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Změny v zastoupení trofických skupin hlístic (Nematoda) na přirozeném úhoru a v půdách osetých regionálními a komerčními travními směskami
Háněl, Ladislav
Secondary succession started from a cultivated field soil with relatively low abundance of nematodes (five-year mean value 85 x 10.sup.4./sup. ind.m.sup.-2./sup.), especially with reduced populations of plant feeding species. The most dominant nematodes in the field were bacterivorous genera (55 %). During succession the total abundance of nematodes in the abandoned field plots (AF; natural fallow), regional grass mixture plots (RGM), and commercial grass mixture plots (CGM) increased to 109, 140, and 154 x 10.sup.4./sup. ind.m.sup.-2./sup.. The dominance of bacterivorous nematodes decreased to 30 %, 30 %, and 35 %, respectively. The abundance and the dominance of root-fungal feeding nematodes increased in RGM (25 %) and CGM(24 %) treatments, that of plant-parasitic nematodes increased in AF (12 %). The abundance and the dominance of omnivorous nematodes increased mainly in AF (24 %), that of predacious nematodes increased in all treatments (6 %, 4 %, 3 %, respectively).
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Společenstva půdních hlístic (Nematoda) ve vybraných mokřadních habitatech Národního parku Biebrza
Háněl, Ladislav
Nine marshland habitats of the Biebrza National Park in north-east Poland were investigated for nematodes in a single survey. In total, about 170 species and 89 genera of nematodes were determined. The abundance of nematodes in individual habitats ranged from 75 to 470 x 10.sup.4./sup. ind.m.sup.-2./sup.. The order Tylenchida represented 33 % of all nematode individuals, Dorylaimida 23 % and Araeolaimida 18 %. The respective numbers of genera in these orders were 22, 22 and 9, of species 43, 43 and 24.
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Long-term monitoring of the populations of Eudontomyzon mariae in the Račí potok brook (1998-2006)
Hanel, L. ; Lusk, Stanislav
The occurrence of the Ukrainian lamprey (Eudontomyzon mariae) in the Račí potok Brook is the only known population of this lamprey in the Czech republic. The status of the locality and population numbers of this species was followed up in 1998 through 2006. It is evident that the population size (as shown by the results of electro-fishings using invariably the same technique) is slightly increasing. Compared to 16 larvae.ha-1 in 1998, their number increased to 327 larvae.ha-1 in 2006. The abundance data were converted to the bottom surface, not only to that of suitable fine sediment deposits. In 2006, the same stream section was experimentally fished twice, and it has appeared that additional larvae were present in the second run (the increase in abundance being ca 38 %). In our opinion, the gradual increase in the population size of the Ukrainian lamprey in the Račí potok Brook is due to the recent revitalisation modifications of the brook bed.
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The Red List of lampreys and fishes in the Czech Republic - Version 2005
Lusk, Stanislav ; Hanel, L. ; Lusková, Věra ; Lojkásek, B. ; Hartvich, P.
The new Red List was compiled on the basis of data obtained in the course of five past years. Besides the overall evaluation for the Czech Republic, the data were separately evaluated for the North Sea, Baltic Sea, and Black Sea basins. The status and degree of danger imminent to the populations of the particular species were evaluated also separately for each of the 16 water regions. Compared to the 2000 evaluation, classification was changed for following species: Salmo salar (previously EW, now CE), Acipenser ruthenus (NE / CE), Sabanejewia balcanica (EX / CE), Zingel streber (EX / CE), Chondrostoma nasus (EN / VU), Lota lota (VU / NT), Rhodeus amarus (NT / EN), Leucaspius delineatus (NT / EN), Alburnoides bipunctatus (VU / EN), and Carassius carassius (VU / EN). The degree of jeopardy for Alburnoides bipunctatus, Vimba vimba, Rhodeus amarus, Carassius carassius, Misgurnus fossilis is basically different in different water regions, varying between Extinct and Near Threatened.
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Hlístice (Nematoda) v jílech hald uhelných dolů a v pokusně introdukovaných pásech luční půdy
Háněl, Ladislav
Soil nematodes were studied in coal-mining clay spoil denuded by a landslide of the upper part of a colliery dump three years ago. This control plot was compared with nematodes in introduced strips of fresh meadow soil heaped up on the spoil and in spoil strips between these soil strips. .i.Ecumenicus monohystera./i. (25% of all nematode individuals) and .i.Aporcelaimellus obtusicaudatus./i. (23%) dominated in the control spoil whereas in spoil between soil strips their population densities decreased. The greatest number of nematode species and genera was present in the soil strips. The number of species and genera increased in spoil strips adjacent to soil strips and proportions between trophic groups partially changed. Introduction of fresh meadow soil into colliery spoils may influence nematode assemblages in post-mining clays. Nevertheless, clay patches can harbour peculiar nematode assemblages that can contribute to the overall diversity of a post-mining landscape.
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Vývoj půdní fauny na loukách obnovených na orné půdě: Iniciální fáze sukcesního vývoje
Tajovský, Karel ; Pižl, Václav ; Starý, Josef ; Balík, Vladimír ; Frouz, Jan ; Schlaghamerský, J. ; Háněl, Ladislav ; Rusek, Josef ; Kalčík, Jiří
The development of soil fauna assemblages (testate amoebae, nematodes, enchytraeids, earthworms, terrestrial isopods, millipedes, centipedes, collembolans, dipteran larvae) has been investigated in a -field experiment since autumn 1999. Four types of treatment were studied in plots previously managed as arable land: 1) sowing with a native seed mixture, 2) sowing of a 5 m wide central strip with native and the lateral strips with commercial seed mixture, 3) sowing of a 5 m wide central strip with native seed mixture, leaving the lateral strips to spontaneous succession, and 4) leaving to spontaneous succession (abandoned field). The observed increase of qualitative and quantitative parameters of the individual soil animal groups corresponded to the initial phase of successional development. Eurytopic and euryvalent representatives as well as epigeic species of soil micro-, meso- and macrofauna prevailed in the studied treatments during the first years of observation.
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Fauna of soil nematodes and other soil micro-mesofauna in spruce clearings in the Šumava Mts., Czech Republic
Háněl, Ladislav
Soil micro- and mesofauna was studied in four spruce clearings in the Šumava Mts., covered by vegetation of Junco effusi-Calamagrostietum villosae. The total average abundance of nematodes varied from 1527 to 3864 x 10 3 ind.m-2 in individual localities (mean value 2833 x 10 3 ind.m-2). Root-fungal feeders were the most abundant nematodes mainly represented by Aglenchus agricola (about 50% of all nematodes) and by Filenchus spp. (5%, mostly F. misellus). The second most abundant trophic group were bacterivores (29%,mostly Acrobeloides nanus and Plectus spp.) followed by omnivores (6%, mostly Eudorylaimus spp.). The number of nematode species in individual localities varied from 51 to 57, the number of genera from 29 to 33. Generic heterogeneity of spruce clearing fauna was relatively low (mean H´gen = 1,92), as well as the value of maturity indices (SMI = 2,19, MI = 2,40, PPI = 2,01. (The mean abundance of enchytraeids in the set of localities studied was 55 x 10 3 ind.m-2, of rotifers 134 x 10 3 ind.m-2, of tardigrades 125 x 10 3 ind.m-2, and of copepods 5 x 10 3 ind.m-2.
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Short-term effects of grass mixtures on nematodes inhabiting agricultural soil in the Bílé Karpaty Mts., Czech Republic - a preliminary study
Háněl, Ladislav
Short-term changes of nematode assemblages were studied in field soil sown with regional and commercial grass mixtures and compared with those in a cultivated field in the course of one year. Total average abundance of nematodes in the grass mixture plots increased rapidly to 1308-2075 x 10 3 ind.m.-2 whereas in the field it remained relatively low (625 x 10 3 ind.m-2). The increase in population densities mainly concerned microbivores such as Panagrolaimus, Paraphelenchus, Aphelenchus and Aphelenchoides (950-1779 x 10 3 ind. m-2) followed by omnivores + predators (178-296 x 10 3 ind.m-2), while increase in plant parasite populations was slower (105-140 x 10 3 ind. m-2). The development of nematode assemblages suggests a great role of accumulation of above-ground as well as below-ground litter supporting microflora and microbial feeding fauna in initial stages of meadow restoration. In older stages, an increase of root density is expected simultaneously with multiplication of plant parasitic nematodes. Early successional development of soil nematode assemblages seemed to be faster in plots sown with regional grass mixture than in that sown with commercial grass mixture.
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Comparison of soil nematode communities in spruce forests of the Žofín woodland area (Novohradské hory Mts.) and the upper Vydra river basin (Šumava Mts.), Czech Republic
Háněl, Ladislav
Soil nematodes were studied in two spruce forests at the Žofín National Nature Reserve and in three spruce forests of the upper Vydra river basin, National Park Šumava, in South Bohemia. The total mean abundance of nematodes in the spruce forests ranged from 863 to 4877x10 3 ind.m-2 with variation from 231 to 6947x10 3 ind.m-2 on individual sampling dates. The most abundant nematode genera were root-fungal feeding Filenchus (48,3% of all nematode individuals in the spruce forests studied), bacterivorous Plectus (11,2%), and omnivorous Eudorylaimus (8,5%). The lowest abundance but the greatest variety of nematodes was found in a waterlogged spruce forests at the Žofín Reserve whereas the greatest abundance of nematodes occurred in the spruce forests of the Vydra river basin. The nematode fauna in the two regions compared showed particular differences, especially in the groups of bacterivorous, plant parasitic and predatory species.
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