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Diversity and Community Structure of Oribatid Mites (Acari, Oribatei) at Memorial Complexes of a Megapolis

Abstract

In different types of substrate (soil, litter, lichens and mosses) collected at three memorial complexes (cemeteries) of Kyiv (Ukraine), 70 species from 57 genera, 34 families of oribatid mites were found. A few eurytopic species capable of tolerance to different types of pollution make up an essential part in each species complex. The species diversity and complexity of oribatid community structure at researched areas increased with distance from the city center. There was no direct relation between the degree of dominance of most common species and the cemetery’s relative remoteness from the center of the city.

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The Influence of Selected Factors on the Distribution of Epilithic Diatoms in a Torrential River the Kamniška Bistrica (Slovenia)

Abstract

Physical and chemical characteristics of habitats and species diversity in streams and rivers are strongly influenced by the catchment area. We analysed the influence of selected environmental and spatial variables on the diversity and species composition of epilithic diatom communities in periphyton. Samples were collected along the river course in a torrential river the Kamniška Bistrica. Sampling sites were selected in reaches distributed from the source to the outlet of the river and were under different influences from the catchment area and with different physical and chemical characteristics. The most common and dominant diatom species in the periphyton community were Achnan-thes biasolettiana and A. minutissima. Achnanthes species often inhabit rivers and springs with moderate organic pollution. Another common diatom taxon was Gomphonema pumi-lum - a key species indicating oligosaprobic conditions. The results of the canonical cor-respondence analyses revealed that variance of the periphytic diatom community was explained by water temperature and conductivity as well as altitude. Diatom species richness was positively correlated with saprobic index values and abundance of filamentous algae in the river bed indicating a relatively low organic matter and nutrient input into the river system.

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Preliminary study of the impact of pig or goat manure fertilization of a meadow on oribatid mites

Abstract

We investigated the impact of pig or goat manure fertilization of a meadow with doses of 80 kg N ha−1, 140 kg N ha−1, and 200 kg N ha−1 (plots 1-6) on oribatid mites. A control plot (0) was left unfertilized. The manure was applied to the meadow in the early spring of 2012, and soil samples were collected in the spring of 2012 and 2013. In total, 6053 oribatid mites were examined, including 1163 juveniles. The effect of fertilizing on the Oribatida depended on the dose of manure, but not on its type. A low dose of pig or goat manure did not affect the density of Oribatida, whereas the other doses decreased it, but only the highest doses decreased it significantly, compared to the control. Species diversity decreased with the dose of manure. In total, 24 species of Oribatida were found and some species reacted differently to both types of manure. For example, a low dose of pig manure significantly increased the density of Eupelops occultus, whereas the density of other species significantly decreased under the influence of the highest dose of pig manure (Achipteria coleoptrata), highest doses of pig and goat manure (Galumna obvia, Liebstadia similis), and medium and highest doses of goat manure (Scheloribates laevigatus).

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The influence of forest management and timber use options on carbon sequestration and the consequences on biodiversity

Abstract

The results of scientific studies dealing with the influence of forest management on carbon dynamics are often controversial. Substituting fossil fuels with wood is not always a climate-friendly solution, and besides, it has often a negative impact on biodiversity. The current paper reviews the literature about the influence of different forest management and timber use options on climate change and brings out the accompanying consequences on biodiversity in temperate and boreal climate zones. The forest’s ability to sequestrate and store carbon can be enlarged by appropriate forest management planning and practices. Generally, for mitigation of climate change, the moderate (not intensive) forest management is most favourable, but intensification of management enhances global warming, since forest carbon storage in tree biomass and soil decreases. The mitigation of climate change is just one of the many roles of forest, and climate policy actions cannot come at the expense of species diversity. The complex studies dealing with several forest goals conclude that high carbon store and biodiversity protection do not contradict each other, but the achievement of maximum economic profit at the same time is not possible. The mitigation of climate change and wildlife protection is most effective when it is first of all the forests with a high biodiversity that are managed less intensively. Concerning climate change, the most negative forest biomass use is wood combustion. It is reasonable to burn only such biomass (cut and industrial residues) which cannot be used for producing goods holding carbon for a long time.

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Limnological study of Serbian oxbow shaped Lake Srebrno, with special emphasis on the benthic community composition and structure

Abstract

Detailed limnological study of the Lake Srebrno (Serbia) bottom fauna was performed in March 2007. Investigations included qualitative, quantitative, and saprobiological analysis of bottom fauna communities, physical and chemical analysis of sediments and determination of chlorophyll a concentration, as well as saprobic and trophic status analyses. Samples were collected at eighteen sites distributed along a shoreline and in deeper sections of the lake. Twenty taxa from nine macroinvertebrate groups were recorded. Family Chironomidae had the biggest index of participation, the highest species diversity and the largest density of populations in benthocenoses of Lake Srebrno. Faunistic similarity between sites was estimated according to Sorensen’s Quotient of Similarity (QS). The majority of benthocenoses - 56% showed a medium level of faunistic similarity (QS = 21-60%), and 42% of benthocenoses showed a high level of faunistic similarity (QS = 61-100%). The classification of Lake Srebrno based on saprobic and trophic levels was assessed. Saprobic level was in the range from alpha-meso- to poly-alpha-mesosaprobity. The water quality of the lake ranged from class III and between IV and III class. Generally, Lake Srebrno had eutrophic status with the gradation to hypertrophy.

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Land Snails in the Slovak Open-Air Garden Centres

Abstract

In last decades, the number of non-native land snails increased up to 15 percentages; they create more than eight percent of all the Slovakian species. Trend of newly established snail species corresponds with increases in the average temperatures as well as the intensity of foreign trade, suggesting a synergistic effect of both climatic conditions and socioeconomic factors. The research of the open-air garden centres in Slovakia confirmed both factors. We report here some of the newly established populations of sixteen mollusc species. In the old garden centres, the number of species as well as the number of individuals decreased slightly. Area of the garden centre has a very high impact on both abundance and species diversity. The size and age of garden centre proportionally influences the composition of mollusc assemblages. Two new species Cornu aspersum and Cepaea nemoralis were noticed for the first time in Slovakia. The recent findings of the introduced populations demonstrate the potential of this snail to colonise new areas.

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Do Tillage Methods Affect Germination and Species Similarity of Soil Weed Seeds Bank?

Abstract

Cultural practices such as tillage used for crop production influence the composition of the weed seed bank in the soil. In order to investigate the effects of different tillage methods on seed bank properties, species diversity and similarity, two laboratory and greenhouse experiments were carried out as randomized complete block design with four replications in 2011. Treatments included: once tillage per year (T1), twice tillage per year (T2), more than twice tillage (T3) and no tillage (T4). Laboratory results showed that the T3 and T4 treatments had the highest and the lowest observed seeds numbers, respectively. Between the laboratory observed weed seeds, the maximum weed seed numbers were Echinochloa crus-galli and Amaranthus retroflexus in the T3 treatment, while Chenopodium album, Polygonum aviculare and Cuscuta campestris had the highest seed numbers in the T2 treatment. At the greenhouse study, Chenopodium album, Amaranthus retroflexus and Hordeum morinum in the T2 treatment were dominant species. The highest diversity was observed in the T2 treatment, and Chenopodium album and Echinochloa crus-galli were dominant species in the T2 and T3 treatments. Maximum species similarity index was achieved from the T1 and T3 treatments. Thereby this study concluded that increasing of tillage number could affect the similarity index of weed seeds and subsequently alters the weed community composition.

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Species composition and abundance of the oribatid fauna (Acari, Oribatida) at two lakes in the Fløyen area, Bergen, Norway

Species composition and abundance of the oribatid fauna (Acari, Oribatida) at two lakes in the Fløyen area, Bergen, Norway

Oribatid communities from the edges of two lakes in the Fløyen area, Bergen, Norway, were compared in June 2005. The lower lake, Blåmansvannet (412 m a.s.l.), is surrounded by spruce forest, while the ‘Higher Lake’ (513 m a.s.l.), is above the tree line. Both lakes have a low pH and their edges are dominated by Sphagnum mosses. The abundance of total mites, as well as of Oribatida, were almost 2-fold higher at the ‘Higher Lake’ (51 510 and 51 160 ind./m2, respectively), while species diversity was lower than at Blåmansvannet. On the shore of Blåmansvannet, the eudominant (20% < D ≤ 40%) species was Trimalaconothrus maior, while Liochthonius peduncularis, Limnozetes ciliatus, and Nanhermannia cf. coronata were dominant (10%< D ≤ 20%). At ‘Higher Lake’, the eudominant species was Limnozetes ciliatus, which reached a 4-fold higher abundance (15 930 ind./m2) than at Blåmansvannet, and dominant species were Liochthonius alpestris, Nanhermannia cf. coronata, and Platynothrus punctatus. At both lakes, juveniles made up about 30% of all oribatids. Four species are new to Norway: Ceratoppia sexpilosa, Liochthonius alpestris, Liochthonius peduncularis, and Trhypochthoniellus longisetus.

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Oochoristica koubeki n. sp. (Cestoda, Anoplocephalidae) from African Chamaeleo senegalensis (Chamaeleonidae) and emendation of the genus Oochoristica Lühe, 1898

Abstract

During a survey of species diversity and ecology of selected West African vertebrates in the Niokolo Koba National Park, Senegal, two Chamaeleo senegalensis Daudin, 1802 (Chamaeleonidae) were collected and examined for parasites. A new species, Oochoristica koubeki n. sp., anoplocephalidian cestode of the genus Oochoristica Lühe, 1898 is described from the intestine of this host. The new species is related to O. theileri Fuhrmann, 1924; O. theileri Fuhrmann, 1924 f. major Baer, 1933; O. celebensis Yamaguti, 1954 and O. rostellata Zschokke, 1905 var. agamicolla Dollfus, 1957. All the forenamed species share characteristic strobila with proglottids wider than long. Oochoristica koubeki n. sp. differs from these species in different proportions of scolex, cirrus sac, ovarium and vitellarium, further differences are in number of testes and presence of reinforced genital atrium. Only O. theileri shares two last mentioned features, however it differs in shape of testes (rounded) and in distribution of testes (two clusters). The new species differs from all other species in extremely high number of egg’s capsules, different host species and zoogeographic distribution. Emendation of genus diagnosis sensu Beveridge (1994) is provided.

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Diatoms in an extreme euxinic environment (Rogoznica Lake, eastern Adriatic coast)

Abstract

The Rogoznica Lake marine system is a small, karstic, naturally eutrophic and euxinic marine environment. Abundance and temporal distribution of phytoplankton was investigated in relation to environmental conditions in the period from 1998 to 2013. The 36 determined diatoms contributed 90% of the total phytoplankton abundance. The diatom composition is characterized by low species diversity and high single species abundance (up to 107 cells L-1). There were, on average, 2.6 diatom species per sample (maximum 14 diatom species per sample) reflecting extreme environmental conditions. Dominant diatoms Thalassionema nitzschioides, Cyclotella choctawhatcheeana, Dactyliosolen fragilissimus and Chaetoceros curvisetus occurred repeatedly and were alternately dominant in the lake during the whole research period. Some diatoms were dominant only in limited period, like Cyclotella choctawhatcheeana (evident since 2001), and Pseudo-nitzschia spp. (evident in the period 2002 to 2009). It appears that the interplay of environmental conditions such as variability in thermohaline and redox conditions, nutrient and reduced sulphur concentration influence the phytoplankton development and abundance in the lake.

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