Тaxonomic diversity of phytoplankton of fish ponds of Lviv Region

This article presents the results of a study on the taxonomic diversity and ecological characteristics of phytoplankton in fish ponds of the Lviv Region. It was found that the phytoplankton of the studied water bodies were characterized by high taxonomic diversity and was represented by 170 species and intraspecific taxa belonging to 95 genera, 52 families, 29 orders, 13 classes and 7 systematic divisions. The dominant group of the floristic composition were <i>Chlorophyta</i> (49-64% of the total number of detected species), the subdominants were <i>Bacillariophyta</i> (11-15%), <i>Euglenozoa</i> (7-20%) and <i>Cyanobacteria</i> (5-12%). The Sorensen's similarity index (<i>Ks</i> = 0.62-0.83) and Kendel's rank correlation coefficient for leading families (τ = 0.54-0.73) and genera (τ = 0.41-0.70) were high, indicating the similarity of the species composition of algal communities of different fish farms. The analysis of the ecological characteristics of algae showed that planktonic (33-38%) forms predominated in phytoplankton in terms of biotope distribution. Plankton-benthic, epiphytic forms were of secondary importance, accounting for 26-29% and 20-29% of the total number of species with a known biotope distribution, respectively. Slow-flowing forms dominated in terms of rheophilicity (79-88%), while indifferent species dominated in terms of salinity (82-91%) and relation to pH (73-86%). The main share of phytoplankton saprobic indicator species was formed by β-mesosaprobes (51-59%) and o-α-mesosaprobes (17-19%), which characterize these water bodies as those with a moderate level of organic pollution.

The taxonomic diversity of algae in the Western Bug River and its tributaries during the low-water summer-autumn season comprised 303 species (318 intraspecies taxa, ist) from 131 genera, 74 families, 45 orders, 16 classes and 8 phyla. <i>Bacillariophyta</i> and <i>Chlorophyta</i> lead in species and taxonomic diversity. In phytoplankton 140 ist were revealed, in microphytobenthos - 191, and in phytoperiphyton - 172 ist. The floristic core of algal communities was formed by 17 families. In phytoplankton the highest rank belonged to <i>Scenedesmaceae</i>, while in contour algal communities - <i>Naviculaceae</i>. The highest floristic similarity was observed for microphytobenthos and phytoperiphyton, and the highest dissimilarity - for phytoplankton and phytoperiphyton. The spatial differentiation between contour and plankton communities during the low-water period, uncovered high similarity of their floristic structure, indicating unity of structural organization of algae from different ecological groups in transboundary rivers. According to geographic range cosmopolites prevailed; according to water current and oxygen regime - indifferents; according to pH preference - alkaliphilic and indifferent species; according to salinity preference - indifferent species; according to saprobiological characteristics - χ-o-saprobic and β-mesosaprobic species According to biotopic preference, eurytopic and benthic forms prevailed. The dialectic unity between contour algal communities and phytoplankton largely depends on morphometric and hydrological characteristics of the rivers under study. High taxonomic diversity clearly marked spatial differentiation between planktonic and contour communities, noteworthy species of <i>Bacillariophyta</i> - all these features are indicative of the uniqueness and importance of algae in forming the biodiversity of the transboundary Western Bug River and its tributaries as the components of the EU hydrological network.

The taxonomic diversity of algae in the Western Bug River and its tributaries during the low-water summer-autumn season comprised 303 species (318 intraspecies taxa, ist) from 131 genera, 74 families, 45 orders, 16 classes and 8 phyla. Bacillariophyta dominated, Chlorophyta were recorded as subdominants. The phytoplankton taxonomic diversity included 140 ist, microphytobenthos – 191, phytoperiphyton – 172. The floristic nucleus of algal communities was formed by 17 families. In phytoplankton the highest rank belonged to Scenedesmaceae, while in contour algal communities – Naviculaceae. The highest floristic similarity was observed for microphytobenthos and phytoperiphyton, and the highest dissimilarity – for phytoplankton and phytoperiphyton. The spatial differentiation between contour and plankton communities during the low-water period, rather high similarity of their floristic structure indicate the unity of structural organization of algae from different ecological groups as an important component of biodiversity in the transboundary rivers. According to geographic distribution cosmopolites dominated; according to flow and oxygen regime – indifferents; according to pH preference – alkaliphilic and indifferent species; according to salinity preference – indifferent species; according to saprobiological characteristics – χ-ο- and β-mesosaprobic species. According to biotopic preference eurytopic and benthic forms prevailed. The dialectic unity between contour algal communities and phytoplankton to a great extent depends on morphometric and hydrological characteristics of the rivers under study. High taxonomic diversity, clearly marked spatial differentiation between planktonic and contour communities, interesting species of Bacillariophyta – all these features are indicative of the uniqueness and importance of algae in forming the biodiversity of the transboundary Western Bug River and its tributaries as the components of the EU hydrological network.

-Physicochemical measurements and phytoplankton were collected every 3 h during four, 24-h sampling periods in summer, 1976 and 1977, from Otter Creek, Oklahoma. Chlorophyll concentration and phytoplankton density were correlated with highest values occurring in late morning or afternoon. Ninety-four taxa of phytoplankton were collected; most were planktonic diatoms, green algae, or euglenophytes. Diel variations in species diversity and equitability was small and generally reflected changes in one or two dominant species. The algal pollution index exhibited considerable diel variation, indicating the importance of considering time of day when using the index. Most of the early literature on stream phytoplankton was qualitative. Numerous lists of the species of phytoplankton present in a stream have been published (Fritsch, 1903; Butcher, 1932; Lackey, 1942; Brinley and Katzin, 1942). In recent years the use of quantitative measures such as species diversity and density of phytoplankton has increased. Staub et al. (1970) studied the species diversity of phytoplankton in the Wolf River and its tributaries in Memphis, Tennessee. Diversity of phytoplankton was measured in the Cape Fear River, North Carolina (Carpenter, 1971) and in the Arkansas River near Ponca City, Oklahoma (Wilhm et al., 1977). Numerous authors have reported density values for stream phytoplankton (Williams, 1964; Weber and Moore, 1967; Carpenter, 1971; Wilhm et al., 1977). Diel periodicities of phytoplankton have been shown in many studies. The phytoplankton of the Saline River, Michigan, exhibited a diel pulse in downstream drift of certain benthic algae, apparently due to daytime oxygen production, which makes them more buoyant and easily carried away by the current (Blum, 1954). Rhythms also have been reported in uptake of nitrogen (Goering et al., 1964), photosynthetic activity (Lorenzen, 1963), and chlorophyll content (Yentsch and Ryther, 1957; Shimada, 1958). Diel rhythm in species diversity of stream phytoplankton has not been studied. The objectives of this study are to: (1) observe the diel rhythm of density, chlorophyll a and pheophytin a content, species diversity, and equitability of stream phytoplankton and (2) measure the diel rhythm of water temperature, dissolved oxygen, pH, and conductivity. STUDY AREA.-Otter Creek is an intermittent stream which flows through Garfield and Logan counties in north-central Oklahoma. The stream originates near Covington, flows 42 km southward, and empties into Skeleton Creek, a tributary of the Cimarron River. The elevation is 363 m at the source and 287 m at the mouth, with an average gradient of 1.8 m/km. The stream has narrow, eroding valleys which reach a depth of 23 m. Stream depth was 1 m at the sampling station. Otter Creek's drainage basin is 302 km2 and is in the mixed-grass prairie association. Broad-leaf trees line the stream banks. Most land in the basin is cultivated or used for pasture. T E SOUTHWESTERN NATURALIST 27(1):79-86 February 19, 1982 This content downloaded from 207.46.13.136 on Sat, 01 Oct 2016 05:52:34 UTC All use subject to http://about.jstor.org/terms The Southwestern Naturalist Further information about the stream is given by Harrel and Dorris (1968) and Seyfer and Wilhm (1977). MATERIALS AND METHODS.-Phytoplankton samples were collected on 28 June 1976 and 11 June, 11 July, and 21 August 1977. Surface samples were taken every 3 h beginning at 0500 h. Eight surface l-liter water samples were taken at each sampling time; four for analysis of phytoplankton were preserved in Lugol's solution and four for chlorophyll determination were placed in an ice chest. Water temperature and conductivity were measured with a Yellow Springs Instrument Co. YSI Model 33 54 oxygen meter. A portable Beckham pH meter was used for determining hydrogen-ion concentration. Three surface measurements of each physiocochemical parameter were made at each sampling time. In the laboratory, l-liter samples for chlorophyll a and pheophytin a determinations were extracted in 20 ml of 90% aqueous acetone. Following storage in a refrigerator at 4? C for 24 h, the optical density of the liquid extract was read before and after acidification with concentrated HC1 on a Beckman DBG spectrophotometer. The optical density readings were used to calculate chlorophyll a using the equations of Lorenzen (1967). Samples for species identification of diatoms were cleaned on a hot plate according to the method described by Weber (1971). Total counts of all species were made on cleared 0.45 jum membrane filters using a magnification of OOO1X. Species diversity and equitability were calculated for each sample by the equations of Shannon and Weaver (1963) and Pielou (1966), respectively. Density was computed for each phytoplankton sample by the equation,

The paper considers the present-day taxonomic and ecological diversity, spatial patterns of phytoplankton and algae on the interface of two phases: water – substratum (microphytobenthos and phytoepiphyton) in the most typical biotopes of Kaniv Reservoir in summer seasons of 2017–2022. 301 species (311 intraspecific taxa) of algae have been identified from 142 genera, 75 families, 44 orders, 15 classes and 8 phyla. At the phyla level Bacillariophyta, Chlorophyta and Cyanobacteria dominated. The highest number of species and infraspecific taxa – 143 (146) have been found in microphytobenthos. The highest diversity at the level of genera (98), families (57), orders (37), classes (11) and phyla (7) was observed for the phytoplankton. The phytoplankton was dominated by Chlorophyta and Bacillariophyta, the microphytobenthos and phytoepiphyton – by Bacillariophyta. The highest level of species similarity has been recorded between the algal communities at the interface of two phases: water – substratum, the highest dissimilarity – between phytoplankton and phytoepiphyton. According to geographic distribution cosmopolite species prevail, according to saprobity – χ-ο- and β-mesosaprobic organisms, according to salinity preferences – indifferent species, according to pH preferences – alcalifilic species. According to biotopic preference typically planktonic and eurytopic forms dominate the phytoplankton, and benthic and eurytopic forms dominate the microphytobenthos and phytoepiphyton. Comparing the present-day findings with the retrospective data has not shown any significant changes in the phytoplankton and the microphytobenthos structures. As before, Chlorophyta, Bacillariophyta and, to a lesser extent, Cyanobacteria continue to dominate in phytoplankton, and Bacillariophyta and Chlorophyta – in microphytobenthos. It is explained by natural internal processes prevailing in Kaniv Reservoir, relatively stable level of human impact, and constant algal flow from Kyiv Reservoirs and tributaries. Nowadays phytoplankton, microphytobenthos and phytoepiphyton are distinguished by high taxonomic diversity and play an important role in Kaniv Reservoir biodiversity.

Understanding the complex dynamics of aquatic ecosystems is very important for sustainable resource management in the field of aquatic resource management studies. This study aims to determine the distribution, abundance and diversity of phytoplankton and its correlation with water temperature around the PLTU Nii Tanasa area. The sampling method used is purposive sampling by taking water samples using a plankton net at predetermined stations. Data analysis of abundance, diversity, dominance, and correlation using Microsoft excel software. The number of samples found was 12 types of phytoplankton and came from several different classes. Abundance index (N) = low-moderate fertility (low enough), diversity index (H) = moderate category, dominance (C) = low, indicating stable community structure conditions. Water quality is classified as waters with moderate levels of pollution. Correlation of abundance, diversity and dominance of phytoplankton with water temperature has a positive and negative linear relationship.

In order to understand species composition and diversity of fish communities in the ecotone between the Yellow Sea and Bohai Sea, we examined species composition and temporal and spatial variations of fish species diversity using the relative importance index (IRI), species diversity index and k dominance curve based on bottom trawl survey data of fish resources in the adjacent waters of the Changshan Islands in October 2016, January, May and August 2017. The results showed that 77 fish species were captured, mainly temperate water fishes, demersal fishes and migratory fishes. The dominant species exhibited obvious seasonal variation. The dominant species in spring and winter were Lophius litulon, and those in summer were pelagic species such as Scomber japonicus and Engraulis japonicus. A total of 46 migratory fish species were found throughout the year. The seasonal species migration indices were all higher than 100, while the species migration index was the largest in autumn. The species diversity index showed high spatial and temporal dynamics, with the highest species richness in spring and the highest Shannon diversity and evenness in autumn. There was a significant negative correlation between species richness and sea surface temperature in summer, significant positive correlations between species richness and depth and bottom temperature in winter, and a significant positive correlation between Shannon diversity index and sea bottom temperature. In short, fish community showed high species diversity, rich migratory species and obvious temporal and spatial heterogeneity in the adjacent waters of the Changshan Islands, which is an ecotone between the Yellow Sea and the Bohai Sea.

Plant communities are coupled with abiotic factors, as species diversity and community composition both respond to and influence climate and soil characteristics. Interactions between vegetation and abiotic factors depend on plant functional types (PFT) as different growth forms will have differential responses to and effects on site characteristics. However, despite the importance of different PFT for community assembly and ecosystem functioning, research has mainly focused on vascular plants. Here, we established a set of observational plots in two contrasting habitats in northeastern Siberia in order to assess the relationship between species diversity and community composition with soil variables, as well as the relationship between vegetation cover and species diversity for two PFT (nonvascular and vascular). We found that nonvascular species diversity decreased with soil acidity and moisture and, to a lesser extent, with soil temperature and active layer thickness. In contrast, no such correlation was found for vascular species diversity. Differences in community composition were found mainly along soil acidity and moisture gradients. However, the proportion of variation in composition explained by the measured soil variables was much lower for nonvascular than for vascular species when considering the PFT separately. We also found different relationships between vegetation cover and species diversity according the PFT and habitat. In support of niche differentiation theory, species diversity and community composition were related to edaphic factors. The distinct relationships found for nonvascular and vascular species suggest the importance of considering multiple PFT when assessing species diversity and composition and their interaction with edaphic factors. Synthesis: Identifying vegetation responses to edaphic factors is a first step toward a better understanding of vegetation–soil feedbacks under climate change. Our results suggest that incorporating differential responses of PFT is important for predicting vegetation shifts, primary productivity, and in turn, ecosystem functioning in a changing climate.

Theory predicts that species diversity of isolated habitat patches depends on patch size and isolation. However, there are few previous studies of how patch size and isolation influence community composition. This study tested theory using small and isolated farmland patches in a forested matrix. I tested whether bird species diversity and community composition of isolated farmland patches depended on patch size, measures of isolation (e.g. distance from the main farmland areas; up to 15 km), and other variables such as presence of human habitation. Farmland bird species diversity and community composition (relative proportions of different ecological guilds) of 130 farmland patches within forest landscapes were recorded in Norway. Species diversity and proportion of the species that nested on the ground or low in bushes increased with patch size. Distance from the main farmland region was not related to species diversity or community composition, but species diversity increased when there were stepping stones present. Sites inhabited by humans had higher species diversity, a larger proportion of species nesting high in trees or in cavities (such as in buildings), and a larger proportion of resident species. Other variables were less important. There was also a strong relationship between the occupancy of individual species in the main farmland region and their occupancy in the forest region, suggesting that colonisation pressure also influenced species diversity of these habitat islands. I found weak evidence of isolation effects on bird species diversity and community composition of farmland patches within forest, whereas most of the variation was explained by patch size and presence of humans.

Ecosystems with forest and grassland patches as alternative stable states usually contain various closed, semi‐open and open habitats, which may be aligned along a vegetation cover gradient. Taxonomic diversity usually peaks near the middle of the gradient, but our knowledge on functional and phylogenetic diversity trends along gradients is more limited. We investigated the eight main habitats of Hungarian forest‐grassland mosaics, representing various vegetation cover values, and compared their species composition as well as their taxonomic, functional and phylogenetic diversity. We found a compositional gradient ranging from large forest patches through smaller‐sized forest patches and edges to closed and open grasslands. Species richness peaked at the middle of the gradient (at edges). Shannon diversity was high near the middle and at the open end of the gradient. Functional diversity was high throughout woody habitats (in forests and at edges) and was significantly lower in grasslands. When considering all species, phylogenetic diversity tended to peak at north‐facing forest edges. When excluding non‐angiosperms, this peak disappeared. The high taxonomic diversity at the middle of the gradient is in line with the edge‐effect theory. Our results suggest that community assembly in grasslands may be dominated by environmental filtering, while competition may be decisive in woody habitats. The low phylogenetic diversity of grassland habitats can be explained by their young evolutionary age compared to forests. Synthesis. Functional and phylogenetic diversity do not necessarily coincide with taxonomic diversity along vegetation cover gradients. In ecosystems where forest and grassland patches represent alternative stable states, the trends of taxonomic diversity may be similar to those revealed here, but functional diversity patterns may be more system‐specific for some traits. Trends in phylogenetic diversity may vary according to the evolutionary age of the habitats.

BackgroundAntibiotic resistance genes (ARGs) are widespread but cause problems only when present in pathogens. Environments where selection and transmission of antibiotic resistance frequently take place are likely to be characterized by high abundance and diversity of horizontally transferable ARGs. Large-scale quantitative data on ARGs is, however, lacking for most types of environments, including humans and animals, as is data on resistance genes to potential co-selective agents, such as biocides and metals. This paucity prevents efficient identification of risk environments.ResultsWe provide a comprehensive characterization of resistance genes, mobile genetic elements (MGEs) and bacterial taxonomic compositions for 864 metagenomes from humans (n = 350), animals (n = 145) and external environments (n = 369), all deeply sequenced using Illumina technology. Environment types showed clear differences in both resistance profiles and bacterial community compositions. Human and animal microbial communities were characterized by limited taxonomic diversity and low abundance and diversity of biocide/metal resistance genes and MGEs but a relatively high abundance of ARGs. In contrast, external environments showed consistently high taxonomic diversity which in turn was linked to high diversity of both biocide/metal resistance genes and MGEs. Water, sediment and soil generally carried low relative abundance and few varieties of known ARGs, whereas wastewater/sludge was on par with the human gut. The environments with the largest relative abundance and/or diversity of ARGs, including genes encoding resistance to last resort antibiotics, were those subjected to industrial antibiotic pollution and a limited set of deeply sequenced air samples from a Beijing smog event.ConclusionsOur study identifies air and antibiotic-polluted environments as under-investigated transmission routes and reservoirs for antibiotic resistance. The high taxonomic and genetic diversity of external environments supports the hypothesis that these also form vast sources of unknown resistance genes, with potential to be transferred to pathogens in the future.Electronic supplementary materialThe online version of this article (doi:10.1186/s40168-016-0199-5) contains supplementary material, which is available to authorized users.

The species diversity of ants in three different land use types: a mixed deciduous forest, and a derived commercial teak plantation and a durian orchard, were studied to determine and compare the ant species diversity in these areas. Five sampling methods: handling capture over constant time, sugar-protein bait trap, pitfall trap, leaf litter sifting and soil sifting, were conducted each month from September 2007 to September 2008, inclusive. The species richness of ants in the area was 62 identified species and 67 morphospecies, belonging to 49 genera in nine subfamilies. The Shannon-Wiener’s species diversity index indicated that the diversity was the highest in the mixed deciduous forest (2.387), followed by the durian orchard (1.997) and lastly the teak plantation (1.463). The β-diversity, using Sorensen’s similarity coefficient to determine the similarity in community composition, was highest between the forest and the teak plantation at 65.5%, and then between the teak plantation and the durian orchard at 45.5%, and between the forest and the durian orchard at 39.7%, indicating that both ant species diversity and community composition were distinctly varied in these three sites which may relate to their different land use types. Therefore, the information from this preliminary study suggests that, subject to confirmation and further clarification, ant species diversity may be used to assist the conservation and management planning of agro-forestry ecosystems.

Habitat fragmentation is considered as major threat to biodiversity worldwide. Biodiversity can be described as taxonomic, functional and phylogenetic diversity. However, the effect of forest fragmentation on taxonomic, phylogenetic and functional diversity is barely understood. We compare the response of taxonomic (species richness), phylogenetic and functional diversity of birds to forest fragmentation. We hypothesised that with increasing forest patch isolation and/or decreasing patch size the diversity of birds decreases but only if certain thresholds of fragmentation metrics are reached. Specifically, we hypothesized that out of the three diversity components the taxonomic diversity is the most sensitive to forest fragmentation, which means that it starts declining at larger patch size and higher connectivity values than phylogenetic and functional diversity do. We compared the three biodiversity metrics of central European bird species in a large set of forest patches located in an agricultural landscape. General additive modeling and segmented regression were used in analyses. Habitat fragmentation differentially affected studied biodiversity metrics. Bird taxonomic diversity was the most responsive towards changes in fragmentation. We observed an increase in taxonomic diversity with increasing patch area, which then stabilized after reaching certain patch size. Functional diversity turned out to be the least responsive to the fragmentation metrics and forest stand characteristics. It decreased linearly with the decreasing isolation of forest patches. Apart from the habitat fragmentation, bird taxonomic diversity but not phylogenetic diversity was positively associated with forest stand age. The lower share of dominant tree species, the highest taxonomic diversity was. While preserving a whole spectrum of forests (in terms of age, fragmentation and size) is important from the biodiversity perspective, forest bird species might need large, intact, old-growth forests. Since the large and intact forest becomes scarcer, our study underscore their importance for the preservation of forest specialist species.

Responses of forest-floor small mammals to clearcutting are species-specific with generalists occupying a range of habitats, and specialists persisting on clearcuts for variable periods. We investigated the responses in abundance and species composition of small mammal communities to cumulative clearcutting of coniferous forests on a landscape that had four independent clearcutting events (Periods 1 to 4) over a 42-year interval from 1979 to 2020 in south-central British Columbia, Canada. We ask if the small mammal communities have changed significantly over these decades owing to removal of old-growth forest by clearcut harvesting. Hypotheses (H) predicted that the small mammal community would (H1) increase in abundance, species richness, and diversity on new clearcuts owing to the availability of early seral post-harvest habitats from cumulative clearcutting; and (H2) have higher mean abundance, species richness, and species diversity in clearcut than uncut forest sites, owing to availability of vegetative food and cover. A third hypothesis (H3) predicted that abundance of (i) early seral vegetation (herbs and shrubs) and (ii) small mammal populations, will be greater in ungrazed clearcut sites than in those grazed by cattle (Bos taurus). Mean total numbers of small mammals on new clearcuts declined in Periods 3 and 4, and hence did not support the abundance part of H1. Much of this decline was owing to low numbers of the long-tailed vole (Microtus longicaudus) and meadow vole (M. pennsylvanicus). Two generalist species: the deer mouse (Peromyscus maniculatus) and northwestern chipmunk (Neotamias amoenus), contributed to high mean species richness and diversity in Periods 2 and 3 before these metrics declined in Period 4, and hence partly supported H1. The similarity in mean total numbers of small mammals in Periods 2 to 4 did not support the abundance prediction of H2 that total numbers would be higher in clearcut than uncut forest sites. Higher mean species richness (Periods 2 and 3) and diversity (Period 3) measurements on clearcut than forest sites, particularly in the early post-harvest years, did support these parts of H2. The vegetation part (i) of H3 was not supported for herbaceous plants but it was for shrubs. The small mammal part (ii) of H3 that populations would be higher in ungrazed than grazed clearcut sites was supported for abundance but not for species richness or diversity. The decline and near disappearance of both species of Microtus was possibly related to the reduction in plant community abundance and structure from grazing (at least for shrubs) and potentially from drought effects associated with climate change. Loss of microtines from these early seral ecosystems may have profound negative effects on various ecological functions and predator communities.

Pure or mixed plantings equally enhance the recovery of the Atlantic forest