Homogeneous Species Research Articles

The omission of critical data in the pursuit of ‘revolutionary’ methods to accelerate the description of species

The omission of critical data in the pursuit of ‘revolutionary’ methods to accelerate the description of species

Species interaction: Revisiting its terminology and concept

AbstractTerminology can profoundly influence scientific research. Here, I discuss the term “species interaction,” which constitutes the core of ecology. The term has the merits of underlying many fundamental ecological ideas (e.g., competitive exclusion, trophic cascade and keystone predation) and making ecological research more interdisciplinary (e.g., biodiversity conservation and ecosystem management). Meanwhile, it has the demerits of causing problems of synonymy and polysemy, masking the fact that interactions occur at the individual level, and reinforcing the counterfactual view that an ecological community is a network of interactions between homogeneous species. This means that the facile use of the term may impede our understanding of community dynamics, which is a great concern considering recent evidence that individual heterogeneity is ubiquitous (e.g., due to ontogeny, sex and genotype) and crucial for community dynamics. To further extend the debate, I present some prospective scenarios in which future research trends may affect the importance of the terminological debate. For example, the term may obtain other definitions due to the establishment of new analytical techniques (e.g., DNA metabarcoding and causation analysis), or the debate may become obsolete if a consensus is reached that interactions occur between individuals (i.e., a paradigm shift). These arguments indicate that how we can use the term depends on how we view interactions between organisms. I suggest that multifaceted approaches that consider not only the terminology but also its associated concept and relevant research methodology are needed to overcome the issues of such ambiguous terminology and guide the future development of ecology.

Recent hybrid speciation at the origin of the narrow endemic Pulmonaria helvetica.

Hybridization is known to drive plant speciation through the establishment of homoploid or allopolyploid hybrid species. Here we investigate the origin of Pulmonaria helvetica, a narrow endemic species described across a restricted area of Switzerland that was entirely covered by ice during the last glacial maximum. This species presents an original number of chromosomes (2n = 24) and morphological traits suggestive of a hybrid origin. We sequenced a plastid locus and 1077 double-digest restriction-site-associated DNA (ddRAD) loci in 67 individuals from across the distribution range of P. helvetica and candidate progenitor species growing in the same area. Assignment of genotypes to main genetic clusters within and among taxa using STRUCTURE tested whether P. helvetica represents a genetically differentiated lineage and addressed the hypothesis of its hybrid origin. Comparative ecological modelling further addressed possible niche differentiation among taxa. Pulmonaria helvetica was highlighted as a genetically homogeneous species distinct from co-occurring taxa. Consistent with a scenario of hybrid speciation, it presented clear evidence of balanced admixture between Pulmonaria officinalis (2n = 16) and Pulmonaria mollis s.l. (2n = 18, 22), which was also highlighted as a maternal progenitor based on plastid sequences. Limited genetic structure within the maternal progenitor is consistent with an origin of P. helvetica through either homoploid hybridization with considerable karyotype changes or via complex scenarios of allopolyploidy involving a dysploid taxon of P. mollis s.l. Comparative niche modelling indicated non-significant ecological differences between P. helvetica and its progenitors, supporting intrinsic factors resulting from hybridization as main drivers of speciation. Hybridization appears as a major process having promoted the postglacial origin of the narrow endemic P. helvetica, suggesting hybrid speciation as an effective process that rapidly produces new species under climate changes.

Evaluation of antioxidant activity and toxicity of sulfur- or selenium-containing 4-(arylchalcogenyl)-1H-pyrazoles.

Pyrazoles represent a significant class of heterocyclic compounds that exhibit pharmacological properties. The present study aimed to investigate the antioxidant potential of pyrazol derivative compounds in brain of mice in vitro and the effect of pyrazol derivative compounds in the oxidative damage and toxicity parameters in mouse brain and plasma of mice. The compounds tested were 3,5-dimethyl-1-phenyl-4-(phenylselanyl)-1H-pyrazol (1a), 3,5-dimethyl-4-(phenylselanyl)-1H-pyrazole (2a), 4-((4-methoxyphenyl)selanyl)-3,5-dimethyl-1-phenyl-1H-pyrazole (3a), 4-((4-chlorophenyl)selanyl)-3,5-dimethyl-1-phenyl-1H-pyrazole (4a), 3,5-dimethyl-1-phenyl-4-(phenylthio)-1H-pyrazole (1b), 3,5-dimethyl-4-(phenylthio)-1H-pyrazole (2b), 4-((4-methoxyphenyl)thio)-3,5-dimethyl-1-phenyl-1H-pyrazole (3b), 4-((4-chlorophenyl)thio)-3,5-dimethyl-1-phenyl-1H-pyrazole (4b), and 3,5-dimethyl-1-phenyl-1H-pyrazole (1c). In vitro, 4-(arylcalcogenyl)-1H-pyrazoles, at low molecular range, reduced lipid peroxidation and reactive species in mouse brain homogenates. The compounds also presented ferric-reducing ability as well nitric oxide-scavenging activity. Especially compounds 1a, 1b, and 1c presented efficiency to 1,1-diphenyl-2-picryl-hydrazyl-scavenging activity. Compounds 1b and 1c presented 2,20 -azino-bis(3-ethylbenzthiazoline-6-sulfonic acid)-scavenging activity. In vivo assays demonstrated that compounds 1a, 1b, and 1c (300 mg/kg, intragastric, a single administration) did not cause alteration in the of δ-aminolevulinic acid dehydratase activity, an enzyme that exhibits high sensibility to prooxidants situations, in the brain, liver, and kidney of mice. Compound 1c reduced per se the lipid peroxidation in liver and brain of mice. Toxicological assays demonstrate that compounds 1a, 1b, and 1c did not present toxicity in the aspartate aminotransferase, alanine aminotransferase, urea, and creatinine levels in the plasma. In conclusion, the results demonstrated the antioxidant action of pyrazol derivative compounds in in vitro assays. Furthermore, the results showed low toxicity of compounds in in vivo assays.

Hypoglycemic effect of biscuits produced from flour blends of three medicinal foods on high-fat diet-streptozotocin-induced diabetic rats.

The study evaluated the hypoglycemic effect of biscuits produced from flour blends of three medicinal foods (Unripe plantain fruits, Moringa seed, and pigeon pea) on high-fat diet (HFD)/streptozotocin (STZ)-induced (HFD/STZ) diabetic rats. The formulated biscuits were produced at different proportion of the flour blends and fed to HFD-STZ-induced diabetic rats for 14days. The result showed that the formulated biscuits caused a significant increase in pancreas, liver, and kidney antioxidant molecules, decreased the production of thiobarbituric reactive acid species (TBARS) in pancreas, liver, and kidney homogenates, and reduced pancreatic α-amylase and intestinal α-glucosidase activities as against untreated diabetic rats. In conclusion, the use of formulated biscuits from the blends of flours from unripe plantain, Moringa seed, and pigeon pea could serve as functional food toward the treatment/management of diabetes and its possible complications such as diabetes-induced liver and kidney damage. PRACTICAL APPLICATIONS: The drug use in the management of diabetes such as acarbose have been reported to have side effects, while diet therapy is gaining much interest in the management of diabetes. Hence, there is a need for diets base therapy that will not only cure diabetes, but also combat its complications. In sight of this, unripe plantain, Moringa seed, and pigeon pea flours were blended and used to produce functional biscuits for diabetic rats. The biscuit could be produced on the large scale under hygienic and regulated condition.

Species Distribution and Comparison between EUCAST and Gradient Concentration Strips Methods for Antifungal Susceptibility Testing of 112 Aspergillus Section Nigri Isolates.

Aspergillus niger, the third species responsible for invasive aspergillosis, has been considered as a homogeneous species until DNA-based identification uncovered many cryptic species. These species have been recently reclassified into the Aspergillus section Nigri However, little is yet known among the section Nigri about the species distribution and the antifungal susceptibility pattern of each cryptic species. A total of 112 clinical isolates collected from 5 teaching hospitals in France and phenotypically identified as A. niger were analyzed. Identification to the species level was carried out by nucleotide sequence analysis. The MICs of itraconazole, voriconazole, posaconazole, isavuconazole, and amphotericin B were determined by both the EUCAST and gradient concentration strip methods. Aspergillus tubingensis (n = 51, 45.5%) and Aspergillus welwitschiae (n = 50, 44.6%) were the most common species while A. niger accounted for only 6.3% (n = 7). The MICs of azole drugs were higher for A. tubingensis than for A. welwitschiae The MIC of amphotericin B was 2 mg/liter or less for all isolates. Importantly, MICs determined by EUCAST showed no correlation with those determined by the gradient concentration strip method, with the latter being lower than the former (Spearman's rank correlation tests ranging from 0.01 to 0.25 depending on the antifungal agent; P > 0.4). In conclusion, A. niger should be considered as a minority species in the section Nigri The differences in MICs between species for different azoles underline the importance of accurate identification. Significant divergences in the determination of MIC between EUCAST and the gradient concentration strip methods require further investigation.

Direct synthesis of oxygenates via partial oxidation of methane in the presence of O2 and H2 over a combination of Fe-ZSM-5 and Pd supported on an acid-functionalized porous polymer

Aqueous-phase partial oxidation of methane over a combination of heterogeneous Fe-ZSM-5 and Pd catalysts was demonstrated in the presence of O2 and H2. Fe-ZSM-5 catalyst active for partial oxidation of methane with H2O2 was prepared by an ion-exchange method. For comparison, homogeneous Fe species (FeSO4) were also used as a catalyst for partial oxidation of methane. Several supported Pd catalysts for the direct synthesis of hydrogen peroxide from H2 and O2 were prepared using activated carbon (AC), AC treated with sulfuric acid (s-AC), as-synthesized hyper-crosslinked porous polymer (HCPP), HCPP with carboxylic group (c−HCPP), and HCPP with carboxylic and sulfonic groups (c-s−HCPP). Among them, the Pd catalyst supported on c-s−HCPP was effective for generating H2O2in situ, which enabled methane oxidation over Fe-ZSM-5 without any leaching.

Utilizing auxology to understand ontogeny of extinct hominins: A case study on Homo naledi.

The methods used to study human growth and development (auxology) have not previously been applied within the setting of hominin maturation (ontogeny). Ontogeny is defined here as the pattern of biological change into an adult form, both at the individual and species level. The hominin fossil record has a lack of recovered immature materials, due to such factors as taphonomic processes that destroy pre-adults; the fragility of immature compared to adult bone; and the lower mortality rates of juveniles compared to adults. The recent discovery of pre-adult hominin skeletal material from a single, homogeneous Homo naledi species from the Rising Star cave system in South Africa provides the opportunity for a broader application of auxology methods and thus the need to understand their use in a modern context. Human auxology studies benefit from a robust database, across multiple populations, and with longitudinal studies in order to assess the patterns and variations in typical growth, development and life history stages. Here, we review the approach, vocabulary, and methods of these human studies, investigate commonalities in data with the fossil record, and then advance the reconstruction of ontogeny for the extinct hominin species H. naledi. To this end, we apply an auxology model into the paleontological context to broadly predict H. naledi birthweight of the offspring at 2.06 kg with a range (±1 SD) of 1.89 to 2.24 kg, with a length at birth 45.5 cm. We estimate a H. naledi juvenile partial skeleton DH7 to be a height of 111-125 cm at death.

Rapid recovery of tropical forest diversity and structure after shifting cultivation in the Philippines uplands.

Shifting cultivation is a widespread land‐use in the tropics that is considered a major threat to rainforest diversity and structure. In the Philippines, a country with rich biodiversity and high rates of species endemism, shifting cultivation, locally termed as kaingin, is a major land‐use and has been for centuries. Despite the potential impact of shifting cultivation on forests and its importance to many people, it is not clear how biodiversity and forest structure recover after kaingin abandonment in the country, and how well these post‐kaingin secondary forests can complement the old‐growth forests. We investigated parameters of forest diversity and structure along a fallow age gradient in secondary forests regenerating after kaingin abandonment in Leyte Island, the Philippines (elevation range: 445–650 m asl). We first measured the tree diversity and forest structure indices in regenerating secondary forests and old‐growth forest. We then measured the recovery of tree diversity and forest structure parameters in relation to the old‐growth forest. Finally, using linear mixed effect models (LMM), we assessed the effect of different environmental variables on the recovery of forest diversity and structure. We found significantly higher species density in the oldest fallow sites, while Shannon’s index, species evenness, stem number, basal area, and leaf area index were higher in the old‐growth forest. A homogeneous species composition was found across the sites of older fallow age. Multivariate analysis revealed patch size as a strong predictor of tree diversity and forest structure recovery after shifting cultivation. Our study suggests that, secondary forests regenerating after shifting cultivation abandonment can recover rapidly. Although recovery of forest structure was not as rapid as the tree diversity, our older fallow sites contained a similar number of species as the old‐growth forest. Many of these species are also endemic to the Philippines. Novel and emerging ecosystems like tropical secondary forests are of high conservation importance and can act as a refuge for dwindling tropical forest biodiversity.

A Purification Strategy Utilizing Hydrophobic Interaction Chromatography to Obtain Homogeneous Species from a Site-Specific Antibody Drug Conjugate Produced by AJICAP™ First Generation.

In recent years, site-specific antibody drug conjugates (ADC)s have been in great demand because they have an expanded therapeutic index compared with conventional ADCs. AJICAP™ technology is a chemical conjugation platform to obtain site-specific ADCs through the use of a class of Fc-affinity compounds. Promising results from early technology development studies led to further investigation of AJICAP™ ADC materials to obtain site-specific and homogeneous drug antibody ratio (DAR) ADCs. Here we report site-specific conjugation followed by a preparative hydrophobic interaction chromatography (HIC) purification strategy to obtain purified “DAR = 1.0” and “DAR = 2.0” AJICAP™ ADC materials. Optimization of the mobile phase conditions and resin achieved a high recovery rate. In vitro biological assay demonstrated the target selective activity for purified homogeneous DAR ADCs. These results indicate the ability of a HIC purification strategy to provide “DAR = 1.0” and “DAR = 2.0” AJICAP™ ADCs with considerable potency and target selectivity.

Global biodiversity of the genus Ommastrephes (Ommastrephidae: Cephalopoda): an allopatric cryptic species complex

AbstractCryptic speciation among morphologically homogeneous species is a phenomenon increasingly reported in cosmopolitan marine invertebrates. This situation usually leads to the discovery of new species, each of which occupies a smaller fraction of the original distributional range. The resolution of the taxonomic status of species complexes is essential because species are used as the unit of action for conservation and natural resource management politics. Before the present study, Ommastrephes bartramii was considered a monotypic cosmopolitan species with a discontinuous distribution. Here, individuals from nearly its entire distributional range were evaluated with mitochondrial DNA (cytochrome c oxidase subunit I and 16S rRNA). Four distinct species were consistently identified using four molecular species delimitation methods. These results, in combination with morphological and metabolic information from the literature, were used to resurrect three formerly synonymized names (Ommastrephes brevimanus, Ommastrephes caroli and Ommastrephes cylindraceus) and to propose revised distributional ranges for each species. In addition, diagnostic characters from the molecular sequences were incorporated in the species description. At present, only one of the four newly recognized species (Ommastrephes bartramii) is commercially exploited by fisheries in the North Pacific, but it now appears that the distributional range of this species is far smaller than previously believed, which is an essential consideration for effective fisheries management.

An experimentally-validated numerical model of diffusion and speciation of water in rhyolitic silicate melt

The diffusion of water through silicate melts is a key process in volcanic systems. Diffusion controls the growth of the bubbles that drive volcanic eruptions and determines the evolution of the spatial distribution of dissolved water during and after magma mingling, crystal growth, fracturing and fragmentation, and welding of pyroclasts. Accurate models for water diffusion are therefore essential for forward modelling of eruptive behaviour, and for inverse modelling to reconstruct eruptive and post-eruptive history from the spatial distribution of water in eruptive products. Existing models do not include the kinetics of the homogeneous species reaction that interconverts molecular (H2Om) and hydroxyl (OH) water; reaction kinetics are important because final species distribution depends on cooling history. Here we develop a flexible 1D numerical model for diffusion and speciation of water in silicate melts. We validate the model against FTIR transects of the spatial distribution of molecular, hydroxyl, and total water across diffusion-couple experiments of haplogranite composition, run at 800–1200 °C and 5 kbar. We adopt a stepwise approach to analysing and modelling the data. First, we use the analytical Sauer-Freise method to determine the effective diffusivity of total water DH2Ot as a function of dissolved water concentration CH2Ot and temperature T for each experiment and find that the dependence of DH2Ot on CH2Ot is linear for CH2Ot≲1.8 wt.% and exponential for CH2Ot≳1.8 wt.%. Second, we develop a 1D numerical forward model, using the method of lines, to determine a piece-wise function for DH2OtCH2Ot,T that is globally-minimized against the entire experimental dataset. Third, we extend this numerical model to account for speciation of water and determine globally-minimized functions for diffusivity of molecular water DH2OmCH2Ot,T and the equilibrium constant K for the speciation reaction. Our approach includes three key novelties: (1) functions for diffusivities of H2Ot and H2Om, and the speciation reaction, are minimized simultaneously against a large experimental dataset, covering a wide range of water concentration (0.25≤CH2Ot≤7 wt.%) and temperature (800°C≤T≤1200°C), such that the resulting functions are both mutually-consistent and broadly applicable; (2) the minimization allows rigorous and robust analysis of uncertainties such that the accuracy of the functions is quantified; (3) the model can be straightforwardly used to determine functions for diffusivity and speciation for other melt compositions pending suitable diffusion-couple experiments. The modelling approach is suitable for both forward and inverse modelling of diffusion processes in silicate melts; the model is available as a MATLAB script from the electronic supplementary material.

Assessing the Recyclability of Supramolecularly Assembled Organocatalytic Species: A Theoretical Insight

AbstractAsymmetric organocatalytic synthesis is a powerful tool in organic chemistry to achieve desired stereoisomers in high purity via mild catalytic routes. The immobilization of homogeneous catalytic species onto heterogeneous phases embodies the evolution of asymmetric catalysis, since it allows the recycling of the catalyst for several runs until degradation. Previously reported non‐covalent immobilization of proline‐based catalysts for aldol reaction onto magnetic nanoparticles functionalized with β‐cyclodextrin (MNP‐β‐CB) demonstrated the viability of the methodology. This paper proposes two new catalyst recycling strategies based on Cucurbit[7]uril (CB[7]) for the aldol reaction and the Robinson annulation. These recycling methodologies are conceptually different. The former relies on the homogeneous encapsulation of the catalyst in cucurbituril, CB[7] ⋅ Cat, and its recycling in the aqueous phase by extraction of the aldol product with organic solvents. The latter relies on the heterogeneous encapsulation of the catalyst as MNP‐CB[7] ⋅ Cat2 system and its recycling by magnetic harvesting. Density functional theory (DFT) calculations have been employed to rationalize the thermodynamics of experimental results, and to suggest caveats and plausible improvements in view of a future catalytic design.

Adipic acid formation from cyclohexanediol using platinum and vanadium catalysts: elucidating the role of homogeneous vanadium species

The applicability of platinum and vanadium catalysts for the production of adipic acid from cyclohexanediol is severely limited by the instability of the latter species in liquid phase reactions.

Reductive Amidation without an External Hydrogen Source Using Rhodium on Carbon Matrix as a Catalyst

AbstractAn efficient method for preparation of secondary amides from primary amides and aldehydes using rhodium on carbon matrix as catalyst was developed. The method does not require any external hydrogen source and carbon monoxide is used as a reducing agent. The most active rhodium catalysts were characterized by BET, TEM and XPS techniques. Unexpectedly, it was found that heterogeneous rhodium on carbon matrix works as precatalyst for homogenous active species due to leaching of rhodium to the solution. Various secondary amides were synthesized and checked for antifungal activity. 4‐Methoxy‐N‐(4‐methoxybenzyl)benzamide demonstrated promising activity against Rhizoctonia Solani.

Temperature effect on the temporal dynamic of terrestrial invertebrates in technosols formed after reclamation at a post-mining site in Ukrainian steppe drylands

The research was carried out at the Research Centre of the Dnipro State Agrarian and Economic University in Pokrov city. Sampling was carried out in 2013–2015 on a variant of artificial soil (technosols) formed on loess-like loam, red-brown clay, green-grey clay, technological mixture of rocks, and also formed on loess-like loam with a humus-rich 70 cm top soil layer. To investigate the spatiotemporal variation in the abundance, species richness and species composition of invertebrate assemblages within the experimental polygon, the animals were sampled using pitfall traps. In total, 60 pitfall traps were operated simultaneously during each sampling period. Each year the pitfalls were emptied 26 times every 7–9 days. Invertebrates (Arthropoda and Mollusca) of 6 classes, 13 orders, 50 families and 202 species or parataxonomic units were recorded. Diplopoda was most abundant taxonomic group, though it was represented by only one species Rossiulus kessleri (Lohmander, 1927). Coleoptera and Araneae were the most numerous taxonomic groups. Readily available water for plants, precipitation, wind speed, atmospheric temperature (daily minimum, daily maximum, daily mean), atmospheric humidity and atmospheric pressure were used as environmental predictors. Two dimension geographic coordinates of the sampling locations were used to generate a set of orthogonal eigenvector-based spatial variables. Time series of sampling dates were used to generate a set of orthogonal eigenvector-based temporal variables. The moisture content in the technosols was revealed to be the most important factor determining the temporal dynamics of the terrestrial invertebrate community in conditions of semi-arid climate and the ecosystem which formed as a result of the reclamation process. Following soil moisture, the factor most strongly affecting invertebrates in the technosols was temperature. From the total set of the invertebrates, two relatively homogeneous species groups in terms of thermal preferences were extracted: the microtemperature and mesotemperature groups. The microtemperature species are more tolerant to the thermal factor, and the mesotemperature species are more sensitive. The Huisman-Olff-Fresco approach expanded by Jansen-Oksanen provides a wide set of ecologically relevant models which are able to explain species response. The species response to temperature is affected by a complex of other environmental, temporal and spatial factors. The effect of other factors on the species response must be previously extracted to find real estimations of the species temperature optima and tolerance. The approaches to solving this problem may be the object of future investigation.

Form of the catalytically active Pd species during the direct synthesis of hydrogen peroxide

AbstractDirect synthesis of H2O2 could produce H2O2 at lower cost than the Riedl–Pfleiderer process, which would enable the broader use of H2O2 for industrial oxidations. The addition of inorganic acids and halides to the solvent increase H2O2 selectivities on Pd nanoparticles but also dissolve Pd and produce dynamic mixtures of complexes including heterogeneous (Pd0) and homogeneous (Pd2+) species, any of which may contribute to H2O2 formation. We combine kinetic measurements and in operando UV–vis spectroscopy to determine how H2O2 rates and selectivities depend on concentrations of these forms of Pd. Introducing HCl to the solvent increases the concentration of Pd2+ complexes by oxidizing Pd0 nanoparticles. The rates of primary H2O2 formation and H2O2 selectivities do not depend directly on the population of the Pd2+ species for catalysts tested in water or methanol. These results suggest that Pd nanoparticles form H2O2 and detectable homogeneous complexes do not act as catalysts.

Polymer-Anchored Bifunctional Pincer Catalysts for Chemoselective Transfer Hydrogenation and Related Reactions.

A series of polymer-supported cooperative PC(sp3 )P pincer catalysts was synthesized and characterized. Their catalytic activity in the acceptorless dehydrogenative coupling of alcohols and the transfer hydrogenation of aldehydes with formic acid as a hydrogen source was investigated. This comparative study, examining homogeneous and polymer-tethered species, proved that carefully designing a link between the support and the catalytic moiety, which takes into consideration the mechanism underlying the target transformation, might lead to superior heterogeneous catalysis.

Dinámica de microalgas frente a la costa de las Peñitas-Poneloya, Nicaragua

Esta es una investigación descriptiva que ha estudiado la dinámica de las microalgas (Cyanophytas, Chlorophytas, Bacillariophyceae y Dinoflagellata) y su relación con los parámetros físico-químicos de las costas de las Peñitas-Poneloya en el período de Junio-Octubre del 2017. Se tomaron muestras de 3 puntos diferentes entre el área comprendida en las coordenadas 12°20´10.63¨N 87°01´59.58¨O y 12°21´59.68¨N 87°04´13.27¨O. Estos muestreos se realizaban una vez al mes y en ellos se tomaban las muestras de agua y los parámetros físico-químicos (pH, salinidad, temperatura, turbidez y oxígeno). Se hacía conteo de células con ayuda de la cámara Neubauer y la identificación de microalgas con ayuda de la cámara Sedgewick-Rafter. Se encontraron microalgas de los cuatro principales grupos, teniendo más representación de la clase Bacillariophyceae con 16 especies, seguidas de las Cyanophytas con 7 especies, Chlorophytas con 6 especies y Dinoflagellata con 5 especies. El parámetro de la salinidad oscilo entre 30 ppm como valor mínimo presentado en el punto 1 y 34 ppm como valor máximo presentado en el punto 3, la temperatura fluctuó entre 27° C y 29.7° C, teniendo el valor mínimo en el mes de agosto en el 2do punto y la máxima en el mes de junio en el 3er punto, la turbidez mantuvo un valor estable de 100 cm en sus 3 puntos durante todo el período de investigación. El oxígeno disuelto varió entre 7.3 mg/l y 8.3 mg/l, teniendo su valor mínimo en el mes de junio en el 1er punto y el máximo en septiembre en su 1er punto. El pH osciló entre 8.6 su mínimo, encontrado en el mes de junio en el 2do punto y su máximo de 10.4 en el mes julio en el 2do punto. A todas las especies encontradas se le aplicaron los índices estadísticos Diversidad de Shannon y Dominancia de Simpson, para indagar si la zona cuenta con abundante biodiversidad o había dominancia de una especie específica, y según los resultados obtenidos se puede asegurar que el área cuenta con una diversidad y abundancia de especies de microalgas homogéneas.

Is There a Pattern for Occurrence of Macrophytes in Polish Ponds?

Although ponds are common elements in the environment, dependences occurring in these ecosystems have not been fully investigated. Our study focuses on the correlation between environmental factors and changes occurring in ponds—mostly the distribution of macrophytes in space and time. The aim of our analyses was to indicate which physicochemical variables were characteristic of ponds in specific habitats (forest, agriculture field, and village) and whether they could associate the distribution of vegetation in these ponds. Thirteen ponds differing in morphometric parameters and location in landscape (ponds located in agriculture fields, forests, and villages) were analyzed. Our research was based on data covering a period of 10 years (2008–2018). The following parameters were analyzed: the water content of NH4+, NO3−, NO2−, TP, PO43−, Na, K, Mg, Ca, and Fe, pH, temperature and morphometric parameters. Macrophytes were observed during the growing season in July 2008, 2010, 2012, 2014, 2016 and 2018. Three homogeneous species groups were distinguished in statistical analyses and the dominance of selective environmental factors was assigned to them. The first group consisted of indicator species for forest ponds. Their waters were characterized by a low content of Ca, Mg, and Na as well as an increased content of NH4+ and Fe. The second group was composed of indicator species for field ponds, where the highest NO3− concentrations were found. The third group was formed by indicator species for village ponds. Water of these ponds was characterized by higher concentration levels of K, Na, and total P.