Phalaris Arundinacea Research Articles

Decontamination of Arsenic and Manganese in Polluted Water by Canary Seed Plant (Phalaris arundinacea L.) in Saturated Sand Culture

Decontamination of Arsenic and Manganese in Polluted Water by Canary Seed Plant (Phalaris arundinacea L.) in Saturated Sand Culture

Cereals-goat's rue agrocenoses in the conditions of the Upper Volga region

During 2015–2021 at the Gubino agro-polygon VNIIMZ, studies were carried out on hay-grass-goat-rue grass stands depending on the composition of the grass mixture and soil difference in the conditions of the Upper Volga region. Varieties of oriental goat's rue (Galega orientalis Lam.) - Gale, Yubilyar, Krivich and seeded cereal grasses - meadow timothy grass (Phleum pratense L.) Vic 9, awnless rump (Bromus inermis L.) Vegur, reed dwarf grass (Phalaris arundinacea L.) Ural. Sowing methods of grass stands are single-species and mixed - legumes, legumes-cereals and cereals. The research methodology included phenological observations, determining the density and height of herbage, studying the structure of the crop, the dynamics of the accumulation of dry and green mass, and processing statistical data. It has been established that, on average, over a seven-year observation period, the yield of legume-grass grass stands varied within 5.1-7.9 t/ha of dry weight. The maximum productivity was noted in 2017 - up to 11.7 t/ha of dried mass. The stem density of the sown legume component - oriental goat's rue, depending on the grass mixture and the year of the study, varied from 17 to 149 pcs/m2. The height of goat's rue plants on average for long-term observations with two-cutting use was 63-93 cm, for grass seeded grasses - 78-108 cm. Goat's rue had good foliage, the average share of leaves in the structure of the Eastern goat's rue crop for all years of research varied from 50.6 to 58.2%. The stem content was 41.4-48.9%. In single-species crops, the leaf content of eastern goat's rue reached 43.6-66.8% on average for 2 cuttings, and in a mixture with cereal grasses - 42.6-69.0%. The most productive were legume-cereal agrocenoses on gleyic soil.

Detecting reed canary grass (Phalaris arundinacea L.) patches from UAV‐based digital surface model images—A case study in a timothy (Phleum pretense L.) meadow field

AbstractAccurate determination of the weed ratio in artificial meadows is critical for efficient pasture renovation. Reed canary grass (Phalaris arundinacea L., RCG) is treated as a troublesome grass in the Hokkaido region of Japan because of its low feed quality and poor palatability in dairy farming. In the present study, we examined a method of identifying the dominant area of RCG in timothy (Phleum pretense L.) meadows by applying the Canny method to unmanned aerial vehicle (UAV)‐based digital surface model (DSM) images. Comparing the actual RCG patches observed in a field survey (50 m quadrats × 4 places) with the predicted patches, the pixel‐based recall and F value were 0.90 and 0.83, respectively. These results demonstrated that the area of RCG can be detected using a simple method without supervised data or deep learning. This study is expected to be utilized in a wide variety of applications using relative height differences.

Growing of Phalaroides arundinacea L. and Bromopsis inermis Leyss for Biofuel Using Sewage Sludge Compost as a Fertilizer

Bromopsis inermis and Phalaroides arundinacea are increasingly grown not only for feed but also for other purposes, such as obtaining energy. Composting sewage sludge and using such compost to fertilize various plants is also becoming more popular. Therefore, the aim of our study was to investigate how the fertilization of the mentioned plants with sewage sludge compost (SSC) affects the biomass yield and biomass quality of these plants. It was also important to determine whether fertilization with SSC is possible in low-yielding soils of light texture without harming these soils There are no similar studies in Lithuania, and there are very few in Europe and the world. It was found that investigated grasses formed a small biomass DM yield (6.6 t/ha within three years). The biomass of B. inermis and Ph. arundinacea had a very high ash content and concentrations of nitrogen and potassium. This greatly reduced the quality of the biomass of these grasses as a solid biofuel. SSC performed poorly as a fertilizer. Fertilization with 125 t/ha SSC significantly increased the total biomass yield of Ph. arundinacea only. At the same time, using SSC as a fertilizer significantly increased the concentration of Cu, Zn, and Cd in the soil.

Catastrophic flooding effects on a Wisconsin wet prairie remnant: A shift in the disturbance regime?

Climate change is likely to imperil native biodiversity through the increased frequency of extreme events. Here we address the short-term effects of an extreme flooding event on an unplowed prairie reserve, the Faville Prairie Wisconsin State Natural Area. This 25-ha property is a remnant of the formerly extensive Crawfish Prairie that lay on the east bank of the Crawfish River, Jefferson County, Wisconsin USA. The Faville remnant has historically been subject to late winter to spring flooding in its lower portions. In June of 2008, however, an extreme rainfall event caused flooding unprecedented in the 87-year history of streamflow, inundating the entire site. Data were available from 180 permanently marked plots sampled in 1978-79. We assessed the change by resampling these plots in 2010-2015. At the m2 scale, we found significant losses of species richness, a result of most species having fewer occurrences than in the earlier data. There was near extinction of several important prairie species and a relative increase in wetland tolerant species. Lower elevation plots, subject to the encroachment of woody plants and the invasion of Phalaris arundinacea for decades prior to the flood, had the lowest levels of species richness. However, some prairie species survived the flooding with little change, and recent anecdotal observations show that others are rebuilding their populations. Thus, if extreme floods are infrequent, the prairie should be able to recover to its former state. If, however, the hydrological regime shifts toward more frequent, growing-season floods, we predict further decline in those plant species that were the object of the preservation of this remnant. It is critical that fire management continue along with monitoring to track species' recovery or replacement, so that corrective measures can be identified and tested to sustain the native prairie species diversity.

Cultivation of Reed Canary Grass (Phalaris arundinacea L.) on Light Soils in Transitional Temperate Climate to Produce Biomass and Seeds

Reed canary grass (RCG) is a native perennial grass with a wide range of uses that naturally occurs in moist habitats. The conducted research indicates the possibilities of RCG cultivation outside natural, humid habitats in monoculture on sandy soils in temperate climates to obtain biomass and seeds. The influence of two factors was analysed: (1) fertilisation with compost from urban greenery in doses of 0, 10, and 20 Mg·ha−1 and (2) mineral nitrogen fertilisation in doses of 0, 40, 80, and 120 kg·ha−1. Compost fertilisation (10 and 20 Mg·ha−1) increased dry matter yields in all years of the study, by 12.1% and 41.0%, respectively. Also, nitrogen fertilisation in doses of 40, 80, and 120 kg·ha−1 increased dry matter yield by 26.8%, 41.6%, and 65.0%, respectively. When harvesting RCG plants for energy biomass at their stage of full maturity, a significant seed yield of 242 to 600 kg·ha−1 can also be obtained in the first three years, while in the fourth year of use, the seed yield was almost three times lower (90–158 kg·ha−1). The obtained results indicate that, in sandy soils, the use of compost fertilisation in RCG cultivation can partially or entirely replace mineral fertilisation and ensure high and stable yields. An additional benefit may be the achievement of a high seed yield in the initial years of cultivation. The use of organic fertilisers and the independence from mineral fertilisers can significantly increase the profitability of bioenergy crops.

Spatiotemporal heterogeneity of inundation pattern of floodplain lake wetlands and impact on wetland vegetation

The inundation pattern is an important ecohydrological indicator for studying floodplain lake wetlands, as it is the key factor affecting the wetland vegetation distribution patterns. Poyang Lake, the largest freshwater lake in China, is a typical floodplain lake wetland. This study presents a hydrodynamic model and vegetation survey of Poyang Lake, analyzed the spatiotemporal heterogeneity of the inundation pattern (inundation duration and depth), assessed the response patterns of wetland vegetation concerning the inundation pattern, and examined the impact of the proposed Poyang Lake Water Conservancy Hub (PLWCH) on the inundation pattern and wetland vegetation. The results revealed that the inundation pattern of Poyang Lake had significant spatial heterogeneity. Inundation pattern was found to have a significant impact on the vegetation succession. The response relationship between the distribution areas of different wetland vegetation types and inundation pattern was in accordance with the Gaussian curve, and the ecological threshold range of the Carex spp. community was the greatest. Owing to factors such as climate change and anthropogenic activities, the inundation pattern of Poyang Lake varied significantly since 2003, with the average inundation duration and average inundation depth decreasing by 15 d and 0.32 m, respectively. Consequently, the spatial distribution of wetland vegetation changed significantly, whereby the Carex spp., Polygonum criopolitanum, and Phalaris arundinacea communities extended down to the lower elevation zone. In the future, the PLWCH may result in increases in the inundation duration and depth, restrain the downward vegetation extension trend, and promote the vegetation to move to higher elevations similar to the status prior to 2003. These findings provide a detailed description of the spatiotemporal heterogeneity of the inundation pattern and the drivers of wetland vegetation distribution patterns in floodplain lake wetlands, serving as a scientific basis for conservation and restoration of these ecosystems.

Energetic Assessment of SCWG Experiments with Reed Canary Grass and Ethanol Solution on Laboratory and Pilot Scale

The energetic assessment of biomass conversion processes is important for evaluating their application potential. Process energy efficiency is often evaluated based on simulation results for processes under idealized conditions. The present work uses data from a laboratory plant to perform an evaluation of the supercritical water gasification (SCWG). For this purpose, experiments were conducted with two types of feedstock, Reed Canary Grass and ethanol. Under the present lab-plant configuration, a cold gas efficiency of up to 79% could be reached, which is comparable to the gasification of biomass in fluidized-bed gasifiers or entrained-flow gasifiers. Based on the obtained data on the produced substances and their distribution, a scale up to pilot plant size was conducted. A model was derived from the available data to energetically assess different SCWG plant sizes based on real laboratory results. This model can be transferred to other feedstocks and other process designs to approximate the optimal size for the used biomass feedstock. The importance of heat recuperation in this process is described in detail based on pilot-scale data.

Identification and Validation of Reference Genes for RT-qPCR Analysis in Reed Canary Grass during Abiotic Stress.

Reed canary grass (Phalaris arundinacea L.) is known for its tolerance to drought, heavy metals, and waterlogging, making it a popular choice for forage production and wetland restoration in the Qinghai-Tibet Plateau (QTP). To accurately assess gene expression in reed canary grass under different abiotic stresses, suitable reference genes need to be identified and validated. Thirteen candidate reference gene sequences were selected and screened using RT-qPCR to detect their expression levels in reed canary grass leaves under drought, salt, cadmium, and waterlogging stresses. Four algorithms were used to assess the stability of the expression levels of the candidate reference genes. The most stably expressed genes were UBC and H3 under drought Cd, ETF and CYT under salt stress, and ETF and TUB under waterlogging stress. GAPDH was found to be less stable under abiotic stresses. PIP-1, PAL, NAC 90, and WRKY 72A were selected as response genes for quantitative expression assessment under drought, salt, Cd, and waterlogging stresses to confirm the accuracy of the selected stable reference genes. These results provide a theoretical reference for assessing gene expression in reed canary grass under abiotic stresses.

Tissue composition and higher heating values differ among six bioenergy grasses

Perennial crops are considered as one of the most promising substitutions for fossil fuels for both ethanol production and direct combustion, but the quality and suitability of bioenergy feedstock is species dependent. The bioenergy feedstock value of different perennial crops is mainly determined by tissue composition and higher heating value (HHV). A common garden field experiment with four replications was conducted to investigate differences in cellulose, hemicellulose, lignin, ash, and 14 different tissue elemental concentrations as well as HHV from tissues of switchgrass (Panicum virgatum L.), Miscanthus (Miscanthus×giganteus), indiangrass (Sorghastrum nutans), eastern gamagrass (Tripsacum dactyloides), reed canary grass (Phalaris arundinacea), and giant reed (Arundo donax L.) grown in 2020 and 2021 in Midwest USA. Results showed that Miscanthus, switchgrass, and indiangrass exhibited higher holocellulose (cellulose + hemicellulose) concentrations compared with eastern gamagrass, reed canary grass as well as giant reed: 684–687 g kg-1 vs 597–646 g kg-1 (2-yr averages). Switchgrass and Miscanthus had higher lignin concentrations (97–108 g kg-1) than the other four species (66–84 g kg-1). Greater 2-yr averaged HHVs were observed in switchgrass (18.1 MJ kg-1) and Miscanthus (17.8 MJ kg-1) than for giant reed (17.3 MJ kg-1), eastern gamagrass (17.0 MJ kg-1), indiangrass (16.9 MJ kg-1), and reed canary grass (16.5 MJ kg-1), which was correlated with differences in ash concentration between switchgrass and Miscanthus (25–29 g kg-1) and the other four species (42–91 g kg-1). Switchgrass, Miscanthus, and indiangrass exhibited significantly lower nitrogen, sulfur, and potassium concentrations than the other grass species, which would lead to less NOx and SOx emission, and sintering or slag formation in the combustion chamber. Giant reed obtained the greatest potential ethanol and combustion yields on a single plant basis, followed by Miscanthus, switchgrass, indiangrass, eastern gamagrass, and reed canary grass; however, further studies are needed to evaluate biomass yields on an area basis.

Assessment of herbaceous vegetation classification using orthophotos produced from the image acquired with unmanned aerial systems

Arguably the most popular remote-sensing products are classified images. However, there are no definitive procedures to assess classification accuracy that simultaneously consider resources available and field efforts. The explosive usage of unmanned aerial systems (UAS) in land surveys adds new challenges to classification assessment, as orthorectified images usually contain significant artifacts. This study aims to identify the optimal ratio between training and validation sample size within a supervised classification approach applied to UAS orthophotos. As a case study, we used a wetland area west of Portland, OR, USA, treated with various glyphosate formulations to control Phalaris arundinacea, commonly known as reed canary grass. A completely randomized design with five replications and six glyphosate formulations was used to assess P. arundinacea vigor following repeated herbicide applications. The change in P. arundinacea vitality was monitored with high-resolution four-band imagery acquired with a SlantRange 3PX camera installed on a DJI Matrice 210. The orthophotos created from images were produced with Pix4D, which was subsequently preprocessed with ERDAS Imagine 2020 to reduce the noise, shadows, and artifacts. All images were classified with the maximum likelihood classification algorithm. Simple random and stratified random sampling methods were applied to collect training and validation samples, evaluating eight ratios of training to validation samples to assess their classification accuracy. We found that increasing the training-to-validation sample size ratio enhances accuracy, with the 3:1 ratio being the most reliable in classifying P. arundinacea vigor. Our study provides evidence that image preprocessing and enhancement are essential for UAS-based imagery.

A circular economy approach to drinking water treatment residue management in a catchment impacted by historic metal mines

Drinking water treatment residues (DWTR) from mining areas which remove and contain potentially toxic elements (PTE) could still potentially be used as a soil amendment to restore contaminated sites in the same catchment, thus eliminating waste and reducing the chemical and physical mobility of the pollutants. To assess this restorative and regenerative approach to DWTR management, field and pot trials were established with soils from a historic Pb–Zn mine site in the North East of England, amended with either local DWTR or the nearest available municipal green waste compost (GWC). Soils from the mine site were found to have very low levels of nutrients and very high levels of PTE (Pb and Zn > 13, 000 mg/kg). The perennial grass species Phalaris arundinacea, known for many ecosystem service benefits including soil stabilization, was used throughout this study. The application of the BCR sequential extraction to soils amended with the DWTR in the pot trials found a significant decrease in the bioavailability of Pb and Cu (p < 0.05) after plant growth when compared with an unamended control. The field trial involved 648 pre-grown grass plants planted-out into mine soils amended with either DWTR, GWC or a mixture (MIX) of the two, all at rates of 25–30% w/w. Both amendments and the MIX had significant positive effects on biomass production compared to the unamended control in the following order GWC > MIX > DWTR (p < 0.05). Results of the elemental analysis of biomass from the field trial were generally ambiguous and did not reflect the decreased bioavailability noted in the pot trials using the BCR procedure. Pot trials, however, showed increases in plant growth and decreases in concentrations of Cr, Cu, Pb and Zn in above ground biomass following the application of both amendments. Further work should involve the testing of a mixture of DWTR and other soil amendments to enhance plant growth. The success of these trials should provide confidence for those working in drinking water treatment and catchment management to reuse the waste residues in a circular economy and a sustainable way that could improve water quality over time.

Interactive Effects of Flooding Duration and Sediment Texture on the Growth and Adaptation of Three Plant Species in the Poyang Lake Wetland.

Flooding duration and sediment texture play vital roles in the growth and adaptation of wetland plants. However, there is a lack of research on the interactive effects of flooding duration and sediments on wetland plants. A two-factor experiment with flooding duration and sediment texture was designed in the study, involving three plant species commonly found in the Poyang Lake wetland (i.e., Carex cinerascens, Phalaris arundinacea, and Polygonum criopolitanum). Our findings were as follows: (i) Sediments play a crucial role in the growth and adaptation of hygrophilous plants, but they exhibited a weaker effect than flooding. (ii) Sediment texture mediates flooding to affect the stressing responses of wetland plant functional traits, including the leaf chlorophyll content, the plant height, and the number of leaves and ramets. (iii) Sediment texture forms interactive effects with flooding duration and directly influences hygrophilous plants. The results of this study help provide theoretical insights from a more scientific perspective for the prediction of hygrophilous plant dynamics and to facilitate the formulation of wetland management.

The retention of nitrogen and phosphorus in aboveground biomass of plants growing in constructed wetlands treating agricultural drainage

Three horizontal subsurface flow constructed wetlands (CW1, CW2 and CW3) for treatment of agricultural tile drainage water were built in 2018. Two wetlands were filled with a mixture of washed gravel and birch woodchips (10:1 volume ratio), in the third one the layer of woodchips was on top of a gravel layer. All wetlands were planted with Gyceria maxima and Phalaris arundinacea in parallel bands and parallel to water flow. Four-year study (2019–2022) was aimed at the amount of nutrients retained in aboveground plant biomass. The results revealed that the biomass of both species was lower as compared to biomass of these species growing in constructed wetlands for municipal sewage. Due to low aboveground macrophyte biomass, the nitrogen and phosphorus standing stocks were low (maximum 1.3 g P m−2 and 11.1 g N m−2). When comparing the nitrogen standing stocks with the inflow annual loadings and removed load, it represented on average only 2.38% of the removed load and 0.85% of the inflow load because of very high inflow loading (1298, 866 and 842 g N m−2 yr−1 in CW1, CW2 and CW3, respectively). On the other hand, the respective values for phosphorus amounted to 43.9% and 21.6% due to very low inflow loading (8.8, 6.6 and 6.0 g P m−2 yr−1 in CW1, CW2 and CW3, respectively). The study confirmed that plant contribution to nutrient removal in constructed wetlands expressed as removal percentage is strongly affected by inflow loading. The study also revealed that under low load conditions the plant uptake may substantially contribute to nutrient removal.

Optimal harvest time for high biogas and biomass yield of Typha latifolia, Typha angustifolia and Phalaris arundinacea

Rewetting of peatland is commonly accepted as a useful measure for counteracting climate change. To increase the acceptance, an agricultural use of fen plants is needed. In this study, the optimal harvest date of Typha latifolia, Typha angustifolia and Phalaris arundinacea regarding their biogas potential and biogas yield per hectare was identified. Furthermore, the influence of the chemical composition of Typha spp. and P. arundinacea on the biogas and biochemical methane potential was determined. Finally, the predictability of the biochemical methane potential (BMP) of Typha spp. and P. arundinacea by their composition with published regression models was examined. The three fen plant species were harvested on five different dates in 2018 and/or 2020. For each harvest, the biomass yield, biogas potential and BMP were determined, the chemical composition of the biomass was analyzed, and the biogas yield per hectare was calculated. The biogas potential of T. latifolia, T. angustifolia and P. arundinacea decreased with increasing plant maturity and ranged between 315 and 647 LN kg−1 VS, 405 and 596 LN kg−1 VS and 361 and 597 LN kg−1 VS, respectively. The biogas and BMP of all three plant species investigated were negatively correlated with the lignin content and could be predicted with published regression models, which included the lignin content as main regressor. The derived optimal harvest dates, which were a compromise between biomass yield and biogas potential, for all three fen plants ranged between the development stages of full flowering and shortly after the seed heads turned brown.

Comparison of GHG emissions from annual crops in rotation on drained temperate agricultural peatland with production of reed canary grass in paludiculture using an LCA approach

Drained peat soils contribute significantly to global human-caused CO2 emissions and reducing peat degradation via rewetting is high on the political agenda. Ceasing agricultural activities on rewetted soils might lead to land owner resistance and high societal expenses to compensate farmers. Continued biomass production adapted for wet conditions on peat soils potentially minimizes these costs and helps supplying the growing demand for e.g. materials, fuels and feed. Here we used a life cycle assessment approach (cradle to farm gate) to investigate the greenhouse gas (GHG) emissions related to three cases by applying IPCC (Intergovernmental Panel on Climate Change) emission factors and specific site conditions at a bog and a fen site that represent widely distributed temperate peat soils. Besides soil emissions, upstream emissions from input, operational emissions and emission related to rewetting construction work were included. The analyzed systems were deeply drained cash cropping on agricultural bog (potatoes (Solanum tuberosum L.), spring barley (Hordeum vulgare L.) and oat (Avena sativa L.), permanent Reed canary grass (RCG) (Phalaris arundinacea L.) production on non-drained bog and permanent RCG production on shallow-drained fen. The annual mean water table depths (WTD) were −70, −38 (estimated) and −13 cm, respectively. Results showed estimated GHG emissions of 40.5, 26.1 and 20.6 Mg CO2eq ha−1, respectively, corresponding to a 35% GHG reduction for the non-drained bog case as compared to the drained bog case, despite that the obtained WTD due to ceased drainage did not adhere to the IPCC rewetting threshold of −30 cm. Emissions related to crop management represented 7, 14 and 19% of total emissions. In the RCG cultivation on fen case, the WTD were controlled primarily by the water table of the nearby stream and total GHG emissions were even lower as compared to the RCG production on the non-drained bog reflecting the difference in WTD. Rewetting projects need to include careful knowledge of the specific peat area to foresee the actual reduction potential.

Assessment of Energy–Economy and Environmental Performance of Perennial Crops in Terms of Biogas Production

Biogas production plays an important role in the clean energy economy and is reducing the problems of the energy crisis. The main objective of the current study is to analyze environmental performance by using perennial energy crops in the agricultural sector. Perennial energy crops are neutral for carbon and can be used for electricity and heating, which may mitigate climate change as well. The purpose of this work was to investigate and compare the energy–economy effectiveness and environmental performance of the suitability of four perennial crops for biogas production. Environmental performance was analyzed using the method of the life cycle assessment. To identify the most environmentally sustainable perennial crops for biogas production, a comparative analysis was conducted on four different crops: Lucerne, Miscanthus, Switchgrass, and Reed canary grass. The results of the analysis showed that Lucerne and Miscanthus, during the first–sixth years period, have lower indirect energy input (from 15.2 to 3.2 GJ/ha and 15.6 to 3.2 GJ/ha) than Switchgrass (from 20.9 to 3.2 GJ/ha) and Reed canary grass (from 16.7 to 3.2 GJ/ha). However, the highest direct energy input was determined by Lucerne (from 15.7 to 1.6 GJ/ha), and Miscanthus (from 11.9 to 0.9 GJ/ha) compared to Switchgrass (from 7.4 to 1.8 GJ/ha) and Reed canary grass (from 8.1 to 1.6 GJ/ha). Additionally, the lowest result of the direct economy and indirect economy costs was determined by Lucerne (from 3.9 to 3.7 kEUR/ha (direct) and 9.9 to 2.1 kEUR/ha (indirect)) and by Miscanthus (from 2.4 to 4.9 kEUR/ha (direct) and 11.8 to 1.9 kEUR/ha (indirect)) compared to Switchgrass (5.9 to 5.7 kEUR/ha (direct) and 17.5 to 2.1 kEUR/ha (indirect)), and reed canary grass (from 5.3 to 4.9 kEUR/ha (direct) and 13.7 to 1.9 kEUR/ha (indirect), respectively. The assessment of environmental performance revealed that Reed canary grass and Miscanthus had a more pronounced impact on Acidification. In contrast, Lucerne and Switchgrass had a more significant impact on Eutrophication indicators. The crop cultivation of four perennial crops impacted the environment in various significant ways. Despite the varying environmental impacts of the four perennial crops, the analysis revealed that all of them have the potential to increase biogas production.

Report of two distinct ribotypes in ITS sequences of Phalarisarundinacea (Poaceae) in western Canada and Alaska.

Phalarisarundinacea L. (reed canary grass) is a widely occurring grass throughout the Northern Hemisphere. In North America, it is thought to consist of introduced agricultural forms from Europe as well as native populations. During a survey of Phalarisarundinacea in western Canada, we discovered two distinct ribotypes in the sequences of the internal transcribed spacer (ITS) of the nuclear ribosomal DNA: one full length (ITS-long) and one with a seven base pair deletion (ITS-short). In addition, ITS-long plants have fixed heterozygosity indicating possible polyploidy. Phylogenetic analysis reveals that ITS-short is a unique ribotype that characterises an intraspecific clade. We designed an efficient PCR-based assay that allows sizing of a 238/245 base pair fragment in a capillary sequencer. This approach provides a novel marker that could be useful in future surveys of Phalarisarundinacea.

Enrichment and chemical fractionation of plant nutrients, potentially toxic and economically valuable elements in digestate from mesophilic and thermophilic fermentation

This study investigated the effect of mesophilic (37 °C) and thermophilic (55 °C) digestion on the enrichment and fractionation of plant nutrients (P, Mn, Fe), potentially toxic elements (Cd, Cr, Pb, As, Cu, Ni, Co, Zn) and economically valuable elements (Ge, rare earth elements REE). Batch experiment was conducted with the substrates of Phalaris arundinacea and inoculum for 40 days and the latter digestate was collected for further analysis. Digestate from selected reactors was filtered through 0.2 μm syringe filters to separate dissolved elements from the particulate. The solid digestate was extracted with ammonium acetate (pH 7 and pH 5) to determine the extraction of mobile/exchangeable and acid soluble elements, respectively. In fresh digestate, element concentration increased by more than 20–100% especially Ge (94%) and REEs (119%) and pH (6.5–7.9) was significantly higher compared to mesophilic (6.1–7.5). In dried digestate, thermophilic digestion showed increased enrichment of Fe, Co, Cu, Zn, Cr, As, Cd, Pb and especially Ge (193%) and REEs (90%) compared to mesophilic indicating a strong enrichment in thermophilic digestion. Considering both operating conditions 5% of elements were present in the liquid, less than 30% were exchangeable and acid soluble and more than 70% were stabile bound into solids. Thermophilic conditions significantly increased the portion of dissolved and labile-bound elements in the digestate. Reactor temperature offers a promising way to use digestate as a secondary raw material for element recovery in the spirit of phytomining, which contributes to a “cascade use” of digestate in the circular economy.

Differences in Metal Accumulation from Stormwater by Three Plant Species Growing in Floating Treatment Wetlands in a Cold Climate

Stormwater is a source of pollutants in urban areas and should be treated to prevent negative environmental effects. A newer technique uses floating rafts with plants, called floating treatment wetlands (FTWs), which are placed in the polluted water. Few earlier studies have examined heavy metal removal by FTWs, and none has examined stormwater in cold climates. This study therefore aimed to determine whether plants growing in FTWs could accumulate heavy metals from stormwater ponds in a cold climate. This study examined the abilities of three native wetland species (i.e., Carex riparia, C. pseudocyperus, and Phalaris arundinacea) to accumulate Cd, Cu, Pb, and Zn. The plants were planted on FTWs, which were placed in two stormwater ponds in Stockholm, Sweden, for 12 weeks. Phalaris arundinacea accumulated more Cd, Cu, and Zn than did the Carex species, and C. pseudocyperus accumulated less Pb than did the other species during the experimental period. In most cases, the roots had higher metal concentrations than did the shoots. Carex pseudocyperus had smaller differences between shoot and root metal contents, whereas P. arundinacea had higher Cd and Cu contents and lower Zn contents in its roots than in its shoots. The metal content in the plants increased with higher biomass. The plants that grew in the stormwater pond with a higher Zn concentration had a higher Zn tissue concentration and total Zn content per plant after treatment. This study shows that wetland plants growing on FTWs can accumulate metals from stormwater ponds in a cold climate. Phalaris arundinacea appears to be a good candidate for metal removal use in FTWs. Furthermore, high plant biomass positively affects the metal uptake, meaning that good growing conditions could be essential for metal removal.