Typical Species Research Articles

English

Wetland restoration success is dependent on the likeness of both structure and function of the restored wetland systems comparable to reference sites. Assessing the success of restoration is reliant on the monitoring and evaluation of the restored system overtime as was done with Nakyesanja, a restored wetland, and Kiryagonja, a referenced natural wetland in Wakiso District, Uganda. The objectives of this study were to determine plant characteristics (species abundance, diversity, height and phytomass) in the wetlands and evaluate the effect of water level on plants establishment and phytomass accumulation. Two transects were established in each wetland with five plots measuring 1×1 m2 on each transect. Plant species were identified in the plots while papyrus was measured and harvested. The water level was also measured in each plot. No significant difference was detected in the above ground phytomass of Cyperus papyrus L. in the restored and the natural wetlands (p = 0.202). The restoration process has caused papyrus plants to accumulate productivity similar to the natural level. No significant difference was also observed in the heights of papyrus (p = 0.232). This indicated that the restoration methodology was effective on plants growth; making plants acquiring heights as their counterparts in the natural wetland. Uneven water distribution affected the growth and distribution of plants in the restored wetland. Areas of high water level got colonized with typical wetland species while areas with low water level got colonized by opportunistic plants. However, the water level was positively correlated (R2 = 0.485, p = 0.042) with species diversity in the natural wetland making waterlogging the key determinant of macrophytic plants establishment in a natural environment. Periodic study is therefore recommended to monitor the success of the wetland restoration overtime.   Key words: Abundance, Cyperus papyrus L., diversity, plant species, restoration, water level, wetlands.

Spatial Vegetation Patch Patterns and Their Relation to Environmental Factors in the Alpine Grasslands of the Qilian Mountains

Globally, grasslands are affected by climate change and unsustainable management practices which usually leads to transitions from stable, degraded and then to desertification. Spatial vegetation patch configurations are regarded as key indicators of such transitions. Understanding the relationships between this grass-land vegetation and its environment is key to vegetation restoration projects. Spatial vegetation patch patterns were chosen across different soil and topographic conditions. Patch numbers, perimeter, and cover of each patch were measured along transects of each patch type. Using field surveys and multivariate statistical analysis, we investigated the differences in vegetation biomass and distribution and soil properties of four typical alpine plant species patches along with a range of environmental and topographic conditions. It was found that topographic conditions and soil properties, particularly soil moisture explained most of the variation in spatial patch vegetation characteristics and thus control vegetation restoration in the alpine grassland. The Kobresia humilis, Blysmus sinocompressus and Iris lactea patches under the drylands recorded small patch sizes, large patch numbers, low connectivity, and large total perimeter per unit area. Generally, species within the high moisture sites recorded small patch numbers, a large fraction of vegetation cover and a small total perimeter per m2. Patches in limited soil moisture areas recorded patch configurations indicating they are unstable and undergoing degradation and therefore need urgent restoration attention to forestall their further degradation and its resultant effect of desertification. These results would provide quantitative easy-to-use indicators for vegetation degradation and help in vegetation restoration projects.

The resource potential of fruit and ornamental plants of the order Lamiales in the collection of the Botanical Garden

The multi-vector positioning of the Oles Honchar Dnipro National University Botanical Garden (Dnipro, Ukraine) as an ecological resource, the main functions of which are aimed at preserving, studying, acclimatizing plants, researching the effective use of rare and typical species of local and world flora by creating, replenishing and preserving botanical collections, conducting scientific, educational and tutorial work is reviewed. The resource potential study of the fruit and ornamental plants which are promising for various fields of application is a component of bioeconomy. Such plants include species of the order Lamiales Bromhead. In the Oles Honchar Dnipro National University Botanical Garden (Dnipro, Ukraine) the stock collection of Lamiales order plants on condition of sheltered ground was studied. The paradigm of the modern botanical garden positioned as an ecological resource combining research activities, environmental function, and providing society with cultural ecosystem services is highlighted. An inventory and clarification of the taxonomic composition of Lamiales order representatives was carried out for the stock plant collection. The taxa systematic position was determined according to the Angiosperm Phylogeny Group (APG IV) classification. It was determined the geographical status of the species (origin) and its life forms. The data of species' endurance of the Lamiales order to low temperatures in the sheltered ground of the Botanical Garden is given. It is shown that the Botanical Garden has a collection of more than 3,500 species of plants, including 900 taxa in the greenhouse fund, and 63 species, 230 species and cultivars belonging to the order Lamiales. It is demonstrated that Lamiales fruit and ornamental crops, which are available in the collection of the stock greenhouse, have antioxidant properties, and extracts from their parts are characterized by antifungal, antibacterial, and antimutagenic effects. Three collection species of the family Gesneriaceae (Streptocarpus ionanthus subsp. velutinus (B. L. Burtt) Christenh., Streptocarpus intermedia (B. L. Burtt) comb. ined., and Kohleria amabilis (Planch. & Linden) Fritsch) belong to the International Union for Conservation of Nature’s Red List of Threatened Species. Most members of this order can be considered well-adapted to greenhouse growing conditions (88.9 % of plants in the Lamiales collection bloom). Seven species of the family Acanthaceae are fully adapted and give viable self-seeding. Determining the resource potential of the order Lamiales in the sheltered ground of the National University Botanical Garden showed the presence of plants not only with high decorative qualities, but also species containing an increased amount of biologically active substances with a wide range of antioxidant properties.

Ectomycorrhizal fungal communities of Swiss stone pine (Pinus cembra) depend on climate and tree age in natural forests of the Alps

Background and AimsPinus cembra represent a typical and important tree species growing in European subalpine and alpine habitats. The ectomycorrhizal (ECM) fungal communities associated to this tree under natural conditions are largely unknown.MethodsIn this study, we investigated the ECM fungal abundance and composition at four high-altitude sites (two northern-exposed and two southern-exposed habitats) in South Tyrol (Italy), and included also two different age classes of P. cembra. The ECM partners were characterized morphologically, and identified by rDNA ITS sequence analysis.ResultsThe degree of mycorrhization in adult P. cembra was typically 100% in these natural habitats, with a total species diversity of 20 ECM species. The four high-altitude sites were similar concerning their species richness and mycobiont diversity, but they differed significantly in ECM species composition. Young P. cembra had a mycorrhization degree of 100% and a total of 10 species were observed. All mycorrhizal partners of naturally regenerated young P. cembra were only detected in one specific location, with the exception of Cenococcum sp. and Amphinema sp. which were detected at two sites. Young trees harbour a distinct ectomycorrhizal fungal diversity, which is clearly lower than the diversity detected in adult P. cembra trees. The P. cembra bolete (Suillus plorans) is the most important symbiotic partner of P. cembra at Southern Tyrolean high-altitude sites and is known for its strict, species-specific host association.ConclusionsThe ectomycorrhizal fungal community composition strongly depends on geographic region and on the slope exposure (north or south) of the site.

Genetic Diversity, Habitat Relevance and Conservation Strategies of the Silver Carp in the Yangtze River by Simple Sequence Repeat

The spatial distribution of fish individuals is affected by habitat conditions and species ecological characteristics, and it also reflects the longtime adaptation to habitat at the phenotypic and genotypic level. As a typical river-lake migratory fish species, the silver carp habitat selection was determined by its migration preference and genetic features. In this study, 15 microsatellite fluorescent markers combined with capillary electrophoresis were used to analyze the genetic diversity, genetic differentiation, and structure of nature silver carp populations in the Sanzhou (SZ), Hukou (HK), Anqing (AQ), Zhenjiang (ZJ), and Rugao (RG) sections of the Yangtze River. The results showed that 15 microsatellite loci exhibited medium to high polymorphisms. The overall genetic diversity in the Yangtze River was high, with the average value of Shannon’s information index ranging from 1.559 to 1.668. The numbers of alleles (Ne) ranged from 1.630 to 10.100. The expected heterozygosity (He, 0.690–0.721) was higher than observed heterozygosity (Ho, 0.598–0.646), and the genetic variation mainly originated from within the population (94.69%). However, the entire population was in the state of heterozygous deletion, and HK, RG populations encountered the risk of inbreeding risk (F > 1). Interestingly, there was a distinct genetic structure for the population in the HK section, which indicated that local population has occurred to the silver carp in this river section, and they may also possess aggregation characteristics specific to the river-lake-connected (RLC) habitat. The results mostly support the conclusion that the RLC habitat is essential for geographic population formation. The potential impact of special habitats on natural populations should be considered, and continuous surveys on population dynamics should be performed.

Gold(I)-Catalyzed [4 + 2] Annulation between Arylynes and C,N-Diaryl Nitrones for Chemoselective Synthesis of Quinoline Scaffolds via Gold Acetylide Intermediates.

Gold-catalyzed synthesis of quinoline derivatives via [4 + 2] annulation between terminal arylynes and nitrones is described. Our mechanistic analysis supports the participation of alkynylgold intermediates, instead of a typical gold-carbene species in recently reported gold catalysis. These nucleophilic alkynylgold species react with nitrones via Povarov-type reactions. Cheap, readily available materials and a broad substrate scope manifest the advantage of this method.

Anatomy and histochemistry of Triarrhena lutarioriparia var. humilior from the Jianghan Floodplain, China

This study examined the perennial Triarrhena lutarioriparia var. humilior to identify the anatomical and histochemical features that support the adaptation of this plant to the seasonal flooding of the Jianghan Floodplain, China. The leaves, culms, rhizomes, and adventitious roots of T. lutarioriparia var. humilior were collected in the Jianghan Floodplain. T. lutarioriparia var. humilior is a typical C4 species with Kranz anatomy: chloroplasts were present in the parenchymatous and/or mestome sheaths. The apoplastic barriers of T. lutarioriparia var. humilior consisted of an endodermis and exodermis, as well as a suberized vascular system, peripheral sclerenchyma ring, and epidermis. These structures may prevent oxygen loss and facilitate nutrient transport under submerged conditions. The mechanical tissues of T. lutarioriparia var. humilior included a peripheral mechanical ring, sclerenchyma ring, vascular bundles, and sclerified bundles, as well as a peripheral ring adjacent to the vascular bundles in the culms. T. lutarioriparia var. humilior also had air spaces in the roots and stems. These combinations of traits show that T. lutarioriparia var. humilior, like other species in the same localities, is well adapted to the seasonal flooding of its habitat.

Antagonistic and synergistic effects of warming and microplastics on microalgae: Case study of the red tide species Prorocentrum donghaiense

Bibliometric network analysis has revealed that the widespread distribution of microplastics (MPs) has detrimental effects on marine organisms; however, the combined effects of MPs and climate change (e.g., warming) is not well understood. In this study, Prorocentrum donghaiense, a typical red tide species in the East China Sea, was exposed to different MP concentrations (0, 1, 5, and 10 mg L−1) and temperatures (16, 22, and 28 °C) for 7 days to investigate the combined effects of MPs and simulated ocean warming by measuring different physiological parameters, such as cell growth, pigment contents (chlorophyll a and carotenoid), relative electron transfer rate (rETR), reactive oxygen species (ROS), superoxide dismutase (SOD), malondialdehyde (MDA), and adenosine triphosphate (ATP). The results demonstrated that MPs significantly decreased cell growth, pigment contents, and rETRmax, but increased the MDA, ROS, and SOD levels for all MP treatments at low temperature (16 °C). However, high temperatures (22 and 28 °C) increased the pigment contents and rETRmax, but decreased the SOD and MDA levels. Positive and negative effects of high temperatures (22 or 28 °C) were observed at low (1 and 5 mg L−1) and high MP (10 mg L−1) concentrations, respectively, indicating the antagonistic and synergistic effects of combined warming and MP pollution. These results imply that the effects of MPs on microalgae will likely not be substantial in future warming scenarios if MP concentrations are controlled at a certain level. These findings expand the current knowledge of microalgae in response to increasing MP pollution in future warming scenarios.

Identification, expression and subcellular localization of Orc1 in the microsporidian Nosema bombycis

As a typical species of microsporidium, Nosema bombycis is the pathogen causing the pébrine disease of silkworm. Rapid proliferation of N. bombycis in host cells requires replication of genetic material. As eukaryotic origin recognition protein, origin recognition complex (ORC) plays an important role in regulating DNA replication, and Orc1 is a key subunit of the origin recognition complex. In this study, we identified the Orc1 in the microsporidian N. bombycis (NbOrc1) for the first time. The NbOrc1 gene contains a complete ORF of 987 bp in length that encodes a 328 amino acid polypeptide. Indirect immunofluorescence results showed that NbOrc1 were colocalized with Nbactin and NbSAS-6 in the nuclei of N. bombycis. Subsequently, we further identified the interaction between the NbOrc1 and Nbactin by CO-IP and Western blot. These results imply that Orc1 may be involved in the proliferation of the microsporidian N. bombycis through interacting with actin.

The ‘grooved’ Hildoceras ammonite fauna from the Lower Jurassic (Toarcian) of the Apennines. Overview and proposal for a new species

ABSTRACT It is historically renown that morphotypes referred to Hildoceras bifrons from the Apennines (Italy) and other Mediterranean localities differ in many ways from the typical species of the Central and North-West Europe. Besides overall smaller size (usually < 40 mm), Mediterranean specimens attain marked whorl embracement, comparable to that of the kin species Hildoceras semipolitum (albeit retaining a less compressed whorl section). Relatively larger (and rare) morphotypes may show slight 'uncoiling' (resembling the typical Hildoceras bifrons), though limitedly to the final part of the adult-stage last whorl. Both the common (small-involute) and rare (larger-slightly uncoiled) morphotypes thus reveal of ambiguous taxonomic attribution either as Hildoceras bifrons or as Hildoceras semipolitum. In front of this ambiguity, the new species Hildoceras appenninicus sp. nov. is proposed for grouping 'bifrons-like' Hildoceras occurring in the Apennines and other Mediterranean localities. In contrast with previous works on this subject, definite ranges for whorl compression indexes relative to whorl diameter and embracement are provided, by this attempting at a more objective distinction of this new species from both Hildoceras bifrons and Hildoceras semipolitum. Finally, along with some biostratigraphic remarks, possible evolutionary and paleobiogeographic implications concerning the arising and spreading of Hildoceras species are outlined. lsid: zoobank.org:pub:5C2C159E-61CA-4EE0-996D-D098618B3790

Tea polyphenols mediated Zero-valent Iron/Reduced graphene oxide nanocomposites for electrochemical determination of Hg2+

Herein, we have developed a chemically modified glassy carbon electrode (GCE) using tea polyphenols mediated zero-valent iron/reduced graphene oxide nanocomposites (rGO-ZVI-P) for rapid determination of Hg2+ in water. Highly conductive rGO-ZVI-P were fabricated by a green chemical method using tea polyphenols as the reductant. The rGO-ZVI-P shows a unique affinity to aqueous Hg2+ due to a synergy between ZVI and rGO. The rGO-ZVI-P electrochemical sensor shows optimal performance for Hg2+ determination in pH 5.00 phosphate buffer and 180 s accumulation time at −1.2 V accumulation potential used under square wave anode stripping voltammetry (SWASV). At these conditions, the Hg2+ determination sensitivity is 41.42 μA/μM and the determination limit is 1.2 nM. There are no interferences to the rGO-ZVI-P modified GCE sensor in the presence of 0.5 μM Cd2+, 0.5 μM Pb2+, and 0.5 μM Cu2+ in solution, either in discrete cations or multi-cations modes. Moreover, the typical chemical species found in the matrix of river water samples do not interfere with the as-fabricated Hg2+ electrochemical sensor. The Hg2+ determination by the rGO-ZVI-P modified GCE sensor is repeatable, stable, and robust, and it has potential in environmental applications.

Attractive benzothiazole-based fluorescence probe for the highly efficient detection of hydrogen peroxide

In current work, one novel benzothiazole-based fluorescent chemosensor (TZ-BO) with ESIPT luminescence mechanism was designed for the detection of hydrogen peroxide (H2O2) as typical reactive oxygen species (ROS). The boronate catenary in our designed probe molecule TZ-BO is both the blocking group of ESIPT and the reactive group of H2O2. The synthesized probe TZ-BO has the advantages of large Stokes shift, high sensitivity, good selectivity, and fast reaction speed to H2O2. The ability of the probe to detect H2O2 in aqueous media and exogenous H2O2 in cells by fluorescence signal was investigated. The experimental results manifested that probe TZ-BO is able to sensitively detect H2O2 using a fluorescence method in an excellent linear range of H2O2 concentration from 0 to 60 μM (R2 = 0.994). The detection limit was determined as 1.0 × 10−6 M. Most importantly, the probe TZ-BO with highly low cytotoxicity can effectively detect exogenous H2O2 in HeLa cells. This probe provides a promising tool for monitoring the real concentration level of H2O2 in related physiological and pathological researches.

Studying local species assemblages of salt-affected vegetation for monitoring Natura 2000 habitats

This study aims to characterize saline habitats of the Tuscan coast based on the Natura 2000 Habitats Directive 92/43/ECC. These habitats include Atlantic salt meadows (1330), Mediterranean salt meadows (1410) Mediterranean and thermo-Atlantic halophilous scrubs (1420), and Mediterranean salt steppes (1510). We compiled vegetation data from a total of 418 plots carried out during our own fieldwork (N = 157) and published scientific literature (N = 261). We performed a Linear Discriminant Analysis to associate species to habitats and used the phi coefficient of association to identify diagnostic species of each habitat. For each habitat, we provide a regional syntaxonomic framework, constant species, cover coefficients, diagnostic species (phi) and “typical species”. We identified groups of species, that we called “local assembly of typical species”, composed by species with a phi coefficient &amp;gt; 20 and/or a cover coefficient &amp;gt; 50 that can be used to identify the habitats and to monitor their conservation status at the local level. This study revealed differences in the “local assembly of typical species” among habitats, characterized by fewer species in habitats 1420 and 1510, and many species in habitats 1410 and 1310. Our results showed that the habitat 1510 was recognizable only for the high cover value of Limonium narbonense and, at least in Tuscany, its syntaxonomic attribution to the order Limonietalia is uncertain. We tested this approach only for a few habitats, but a broader applicability based on other habitats is desirable.

A Toolbox for Constructing a Stable Genetic Transformation Platform Allowing Foreign Fragment Integration in the Genome of Neopyropia yezoensis

Neopyropia yezoensis, previously known as Pyropia yezoensis, is regarded as a model macroalgae because of its economic value and typical intertidal seaweed species. However, the genetic transformation system to introduce foreign genes into its cells is inefficient and not stable. This study developed a more efficient transformation toolbox that allows the stable expression of foreign genes in N. yezoensis cells. We constructed an efficient transformation platform with the parameters of biolistic bombardment of 6 cm target distance, 600 μg gold particles/shot, 10 μg plasmid DNA/shot, 1,350 psi of helium, and 30 mmHg vacuum pressure. Thalli at 35 days of age were the most suitable transformation conditions, in which the highest transformation efficiency was generated. The endogenous promoter pPyACT1 could control gene expression efficiently compared to pPyUBC, pPyDPE2, and pPyEF1-a, especially the exogenous promoter d35S. Finally, the foreign genes PyGUS and PyHygR were stably expressed in different generations of transformants, including monospores, gametophytes, and filamentous sporophytes. Southern blotting analysis confirmed that PyGUS was integrated into the genome of N. yezoensis transformants. Establishing an efficient gene expression toolbox provides a strong foundation for functional genomics research and molecular genetic breeding on N. yezoensis.

Functional characterization and vacuolar localization of fructan exohydrolase derived from onion (Allium cepa).

Fructans such as inulin and levan accumulate in certain taxonomic groups of plants and are a reserve carbohydrate alternative to starch. Onion (Allium cepa L.) is a typical plant species that accumulates fructans, and it synthesizes inulin-type and inulin neoseries-type fructans in the bulb. Although genes for fructan biosynthesis in onion have been identified so far, no genes for fructan degradation had been found. In this study, phylogenetic analysis predicted that we isolated a putative vacuolar invertase gene (AcpVI1), but our functional analyses demonstrated that it encoded a fructan 1-exohydrolase (1-FEH) instead. Assessments of recombinant proteins and purified native protein showed that the protein had 1-FEH activity, hydrolyzing the β-(2,1)-fructosyl linkage in inulin-type fructans. Interestingly, AcpVI1 had an amino acid sequence close to those of vacuolar invertases and fructosyltransferases, unlike all other FEHs previously found in plants. We showed that AcpVI1 was localized in the vacuole, as are onion fructosyltransferases Ac1-SST and Ac6G-FFT. These results indicate that fructan-synthesizing and -degrading enzymes are both localized in the vacuole. In contrast to previously reported FEHs, our data suggest that onion 1-FEH evolved from a vacuolar invertase and not from a cell wall invertase. This demonstrates that classic phylogenetic analysis on its own is insufficient to discriminate between invertases and FEHs, highlighting the importance of functional markers in the nearby active site residues.

Chemical composition of Libidibia ferrea var. ferrea aqueous extract for antimicrobial purpose and cytogenotoxicity on human peripheral blood mononuclear cells

Libidibia ferrea (Mart. Ex Tul) L. P. Queiroz (Fabaceae) is a typical Caatinga species, 53 commonly known as “Brazilian ironwood” and “leopard tree” and has been used in folk 54 medicine in the treatment of several diseases such as anemia, ulcer, hypertension, 55 diabetes, and antimicrobial agent. However, its adverse effects on human health are not 56 entirely known. The present work aimed to investigate the chemical composition, 57 antibiofilm formation, and cytogenotoxicity potential of Libidia ferrea aqueous extract 58 (AELf). Phytochemical screening, chromatographic analyses, and fractionation were 59 performed to characterize AELf. Additionally, the AELf effect on Staphylococcus aureus 60 biofilm formation was also investigated. Also, twelve extract concentrations were tested 61 by the MTT assay to verify cytotoxicity, while genotoxic (cytokinesis-block 62 micronucleus assay - CBMN) evaluations were carried out on PBMC cells using three 63 different concentrations (10, 20, and 30 mg/mL). The phytochemical analysis revealed 64 the presence of flavonoids, proanthocyanidins, leucoanthocyanidins, and hydrolyzable 65 tannins in higher concentrations. As also, AELf was able to inhibit biofilm formation (≥ 66 50%) on the tested strain by up to 55.3% (44.7 ± 7.8) and 71.1% (28.9 ± 3.4) at 67 concentrations 1.25 mg/mL and 2.5 mg/mL, respectively. AELf concentrations used in 68 the MTT and CBMN assays showed no cytotoxic and genotoxicity activity. The aqueous 69 extract of L. ferrea var. ferrea fruit presents good potential for the future development of 70 antimicrobial products since concentrations around 2.5 mg/mL showed antibiofilm 71 activity. Additionally, the aqueous extract has a good safety profile.

Identifying typical and early warning species by the combination of functional-based diagnostic species and dark diversity

The European Union Habitats Directive requires the identification of typical species that reflect the structure and functions of habitat types, as well as early changes in the habitat condition, but no common methods are available for their selection. Diagnostic species with high fidelity to a specific group of plots are identified by traditional methods, but their value as typical species is still debated. We designed a protocol for the identification of typical plant species based on a recently proposed method to detect diagnostic species by combining abundances and functional traits. We tested the method on a set of alpine habitat subtypes, comparing diagnostic species based on traits or Grime’s CSR strategies (competitive, stress-tolerant, ruderal) with those based on presence/absence or abundance only, and then we calculated for each species the dark diversity probability—i.e. probability of being absent from a habitat type with suitable ecological conditions. Functional-based methods allowed to recognize larger sets of exclusive species, adding dominant species linked to the structure and functions of habitat subtypes (i.e. to the functional centroid). Dark diversity probability was equally distributed between diagnostic and non-diagnostic species identified by functional-based methods. Species with higher dark diversity probability among those associated with the functional centroid can be considered as early warning indicators of changes in habitat conditions. The protocol proposed here enables species ranking on measurable variables (functional association, dark diversity probability) and can be applied as a standardized tool for the identification of typical plant species for habitat types dominated by plants.

Comparative Study of Algal Responses and Adaptation Capability to Ultraviolet Radiation with Different Nutrient Regimes.

Frequent outbreaks of harmful algal blooms (HABs) represent one of the most serious outcomes of eutrophication, and light radiation plays a critical role in the succession of species. Therefore, a better understanding of the impact of light radiation is essential for mitigating HABs. In this study, Chlorella pyrenoidosa and non-toxic and toxic Microcystis aeruginosa were mono-cultured and co-cultured to explore algal responses under different nutrient regimes. Comparisons were made according to photosynthetically active radiation (PAR), UV-B radiation exerted oxidative stresses, and negative effects on the photosynthesis and growth of three species under normal growth conditions, and algal adaptive responses included extracellular polymeric substance (EPS) production, the regulation of superoxide dismutase (SOD) activity, photosynthetic pigments synthesis, etc. Three species had strain-specific responses to UV-B radiation and toxic M. aeruginosa was more tolerant and showed a higher adaptation capability to UV-B in the mono-cultures, including the lower sensitivity and better self-repair efficiency. In addition to stable μmax in PAR ad UV-B treatments, higher EPS production and enhanced production of photosynthetic pigments under UV-B radiation, toxic M. aeruginosa showed a better recovery of its photosynthetic efficiency. Nutrient enrichment alleviated the negative effects of UV-B radiation on three species, and the growth of toxic M. aeruginosa was comparable between PAR and UV-B treatment. In the co-cultures with nutrient enrichment, M. aeruginosa gradually outcompeted C. pyrenoidosa in the PAR treatment and UV-B treatment enhanced the growth advantages of M. aeruginosa, when toxic M. aeruginosa showed a greater competitiveness. Overall, our study indicated the adaptation of typical algal species to ambient UV-B radiation and the stronger competitive ability of toxic M. aeruginosa in the UV-radiated waters with severer eutrophication.

Benthic ecological restoration under the combined action of slow-release oxygen material and benthic organisms

The oxygen level is key benthic ecosystem health. In this study, a new kind of slow-release oxygen material (SROM) was developed and evaluated in a simulation experiment. The effects of SROM dose and dosing method on the pH and DO, the release of nitrogen and phosphorus, and greenhouse gas emissions were studied. The restoration of typical benthic species (Ceratophyllum represented submerged plants and Cipangopaludina cahayensis represented benthic animals) was also evaluated based on the analysis of catalase and peroxidase activities, survival rate, and biomass. The result shows that dosing SROM on mud surfaces had a better effect than dosing in mud. When dosing SROM on the surface of mud at a suitable dose, the DO of water increased from 0.5 mg/L to higher than 4 mg/L, and the pH was below 9, which would be suitable for the survival of benthos. Dosing SROM could also cause the concentrations of nutrient elements (NH4+-N, TN, TP, and PO43−) in overlying water and the emission flux of CH4 and CO2 to decrease. In addition, the growth of Ceratophyllum and Cipangopaludina cahayensis was accelerated, which benefited the restoration of benthic ecosystems. For microbial community structure, various of bacteria for nitrogen and the phosphorus cycle were found in the sediment (including aerobic denitrifying bacteria). Dosing SROM could increase the Simpson index of the bacterial community, means an increase in bacterial diversity. The results show that the dosing of SROM could be an effective method in the early stage of benthic habitat restoration.

PYROLOGICAL CHARACTERISTICS OF FOREST EDGES UNDER INTENSIVE RECREATIONAL LOADS

-The increase in fires in urban landscapes causes adverse and sometimes irreversible changes in forest ecosystems. The modern solution is to find the places of primary fires and the most dangerous areas. The purpose of this study was to find dependences between the forest typological features of forest stands and their fire danger. To fulfil this purpose, a systematic analysis of forest fire danger and phytoindication were performed. The composition of the flora of edge biotopes was figured out using the route geobotanical method. The article analyses forest fires that occurred in urban forests of Kyiv during 2014-2021. Primary ignition locations have been identified. It was proved that fires often occurred on the forest edges, as well as along highways and railways. Among the standard indicators of fire danger (number and area of forest fires), the method makes provision for establishing the fire frequencies in the same forest area. This indicator allows figuring out the most dangerous areas from the pyrogenic standpoint. It was found that the simple edge is characterised by a minimal taxonomic composition in the ground vegetation and its projective cover of up to 20%. The grass tier stabilises the environment and mitigates the effects of extreme natural phenomena. The vegetation cover of an elementary and multicomponent edge is one of the barriers that can stop surface fires. Taxonomic diversity, especially of deciduous species, determines the pyrological features of forest edges. Analysis of the flora of marginal biotopes showed that oligotrophs, xerophytes, and xeromesophytes predominate among the species of simple edges. The share of ruderal elements in the ground vegetation was 36%, which indicates a significant anthropogenic impact and synanthropisation of the flora of the edges. These processes adversely impact the conservation of typical species but have a fire-retaining effect. Analysis of forest fires dynamics under intensive recreational loads allows substantiating the vectors for fire safety improvement, choosing a strategy for ensuring fire safety, and increasing the economic and social efficiency of fire prevention measures. It is proved that the forest edge is one of the decisive factors in the fire behaviour arising from a nonwooded area. The formation of multicomponent edges will help minimise the risks of fires