Pannonian Plain: comparative analysis of secondary production. — Tiscia 33, 37-44.
Abstract. Production of macrozoobenthos was investigated at 18 localities on the Kudoski, Jelenacki, and Borkovacki brooks during April, July, and October of 2000 and in January of 2001. 16 groups of macroinvertebrates were recorded in the course of the investigation. The dominant groups in the biomass of macrozoobenthos were Hirudinea (Annelida), Mollusca, Gammaridae (Crustacea), and Trichoptera (Insecta). The greatest biomass of the bottom fauna in all months of investigation was recorded in the Kudoski brook, where it ranged from 41.3248 g/m2 in July to 133.2384 g/m2 in October, the next greatest one in the Jelenacki brook, and the least in the Borkovacki brook (from 23.7432 g/m2 in July to 90.3328 g/m2 in January).
Key words: macrozoobenthos; secondary
production; Kudoski, Jelenacki, and Borkovacki brooks
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text)
Harka, Á., Györe, K and, Lengyel, P. (2002): Growth of the golden spined loach [Sabanejewia aurata (Filippi, 1865)] in River Tisza (Eastern Hungary). — Tiscia 33, 45-49.
Abstract. The paper presents data on the growth of golden spined loach, obtained on the basis of the study of 91 fish specimens. The study material was collected from an isolated lock chamber, at the same time and without any selection. Hence, its size and age distributions seem to represent those of the population well.
There were 78 first-year, 12 second-year and 1 third-year fish among the collected specimens. Their standard lengths ranged from 25 to 71 mm, their body weights, from 0.12 to 4.41. According to our results, the average standard length of the fish at age t (Lt in mm) can be expressed with the equation Lt = 92[1-e-0.505(t+0.01)].
There is no significant difference between the growths of males and females. Both body length and body weight increase intensely in the second year. Hence, the biomass of the second-year age group is well above that of the first-year fish, in spite of the high mortality.
The reach of the Tisza studied by us is dammed, and thus, environmental conditions are not optimal for golden spined loach. In addition, the population suffered damages also from the cyanide spill that polluted the river in February 2000. Though, the survival of the population is not in danger, as the species reaches maturity by the second-year age, and thus, there is an adequate proportion of mature specimens.
Keywords: Sabanejewia bulgarica,
Bertalanffy’s model, age structure, mortality, production
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text)
Harka, Á., Sallai, Z. and Wilhelm, S. (2002): Effects of water pollution and global warming on the fish fauna of the Romanian tributaries of the River Tisza. – Tiscia 32, 51-58.
Abstract. In the summer of 2000, we conducted fish faunistical samplings in the Romanian reach of Upper Tisza River and its left tributaries. As a result, we found one new species (Oncorhynchus mykiss Walbaum, 1792) in the Szaplonca/Săpânţa Brook and two new species (Vimba vimba Linné, 1758, Gobio kessleri Dybowski, 1862) in the Iza River. The fauna of the Iza is rich in natural values – 13 of its 23 fish species are legally protected in Hungary. But in the Visó/Vişeu the number of fish species (17) and their density (the number of fish samples caught in the Visó is just about 20 % of that found in the Iza) bear marks of the frequent heavy metal pollutions.
Studying the river zones, we noticed, in their fish communities, species normally inhabiting lower zones as well. This change increasingly observable in other zones of other rivers as well, which can be caused by the warming of the rivers. Numerous factors are likely to contribute to this phenomenon, but the main cause is most probably the warming that increased the surface temperature of the Northern Hemisphere by an average of 0.6 0C and that of Hungary by 0.67 0C in the 20th century.
Key words: Máramaros/Maramureş, zonation of
rivers, expansion of gobiid species, water-system of Danube
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text)
Horváth, R. (2002): The diet of dippers (Cinclus cinclus) in the Aggtelek karst. — Tiscia 33, 59-66.
Abstract. The study highlights the changes in the food-composition of dippers (Cinclus cinclus) based on the method of pellet and faecal analyses. The collected reguriated pellets and faeces were analysed together with the evaluation of the potential food supply for dippers. By applying the two methods simultaneously, I managed to prove the change in the feeding tactics of dippers as well as the efficiency of the two methods.
Keywords: Aggtelek National Park, Cinclus
cinclus, diet of dippers, faecal analysis, pellet analysis
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text)
Szigetvári, Cs. (2002): Initial steps in the regeneration of a floodplain meadow after a decade of dominance of an invasive transformer shrub, Amorpha fruticosa L. — Tiscia 33, 67-77.
Abstract: The flora and vegetation of two floodplain meadow sites invaded by the nonindigenous shrub, Amorpha fruticosa L. were compared. One of the sites (site [A]) was previously completely invaded by the species, which had transformed the habitat into a monodominant thicket for more than ten years before it was cleared in 2000. The other site (site [B]) was more or less continuously mowed therefore Amorpha only reached here 50 % cover on average and large patches of the grassland community remained intact. The two sites are managed similarly, by mowing or stalk-cutting twice a year, which prevents seed set and sprouting of Amorpha. The flora of the sites was censused and vegetation was sampled by estimating species cover in 4×4 m quadrates, 30 sampling units in each site. Our floral investigations detected 107 species in site [A] and 115 in site [B]. The species pool of the two sites was similar, and almost all species characteristic to the target vegetation (represented by site [B]) were present in the recovering area, site [A]. The vegetation investigations revealed that species richness per quadrates was significantly lower in site [A], which was mainly due to the rareness of subordinate species. The cover of Amorpha did not correlate with species richness within the sites. Fifteen species had significantly higher cover in site [B] while only two species, including Amorpha had higher cover in site [A]. PCoA ordination of the quadrates based on species presence information markedly discriminated the two sites, while NMDS ordination based on species cover data did not segregate them to much extent. The points representing site [A] were more scattered in the ordination space. The orientation of the quadrates in the ordination scattergram was not associated with the cover of Amorpha when within site variability was investigated. The variation in species combinations and dominance relationships was associated mainly with the opposite behaviour of two dominants: Alopecurus pratensis and Bidens tripartita. Interspecific correlations showed that the invasive species has almost as mani positive as negative correlations in both sites at the scale of investigations. The most remarkable is the strong negative correlation between Amorpha and the dominant Alopecurus pratensis in site [A].
We concluded that although only weak evidence supports that Amorpha has considerable present impact on the within-site vegetation variation, the lower species richness, the absence or low cover of subordinate meadow species and the patchiness of vegetation in site [A] can be attributed to the past dominance of the invasive species. The species pool of the site [A] area is promisingly rich for future rehabilitation. The dominants of the target vegetation are already quite frequent which assures regeneration, while most of the subordinate species are rare and scattered. The vegetation seems to have low resistance to colonization which might enforce recolonization of both natural species and invasion of aliens. Only systematic management of the area assures successful regeneration.
Keywords: plant invasion, community rehabilitation, Tisza river, inundation area, Alopecurus pratensis, Bidens tripartita