Constructed floating wetlands (CFWs) provide a passive pathway for the retention and accumulation of nutrients and perfluoroalkyl and polyfluoroalkyl substances (PFAS) present in treated wastewater (TWW). This two-year field-scale study investigated the accumulation of PFAS and nutrients in three native wetland species in a lagoon setting. During the plant establishment period and despite measurable nutrient and PFAS uptake in plant tissues, their removal from the water was limited due to short residence times (similar to 10-12 h). The highest nutrient accumulation in shoots was observed in Phragmites australis (0.14 g N/m2/day and 0.02 g P/m2/day), which showed the highest biomass (12.1 g/m2/day). Phragmites australis also exhibited the highest PFAS and precursor accumulation in tissues. PFAS removal improved after plant establishment, and the daily removal rate for PFAS (based on PFAS accumulation in plant tissue and sediment) was 240 ng/m2/d. Overall, CFWs show promise as a passive, modular solution for PFAS reduction in TWW, particularly after root system development and biofilm formation. However, long-term monitoring across multiple growth and harvest cycles and assessing the contribution of other mechanisms (such as sorption to growth media and accumulation in biofilms) are required to evaluate the CFW system sustainability under varying environmental conditions.

The development of constructed floating wetlands (CFWs) as a nature-based solution for water treatment has progressed over the last 25 years. However, full-scale CFW adoption remains relatively limited due in part to the uncertainty regarding the costs of CFWs in terms of capital and operational expenditure (CAPEX and OPEX) and treatment capacity. This study reports on the costs of 11 international CFW schemes including the factors affecting CAPEX and OPEX and levelized costs of nitrogen and phosphorus removal. The estimated levelized CAPEX and OPEX ranged from US$15/m2 to $2537/m2 and from $0.5/m2 y-1 to $181/m2 y-1, respectively, for CFW schemes of 55-3926 m2. Data from six full-scale CFWs showed that the costs per kg of nitrogen removed ($10 to $120/kg) by plant uptake were consistently lower than those of phosphorus ($15 to $3250/kg). CFW scheme scale was found to be a key influencing factor on cost, with cost per kg of nitrogen and phosphorus removed declining as CFW size increased. Use of this cost information can be generalized when considering nutrient removal and adoption of CFW technology compared to other engineered treatment options worldwide.

This review critically examines the long-term management of per- and polyfluoroalkyl substances (PFAS) using constructed floating wetlands (CFW) as a sustainable approach for contaminated water treatment. PFAS, which are persistent and widely distributed environmental contaminants, pose significant challenges due to their resistance to natural degradation. CFW, featuring buoyant platforms that support vegetation, show promise in mitigating PFAS contamination through a range of natural processes such as plant uptake, sorption to growth media, and accumulation in biofilms. The review explores CFW opportunities, emphasizing their suitability for installation in existing urban environments with minimal earthwork and drainage adjustments to address PFAS contamination. It also assesses CFW limitations, such as potential PFAS trophic transfer, highlighting the need for comprehensive studies on PFAS fate and transport within these systems. To ensure CFW efficiency in long-term PFAS management, the review highlights the importance of site-specific assessments, including plant species selection, hydrodynamics, and PFAS-microbial community interactions. The potential of synergistic removal approaches, combining wetland plants' phytoremediation capabilities with removable sorptive materials or other substrates are also discussed. Over-all, the study provides valuable insights into CFW, covering opportunities, limitations, and essential implementation considerations for achieving sustainable, long-term PFAS management in contaminated water treatment.

Arbuscular mycorrhizal fungi were recovered from soil samples from the naturally radioactive soil at the long-abandoned South Terras uranium mine in Cornwall, UK. Species of Rhizophagus, Claroideoglomus, Paraglomus, Septoglomus, and Ambispora were recovered, and pot cultures from all except Ambispora were established. Cultures were identified to species level using morphological observation and rRNA gene sequencing combined with phylogenetic analysis. These cultures were used in pot experiments designed with a compartmentalised system to assess the contribution of fungal hyphae to the accumulation of essential elements, such as copper and zinc, and non-essential elements, such as lead, arsenic, thorium, and uranium into root and shoot tissues of Plantago lanceolata. The results indicated that none of the treatments had any positive or negative impact on shoot and root biomass. However, Rhizophagus irregularis treatments showed higher accumulation of copper and zinc in shoots, while R. irregularis and Septoglomus constrictum enhanced arsenic accumulation in roots. Moreover, R. irregularis increased uranium concentration in roots and shoots of the P. lanceolata plant. This study provides useful insight into fungal-plant interactions that determine metal and radionuclide transfer from soil into the biosphere at contaminated sites such as mine workings.

Effectiveness of constructed floating wetlands (CFWs) is largely unknown for wastewater treatment in cold climates. An operational-scale CFW system was retrofltted into a municipal waste stabilization pond in Alberta, Canada. During the flrst year (Study I), insigniflcant performance was recorded for water quality parameters, although phyto-uptake of elements was evident. In Study II, doubling of the CFW area and addition of underneath aeration promoted plant up -take of elements, including nutrients and metals, following signiflcant pollutant reduction in the water; 83 % of chem-ical oxygen demand, 80 % of carbonaceous biochemical oxygen demand, 67 % of total suspended solids, and 48 % of total Kjeldhal nitrogen. A mesocosm study, conducted in parallel to the pilot scale fleld study, conflrmed the impact of both vegetation and aeration on water quality improvement. The phytoremediation potential was linked to accumu-lation within plant shoot and root biomass and was conflrmed by mass balance. Bacterial community analyses reflected that heterotrophic nitriflcation, aerobic denitriflcation, complete denitriflcation, organic matter decomposi-tion, and methylotrophy were dominant mechanisms in the CFW, likely resulting in successful transformation of or-ganics and nutrients. CFWs appear to be a viable ecotechnology to treat municipal wastewater in Alberta; however, larger and aerated CFW systems are recommended to achieve maximum remediation. The study aligns with the United Nations Environment Program to scale up restoration of degraded ecosystems, and to improve conditions for water supply and biodiversity following recognition of 2021-2030 as the Decade on Ecosystem Restoration.

Floating treatment wetlands (FTWs) use plants’ roots for water quality improvement. The plants are supported by a buoyant structure deployed at the water surface. The roots form a porous zone beneath the structure and remove pollutants carried in suspension through filtering, absorption and uptake. This paper used CFD simulation to model FTWs arranged in series and spanning the channel width and to study the effects of root length and spacing between FTWs on flow distribution and mass removal. The root zone was modelled as a porous media, and removal was computed using first-order decay, for which a range of removal constants was tested. Longer roots increased the reactive volume of the root zone, which increased the fraction of pollutant inflow entering the FTWs. Increasing the distance between FTWs allowed greater mixing between water that went through and beneath the upstream FTW. This increased the concentration entering each FTW, which enhanced mass removal per FTW. However, a larger distance between FTWs reduced the number of FTWs in the channel, reducing the reactive volume. In the tradeoff between mixing and reactive volume, the reactive volume was more important, such that total removal in the channel increased with longer roots and more units of FTW (shorter gap distance). However, removing the gap entirely was detrimental, as FTWs in series removed more mass than a continuous FTW of same volume. This study points to two design recommendations for FTWs in series. First, if resources for building FTWs are not limiting, but the channel length is, it is preferable to prioritize higher reactive volume (shorter gap distance) to achieve maximum removal per channel length. Second, if resources for FTWs are limiting, but channel length is not, it is better to place the FTWs with a longer gap distance, preferably along enough to allow mixing over the full depth between FTWs, as this will achieve maximum removal per FTW.

Glomeromycotan propagules (spores) are morphologically diverse in the Early Devonian Rhynie chert; however, only relatively few of these fossils have been documented and critically evaluated. This study re-examines propagules previously described informally as ‘reproductive unit 1’, and identified as glomeromycotan acaulospores borne within the neck of a sporiferous saccule. Size and morphology, spore wall structure, and the close association of specimens in land plant axes with small glomoid spores, are solid arguments for affinities of ‘reproductive unit 1’ to the Ambisporaceae (Archaeosporales). Moreover, the acaulospores correspond morphologically to Mycokidstonia sphaerialoides, a Rhynie chert fossil originally interpreted as an ascomycete perithecium that, consequently, is redefined here as a member of the Glomeromycota conspecific with ‘reproductive unit 1’. The diagnosis for M. sphaerialoides is emended to be compliant with glomeromycotan taxonomy; features of the saccule, acaulospore wall, and associated glomoid spores are included. An epitype is also designated. Mycokidstonia sphaerialoides adds to an increasing body of fossil data depicting Devonian Glomeromycota as a diverse fungal lineage which is likely to have been an ecologically important constituent of early terrestrial ecosystems.

This study reports the biomass accumulation, plant nutrient concentration, and nutrient uptake rates of plants in a constructed floating wetland (CFW) installed for a sewage treatment application in Australia. Plant biomass accumulation was estimated based on field samplings throughout the duration of the study. Analysis of samples of each plant species was also completed to estimate the mean plant tissue nutrient content. The plant biomass accumulation estimate and the mean plant tissue nutrient concentration were then used to estimate the total nutrient uptake for each species. Each of the species were found to differ in biomass accumulation and plant tissue nutrient concentration and the distribution of biomass and nutrients between the shoots and roots. The nutrient uptake rates varied between the species, with B. articulata having the greatest nutrient uptake rates (shoots: N, 104 ± 31.5 g/m2, P, 12.9 ± 3.87 g/m2; roots: N, 23.9 ± 7.23 g/m2, P, 5.54 ± 1.67 g/m2). Harvesting of the four CFW islands after 375 days of growth removed an estimated 23.2 kg of N and 2.97 kg of P. The results of this study indicate that the use of CFWs with carefully selected plant species can successfully remove significant amounts of nutrients from domestic wastewater.

The data, presented here, come from samples collected during three research projects which aimed to assess the impact of land-use type on Arbuscular Mycorrhizal Fungi (AMF) diversity and community composition in pastures of Terceira Island (Azores, Macaronesia, Portugal) and also in the native forest of two Azorean Islands (Terceira and São Miguel; Azores, Macaronesia, Portugal). Both projects contributed to improving the knowledge of AMF community structure at both local and regional scales. Little is known on the AMF communities from Azores islands and this study reports the first survey in two Azorean Islands (Terceira and São Miguel). A total of 18,733 glomeromycotan spores were classified at the species level from 244 field soil samples collected in three different habitat types – native forests (dominated by Juniperus brevifolia and Picconia azorica), semi-natural and intensively-managed pastures. Thirty-seven distinct spore morphotypes, representing ten glomeromycotan families, were detected. Species of the family Acaulosporaceae dominated the samples, with 13 species (38% of the taxa), followed by Glomeraceae (6 spp.), Diversisporaceae (4 spp.), Archaeosporaceae (3 spp.), Claroideoglomeraceae (3 spp.), Gigasporaceae (3 spp.), Ambisporaceae and Paraglomeraceae, both with the same number of AMF species (2 spp.), Sacculosporaceae (1 sp.) and Entrophospora (family insertae sedis). Members of the family Acaulosporaceae occurred almost exclusively in the native forests especially associated with the Picconia azorica rhizosphere, while members of Gigasporaceae family showed a high tendency to occupy the semi-natural pastures and the native forests of Picconia azorica. Members of Glomeraceae family were broadly distributed by all types of habitat which confirm the high ecological plasticity of this AMF family to occupy the more diverse habitats.

More knowledge of community composition of arbuscular mycorrhizal (AM) fungi in ecosystems in relation to habitat type and land use intensity is needed. We studied AMF in 106 soil samples from pristine natural forests and a gradient of disturbance including semi-natural and intensively managed pastures of Terceira, Azores. Altogether, 42 spore morphotypes were detected from eight AMF families, revealing different fungal community structures among the three land use types. Spore density was highest in native forests and lowest in intensively managed pastures, but fungal richness was highest in semi-natural pastures and lowest in native forests. No significant difference occurred between intensively managed pastures and native forests. Members of Acaulosporaceae and Glomeraceae were dominant in native forests, while fungi from Gigasporaceae and Claroideoglomeraceae were most abundant in semi-natural and intensively managed pastures respectively, indicating family-based ecological preferences. Rarefaction analysis revealed that pastures supported more diverse AMF communities than native forests, because in high elevation pristine forests, a few rare species dominate. It is therefore likely that more species would be found with increasing survey effort. Further research is needed to clarify the influence of land use type on AMF diversity and distribution in remote islands, and the role of native AMF on soil ecosystem processes and the spread of exotic plants.

Background and Aims Structurally preserved arbuscular mycorrhizas from the Lower Devonian Rhynie chert represent core fossil evidence of the evolutionary history of mycorrhizal systems. Moreover, Rhynie chert fossils of glomeromycotan propagules suggest that this lineage of arbuscular fungi was morphologically diverse by the Early Devonian; however, only a small fraction of this diversity has been formally described and critically evaluated. Methods Thin sections, previously prepared by grinding wafers of chert from the Rhynie beds, were studied by transmitted light microscopy. Fossils corresponding to the description of Archaeospora spp. occurred in 29 slides, and were measured, photographed and compared with modern-day species in that genus. Key Results Sessile propagules <85 µm in diameter, some still attached to a sporiferous saccule, were found in early land plant axes and the chert matrix; they developed, in a similar manner to extant Archaeospora, laterally or centrally within the saccule neck. Microscopic examination and comparison with extant fungi showed that, morphologically, the fossils share the characters used to circumscribe the genus Archaeospora (Glomeromycota; Archaeosporales; Archaeosporaceae). Conclusions The fossils can be assigned with confidence to the extant family Archaeosporaceae, but because molecular analysis is necessary to place organisms in these taxa to present-day genera and species, they are placed in a newly proposed fossil taxon, Archaeosporites rhyniensis.

Constructed waterbodies serve a variety of purposes. Urban lakes are a contemporary constructed waterbody, which often serve to increase amenity and property values, fulfill a flood mitigation purpose, and may provide a source of land fill for development purposes. Although popular, urban lakes have degraded in many areas as a result of: (1) poor quality of inflow; (2) significant water level variation; (3) persistent stratification; (4) long stormwater residence times; and (5) high loading of organic carbon. The failure of many urban lakes to remain as a resilient and healthy ecosystem stems from poor design and a lack of pretreatment to runoff. Recent design guidelines have better informed designers as to the key design elements for urban lakes; however, management of these waterbodies remains reactive, rather than proactive. Utilizing the Ecosystem Health Paradigm as a template for urban lake management may allow for a more holistic assessment of urban lake health and better inform management requirements. This chapter looks at the history of urban lakes and how such systems are integrated and managed in the urban context.

A new glomeromycotan fungus, Archaeospora ecuadoriana sp. nov., was found in the south Ecuadorian mountain rainforest region, a global plant biodiversity hotspot. It was cultivated as single spore isolate originating from nursery-grown native tree seedlings inoculated with mixed soil from pristine forest and agricultural fields. The new species is known from the Loja area, southern Ecuador, at about 2100 m above mean sea level (mamsl) and has been detected in potato roots from an Andean region in Peru at 2658 mamsl by previous molecular data. The fungus forms small, colourless to frosted white, mainly globose spores, averaging 61 × 60 μm, formed singly or very rarely in clusters. There is no reaction to Melzer’s reagent, other than a slight unspecific overall yellow iodine staining. The spores are very similar to those of Archaeospora trappei and A. schenckii. However, molecular phylogenetic analysis shows the species to be clearly separate from all other described Archaeospora species. The analysis of the available Archaeospora sequence data shows that sequences of Palaeospora spainiae, of the monospecific genus Palaeospora, cluster within the genus Archaeospora. Palaeospora therefore is synonymised with Archaeospora and P. spainiae is transferred to Archaeospora, as A. spainiae comb. nov.

Constructed Floating Wetlands (CFWs) are increasingly being used globally in freshwater environments such as urban lakes and ponds to remove pollutants from urban stormwater runoff. However, to date there has been limited research into the use and performance of these systems in saline environments. This study compared the root and shoot biomass growth and nutrient uptake of five different plant species, Chrysopogon zizanioides, Baumea juncea, Isolepis nodosa, Phragmites australis and Sarcocornia quinqueflora, in three different saltwater treatments over a 12-week period. The aim of the study was to identify which of the plant species may be most suitable for use in CFWs in saline environments. Plant nutrient uptake testing revealed that Phragmites australis had the greatest percentage increase (1473–2477%) of Nitrogen mass in the shoots in all treatments. Sarcocornia quinqueflora also had impressive Nitrogen mass increase in saltwater showing an increase of 966% (0.208 ± 0.134 g). This suggests that the use of Phragmites australis and Sarcocornia quinqueflora plants in CFWs installed in saline water bodies, with regular harvesting of the shoot mass, may significantly reduce Nitrogen concentrations in the water. Isolepis nodosa had the greatest percentage increase (112% or 0.018 ± 0.020 g) of Phosphorous mass in the shoots in the saltwater treatment. Baumea juncea had the greatest percentage increase (315% or 0.026 ± 0.012 g) of Phosphorous mass in the roots in the saltwater treatment. This suggests that the use of Isolepis nodosa and Baumea juncea plants in CFWs installed in saline water bodies may significantly reduce Phosphorous concentrations in the water if there was a way to harvest both the shoots above and the roots below the CFWs. The study is continuing, and it is anticipated that more information will be available on CFW plants installed in saline environments in the near future.

Purpose Arbuscular mycorrhizal fungi (AMF) play important key roles in the soil ecosystems as they link plants to the root-inaccessible part of soil. The aims of this study were to investigate which environmental factors influence the spatial and temporal structuring of AMF communities associated to Picconia azorica in two Azorean islands (Terceira and São Miguel islands), and investigate the seasonal variation in AMF communities between the two islands. Methods Communities of AMF associated with P. azorica in native forest of two Azorean islands (Terceira and São Miguel) were characterised by spore morphology or molecular analysis. Results Forty-five AMF spore morphotypes were detected from the four fragments of P. azorica forest representing nine families of AMF. Acaulosporaceae (14) and Glomeraceae (9) were the most abundant families. AMF density and root colonisation varied significantly between islands and sampling sites. Root colonisation and spore density exhibited temporal patterns, which peaked in spring and were higher in Terceira than in São Miguel. The relative contribution of environmental factors showed that factors such as elevation, relative air humidity, soil pH, and soil available P, K, and Mg influenced AMF spore production and root colonisation. Conclusion Different sporulation patterns exhibited by the members of the commonest families suggested different life strategies. Adaptation to a particular climatic and soil condition and host phenology may explain seasonal differences in sporulation patterns. Cohorts of AMF associated to P. azorica are shaped by regional processes including environmental filters such as soil properties and natural disturbance.

This study investigated plant growth, nutrient partitioning and total nutrient uptake by tall sedge (Carex appressa) plants in two large-scale Constructed Floating Wetlands (CFW1 and CFW2). These CFWs were installed to treat stormwater runoff discharging into a newly-constructed 2.6-ha lake during the construction phase of a 45-ha residential development. Nutrient concentrations of C. appressa shoot above the mat, biomass within the mat, and roots below the mat were analysed 0, 12 and 16 months after planting. Extensive root growth was evident after 12 and 16 months. Some nutrients (nitrogen, phosphorus, sulphur) were distributed almost evenly among the above-, within-, and below-mat components, while others (aluminium, copper, iron, manganese) were concentrated in or on the roots. Given the low concentrations of nutrients within the water column, large amounts of nutrients were removed from stormwater by the plants. Total nitrogen uptake was 20.20 ± 2.88 kg in CFW1 and 15.00 ± 2.07 kg in CFW2 over the 16-month study period. Total potassium uptake was 12.59 ± 1.64 kg in CFW1 and 7.20 ± 1.56 kg in CFW2. Phosphorus uptake was low as a consequence of low phosphorus availability in the water. High aluminium, iron and manganese concentrations were found in the roots, demonstrating that C. appressa removed and sequestered large quantities of these water pollutants from urban stormwater runoff. For example, total aluminium uptake was 7.82 ± 1.73 kg in CFW1 and 5.62 ± 0.75 kg in CFW2. This study demonstrated multiple benefits of CFWs for stormwater treatment in the early stages of an urban development.

In 1977, the fine root endophyte, originally named Rhizophagus tenuis, was transferred into the genus Glomus as G. tenue, thus positioning the species with all other known arbuscular mycorrhizal fungi (Glomeromycota, Glomeromycotina). Recent molecular evidence, however, places it in a different subphylum, Mucoromycotina in the Mucoromycota. No suitable genus exists in the Mucoromycotina to accommodate G. tenue, so it is moved to Planticonsortium gen. nov. as P. tenue comb. nov.

Compared to the higher fungi (Dikarya), taxonomic and evolutionary studies on the basal clades of fungi are fewer in number. Thus, the generic boundaries and higher ranks in the basal clades of fungi are poorly known. Recent DNA based taxonomic studies have provided reliable and accurate information. It is therefore necessary to compile all available information since basal clades genera lack updated checklists or outlines. Recently, Tedersoo et al. (MycoKeys 13:1–20, 2016) accepted Aphelidiomycota and Rozellomycota in Fungal clade. Thus, we regard both these phyla as members in Kingdom Fungi. We accept 16 phyla in basal clades viz. Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota. Thus, 611 genera in 153 families, 43 orders and 18 classes are provided with details of classification, synonyms, life modes, distribution, recent literature and genomic data. Moreover, Catenariaceae Couch is proposed to be conserved, Cladochytriales Mozl.-Standr. is emended and the family Nephridiophagaceae is introduced.

The communities of glomeromycotan fungi (arbuscular mycorrhizal fungi, AMF) under native Juniperus brevifolia forest from two Azorean islands, Terceira and São Miguel, were compared, mainly by spore morphology, and when possible, by molecular analysis. Thirty-nine morphotypes were detected from 12 genera. Glomeromycotan fungal richness was similar in Terceira and São Miguel, but significantly different among the four fragments of native forest. Spore diversity and community composition differed significantly between the two islands. The less degraded island, Terceira, showed 10 exclusive morphotypes including more rare types, whereas the more disturbed forest on São Miguel showed 13 morphs, mostly of common types. Forests from Terceira were dominated by Acaulosporaceae and Glomeraceae. Whereas members of Acaulosporaceae, Glomeraceae and Ambisporaceae were most frequent and abundant in those from São Miguel. Spore abundance was greatest on Terceira, and correlated with soil chemical properties (pH), average monthly temperature and relative humidity.