Nymphaea Tetragona Research Articles

Vegetation Spatial Distribution on Taean Duung Wetland Protect Area

In this study, we conduct for providing information on the status of vegetation space distribution in the Duung wetland protected area and to help manage the wetland protected area. To understand the spatial distribution of vegetation in Duung Wetland, used the results of surveys in 2019 and 2023. As a result of the study, the number of vegetation types increased by 4 from 20 to 24. Four communities were newly investigated, including the <i>Utricularia tenuicaulis</i> community, <i>Pueraria montana</i> var. <i>lobata-Elymus tsukushiensis</i> community, <i>Spiraea prunifolia</i> for. <i>simpliciflora</i> community, and <i>Miscanthus sinensis</i> var. <i>purpurascens</i> community. In accordance with the environment, the range of aquatic plant communities such as <i>Trapa japonica</i> community and <i>Nymphaea tetragona</i> var. <i>angusta</i> community increased, and the succession zone of cultivated land expanded dry grassland. The survey results can be used as basic data for systematic management of the Duung wetland protected area.

СОВРЕМЕННОЕ СОСТОЯНИЕ РАСТИТЕЛЬНЫХ СООБЩЕСТВ ТЕРРИТОРИИ ОЗЕРА БОЛЬШОЕ ВАВАЙСКОЕ

This article analyzes the current state of plant communities on the territory of Lake Bolshoye Vavayskoye. The study covers the abundance, distribution and ecological relationships of the plant world.
 The article presents the results of field research conducted in different seasons of the year. The composition and structure of plant communities, as well as their functional characteristics, are described. Special attention is paid to the analysis of the impact of anthropogenic activities on the state of plant communities and their biodiversity.
 The study found that the plant communities of Lake Bolshoye Vavayskoye are characterized by a high level of biodiversity. In the studied phytocenoses (shrub larch with dwarf cedar, cedar dwarf lingonberry-ledum, lingonberry-lichen larch, fir-spruce moss, fir-spruce shrub, meadow, etc.) grow 283 species of vascular plants, which represent 18.03% of the total number of vascular plants o. Sakhalin, 5 rare plant species listed in the Red Books of the Russian Federation and the Sakhalin Region were also identified, such as Picea glehnii, Taxus cuspidata, Nuphar pumila, Nymphaea tetragona, Arália cordata. However, the study also showed that anthropogenic impact on the lake has a negative impact on the state of plant communities. In particular, signs of water pollution and deforestation have been identified, which leads to a decrease in biodiversity and deterioration of the environmental situation.
 The authors of the article draw attention to the importance of preserving this natural resource and its environmental sustainability, since in recent decades the territory has undergone anthropogenic impact. The study also highlights the importance of long-term monitoring and environmental control of the area to ensure the conservation of the lake's biodiversity and ecosystems for future generations. The results of the study may be useful for organizing nature conservation and developing an environmentally sustainable approach to the use of resources in the region.

On aquatic macrophytes in the ultracontinental climate conditions of the Upper Indigirka River

The first results of the study of aquatic macrophytes of the Upper Indigirka River area are presented. The species composition includes ~84 species (~74 vascular plants and more than 10 cryptogamous macrophytes). 47 water bodies of different age, size and origin (tectonic, glacial, river, thermokarst and artificial) were studied. For each type of water bodies, the main ecological characteristics, features of the species composition and vegetation cover are given. The most common type of water bodies of the territory is thermokarst, and the greatest floristic diversity (54 species of macrophytes) is found here. There are 40 species in tectonic lakes, 37 - in rivers lakes, 35 - in glacial lakes, the lowest diversity was for small artificial waterbodies. For the Oimyakon District, new records of protected species are reported: macroalga Tolypella canadensis, vascular plants Isoetes echinospora, Nuphar pumila, Nymphaea tetragona (common and its rare pink-flowered form) and Subularia aquatica. Possible consequences for aquatic ecosystems while maintaining current trends in climate change (increase in average annual temperature, shift to earlier periods of spring warmth, changes in the amount and distribution of precipitation, depth of seasonal thawing of soils) leading to degradation of permafrost and their impact on the biodiversity of aquatic macrophytes in the region are discussed. The most vulnerable aquatic ecosystems of the Oimyakon Highlands are the mature thermokarst lakes.

Transcriptome and hormone metabolome reveal the mechanism of stem bending in water lily (Nymphaea tetragona) cut-flowers.

Water lilies are popular ornamental cut-flowers with significant economic and cultural value. However, stem bending affects the preservation of cut-flowers during their vase life. To gain further insights into the molecular mechanisms of stem bending, transcriptome profiling, hormone measurement, and morphological analysis were performed using the stems of the 'Blue Bird' water lily. Transcriptome analysis revealed that 607 differentially expressed genes (DEGs) were associated with the dorsal and ventral stems of the water lily, of which 247 were up-regulated and 360 were down-regulated. Significant differences in genes associated with plant hormones, calcium ions, glucose metabolism, and photosynthesis pathways genes involved in the dorsal and ventral areas of the curved stem. In particular, DEGs were associated with the hormone synthesis, gravity response, starch granules, Ca2+ ions, and photosynthesis. The results of qRT-PCR were consistent with that of the transcriptome sequence analysis. A total of 12 hormones were detected, of which abscisic acid, indole-3-carboxaldehyde, indole-3-carboxaldehyde and jasmonic acid were significantly differentially expressed in the dorsal and ventral stems, and were significantly higher in the dorsal stem than in the ventral stem. The cell morphology in the dorsal and ventral areas of the curved stem clearly changed during vase life. The direction of starch granule settlement was consistent with the bending direction of the water lily stem, as well as the direction of gravity. In conclusion, stem bending in water lily cut-flowers is regulated by multiple factors and genes. This study provides an important theoretical basis for understanding the complex regulatory mechanism of water lily stem bending.

Identification for the species of aquatic higher plants in the Taihu Lake basin based on hyperspectral remote sensing.

Aquatic plants are crucial for aquatic ecosystems and their species and distribution reflect aquatic ecosystem health. Remote sensing technology has been used to monitor plant distributions over large scales. However, the fine identification of the species of aquatic higher plants is challenging due to large temporal-spatial changes in optical water body properties and small spectral differences among plant species. Here, an aquatic plant identification method was developed by constructing a decision tree file in the C4.5 algorithm based on the canopy spectra of eight plants in the Changguangxi Wetland water area from hyperspectral remote sensing technology. The method was used to monitor the distribution of different plants in the Changguangxi Wetland area and two other water areas. The results showed that the spectral characteristics of plants were enhanced by calculating their spectral index, thereby improving the comparability among different species. The total recognition accuracy of the constructed decision tree file for eight types of plants was 85.02%. Nymphaea tetragona, Pontederia cordata, and Nymphoides peltatum had the highest recognition accuracy and Eichhornia crassipes was the lowest. The specific species and distributions of aquatic plants were consistent with the water quality in the area. The results can provide a reference for the accurate identification of aquatic plants in the same type of water area.

Know thy enemy: Investigating genetic contributions from putative parents of invasive Nymphaea mexicana hybrids in South Africa as part of efforts to develop biological control

Hybridisation of alien invasive plants complicates efforts to develop biological control, because variations in the genetic makeup of the target plant can impact the survival of host specific agents that have evolved adaptations specific to the original host. To maximise the likelihood of success in a biological control program, potential agents should therefore be collected from populations in the region of origin that are genetically similar to plants in the invaded range. Molecular markers are useful tools to understand genetic contributions in hybrid populations, especially where morphological differentiation is difficult. Nymphaea mexicana Zuccarini (Nymphaeaceae) is an invasive alien plant in South Africa that is being targeted for biological control, but hybrids with intermediate morphological traits are also present at several sites. In this study, ISSR (inter simple sequence repeats) and ITS (internal transcribed spacer) markers were used to determine which Nymphaea species are likely to be putative parents of these hybrids, and morphological characters were also investigated to determine if genetic and morphological traits matched. Two major hybrid groups were identified, with one group clustering with Nymphaea odorata Aiton and the other clustering with Nymphaea alba L. A third, smaller group clustered with Nymphaea tetragona Georgi, whereas the remaining samples clustered with pure N. mexicana from the native range. Morphological features agreed with deductions drawn from molecular data. These results allow us to focus efforts to find compatible biological control agents and better understand the complicated genetic structure of N. mexicana and Nymphaea hybrids in South Africa.

Insights into Adaptive Regulation of the Leaf-Petiole System: Strategies for Survival of Water Lily Plants under Salt Stress.

The water lily (Nymphaea tetragona) is an ancient angiosperm that belongs to the Nymphaeaceae family. As a rooted floating-leaf plant, water lilies are generally cultivated in fresh water, therefore, little is known about their survival strategies under salt stress. Long-term salt stress causes morphological changes, such as the rapid regeneration of floating leaves and a significant decrease in leaf number and surface area. We demonstrate that salt stress induces toxicity soon after treatment, but plants can adapt by regenerating floating leaves that are photosynthetically active. Transcriptome profiling revealed that ion binding was one of the most-enriched GO terms in leaf-petiole systems under salt stress. Sodium-transporter-related genes were downregulated, whereas K+ transporter genes were both up- and downregulated. These results suggest that restricting intracellular Na+ importing while maintaining balanced K+ homeostasis is an adaptive strategy for tolerating long-term salt stress. ICP-MS analysis identified the petioles and leaves as Na-hyperaccumulators, with a maximum content of over 80 g kg-1 DW under salt stress. Mapping of the Na-hyperaccumulation trait onto the phylogenetic relationships revealed that water lily plants might have a long evolutionary history from ancient marine plants, or may have undergone historical ecological events from salt to fresh water. Ammonium transporter genes involved in nitrogen metabolism were downregulated, whereas NO3--related transporters were upregulated in both the leaves and petioles, suggesting a selective bias toward NO3- uptake under salt stress. The morphological changes we observed may be due to the reduced expression of genes related to auxin signal transduction. In conclusion, the floating leaves and submerged petioles of the water lily use a series of adaptive strategies to survive salt stress. These include the absorption and transport of ions and nutrients from the surrounding environments, and the ability to hyperaccumulate Na+. These adaptations may serve as the physiological basis for salt tolerance in water lily plants.

Green synthesis of platinum nanoparticles by Nymphaea tetragona flower extract and their skin lightening, antiaging effects

Platinum nanoparticles (PtNPs) were green synthesized by using chloroplatinic acid (H2PtCl6) as raw material and Nymphaea tetragona (N. tetragona) flower extract as the capping and reducing agents to improve skin health. Size-tunable PtNPs were obtained by volume ratios of the initial H2PtCl6/N. tetragona of 1:1 and 1:4, in which PtNPs prepared by the ratio of 1:1 and 1:4 was defined as L1-PtNPs and L4-PtNPs. Their characterizations were investigated by UV–visible spectroscopy, TEM, XRD and FTIR spectroscopy. TEM image analysis showed the particles were well dispersed with the average particle diameters of L1 and L4-PtNPs were 4.04 ± 1.31 nm and 2.01 ± 0.80 nm, respectively. The synthesized PtNPs showed effective antioxidant property and anti-tyrosinase activity in vitro. And further experiments exclaimed that PtNPs can significantly inhibit tyrosinase activity and UVB-induced melanin biosynthesis in A375 cells. This study also revealed PtNPs can promote collagen I biosynthesis in HFF-1 cells by activating the TGF-β/Smad pathway. This research showed the potential efficacy of PtNPs in the skin field and provided evidence for people to consider applying PtNPs to skin protection.

Wavelength-Dependent Photoreactivity of Root Exudates from Aquatic Plants under UV-LED Irradiation

Aquatic plants and their root exudates play important roles in the removal of trace organic contaminants in aquatic environments. However, the wavelength-dependent photogeneration of reactive species (RS) and photodegradation of organic contaminants by root exudates are poorly understood. This paper presents the first evidence that the photogeneration of 3DOM*, 1O2, and ·OH by root exudates varied under UV light-emitting diode (UV-LED) irradiation in the wavelength range of 265–400 nm. The quantum yields of 3DOM* and 1O2 of the four plants’ root exudates, including Scindapsus aureus, Pistia stratiotes, Eichhornia crassipes, and Nymphaea tetragona, reached the highest value at an irradiation wavelength of 275 nm and further decreased with increasing wavelength, while the ·OH quantum yield decreased gradually from 3.2–5.5 × 10–4 at 265 nm to 1.4–2.6 × 10–6 at 400 nm. The root exudate of Pistia stratiotes showed higher quantum yields of 3DOM* and 1O2 than that of the other three plants, while the highest ·OH quantum yield was observed in that of Eichhornia crassipes. The excitation wavelength affected the indirect degradation of organic contaminants by altering the photogeneration of RS in root exudate solutions. These findings highlight the wavelength-dependent photoreactivity of root exudates and improve the understanding of their photochemical processes in aquatic environments.

Notes on the taxonomy of Nymphaeaceae and Menyanthaceae in Mongolia

In this study, we investigated four aquatic plants, namely Nuphar pumila (Timm) DC. and Nymphaea candida C.Presl in Nympaeaceae as well as Menyanthes trifoliata L. and Nymphoides peltata (S.G. Gmel.) Kuntze in Menyanthaceae from Mongolia based on field surveys, herbariums, and scientific literature. In addition, we carefully examined for Nymphaea tetragona Georgi, which was previously recorded in several lakes, Khar-Us, Khar, Buuntsagaan, and Tsetsegt as well as the Ider river in Mongolia. Because we did not find N. tetragona in the field and because it is difficult to identify from herbarium specimens, we believe it has been misidentified at the Khar-Us, Khar, and Tsetsegt lakes to date. More surveys are needed to document its presence. Finally, we provide detailed distribution maps, photo illustrations, and taxonomic notes of four species.

ПОЛИПЛОИДИЯ У ВОДНЫХ И ПРИБРЕЖНО-ВОДНЫХ СОСУДИСТЫХ РАСТЕНИЙ СЕВЕРО-ВОСТОКА АЗИИ

The chromosome numbers of aquatic and semiaquatic vascular plants growing in extreme North-East Asia, east of the Lena River, were analyzed. We have reviewed the information about the karyological peculiarity of the aquatic flora based on published data, including our own definitions. The karyological data are considered depending on the taxonomic position, distribution and ecological characteristics of the species. The chromosome numbers are known for 119 out of 123 species. There is no data on Zannichellia komarovii, Eleocharis termale, Stuckenia subretusa and Potamogeton sibiricus. In the aquatic flora of North-East Asia, the proportion of polyploids is higher (79%) than that reported for the entire Beringian flora (69%). We analyzed species for the presence of polyploidy depending on the type of area. Analysis by latitudinal groups revealed that all Arctic and hypoarctic species of aquatic plants are polyploids. The minimum proportion of polyploids is observed among arctoboreal species. Analysis by longitudinal groups revealed that the lowest proportion of polyploids was noted among species found only in Eurasia and absent in North America (61%), and it was the highest among pluriregional species (96%). The species of the families Cyperaceae, Lemnaceae, Ranunculaceae and Poaceae are characterized by a high level of variability in the number of chromosomes. The greatest variety of chromosome numbers is observed in the polymorphic species Caltha palustris s. l., Agrostis stolonifera, Dupontia fisheri s. l., Phragmites australis, in all species of the genus Eleocharis, and in Nymphaea tetragona, Acorus calamus, Calla palustris. The isolated cases of a high level of ploidy were found in the extreme northeast, at the northern borders of ranges, in 3 species - Hippuris vulgaris, Arctophila fulva and Beckmannia syzigachne. Only diploids are known in the families Equisetaceae, Typhaceae, Zosteraceae from the flora of North East Asia. We revealed the existence of several chromosomal races in Ranunculus gmelinii and Caltha palustris (Ranunculaceae) in the Magadan region; the distribution of chromosomal races is partly related to geographic location and partly to plant habitats. Rare karyotypes in these species are observed in aquatic forms with mainly vegetative reproduction, growing in non-freezing watercourses.

In silico analysis of glycosyltransferase 2 family genes in duckweed (Spirodela polyrhiza) and its role in salt stress tolerance.

Plant glycosyltransferase 2 (GT2) family genes are involved in plant abiotic stress tolerance. However, the roles of GT2 genes in the abiotic resistance in freshwater plants are largely unknown. We identified seven GT2 genes in duckweed, remarkably more than those in the genomes of Arabidopsis thaliana, Oryza sativa, Amborella trichopoda, Nymphaea tetragona, Persea americana, Zostera marina, and Ginkgo biloba, suggesting a significant expansion of this family in the duckweed genome. Phylogeny resolved the GT2 family into two major clades. Six duckweed genes formed an independent subclade in Clade I, and the other was clustered in Clade II. Gene structure and protein domain analysis showed that the lengths of the seven duckweed GT2 genes were varied, and the majority of GT2 genes harbored two conserved domains, PF04722.12 and PF00535.25. The expression of all Clade I duckweed GT2 genes was elevated at 0 h after salt treatment, suggesting a common role of these genes in rapid response to salt stress. The gene Sp01g00794 was highly expressed at 12 and 24 h after salt treatment, indicating its association with salt stress resilience. Overall, these results are essential for studies on the molecular mechanisms in stress response and resistance in aquatic plants.

The Use of Constructed Wetland for Mitigating Nitrogen and Phosphorus from Agricultural Runoff: A Review

The loss of nitrogen and phosphate fertilizers in agricultural runoff is a global environmental problem, attracting worldwide attention. In the last decades, the constructed wetland has been increasingly used for mitigating the loss of nitrogen and phosphate from agricultural runoff, while the substrate, plants, and wetland structure design remain far from clearly understood. In this paper, the optimum substrates and plant species were identified by reviewing their treatment capacity from the related studies. Specifically, the top three suitable substrates are gravel, zeolite, and slag. In terms of the plant species, emergent plants are the most widely used in the constructed wetlands. Eleocharis dulcis, Typha orientalis, and Scirpus validus are the top three optimum emergent plant species. Submerged plants (Hydrilla verticillata, Ceratophyllum demersum, and Vallisneria natans), free-floating plants (Eichhornia crassipes and Lemna minor), and floating-leaved plants (Nymphaea tetragona and Trapa bispinosa) are also promoted. Moreover, the site selection methods for constructed wetland were put forward. Because the existing research results have not reached an agreement on the controversial issue, more studies are still needed to draw a clear conclusion of effective structure design of constructed wetlands. This review has provided some recommendations for substrate, plant species, and site selections for the constructed wetlands to reduce nutrients from agricultural runoff.

Macrophytes restoration and its effects on eutrophication control in rehabilitated lakeshore zone of Gonghu Bay, Lake Taihu

以太湖贡湖湾人工湖滨带为对象，研究湖滨水生植物修复过程及其富营养化控制效果.人工湖滨区域内的消浪带、岸上护坡措施为水生植物修复提供了良好的生境条件，形成了包括荇菜（Nymphoides peltatum（Gmel.）Kuntze）、睡莲（Nymphaea tetragona Georgi）、菱（Trapa bispinosa Roxb.）为主的浮叶植物群落，以及以黑藻（Hydrilla verticillata（Linn.f.）Royle）、狐尾藻（Myriophyllum verticillatum L.）、小眼子菜（Potamogeton pusillus L.）、竹叶眼子菜（Potamogeton malaianus）为主的沉水植物群落.通过设置研究区、对照区，持续监测溶解氧、总氮、总磷、氨氮、叶绿素a浓度等水体指标，烧失量、氮含量、磷含量等沉积物指标，水生植物生物量、覆盖度，浮游藻类等指标.不同时期、不同区域间的时空分布显示：随着水生植物的恢复，水体营养状态指数（TLI）、沉积物生物生产力指数（BPI）显著下降，水体透明度显著提升；较高浓度的总氮（>3.0 mg/L）、氨氮（>0.6 mg/L）环境不利于浮叶植物的生长，沉水植物对其则表现出更好的适应性，同时水生植物在成长过程中直接从水体/沉积物中吸收氮；颤藻（Cyanophyta oscillatoria）、直裂藻（Cyanophyta merismopedia）等浮游藻类吸收了水体磷，水生植物利用了沉积物磷，共同缓解了磷在湖滨区域的累计.总结以上，湖滨带的水文水质条件可以影响水生植物群落结构，进而决定氮、磷的控制效果，所以在湖滨带修复中构建合适的生境条件是水生植物发挥氮磷控制效果的重要前提.水生植物在恢复过程中对浮游藻类群落结构的影响是显著的，并且以此影响到湖滨水体中磷的分布.;A rehabilitated lakeshore zone in Gonghu Bay, Lake Taihu, China was chosen to study macrophytes restoration and its effects on eutrophication control. The facilities including wave-weakening belts and bank revetment in rehabilitated lakeshore provided habitat for floating-leaved macrophytes, like Nymphoides peltatum (Gmel.) Kuntze, Nymphaea tetragona Georgi, Trapa bispinosa Roxb., etc. and submerged macrophytes, like Hydrilla verticillate, Myriophyllum verticillatum L., Potamogeton pusillus L., Potamogeton malaianus, etc.. The continuously monitoring on dissolved oxygen, total nitrogen, total phosphorus, ammonia, chlorophyll-a concentrations of water, ignition loss, nitrogen, phosphorus contents of sediment, macrophytes' coverages and biomass, phytoplankton's density were performed between two study areas and reference area. The space-time distribution of different areas and stages indicated that the trophic level index (TLI) of water and the bioproduction index (BPI) of sediment were remarkedly reduced, the water transparency was significantly increased as the macrophytes restored. The relatively high levels of total nitrogen (>3.0 mg/L) and ammonia (>0.6 mg/L) were the condition unfavorable for the floating-leaved macrophytes but not for the submerged macrophytes, in the meanwhile nitrogen of water and sediment were utilized directly during the macrophytes' restoration. Phytoplankton like Cyanophyta oscillatoria, Cyanophyta merismopedia and etc. absorbing phosphorus from water directly and macrophytes utilizing phosphorus in sediment collaboratively alleviated the phosphorus accumulation in lakeshore. Overall, it is concluded that the hydrological condition and water quality have impact on structure of macrophyte communities in the restoration, thus affecting the efficiency of nitrogen and phosphorus control. The macrophytes restoration had significant influences on planktonic communities, of which were directly correlated with phosphorus distribution in lakeshore water.

Effects of Escherichia coli pollution on decomposition of aquatic plants: Variation due to microbial community composition and the release and cycling of nutrients

Determination of the effects of Escherichia coli (E. coli) pollution on agricultural pond ecosystems with vegetation at different life stages is essential for the protection of ecological functions. However, no comprehensive study has yet shown the responses of epiphytic microbial communities to E. coli invasion during plant decay. Thus, this study was conducted to clarify variation in the decay of the following aquatic plants—Myriophyllum aquaticum, Nymphaea tetragona and Phragmites australis after E. coli pollution. Exogenous E. coli especially shifted the epiphytic microbial composition and distribution of P. australis. Stronger effects of E. coli on the archaeal community (edges/nodes = 0.818 < 1, modularity = 0.654; lower clustered structure, 0.389) were found than on the bacterial community (edges/nodes = 1.538 > 1, modularity = 1.291 > 0.654; higher clustered, 0.593). During plant decomposition, E. coli weakened methanogenesis by regulating the network of core genera Methanobacterium and Methanospirillum (spearman, P < 0.05), stimulated the accumulation of organic matters in water (P < 0.05). Similarly, nitrification and denitrification increased and decreased through network regulation in relative biomass of genera Devosia and Desulfovibrio (P < 0.05), respectively. The results provided theoretical supports for eutrophication management in pond ecosystems threatened by E. coli pollution.

Study on phytoremediation for heavy metal contaminated sediments by hydrophytes

The remediation performances of heavy metals contaminaged sediment by hydrophytes including Alternanthera Philoxeroides, Canna indica L., Nymphaea tetragona, Typha orientalis, Phragmites australis, Phragmites australis, Hydrilla verticillata, Cyperus alternifolius L., Eichhornia crassipes, Acorus tatarinowii, Digitaria sanguinalis (L.) Scop were investigated through batch pot experiments. The results showed that the enrichment effect of Pb was better in Alternanthera Philoxeroides and Acorus tatarinowii with the BCFs of 4.42 and 1.22, and the TFs of 7.84 and 4.23, respectively. The Cr enrichment effects by Nymphaea tetragona, Hydrilla verticillata and Eichhornia crassipes (Mart.) Solms were better, which BCFs were 2.69, 1.91 and 3.71, and which TFs were 7.93, 2.07 and 2.18, respectively.

Флористические находки редких видов растений в Республике Хакасии

The article contains an information on the locations for nine of rare plant species in the Republic of Khakassia. Utricularia ochroleuca, higher vascular species of hybridogenic origin, is shown for Siberia for the first time. One species from Marchantiophyta – Riccia fluitans – have been found in Khakassia for the first time. The information for new locations of rare species: orchids from Red List – Cypripedium macranthon, Epipogium aphyllum, Neottianthe cucullata and Orchis militaris, endemic from southern Siberia Saussurea parviflora subsp. purpurata, rare aquatic plants Nymphaea tetragona (previously considered extinct in Khakassia) and Zannichellia repens, is provided also.

Ecological aesthetic assessment of a rebuilt wetland restored from farmland and management implications for National Wetland Parks.

While wetlands are usually used as a natural approach to remove biodegradable pollutants in surface water, their purification efficiencies coupled with their aesthetic features are of less concern. The water quality, plant landscape, acoustic environment and odour indicators were investigated in the surface water inlet and outlet of the Fujin National Wetland Park (FNWP), restored from farmlands in Northeast China. Major concentrations of pollutants in the inlet and the outlet subjected to surface flow wetland treatment were monitored, and the removal efficiencies were calculated based on 54 water samples (6 sites×3 seasons×3 replicates). The results showed that the total nitrogen (TN) and organic carbon in surface water decreased significantly after the wetland treatment, while the total phosphorus (TP) did not decrease significantly. The removal efficiencies for TN and BOD5 changed seasonally and reached 69.08% and 60.44%, respectively. An ecological aesthetic index (EAI) was developed based on the trophic state index coupled with plant landscape, acoustic and odour indicators, and the calculated EAI showed that the outlet delivered a more aesthetically harmonious appearance than the inlet in spring and autumn, but not in summer. Based on the current aquatic macrophyte species and documented purification efficiencies in FNWP, we recommend an improved ecological aesthetic management approach that utilizes and arranges diverse native plants from the surrounding wetlands (e.g. Scirpus validus) in addition to local Nelumbo nucifera, Nymphaea tetragona and Myriophyllum spicatum, and conserves the indicative and endangered species (Aldrovanda vesiculosa), from the visual appeal of the waterscape.

Uptake of uranium from aqueous solution by Nymphaea tetragona Georgi: The effect of the accompanying heavy metals

This study evaluated the application value of Nymphaea tetragona Georgi (N. tetragona) in the remediation of water co-contaminated with U and the U-accompanying heavy metals (UAHMs). Under greenhouse conditions, a 5-factor quadratic regression orthogonal rotation combination design (QRORCD) was employed to set up a hydroponic experiment to evaluate the effect of U and UAHMs on the enrichment of U from water in N. tetragona. The results showed that the coexisting U and UAHMs tend to inhibit the amount of U enriched in the whole plant. Under co-contaminated conditions, Mn and Hg can increase the enrichment of U from water in N. tetragona, while Pb and As usually inhibit it. The predicted amount of U enriched in the whole plant (UWP) was 57,131.32 μg (1938.66 mg•kg−1 D.W.), and the validation result of the optimization scheme was 53,285.88 μg. A single-factor effect analysis showed that the influence of the 5 types of contamination on the UWP was in the order of U > Hg > Pb > Mn > As. The interactive effects analysis showed that the concentrations of U and As, Mn and As, and Pb and Hg all had significant interactive effects on the UWP, and the change trend exhibited a basin or saddle shape.

Occurrence of microcystin-LR in vegetated lagoons used for urban runoff management

Phytoremediation with aquatic macrophyte has been considered as an eco-friendly technique for controlling harmful cyanobacteria outbreak and proven to be effective. The conventional water quality parameters are frequently measured to evaluate the effectiveness of phytoremediation. However, the concentration of microcystin-leucine-arginine (MC-LR) in different vegetated water still remains uncertain. In this study, the contents of MC-LR in four macrophyte-vegetated lagoons were determined by solid phase extraction and ultra-high-performance liquid chromatography with tandem mass spectrometry technology. Results indicated that MC-LR was found in Nymphaea tetragona lagoon (lagoon-S), Vallisneria spiralis lagoon (lagoon-B) and another Vallisneria spiralis lagoon (lagoon-J). Only in lagoon dominated by Pistia stratiotes L. (lagoon-D), MC-LR concentration was undiscovered regardless of seasonal variation. The levels of MC-LR varied seasonally and were affected by the different vegetated aquatic macrophytes. The results suggest that in addition to conventional physicochemical parameters and indicators of water quality, MC-LR levels should be taken into consideration when the effectiveness of phytoremediation is assessed.