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The partitioning of overall beta diversity into local contributions (LCBD; compositional uniqueness) and species contributions (SCBD) has enhanced the understanding of the organization of metacommunities. Here, we evaluated LCBD and SCBD of aquatic macrophyte metacommunities from 29 subtropical coastal wetlands, covering an extension of 640 km, in Southern Brazil. Furthermore, we assessed the environmental uniqueness, considering both the physical and chemical variables of water in wetlands, as well as climatic variables. We assessed the environmental and spatial correlates of LCBD and the environmental correlates of SCBD. We expected that (i) communities with greater compositional uniqueness would be found in environmentally more unique wetlands, (ii) the compositional uniqueness would also be related to climatic variables that determine the hydrological changes in wetlands, and (iii) the contribution of emergent species to beta diversity would be lower than of floating and submerged species. The compositional uniqueness did not present a clear spatial structure, being positively related to uniqueness in water chemistry and negatively to the mean air temperature during the driest quarter. The species contribution to beta diversity was higher for floating species than for emergent ones. Moreover, SCBD correlated to climatic variables and presented a positive relationship with site occupation, suggesting that more frequent species in terms of site occurrence contribute most to beta diversity. Our results show the importance of local environmental and broader climatic predictors in determining the compositional uniqueness of macrophyte communities and species contributions to overall beta diversity in the coastal wetlands of Southern Brazil. [ABSTRACT FROM AUTHOR]

Population increase and socio-economic progress exert pressure on land use and land cover (LULC) in any geophysical environment. If not minimized, the pressure has the potential to unfold as unplanned and uncontrolled alterations in LULC. Remote sensing (RS) and geographical information systems (GIS) prove to be powerful tools for obtaining accurate and real-time information on the spatial distribution of land use and land cover change (LULCC) both spatially and temporally over a wide area. This research paper uses remotely sensed spatial data and a literature review to examine the extent of LULCC over three decades in the distal Okavango Delta with specific attention on Maun, Botswana. The study assesses changes in population growth, built-up areas, road/pavements, water fluctuations, hydrophytes and shrubs/trees dynamics from April 1990 to April 2020. Findings reveal that while the population of Maun increased from 26,768 to 85,293 between 1990–2020 built-up areas increased from 0.68 km2 to 9.61 km2 and shrubs/trees decreased from 13.53 km2 to 7.06 km2, respectively, within the same period. Grasslands increased from 8.57 km2 in 1990 to 13.44 km2 by 2020. The paper thus recommends the establishment of a two-kilometre-wide green belt around the settlement to stem any progressive encroachment into agricultural reserved land.

Highlights: What are the main topic discussed? Description of the formation process of iron plaque. The factors affecting the formation of iron plaque were summarized. What are the implications of these discussions? Understanding the role of iron plaque in environmental processes. Insights into the interactions between iron plaque, plants, and microbes for environmental remediation. Soils play a dominant role in supporting the survival and growth of crops and they are also extremely important for human health and food safety. At present, the contamination of soil by heavy metals remains a globally concerning environmental issue that needs to be resolved. In the environment, iron plaque, naturally occurring on the root surface of wetland plants, is found to be equipped with an excellent ability at blocking the migration of heavy metals from soils to plants, which can be further developed as an environmentally friendly strategy for soil remediation to ensure food security. Because of its large surface-to-volume porous structure, iron plaque exhibits high binding affinity to heavy metals. Moreover, iron plaque can be seen as a reservoir to store nutrients to support the growth of plants. In this review, the formation process of iron plaque, the ecological role that iron plaque plays in the environment and the interaction between iron plaque, plants and microbes, are summarized. [ABSTRACT FROM AUTHOR]

Soils play a dominant role in supporting the survival and growth of crops and they are also extremely important for human health and food safety. At present, the contamination of soil by heavy metals remains a globally concerning environmental issue that needs to be resolved. In the environment, iron plaque, naturally occurring on the root surface of wetland plants, is found to be equipped with an excellent ability at blocking the migration of heavy metals from soils to plants, which can be further developed as an environmentally friendly strategy for soil remediation to ensure food security. Because of its large surface-to-volume porous structure, iron plaque exhibits high binding affinity to heavy metals. Moreover, iron plaque can be seen as a reservoir to store nutrients to support the growth of plants. In this review, the formation process of iron plaque, the ecological role that iron plaque plays in the environment and the interaction between iron plaque, plants and microbes, are summarized.

In order to determine optimum and ecologically acceptable conditions for aromatic amines (benzidine was chosen as an example) elimination by chara algae Nitella sp. a multi-factor experiment has been undertaken. The benzidine elimination process by chara algae was studied by variation of four factors, such as benzidine initial concentration in water solution, algae biomass, temperature, time and at the interaction of these factors as well. A mathematical model adequately describing the benzidine elimination process by chara algae at the optimal conditions has been obtained by means of design of experiments method. Suggested model might be useful for obtaining the data important for hydro botanical treatment facilities design and self-cleaning processes understanding. [ABSTRACT FROM AUTHOR]

Aquatic bodies contaminated by heavy metals (HMs) are one of the leading issues due to rapidly growing industries. The remediation of using algae and hydrophytes acts as an environmentally friendly and cost effective. This study was performed to investigate the pollution load, especially HMs, in the wastewater of the Gadoon Industrial Estate and to utilize the hydrophytes (Typha latifolia (TL) and Eicchornia crassipes (EI)) and algae (Zygnema pectiantum (ZP) and Spyrogyra species (SS)) as bioremediators. The wastewater was obtained and assessed for physiochemical parameters before treating with the selected species. The pot experiment was performed for 40 days. Then the wastewater samples and selected species were obtained from each pot to analyze the metal removal efficiency and assess for metal concentrations using atomic absorption spectrophotometry. The dissolved oxygen (DO; 114 mg/L), total suspended solids (TSS; 89.30 mg/L), electrical conductivity (EC; 6.35 mS/cm), chemical oxygen demand (COD) (236 mg/L), biological oxygen demand (BOD; 143 mg/L), and total dissolved solids (TDS; 559.67 mg/L), pH (6.85) were analyzed. The HMs were noted as Zn (5.73 mg/L) and Cu (7.13 mg/L). The wastewater was then treated with the species, and significant reductions were detected in physicochemical characteristics of the wastewater such as DO (13.15–62.20%), TSS (9.18–67.99%), EC (74.01–91.18%), COD (25.84–73.30%), BOD (21.67–73.42%), and TDS (14.02–95.93%). The hydrophytes and algae removed up to 82.19% of the Zn and 85.13% of the Cu from the wastewater. The study revealed that the hydrophytes and algae significantly decreased the HM levels in the wastewater (p ≤ 0.05). The study found TL, EI, ZP, and SS as the best hyper accumulative species for Zn and Cu removal from wastewater. The HMs were removed in the order of Cu > Zn. The most efficient removal for Cu was found by Typha latifolia and Zn by Zygnema pectiantum. It was concluded that bioremediation is an environmentally friendly and cost-effective technique that can be used for the treatment of wastewater due to the efficiency of algae and hydrophytes species in terms of HM removal. [ABSTRACT FROM AUTHOR]

One of the identified obstacles to the development of biogas plants is the limited sources of organic substrates. Hydrophytes varying in morphology, chemical composition, and origin proved to be viable alternatives. This study's aim was to determine the feasibility of deploying biomass from the cleansing of water reservoirs for anaerobic digestion. A mass and energy balance was estimated for Warmia–Mazury Province (Poland), the so-called Thousand Lake District. The effectiveness of anaerobic digestion was determined in anaerobic batch respirometric reactors. The biomass of hydrophytes harvested from this area approximated 38,070 Mg FM/year. The biogas yield from emergent plants approximated 350 m3/MgVS, and the average CH4 content of biogas reached 55%, whereas the respective values obtained from submerged biomass reached 270 m3/MgVS and 58% CH4. The total CH4 volume achievable from the facility fed with waste biomass of this type allows producing ca. 1,654,560 m3CH4/year, which enables reaching 866 kW theoretical thermal power and 636 kWe net electrical power with the facility. The contribution of biomass from mowing in this energy effect was about 84%, whereas that of the submerged vegetation obtained by hacking the bottom was 16%. [ABSTRACT FROM AUTHOR]

Lake vegetation is divided into 3 ecological groups: hygrophytes, hydrophytes and hydratophytes. Hygrophytes make up 27.2%, hydrophytes-9.0% and hydrophytes-63.6%. Hygrophytes are plants that grow in moist places, on the shores, and hydrophytes are half aquatic. This plant species is found in small numbers in the lake. Hydrotophytes are dominant in abundance and biomass. The area of the lake is 7,200 hectares, of which the water part is 3,800 hectares, the area of wetlands covered by various parts is 3,400 hectares. The lake is rich in organic nutrients. A wide variety of higher algae grows in the lake (Phragmites communis, typha angustifolia, Potamogeton crispus, Myriophyllum spicatum, Ceratophyllum demersum, Chara infarmedia, Spirogyra, as well as many species of algae), which prevents sunlight from penetrating into the water to a depth of 3 meters, which negatively affects the development of zooplankton.

Copyright of Nova Acta Científica Compostelana is the property of Universidad de Santiago de Compostela, Servicio de Publicaciones and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Information on 15 species of aquatic vascular plants growing in the mires of the Volga upland is provided. It is revealed that Lemna minor, Persicaria amphibia, and Utricularia vulgaris are common representatives of the flora of fens and, less often, transitional mires. Hydrocharis morsus-ranae and Potamogeton natans have a slightly smaller distribution, which are confined mainly to disturbed mires. Utricularia intermedia and U. minor are rare species in most regions of the Volga upland; they grow mainly in transitional mires, where their occurrence is estimated as sporadic. Potamogeton gramineus and Salvinia natans are included in the regional Red Data Books; most of the finds are known from the reaches of the Volga reservoirs, but these species are characterized by habitats on some subtypes of mires. Six species are common on the Volga upland for lakes, but they are rare in mires: Lemna trisulca and Spirodela polyrhiza only in the most mineral-rich fens, Nuphar lutea and Nymphaea candida in coastal strips of intracoastal reservoirs, and Ceratophyllum demersum and Stratiotes aloides in mires of the initial stage of formation from mainly ancient lakes. [ABSTRACT FROM AUTHOR]

Abstract Floristic studies of aquatic plants and flora associated with aquatic ecosystems carried out in the Neotropical region have demonstrated the predominance and co-occurrence of the same plant families under different climatic conditions. One way to interpret this co-occurrence of groups with non-random patterns in assemblages is to understand their phylogenetic structure. Herein, we present an investigation that studied the rule of phylogenetic assembly on plants associated with reservoirs in a tropical climosequence in Northeast Brazil. We studied eight areas during the dry and rainy periods and characterized their climatic, chemical, and trace elements, as well as richness, diversity, and phylogenetic structure of their assemblages. We found a predominance of the families Fabaceae, Poaceae and Cyperaceae, especially in border areas. Among the species surveyed, we highlight those with amphibian life-form, autochoric-type dispersion syndrome and the taxa with patterns of wide geographical distribution. We observed that the seasonal effect ruled patterns of phylogenetic structure with tendency for non-co-familiarity. Water quality and sediment were the abiotic factors most efficient as predictors of richness and variations in phylogenetic metrics. In this sense, the family co-occurrence identified in the assemblages was less deterministic than expected through non-randomness, because temporally, guilds were distinctly structured in function of seasonality.

The aquatic vegetation (macrophyte) of the Aghstev river basin is very poor. 29 species of aquatic plants belonging to 19 families were found here, of which 5 species are hydrophytes, 9 – helophytes, 10 – hygrohelophytes, and 5 – hygrophytes. The distribution of macrophytes is limited by waterfalls, chutes and floods, typical of mountain rivers. The hydrophytic index is equal to 0.03, which makes it difficult to assess water quality through macrophytes. [ABSTRACT FROM AUTHOR]

ABSTRACT The semiarid region of northeastern Brazil possesses a set of wetlands characterized by hydrographic basins with deficient drainage networks, a few large and permanent lotic systems and several permanent and temporary lagoons. Aquatic plants are widely distributed in these wetlands and the present study aims to determine if those of Ceará state have similar species compositions and differences in species richness. We hypothesized that lentic ecosystems would have more species and different growth forms of aquatic angiosperms than lotic ecosystems. A total of 1619 records of aquatic angiosperms in 43 wetland areas were analysed. The most representative families were Cyperaceae, Poaceae, Fabaceae, Alismataceae, Malvaceae, Nymphaeaceae and Pontederiaceae. Most of the species are helophytes and bottom-rooted emergent hydrophytes. Permanent lentic ecosystems had the highest number of exclusive species (27.85 %), followed by temporary lentic ecosystems (20.54 %). Contrary to our hypothesis, the different aquatic ecosystems were found to possess distinct species compositions and different proportions of growth forms, and all wetland types contributed to the macrophyte richness of the study area, although they differ in species richness. Therefore, conservation plans for the native aquatic macrophyte biota should include all wetland ecosystems in the semiarid state of Ceará.

ABSTRACT Until the mid-XX century, little awareness on the ecological services or socio-environmental problems and benefits related to aquatic plants culminated in bottlenecks on their natural history, especially for the Neotropics. In this context, Acta Botanica Brasilica (ABB) organized this special issue to promote the advancement of knowledge on this ecological group in the Neotropics, supported by Sociedade Botânica do Brasil’s group of aquatic plants specialists. We selected and evaluated manuscripts gathering unprecedented findings, resulting from studies on aquatic plants, with little investigated or documented approaches, such as the improper use of methodological paradigms and aspects of biogeography, ecophysiology, morphoanatomy, structuration of communities, functional ecology, and human use. Here we present a synthesis of these reports’ findings that shall contribute to deepening the knowledge on the natural history, sustainable use, and conservation of aquatic plants and guide future research, mainly in Neotropical aquatic ecosystems. The publication of special issues on themes with insufficient knowledge to Science can reduce such gaps and expand the journal’s perspectives. Therefore, we believe that this special issue of ABB will boost the understanding of aquatic plants’ natural history as much as incentivizing journals with specific scopes of the area of Plant Biology to similar initiatives.

Aquatic bodies contaminated by heavy metals (HMs) are one of the leading issues due to rapidly growing industries. The remediation of using algae and hydrophytes acts as an environmentally friendly and cost effective. This study was performed to investigate the pollution load, especially HMs, in the wastewater of the Gadoon Industrial Estate and to utilize the hydrophytes (Typha latifolia (TL) and Eicchornia crassipes (EI)) and algae (Zygnema pectiantum (ZP) and Spyrogyra species (SS)) as bioremediators. The wastewater was obtained and assessed for physiochemical parameters before treating with the selected species. The pot experiment was performed for 40 days. Then the wastewater samples and selected species were obtained from each pot to analyze the metal removal efficiency and assess for metal concentrations using atomic absorption spectrophotometry. The dissolved oxygen (DO; 114 mg/L), total suspended solids (TSS; 89.30 mg/L), electrical conductivity (EC; 6.35 mS/cm), chemical oxygen demand (COD) (236 mg/L), biological oxygen demand (BOD; 143 mg/L), and total dissolved solids (TDS; 559.67 mg/L), pH (6.85) were analyzed. The HMs were noted as Zn (5.73 mg/L) and Cu (7.13 mg/L). The wastewater was then treated with the species, and significant reductions were detected in physicochemical characteristics of the wastewater such as DO (13.15–62.20%), TSS (9.18–67.99%), EC (74.01–91.18%), COD (25.84–73.30%), BOD (21.67–73.42%), and TDS (14.02–95.93%). The hydrophytes and algae removed up to 82.19% of the Zn and 85.13% of the Cu from the wastewater. The study revealed that the hydrophytes and algae significantly decreased the HM levels in the wastewater (p ≤ 0.05). The study found TL, EI, ZP, and SS as the best hyper accumulative species for Zn and Cu removal from wastewater. The HMs were removed in the order of Cu > Zn. The most efficient removal for Cu was found by Typha latifolia and Zn by Zygnema pectiantum. It was concluded that bioremediation is an environmentally friendly and cost-effective technique that can be used for the treatment of wastewater due to the efficiency of algae and hydrophytes species in terms of HM removal.

Five populations of Typha domingensis Pers. were evaluated for their tolerance to different regimes of cadmium (Cd). Plants were collected from different sites in Punjab province of Pakistan viz. Jaranwala (S1), Farooq Abad (S2), Chiniot (S3), Khurianwala (S4), and Sidhnai (S5). Collected plants were established for three months and then subjected to Cd levels, i.e., 0, 50, 100, and 150 µM L−1. Differential changes in attributes presented variation in tolerance level of T. domingensis populations against Cd toxicity. Fresh and dry biomass, photosynthetic pigments, and total soluble sugars were decreased in all populations under Cd stress, but reduction in biomass of S2 plants was least. Similarly, amino acids, protein contents, and antioxidant enzymatic activity were increased in S2 and S3 under Cd. The populations, i.e., S2, S3, with better anti-oxidative metabolism, ionic partitioning, and growth presented useful structural changes in root and leaves. Contrary to increased leaf thickness, area of leaf and root conducting vessels was decreased with increasing Cd concentrations but these changes were lowest in S2 plants as compared to other populations. Our data indicate that the higher tolerance to Cd toxicity observed in S2 population of T. domingensis could be related to the collective role played by physiological, biochemical and anatomical changes. [ABSTRACT FROM AUTHOR]

Distribution of rivers, pools and grasslands, being large or small and perennial or temporary, have created conditions suitable for the establishment of wetlands, especially in the highland regions of the Country. These habitats are highly important for the preservation of biodiversity and other ecological aspects. The present study aimed to identify wetlands in the Kermanshah Province, Iran, and map their distribution. The investigation was carried out on the basis of the conventional taxonomic studies of the region by doing field observation in 31 aqueous habitats in Kermanshah Province. The flora of each habitats and the life form and geographical distribution of the species were investigated. In total, 617 plant specimens, belonging to 288 species, 218 genera and 62 families, were collected identified and stored in the herbarium of the research center of agriculture and natural resources of Kermanshah Province (RANK). Asteraceae with 41 species, Poaceae with 31 species, Fabaceae with 31 species and Brassicaceae with 24 species were found to be the most important families of the wetlands studied. Trifolium with 11 species and Bromus with 6 species were the most important genera, in terms of species richness. Detection of the biological forms showed that 40.3% of the species were trophytes, 35/5% were hemicryptophyts, 6/1% were phanerophytes, 14/23% were cryptophytes and 3/72% were chamaephytes. The chorology of species showed that 93 species belonged to more than two elements (32%), 92 species (31%) to the Irano-Touranin elements, 32 species to Irano-Touranin- Mediterranean (11%), 9 species to Irano-Touranin- Euro-Siberian with (3%) and 23 species were found to be cosmopolitan elements (8%).

The widespread existence and persistence of antibiotics in the aquatic environment, and their extensive ecological risks, have attracted considerable attention. The objective of this study was to evaluate the occurrence and distribution of 25 antibiotics in environmental and biological samples from Poyang Lake Basin in China. SPE–HPLC–MS/MS was used to quantify the concentrations in different matrices. The total concentrations ranged from 144 to 933 ng/L in the water and 346 to 1154 ng/g in the sediment. In the spatial distribution analysis of this basin, the concentrations in the Ganjiang River were generally higher than those in Poyang Lake. The seasonal distribution in the wet and dry seasons showed comparatively higher concentrations during the dry season than the wet season. Additionally, antibiotics were found in various hydrophytes and animals, and the bioconcentration factor values followed the order: emergent plants > floating plants > submerged plants and benthic organisms > ducks > fish. Moreover, correlations among different matrices showed that antibiotics in viviparid snails were significantly positively correlated with those in ducks, and negatively correlated with those in carps, indicating the transmission relationship through the food chain. The results showed the trophic transfer of antibiotics in the food web and their potential environmental impacts on Poyang Lake Basin need constant attention. [Display omitted] • Antibiotics in Ganjiang River were higher than that in Poyang Lake. • K ow and pK a values of antibiotics were critical to their concentrations. • Viviparid snails were significantly correlated with ducks and carps. • Macrolides presented the main ecology risk factors to Poyang Lake Basin. [ABSTRACT FROM AUTHOR]

The huge biodiversity of inland waters and the many different aquatic habitats or ecosystems occurring there are particularly threatened by human impacts. In this Special Issue, ten articles have been collected that show new data on the distribution and ecology of some rare aquatic macrophytes, including both vascular plants and charophytes, but also on the use of these organisms for the monitoring, management, and restoration of wetlands. [ABSTRACT FROM AUTHOR]

Background. There is very little information on the productivity of hydrophytes in the water bodies of the European Northeast. At the same time, the study of the specifics of the processes of accumulation of organic matter in the northern regions is of great interest and is of great practical importance. The reservoirs where productivity studies have been carried out are used for fishery and recreational purposes. The purpose of this work is to characterize the communities of hydrophytes of small reservoirs and calculate their productivity. Materials and methods. The study of the productivity of hydrophytes was carried out at three small reservoirs located in the southern part of the Komi Republic at the end of June – July 2019–2020. To assess the aboveground phytomass, cutting plots with a size of 0.25 m2 were laid. Mows were selected in each community in triplicate, sorted by species and dried, after which their absolutely dry weight was weighed. When converting absolutely dry weight into pure annual products, a coefficient of 2,5 was used. Results. The studied reservoirs are moderately overgrown (21,7 % and 17,5 %) and significantly overgrown (26,1 %). The most productive are the Potamo natantis – Polygonetum natantis and Potametum natantis communities. The net annual production of hydrophytes with low heat supply for the year was 6,3 t/year for the Kazhim reservoir, 23,2 t/year for the Nyuvchim reservoir, 0,3 t/year for the Nyuchpassky reservoir, and 11,6, 61,4, 0,4 t/year, respectively. Conclusions. 10 associations of hydrophytes were characterized and the values of their productivity were obtained. The influence of the temperature factor on the accumulation of organic matter by own-water plants was revealed. The main producers, which make the greatest contribution to the total productivity of the reservoir, have been identified.

One of the identified obstacles to the development of biogas plants is the limited sources of organic substrates. Hydrophytes varying in morphology, chemical composition, and origin proved to be viable alternatives. This study’s aim was to determine the feasibility of deploying biomass from the cleansing of water reservoirs for anaerobic digestion. A mass and energy balance was estimated for Warmia–Mazury Province (Poland), the so-called Thousand Lake District. The effectiveness of anaerobic digestion was determined in anaerobic batch respirometric reactors. The biomass of hydrophytes harvested from this area approximated 38,070 Mg FM/year. The biogas yield from emergent plants approximated 350 m3/MgVS, and the average CH4 content of biogas reached 55%, whereas the respective values obtained from submerged biomass reached 270 m3/MgVS and 58% CH4. The total CH4 volume achievable from the facility fed with waste biomass of this type allows producing ca. 1,654,560 m3CH4/year, which enables reaching 866 kW theoretical thermal power and 636 kWe net electrical power with the facility. The contribution of biomass from mowing in this energy effect was about 84%, whereas that of the submerged vegetation obtained by hacking the bottom was 16%.

Aim: The regionalized patterns of biodiversity distributions are actively studied in terrestrial and marine ecosystems, but much less is known on the geographical patterns of ecoregions founded on freshwater taxa. Here, we studied, for the first time, how well existing freshwater ecoregions describe the geographical distribution of inland water plants. Location: Greenland, continental Canada and USA. Taxon: Freshwater vascular plants of all taxa and multiple functional groups (i.e. growth forms). Methods: Using newly available fine‐grained data on freshwater plant distributions, we studied how ecoregions founded on fish are suitable for freshwater plant regionalization across North America. Specifically, we calculated internal homogeneity and distinctness among neighbouring ecoregions in relation to species replacements and richness differences. We also explored how a complex suite of ecogeographical characteristics affect ecoregion delineation of freshwater plants using spatially explicit regression routines. Results: We found a clear geographical patterning of ecoregion robustness for North American freshwater plants, with communities being more internally homogeneous and more similar to one another in Polar and Subtropical inland waters. The degree of internal homogeneity and ecoregion distinctness were almost equally driven by species replacements and richness differences. Considering different life‐forms, ecoregion delineation performed best for emergent and floating‐leaved plants. Finally, within‐ecoregion homogeneity and distinctness were best explained by annual mean temperature and terrain ruggedness, respectively, with mean water alkalinity, ecoregion area and late Quaternary glacial legacies having supplementary effects. Main conclusions: Our findings suggest that selection through climate filtering (e.g. mean annual temperature) is likely the main mechanistic driver of freshwater plant ecoregions. Geographical regionalizations founded on a particular organismal group may not be directly applicable for all taxa but can be a good basis for further adjustments. Our study is a promising starting point for further investigations of geographical delineations for freshwater taxa other than fish. [ABSTRACT FROM AUTHOR]

Floristic studies of aquatic plants and flora associated with aquatic ecosystems carried out in the Neotropical region have demonstrated the predominance and co-occurrence of the same plant families under different climatic conditions. One way to interpret this co-occurrence of groups with non-random patterns in assemblages is to understand their phylogenetic structure. Herein, we present an investigation that studied the rule of phylogenetic assembly on plants associated with reservoirs in a tropical climosequence in Northeast Brazil. We studied eight areas during the dry and rainy periods and characterized their climatic, chemical, and trace elements, as well as richness, diversity, and phylogenetic structure of their assemblages. We found a predominance of the families Fabaceae, Poaceae and Cyperaceae, especially in border areas. Among the species surveyed, we highlight those with amphibian life-form, autochoric-type dispersion syndrome and the taxa with patterns of wide geographical distribution. We observed that the seasonal effect ruled patterns of phylogenetic structure with tendency for non-co-familiarity. Water quality and sediment were the abiotic factors most efficient as predictors of richness and variations in phylogenetic metrics. In this sense, the family co-occurrence identified in the assemblages was less deterministic than expected through non-randomness, because temporally, guilds were distinctly structured in function of seasonality. [ABSTRACT FROM AUTHOR]

Copyright of Contributii Botanice is the property of Contributii Botanice and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article is devoted to the analysis of current data on the ecological features and functions of the aquatic macrophytes which are important components of aquatic and wetland ecosystems across the globe. Macrophytes comprise a taxonomically diverse group of macroscopic plants including representatives of vascular aquatic plants, bryophytes, as well as green macroalgae and charophytes. An assemblage of macrophytic vegetation consists of emergent species whose vegetative parts emerge above the water surface, submerged and floating species, with each ecological group having specific features in morphology and physiological processes. A wide range of the adaptive mechanisms developed by aquatic macrophytes at the morphological, physiological, and biochemical levels enables them to inhabit various types of freshwater, brackish-water, and marine habitats. Macrophytes are an important component of aquatic food webs and perform a host of ecological functions in water ecosystems. The main ones are synthesis and storage of organic compounds and oxygen release, absorption and accumulation of chemical elements, water filtration and detoxification of pollutants, release of biologically active compounds involved in interspecies communications, provision of food, shelter and feeding places for aquatic animals, impact on the hydrological regime of water bodies, etc. A wide array of macrophyte species aresed in various human activities, including bioindication of water quality, phytoremediation of contaminated water bodies and wastewater treatment. However, human activities leading to surface water pollution, eutrophication and global warming have led to a concomitant decrease in macrophyte diversity in many freshwater ecosystems and in marine environment. Therefore, proper management of aquatic and wetland ecosystems, including their monitoring and control, is a prerequisite for a successful conservation of habitats and species richness of the aquatic macrophytes.

The huge biodiversity of inland waters and the many different aquatic habitats or ecosystems occurring there are particularly threatened by human impacts. In this Special Issue, ten articles have been collected that show new data on the distribution and ecology of some rare aquatic macrophytes, including both vascular plants and charophytes, but also on the use of these organisms for the monitoring, management, and restoration of wetlands.

Aquatic and wetland systems are widely used for landscapes and water regeneration. Microbiomes and submerged macrophytes (hydrophytes) play essential roles in conversions of organic and inorganic compounds in those ecosystems. The systems were extensively investigated for microbial diversities and compositions. However, little is known about how hydrophytes recruited diverse microbiota and affected functional zonation in aquatic systems. To address this issue, epiphytic leaf and root, sediment, and surrounding water samples were collected from the dragon-shape aquatic system in Beijing Olympic Park. Metagenomic DNAs were extracted and subjected to sequencing. Results showed that epiphytic leaf and root microbiomes and metabolic marker genes were remarkably different from that of surrounding environment. Twenty indicator bacterial genera for epiphytic microbiomes were identified and 50 metabolic marker genes were applied to evaluate the function of epiphytic leaf and root, water, and sediment microbiomes. Co-occurrence analysis revealed highly modularized pattern of metabolic marker genes and indicator bacterial genera related to metabolic functions. These results suggested that hydrophytes shaped microbiomes and drove functional zonation in aquatic systems. Key points: • Microbiomes of hydrophytes and their surrounding environments were investigated. • Twenty indicator bacterial genera highly specific to epiphytic biofilms were identified. • Epiphytes recruited unique microbiomes and drove functional zonation in aquatic systems. [ABSTRACT FROM AUTHOR]

Hydrophytes effect directly canal performance by reducing water flow, enhancing sedimentation, raising water level and reduce canal cross section area. The free-floating hydrophytes trapped in the outlets and culverts dipping its flow. In this apprehension a research study was conducted to investigate the effects of hydrophytes on canal capacity and at the outlets on the performance of the secondary canal known as Yar Hussain Minor (YHM) of Maira branch canal; part of the upper Swat canal irrigation system in Khyber Pakhtunkhwa (KP) province of Pakistan. Maira branch canal and its secondary canals were designed for crop based irrigation operation (CBIO), which could supply irrigation water for maximum cropping intensity (180%) even during peak periods of irrigation requirements. The existing water allowance was 0.67 Ls-1 ha-1 (6.6 mm day-1), which was based on the maximum crop water requirements. The challenges faced by YHM are physical barriers like hydrophytes and the turbid water received from river Swat producing eutrophication, sedimentation and encourage further growth of hydrophytes. Moreover to control the flow of water for the outlets triangular profile crump's weirs have been used in all secondary canals including YHM for comparative division to the tertiary outlets. Hydrophytes growth was observed in head reaches of canal. Five types of aquatic weeds were found. The hydrophytes growth in canal head reaches directly reduces the cross section by more than 50%. Indirectly the free-floating hydrophytes got stuck in the outlets and affected its flow. Therefore, daily discharges were measured with and without detached hydrophytes at each outlet from staff gauging. Frequency was based on days hydrophytes blockage observed divided by total time. It is concluded that the presence of hydrophytes decreased the performance of secondary canal, the hydrophytes and users' interventions (like putting stones to affect flow) influenced the outlets performance by 80%. Furthermore trifurcators type outlets were more prone to influence by hydrophytes followed by bifurcators outlet. [ABSTRACT FROM AUTHOR]

Questions: A range of landscape and local environmental factors, including invasion, interact with species functional diversity and trait composition to shape biodiversity patterns and ecosystem function of wetlands. A trait‐based, mechanistic understanding of community assembly holds promise for wetland conservation, but this has been rarely examined across scales. We examined: (a) the relative influence of climate, landscape matrix, and local physicochemistry on invasion intensity and functional diversity in boreal wetland plant assemblages; and (b) the ecological traits linked to these environmental factors. Location: One hundred fifty‐three wetlands across the Boreal Forest of Alberta, Canada. Methods: We used data on invasion intensity, using two terrestrial invaders (Sonchus arvensis and Cirsium arvense), and environmental factors at local and landscape levels. We used eight traits from 366 vascular plants to assess functional diversity and invasion responses to environmental gradients (generalized linear models) and individual species trait–environment relationships (community‐weighted mean redundancy analysis, fourth‐corner analysis). Results: Landscape matrix and the degree of invasion were the primary drivers of functional diversity, while invasion intensity was driven by physicochemistry and functional diversity. Community trait–environment patterns clearly separated wetlands by invasion status. Uninvaded wetlands were surrounded by lowland conifers and composed of stress‐tolerant associated traits, while invaded wetlands contained high levels of disturbance and traits associated with high resource availability and reproduction rates. This division was further supported by individual trait–environment relationships. Conclusions: Landscape matrix was the dominant driver of functional diversity and composition pattern, while the local physicochemistry and surrounding land‐cover matrix helped explain invasion. Our analysis revealed some of the mechanistic relationships shaping plant community assembly across boreal wetlands, information that can help resource managers identify, predict, and alleviate possible threats from landscape anthropogenic disturbances to wetland ecological integrity. [ABSTRACT FROM AUTHOR]

In order to understand the mechanisms of arsenic (As) accumulation and detoxification in aquatic plants exposed to different As species, a hydroponic experiment was conducted and the three aquatic plants (Hydrilla verticillata, Pistia stratiotes and Eichhornia crassipes) were exposed to different concentrations of As(III), As(V) and dimethylarsinate (DMA) for 10 days. The biomass, the surface As adsorption and total As adsorption of three plants were determined. Furthermore, As speciation in the culture solution and plant body, as well as the arsenate reductase (AR) activities of roots and shoots, were also analyzed. The results showed that the surface As adsorption of plants was far less than total As absorption. Compared to As(V), the plants showed a lower DMA accumulation. P. stratiotes showed the highest accumulation of inorganic arsenic but E. crassipes showed the lowest at the same As treatment. E. crassipes showed a strong ability to accumulate DMA. Results from As speciation analysis in culture solution showed that As(III) was transformed to As(V) in all As(III) treatments, and the oxidation rates followed as the sequence of H. verticillata>P. stratiotes>E. crassipes>no plant. As(III) was the predominant species in both roots (39.4–88.3%) and shoots (39–86%) of As(III)-exposed plants. As(V) and As(III) were the predominant species in roots (37–94%) and shoots (31.1–85.6%) in As(V)-exposed plants, respectively. DMA was the predominant species in both roots (23.46–100%) and shoots (72.6–100%) in DMA-exposed plants. The As(III) contents and AR activities in the roots of P. stratiotes and in the shoots of H. verticillata were significantly increased when exposed to 1 mg·L-1 or 3 mg·L-1 As(V). Therefore, As accumulation mainly occurred via biological uptake rather than physicochemical adsorption, and AR played an important role in As detoxification in aquatic plants. In the case of As(V)-exposed plants, their As tolerance was attributed to the increase of AR activities.

Small lakes have lower water levels during dry years as was the case in 2000–2020. We sought to show the biodiversity of plant communities at various water levels in Lake Arakhley. Changes in moisture content are reflected in the cyclical variations of the water level in the lake, which decreased approximately 2 m in 2017–2018. These variations affect the biological diversity of the aquatic ecosystems. We present the latest data on the state of the plant communities in this mesotrophic lake located in the drainage basin of Lake Baikal. Lake Arakhley is a freshwater lake with low mineral content and a sodium hydrocarbonate chemical composition. Changes in the nutrient concentration were related to precipitation; inflow volume and organic matter were autochtonous at low water levels. The most diverse groups of phytoplankton found in the lake were Bacillariophyta, Chlorophyta, and Chrysophyta. High biodiversity values indicate the complexity and richness of the lake’s phytoplankton community. A prevalence of Lindavia comta was observed when water levels were low and Asterionella formosa dominated in high-water years. The maximum growth depth of lacustrine vegetation decreased from 11.0 m to 4.0 m from 1967 to 2018. Decreasing water levels were accompanied by a reduction in the littoral zone, altering the communities of aquatic plants. The hydrophyte communities were monodominant in the dry years and were represented by Ceratophyllum demersum. The vegetation cover of the lake was more diverse in high-water years and variations in the lake’s water content altered the composition of biogenic substances. These changes were reflected in the lake’s phytocenosis.

Hydrophyte decomposition caused large amounts of dissolved organic matter (DOM) to enter aquatic environment that influence the migration and transformation of heavy metals (HMs). Six hydrophytes with five dry weight gradients (DWG) were used for the decomposition experiments. The results showed that protein-like materials occupy relatively high content in the hydrophyte-derived DOM. The binding properties of DOM-Cu(II) have been explored by using two-dimensional correlation spectroscopy (2D-COS) in conjunction with synchronous fluorescence spectroscopy (SFS) and log-transformed SFS. The weak signals of binding site can be amplified by the log-transformed 2D-COS analysis. Herein, more binding sites can be identified by the log-transformed 2D-COS analysis. The results reveal that tryptophan-like materials show a preferential sequence of binding Cu(II) in the hydrophyte-derived DOM with a relatively low DWG and sediment DOM, and fulvic-like substances indicate a preferential sequence of binding Cu(II) in the hydrophyte-derived DOM with a relatively high DWG. Meanwhile, the results of binding parameters indicate that the log K is the range of 3.61–4.25, 4.33–4.74, 4.59–4.97, 3.91–4.41, and 4.14–4.78 for D1-D5, respectively, suggesting that hydrophyte decomposition can change the binding affinity between DOM components and Cu(II). The complexes of fluorescent components with Cu(II) showed a high log K value at long wavelength (e.g. humic-like substances), and a relatively low fluorescent ligand proportion (f%) at shorter wavelength in the hydrophyte-derived DOM. However, the log K is the range of 3.08–4.31, 4.09–4.45, 3.93–4.35, 4.39–4.75, and 3.95–4.36 for C1-C5, separately. Protein-like substances with Cu(II) showed a relatively high log K value with the exception of C4. The log-transformed 2D-COS can be an analytical tool to understand the binding heterogeneity of DOM with HMs. The study can provide a guide for managing and controlling the effects of hydrophyte decomposition.

The construction of four large reservoirs for hydroelectric power generation in the main channel of the Paraná River and many others in the tributaries has eliminated important wetlands, except over an area of ∼2000 km2 between the reservoirs of the UHE Engenheiro Sérgio Motta (Porto Primavera) and the Itaipu. The up-river reservoirs created large changes in the river's hydrology and in its loads of suspended, bed and dissolved material. A detailed assessment of the impact of these changes requires a description and classification of the floodplain's different subunits, called macrohabitats, according to hydrological, hydromorphological, and vegetational parameters. The classification system presented herein is hierarchical and is embedded in the classifications of Brazilian wetlands. The system differentiates the Paraná River floodplain into 6 functional units, 13 subclasses, and 23 macrohabitats, which are presented in this paper. Changes in hydrology have reduced the flood amplitude, frequency and permanence, and thus confined the macrohabitats to an area currently subjected to a regular flood pulse of ∼3 m rather than the previous ∼6 m. The gradual terrestrialization of macrohabitats at the upper end of the flood gradient is expected, accompanied by a loss of macrohabitats at its lower end because of long-term flooding. The retention of sediments and dissolved nutrients in the reservoirs will lead to the oligotrophication of aquatic macrohabitats, the degradation of near-channel hydromorphic structures and their vegetation, and a general reduction of overall primary production in the floodplain, which may extend also to higher trophic levels. [ABSTRACT FROM AUTHOR]

The present study deals with documentation of hydrophytes in Marlimund lake (Lat: 11°26'16.0" Long: 076°41'94.8"), The Nilgiris district, Tamil Nadu. A total of 37 hydrophytes were recorded in different seasons along with five endemic species. Among these Helophytes are dominant followed by Tenegophytes/Helophytes. Illegal fishing, over grazing and waste dumping leads to reduction in the growth of hydrophytes in the study area. [ABSTRACT FROM AUTHOR]

Small lakes have lower water levels during dry years as was the case in 2000-2020. We sought to show the biodiversity of plant communities at various water levels in Lake Arakhley. Changes in moisture content are reflected in the cyclical variations of the water level in the lake, which decreased approximately 2 m in 2017-2018. These variations affect the biological diversity of the aquatic ecosystems. We present the latest data on the state of the plant communities in this mesotrophic lake located in the drainage basin of Lake Baikal. Lake Arakhley is a freshwater lake with low mineral content and a sodium hydrocarbonate chemical composition. Changes in the nutrient concentration were related to precipitation; inflow volume and organic matter were autochtonous at low water levels. The most diverse groups of phytoplankton found in the lake were Bacillariophyta, Chlorophyta, and Chrysophyta. High biodiversity values indicate the complexity and richness of the lake's phytoplankton community. A prevalence of Lindavia comta was observed when water levels were low and Asterionella formosa dominated in high-water years. The maximum growth depth of lacustrine vegetation decreased from 11.0 m to 4.0 m from 1967 to 2018. Decreasing water levels were accompanied by a reduction in the littoral zone, altering the communities of aquatic plants. The hydrophyte communities were monodominant in the dry years and were represented by Ceratophyllum demersum. The vegetation cover of the lake was more diverse in high-water years and variations in the lake's water content altered the composition of biogenic substances. These changes were reflected in the lake's phytocenosis. [ABSTRACT FROM AUTHOR]

Aim: Range size conservatism suggests that closely‐related species maintain geographic ranges of similar extent. However, consensus regarding this suggestion has not been reached. To shed more light on this phenomenon, we studied freshwater plant range size conservatism, range overlap and environmental niche conservatism using congeneric species comparison in two continents. In addition, we investigated whether a phylogenetic signal is found in the range sizes of aquatic plants. Location: Europe and North America. Taxon: Freshwater plants. Methods: Across spatial resolutions (50 km2, 100 km2 and 200 km2), we applied Spearman correlations among 347 and 730 pairs of congeneric species in Europe and North America, respectively, and 63 pairs shared between them. In addition, Spearman correlations were used to evaluate how the degree of spatial overlap influences range sizes and which environmental variables explain variation in range sizes. Brownian evolutionary model was used to assess the phylogenetic signal in species range sizes. Results: We found no evidence of range size conservatism across spatial resolutions for any species and species shared between the continents. In addition, range sizes of more closely related species did not overlap geographically more than those of distantly related ones and no support for environmental niche conservatism was evidenced. Main conclusions: We found that aquatic plants show no range size conservatism in the Northern Hemisphere. This means that it is challenging to define different range sizes of freshwater plants through species traits. Furthermore, we are unable to predict unknown distributions of extant aquatic plant species based on known distributional attributes of closely related species. However, our findings suggest that the interpretations of previous investigations on the range sizes of aquatic plants remain valid due to lack of range size conservatism. These practical implications encourage studying range size conservatism across realms and regions, especially for understudied organismal groups. [ABSTRACT FROM AUTHOR]

Abstract Wetland plants are often the most conspicuous component of wetland ecosystems. They are grouped into hydrophytes, helophytes, and hygrophytes. In this research, the wetlands flora of Hamedan province, including natural and artificial wetlands, permanent and seasonal rivers and streams and wet mountain meadows, were studied. The results of this study showed that the flora of the wetlands of Hamedan province consisted of 45 families, 111 genera and 163 species. And, 13 families of these plants belonged to monocots, 31 families to dicots and 1 family to the pteridophyta. Families of Asteraceae with 15 genera and 20 species; Poaceae with 19 genera and 23 species, Cyperaceae with 8 genera and 19 species were the largest families of wetlands in Hamadan province. In terms of their life forms, the wetland plants of Hamedan province consisted of 8 species of hydrophytes, 51 species helophyte, 35 species of geophytes, 50 species of hemicryptophytes, 14 species of therophytes, 4 species of phanerophytes, and 1 species of chamaephytes. The chorology of species showed that 29 species of the wetland plants of Hamedan Province belonged to the European-Siberian elements, 38 species to the Iranotouranin elements, 1 species to the Mediterranean elements, 24 species to European-Siberian-Iranotouranin elements, 2 species to Euro-Siberian-Mediterranean elements, 3 species to the Mediterranean-Iranotouranin elements, 46 species to more than two elements, and 20 species to cosmopolitan.

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