Outdoor Plants Research Articles

Plant Characteristics for Green Wall Systems

This research is a preliminary study of planting ornamental plants with a green wall system. This study aims to provide an overview and information about the selection of types of plants that are suitable and commonly used in making green walls and arranging selected plants in green walls system. Green wall system which is often called vertical garden is a technique to plant ornamental plants, vegetables or other types of plants with a free design that considers various resources that allow plants to grow vertically. The advantages of green walls are efficient use of soil, beautifying the environment, adding location value, cleaning the air, lowering temperature, producing oxygen and providing fresh food that is close to the surrounding environment at home. Not all types of plants can be planted vertically. Easy-to-grow plants, short appearance and slow growth are common characteristics used for green walls. The special characters of the selected plants are determined based on the group of indoor or outdoor plants. Consideration of nutritional, light, water and plant requirements will determine the success of planting and the sustainability of vertical planting.

Crop Yield, Ferritin and Fe(II) boosted by Azospirillum brasilense (HM053) in Corn

An increasing global population of over 4.5 billion people drives increasing demand for calories—30% of which are satisfied by grain crops, such as maize. High-density farming practices have been implemented but tend to deplete the soil of essential elements resulting in lower nutritional value, notably iron, of cultivated crops. Low iron content in staple crops can contribute over time to severe, even fatal, micronutrient deficiencies. Enhancing grain iron content using post-harvest biofortification strategies can be costly. However, field inoculation using biologics like Azospirillum brasilense (HM053) can be a cost-effective alternative to improving crop nutritional value. Using ion chromatography with chemiluminescence detection, we have shown that maize seeds harvested from outdoor pot-grown plants possessed a four-fold higher iron content as ferrous iron (Fe+2) compared to non-inoculated plants. Seeds from A. brasilense HM053-inoculated plants also contained approximately 13 nmol of ferritin per ground dried weight of kernel compared to 3 nmol from non-inoculated plants. In addition, A. brasilense HM053 inoculation increased crop yield 30–50% relative to non-inoculated plants.

Horizon scanning to identify invasion risk of ornamental plants marketed in Spain

Horticulture is one of the main pathways of deliberate introduction of non-native plants, some of which might become invasive. Of the 914 commercial ornamental outdoor plant species sold in Spain, 700 (77%) are non-native (archaeophytes excluded) marketed species. We classified these into six different lists based on their invasion status in Spain and elsewhere, their climatic suitability in Spain and their potential environmental and socioeconomic impacts. We found sufficient information for 270 species. We provide a Priority List of eight regulated invasive species that were still available on the market. We also established an Attention List with 68 non-regulated invasive and potentially invasive species that might cause various impacts. To prioritise the species within the Attention List, we further assessed the risk of invasion of these species by using an adaptation of the Australian WRA protocol and the level of societal interest estimated from values of the Google Trends tool. We also propose a Green List of seven species with probably no potential to become invasive, a Watch List with 27 potentially invasive species with few potential impacts and an Uncertainty List with 161 species of known status but with insufficient information to include them in any of the previous lists. We did not find sufficient information for 430 (61%) of the marketed non-native plant species, which were compiled into a Data Deficient List. Our findings of prohibited species for sale highlight the need for stronger enforcement of the regulations on invasive plant species in Spain. In addition, our results highlight the need for additional information on potential impacts and climate suitability of horticultural plants being sold in Spain, as insufficient information could be found to assess the invasion risk for most species.

Poisonous plants-anew approach for assessing the risk of poisoning in small children

Plant poisoning in small children (from 0.5 to <6years of age) is the third most frequent cause for phone contact with apoison center. For prevention of poisonings, alist of poisonous plants that should not be planted close to playgrounds or other places frequently visited by children was published in 2000 by the Bundesanzeiger. This list has been reevaluated and updated by the "Toxicity of Plants" working group of the Committee of the Assessment of Intoxications at the Federal Institute of Risk Assessment (BfR). Relevant plants were taken from arecent publication. Aliterature search was conducted in PubMed concerning all plant poisonings in children and the toxic ingredients of plants. Also, monographs and the database POISINDEX were integrated in the evaluation. A classification was made for plants that after oral, dermal, or ocular contact of small quantities could cause severe, moderate, mild, or no intoxications in small children. Based on data of exposure and potentially toxic ingredients of the involved plants, arisk assessment was executed, which diverges from other publications because it concerns the actual basic risk of an intoxication. In total, 251 plants were reevaluated. For 11plants, there was ahigh risk, for 32amoderate, for 115 amild, and for 93plants no risk of intoxication could be determined. The new assessment of evaluating atoxicity risk for small children on the basis of exposure data and including the toxicity of ingredients allows for amore realistic assessment of the risk of poisoning with outdoor plants. In this way, infant exposure carrying ahigh risk of intoxication can be identified.

Raspberries and gooseberries in south Patagonia: Production, fruit quality, morphology and phenology in two environmental conditions

Fine fruits as raspberry and gooseberries represent the second production with the largest area cultivated in Santa Cruz province (Argentina), and this activity is usually carried out by family farmers in outdoor conditions. The availability of information about productive, morphologic, phenological and quality aspects of these crops in south Patagonia is very scarce. The aim of this work was to evaluate performance of Rubus idaeus cv. Autumn Bliss (RIA), R. idaeus cv. Glean ample (RIG), Ribes rubrum (RR), Ribes nigrum (RN) and Ribes uva crispa (RU) under two environments: outdoors and in greenhouse. An essay with a split plot design, with environment as the main plot and the species as a subplot, with three replicates, was established. Variables related to morphology, phenology, fruit production and fruit quality were measured. Significant differences were found in fruit production according to environment. At the third year, fruit production in greenhouse was 19.6, 130.7, 626.2, 693.1 and 1308.7 g plant−1 for RIG, RR, RN, RIA and RU, respectively. In the same year, production outdoors was 14.3, 80.5, 84.6, 90.7, 343.1 RIG, RN, RR, RIA and RU, respectively. Environment also affected individual fruit weight, being 1.79 g the mean fruit weight in greenhouse and 0.98 outdoors. Morphologic variables had a strong influence on fruit production, mainly on node number and foliar area. Results showed a 65% higher mean production efficiency of plants (gr fruits/m2 foliar area) in greenhouse compared with outdoor plants. In general, raspberries in outdoor condition decreased 90% in production efficiency, whereas gooseberries decreased 40%. In average, RIA were the most efficient plants throughout all the study period and RU had the highest efficiency during the last year of production. In conclusion, outdoor production of these species in South Patagonia is not recommended, because temperature and wind intensity severely affected plant performance. However, if outdoor condition is the only option, cultivate RU is the best option.

Chromosome Location Contributing to Ozone Tolerance in Wheat.

Breeding wheat for higher grain yield can contribute to global food security and sustainable production on less land. Tropospheric ozone can injure wheat plants and subsequently reduce grain yield. Identification of ozone tolerance in the wheat genome can assist plant breeders in developing new sources of tolerant germplasm. Our objective was to use the ‘Chinese Spring’ monosomic lines to screen for ozone response and identify the chromosomic locations contributing to ozone tolerance based on foliar injury. Two methodologies, Continuous Stirred Tank Reactors and Outdoor Plant Environment Chambers, were used to expose wheat monosomic lines to varying concentrations and durations of ozone. Each wheat monosomic line in ‘Chinese Spring’ has a missing chromosome in each of the wheat subgenomes (A, B, and D). In both methodologies, we found significant and repeatable data to identify chromosome 7A as a major contributor to tolerance to ozone injury in ‘Chinese Spring’. In every experiment, the absence of chromosome 7A resulted in significant injury to wheat due to ozone. This was not the case when any other chromosome was missing.

Planting Density and Growth Cycle Affect Actual and Potential Latex and Rubber Yields in Taraxacum kok-saghyz

Rubber dandelion (Taraxacum kok-saghyz, Rodin) is being developed as a temperate-zone source of rubber, but best agronomic practices must be determined before it can become a viable supplement to imported rubber produced from para rubber tree (Hevea brasiliensis, hevea) plantations located mostly in Southeast Asia. In our study, the effect of planting density and harvest time on yield was determined by transplanting 1.5-month-old greenhouse-produced plants at planting densities of 1.24, 2.47, 4.94, and 9.88 million plants/ha, randomized across four planting boxes with two densities per box (i.e., two planting areas at each density). Half of each planting area was selected randomly and hand-harvested after 6 months, and the remaining plants were hand-harvested after 1 year. Rubber yields per plant were greater after 1 year than after 6 months, but yields per unit area were similar as a result of the loss of half the plants during the severe 2013–14 Ohio winter. A maximum rubber yield of 960 kg dry rubber/ha was obtained from the 9.88 million-plants/ha planting density after 1 year, but root size was significantly decreased compared with lower densities, and appeared too small for mechanical harvest. A planting density between 2.47 and 4.94 million plants/ha may produce the optimal combination of root size and total rubber yield. Greater rubber concentrations, faster-growing plants, short-season germplasm, and in-field weed control are required before yields obtained in outdoor planting boxes can be matched or exceeded on farms, especially in a direct-seeded rubber dandelion crop.

Annual outdoor cultivation of the diatom Thalassiosira weissflogii: productivity, limits and perspectives

Diatoms are a promising source of renewable biomass for production of energy and functional ingredients and food products. The eurythermal diatom Thalassiosira weissflogii shows great resistance and robustness, and can be considered a suitable candidate for outdoor cultivation. In this study we investigated the resilience of one strain of this species during one-year outdoor experimentation in inclined tubular photobioreator with a working volume of 40 L. Cells of T. weissflogii overcome temperature and irradiance fluctuations by adapting their growth rate at the different environmental conditions. Calculation of areal biomass productivity based on 30 cultures along the year showed a median value of 3.83 g m−2 day−1 with maximal values of biomass (6.8 g m−2 day−1) and lipids (1.2 g m−2 day−1) reached in February and July, respectively. We observed a decline in biomass productivity with temperature increase, whereas lipid content (10–20% of dry biomass) was not significantly affected by the environmental conditions as far as a high concentration of nutrients was maintained. The outdoor experimentation successfully proved one year-round production of biomass from a single diatom species in closed photobioreactor, making T. weissflogii a suitable candidate for guaranteeing stable annual productive cycles in outdoor plant.

First Report of Xanthomonas hortorum pv. hederae Causing Bacterial Leaf Spot of Hedera helix in Taiwan

Hedera helix (ivy) is a popular evergreen commonly grown worldwide as outdoor and indoor plants. In 2018, symptoms similar to bacterial leaf spot were observed on potted ivies in two nurseries, one located in Tianwei Township, Changhua County (observed in January) and the other in Nantun District, Taichung City, Taiwan (observed in May). In both locations, leaf spot symptoms were seen on over 90% of the plants. The lesions were irregularly shaped and were necrotic or water-soaked. A total of seven infected plants were sampled and brought to the laboratory, one collected in Changhua and six sampled in Taichung. Diseased tissues were cut, and bacterial streaming was observed under a light microscope. The samples were streaked onto nutrient agar (NA) and onto NA with 0.2% yeast extract and then were incubated at 25°C. Round yellow colonies were recovered from all seven plants, and seven independent bacterial strains (Hed1 to Hed7) were isolated (each from a different plant). Hed1 was obtained from the plant collected in Changhua, whereas the others were isolated from plants collected in Taichung. All seven strains produced yellow mucoid colonies on yeast dextrose calcium carbonate agar, similar to most known xanthomonads (Schaad et al. 2001). They tested positive for esculin degradation, weak positive for casein hydrolysis, and negative for the abilities to degrade Tween 80 and starch (Schaad et al. 2001). Infiltration of these strains’ suspensions into tomato leaves (cv. Known-you 301) induced hypersensitive responses. Identification of Hed1 to Hed7 was conducted via multilocus sequence analysis targeting the fusA, gyrB, gapA, gltA, lacF, and lepA genes (Almeida et al. 2010). Gene fragments were sequenced for all seven strains. For every fragment tested, Hed1 to Hed7 all had the same sequences (GenBank accession nos. MK124762 to MK124767). Comparing the concatenated 2,745-bp sequences of Hed1 to Hed7 among each other and against sequences included in the Plant-Associated Microbes Database (http://genome.ppws.vt.edu/cgi-bin/MLST/home.pl) (Almeida et al. 2010) revealed that all seven strains shared identical sequences with the type strain of Xanthomonas hortorum pv. hederae (LMG733) and had lower than 98% identity with the other Xanthomonas species and pathovars. To fulfill Koch’s postulates, three strains (Hed1, Hed2, and Hed6) were randomly selected and spray inoculated onto potted ivies at a concentration of approximately 1 × 10⁸ CFU/ml (in 0.02% Silwet L-77). Each strain was inoculated onto three plants. Three additional plants sprayed with 0.02% Silwet L-77 solution without bacteria served as controls. The plants were then bagged in plastic bags for 3 days to maintain high humidity. Within 3 weeks, necrotic leaf spots developed on all bacteria-inoculated plants but not on the control plants. Bacterial strains were reisolated from the plants inoculated with Hed1, Hed2, and Hed6, and all reisolates shared the same gapA sequence with the original strains. Bacterial leaf spot on ivy has been reported in Greece, Japan, and other parts of the world (Pirc et al. 2012; Suzuki et al. 2002; Trantas et al. 2016). The present study is, to our knowledge, the first report of the occurrence of this disease in Taiwan. Ivies are often planted in shaded/indoor areas at high densities and are watered frequently in nurseries. These conditions could favor the development of bacterial leaf spot and the transmission of its pathogen.

Optimising an outdoor membrane photobioreactor for tertiary sewage treatment

The operation of an outdoor membrane photobioreactor plant which treated the effluent of an anaerobic membrane bioreactor was optimised. Biomass retention times of 4.5, 6, and 9 days were tested. At a biomass retention time of 4.5 days, maximum nitrogen recovery rate:light irradiance ratios, photosynthetic efficiencies and carbon biofixations of 51.7 ± 14.3 mg N·mol−1, 4.4 ± 1.6% and 0.50 ± 0.05 kg CO2·m3influent, respectively, were attained. Minimum membrane fouling rates were achieved when operating at the shortest biomass retention time because of the lower solid concentration and the negligible amount of cyanobacteria and protozoa.Hydraulic retention times of 3.5, 2, and 1.5 days were tested at the optimum biomass retention times of 4.5 days under non-nutrient limited conditions, showing no significant differences in the nutrient recovery rates, photosynthetic efficiencies and membrane fouling rates. However, nitrogen recovery rate:light irradiance ratios and photosynthetic efficiency significantly decreased when hydraulic retention time was further shortened to 1 day, probably due to a rise in the substrate turbidity which reduced the light availability in the culture. Optimal carbon biofixations and theoretical energy recoveries from the biomass were obtained at hydraulic retention time of 3.5 days, which accounted for 0.55 ± 0.05 kg CO2·m−3influent and 0.443 ± 0.103 kWh·m−3influent, respectively.

OFFICE BUILDING LOCATION RELATED TO GREENERY TYPE CASE STUDY OF THE MAIN BUSINESS DISTRICTS IN PARIS

Emerging built landscapes and urban densities, together with a distressing human-nature estrangement, represent the main challenges of today`s developers. Real concerns such as pollution, climate change or nature-deficit-syndromes impact the human world on every scale, raising attention towards seeking change in attitude and low impact methodologies in the built context. Beginning with the Industrial Revolution when new technologies encouraged architectural reinvention, continuing through the Digital Era that transformed building and thinking once again, the natural environment has undergone a constant decrease in surface and importance in cities worldwide. Corporate architecture has always adopted building innovation, aiming for higher prestige and marketability through a polished, impressive, even intimidating image. Exterior a spect, energy performance, indoor quality and technology-proneness are some of the points pursued by both managers and investor when choosing a new business site. But the foremost aspects when buying or renting a new office building are location and price. Increasing demands for office surface have led to vertical building, which rose new issues in the European urban network, due to strict urban requirements. Thus, the selection of optimal office building location has been a challenge for the narrow-street structure of European cities, leading to several typologies: historical districts, urban and suburban areas or independent workplace centers. Each location has in turn determined different intervention types: refurbishment or renovation, functional conversion, new building, causing various dialogues with the urban nature. As every European city and country has its own regulations depending on geographical, climatic, cultural and political factors, the research was focused on one case study that allowed drawing relevant conclusions on the matter. With its rich urban and architectural background, a diverse and ever developing business environment, the French capital, Paris, is among the most interesting European metropolis for its urban development. A clear distinction can be made here between three different typologies of commercial districts: historical type (the Central Business District, in western Paris), the modernist La Défense (on the Northern-Western outskirts), the newer Saint-Denis/Saint-Ouen and Issy-les-Moulineaux (in the Northern and Southern suburbs). Approximately 100 buildings from these locations and the close vicinity have been analyzed aiming to classify their connection to outdoor and indoor plants and observe how these reflect on real estate rent cost. Another argument for choosing Paris for this case study is the relative recent implementation of the “Biotope Area Factor” principle that demands a balanced use of vegetation in the built fabric for both new constructions and refurbishment projects. Alike other several European capitals (Berlin, Stockholm, London) the urban landscape is slowly transforming towards a more sustainable one, while keeping a certain flexibility in selecting the green systems. The main objective of this research is to determine the office building-greenery relation from economical, urban and architectural points of view. It is essentially important to understand how energetic certificates and green space proximity rise the real estate value, making the building more attractive, updated and innovative regarding ecological visions. Furthermore, establishing link typologies between location, building type and vegetation can highlight the optimal greening potential of each site type. A construction located in the dense city center is expected to benefit from more introverted nature (interior courtyards, green walls, etc.) comparing to a less dense suburban site. Although the study was conducted on a small sample relative to the complexity of the topic, the model might be further applied on a larger scale, comparing different cities worldwide, practically creating local frameworks for architects, managers and investors, towards responsible implementation of vegetated material in the office building sector.

Source localization for hazardous material release in an outdoor chemical plant via a combination of LSTM-RNN and CFD simulation

Chemical leak accidents not properly handled at the early stage can spread to major industrial disasters escalating through fire and explosion. Therefore, it is very important to develop a method that enables prompt and systematic response by identifying the location of leakage source quickly and accurately and informing on-site personnel of the probable location(s). In this study, a model that predicts the suspicious leak location(s) in real-time, using sensor data, is proposed. Feed-forward neural network and recurrent neural network with long short-term memory that learned the data gathered from the installed sensors are proposed to predict the Top-5 points in the order of highest likelihood. In order to train and verify the neural networks, the sensor data generated from computational fluid dynamics simulations for a real chemical plant are used. The model learns the inverse problem solving for accident scenarios and predicts the leak point with very high accuracy.

First Record of Erysiphe elevata on Plumeria rubra in Taiwan

Plumeria rubra L., native to tropical Central America, is a widely cultivated ornamental woody plant. In two municipalities in northern Taiwan we observed brown discolorations irregularly following veins on the abaxial surface of green or yellowing lower (old) leaves of two outdoor plants of P. rubra. The upper side did not show symptoms or diffuse yellow spots. About 80% of leaves exhibited superficial mycelia and conidiophores typical of a powdery mildew. Specimens collected from a garden plant in Taipei City on 31 May 2018, and from a pot plant in Taoyuan City, Zhongli District, on 7 June 2018, were deposited under the collection numbers R. Kirschner 4647 and 4651 in the National Museum of Natural Science, Taichung, Taiwan (TNM). Fresh specimens were mounted in approximately 10% KOH and observed with light microscopy. The mycelium was hypophyllous, forming irregular patches. Hyphae were hyaline, walls thin, smooth, 3 to 8 μm wide, with hyphal appressoria single or opposite in pairs, nipple shaped or lobed. Conidiophores were 35 to 76 μm long, 7 to 9 μm wide, erect, straight or curved at the base, mostly three-celled, occasionally one- or two-celled. Foot cells were rough at the base, 24 to 35 μm long, 6 to 8 μm wide, with basal septum mostly even with the surface of the supporting hypha. Conidia were solitary, ellipsoidal to cylindrical, smooth, 28 to 35 μm long, 13 to 16 μm wide, and germination was not observed. The specimens were compared with a specimen (R. Kirschner 1945, TNM) of E. elevata on Catalpa sp. (Bignoniaceae), collected in Germany, Frankfurt am Main, Bergen-Enkheim, 18 July 2004. The anamorphic specimens from Catalpa sp. in Germany and P. rubra from Taiwan were morphologically indistinguishable. The internal transcribed spacer (ITS) region of rDNA of both Taiwanese specimens was amplified with the primers ITS1F/ITS4 and sequenced. The 660-bp-long ITS sequences of R. Kirschner et al. 4647 (GenBank MH507182) and 4651 (GenBank MH507183) were 100% identical to each other and 99 to 100% identical to the 10 available sequences of E. elevata in GenBank (Meeboon and Takamatsu 2017), whereas the similarity was 98% or lower for other species. Erysiphe sp. (labeled as E. elevata in GenBank under MF092833) recorded on Plumeria pudica by Suarez et al. (2017) had a similarity of 97% (582/597 bp). The sequence MF092833 contained seven unclear positions (“N”), indicating technically insufficient quality. Because of the high similarity of sequences and anamorph morphology, the specimens on P. rubra from Taiwan are conspecific with E. elevata. It seems to be limited to the lower side of the older leaves, where it forms inconspicuous mycelia so that the brown scribble-like discolorations along the leaf veins are more diagnostic symptoms than the mycelial colonies. Powdery mildew of Plumeria leaves is often reported anecdotally, but confirmed reports are lacking. Recently, Suarez et al. (2017) identified the causative agent as the genus Erysiphe on P. pudica in the United States. Because P. rubra was introduced to Taiwan in the 17th century and the first hybrid in 1967 (Hsueh and Yang 2009), the pathogen may have gone unnoticed for a long time. According to our observation, however, the powdery mildew appears to be less frequent than the recently reported rust Coleosporium plumeriae (Chung et al. 2006) and might have been recently introduced. The fungus may be involved in an accelerated leaf-fall, particularly in connection with additional stress factors such as drought or coinfection with the rust fungus.

Насекомые-фитофаги в коллекции растений открытого грунта Ботанического сада Петра Великого

Насекомые-фитофаги в коллекции растений открытого грунта Ботанического сада Петра Великого

Consumer Involvement with and Expertise in Water Conservation and Plants Affect Landscape Plant Purchases, Importance, and Enjoyment

The strain on potable water supplies heightens the competition for water resources and potentially reduces the demand for outdoor plantings and landscaping. We conducted an online survey with 1543 respondents in 2016 to ascertain their water conservation and plant expertise, their involvement in water conservation and plant issues, and the importance of plants and landscaping. We also collected demographic characteristics. Cluster analysis results identified two key market segments comprising ≈50% of the sample each: those who are Actively Interested in Water Conservation and those who are Disinterested in Water Conservation. The Actively Interested segment was younger, had more adults and children in the household, and had a higher household income. In addition to having a higher mean score for water conservation involvement and expertise, the Actively Interested segment had a higher mean score for water conservation importance and impact, as well as plant expertise and involvement. The Actively Interested segment scored higher on select components relating to horticultural importance, including aesthetically beautiful landscapes, active landscape enjoyment, desire for a low maintenance landscape, and response in drought, compared with the Disinterested segment. The Disinterested segment scored higher on the Non-Landscape Use with no enjoyment. Findings suggest that pro–water-conserving attitudes are found among consumers who value outdoor landscapes and those individuals who spend more on plants. Results suggest that producers and retailers should focus marketing and communication efforts on low water use cultivar selection and operationalizing water-conserving behaviors more than convincing consumers that plant purchases and landscaping are important.

Retention and remobilization mechanisms of environmentally aged silver nanoparticles in an artificial riverbank filtration system

Riverbank filtration systems are important structures that ensure the cleaning of infiltrating surface water for drinking water production. In our study, we investigated the potential risk for a breakthrough of environmentally aged silver nanoparticles (Ag NP) through these systems. Additionally, we identified factors leading to the remobilization of Ag NP accumulated in surficial sediment layers in order to gain insights into remobilization mechanisms.We conducted column experiments with Ag NP in an outdoor pilot plant consisting of water-saturated sediment columns mimicking a riverbank filtration system. The NP had previously been aged in river water, soil extract, and ultrapure water, respectively. We investigated the depth-dependent breakthrough and retention of NP. In subsequent batch experiments, we studied the processes responsible for a remobilization of Ag NP retained in the upper 10 cm of the sediments, induced by ionic strength reduction, natural organic matter (NOM), and mechanical forces. We determined the amount of remobilized Ag by ICP-MS and differentiated between particulate and ionic Ag after remobilization using GFAAS. The presence of Ag-containing heteroaggregates was investigated by combining filtration with single-particle ICP-MS.Single and erratic Ag breakthrough events were mainly found in 30 cm depth and Ag NP were accumulated in the upper 20 cm of the columns. Soil-aged Ag NP showed the lowest retention of only 54%. Remobilization was induced by the reduction of ionic strength and the presence of NOM in combination with mechanical forces. The presence of calcium in the aging- as well as the remobilizing media reduced the remobilization potential. Silver NP were mainly remobilized as heteroaggregates with natural colloids, while dissolution played a minor role.Our study indicates that the breakthrough potential of Ag NP in riverbank filtration systems is generally low, but the aging in soil increases their mobility. Remobilization processes are associated to co-mobilization with natural colloids.

Differentiating plant functional types using reflectance: which traits make the difference?

AbstractAbiotic ecosystem properties together with plant species interaction create differences in structural and physiological traits among plant species. Certain plant traits cause a spatial and temporal variation in canopy reflectance that enables the differentiation of plant functional types, using earth observation data. However, it often remains unclear which traits drive the differences in reflectance between plant functional types, since the spectral regions in which electromagnetic radiation is influenced by certain plant traits are often overlapping. The present study aims to assess the relative (statistical) contributions of plant traits to the separability of plant functional groups using their reflectance. We apply the radiative transfer model PROSAIL to simulate optical canopy reflectance of 38 herbaceous plant species based on field‐measured traits such as leaf area index, leaf inclination distribution, chlorophyll content, carotenoid content, water and dry matter content. These traits of the selected grassland species were measured in an outdoor plant experiment. The 38 species differed in growth form and strategy types according to Grime′s CSR model and hence represented a broad range of plant functioning. We determined the relative (statistical) contribution of each plant trait for separating plant functional groups via reflectance. Therein we used a separation into growth forms, that is graminoids and herbs, and into CSR strategy types. Our results show that the relative contribution of plant traits to differentiate between the examined plant functional types (PFT) groups using canopy reflectance depends on the PFT scheme applied. Plant traits describing the canopy structure were more important in this regard than leaf traits. Accordingly, leaf area index (LAI) and leaf inclination showed consistently high importance for separating the examined PFT groups. This indicates that the role of canopy structure for spectrally differentiating PFT might have been underestimated.

Outdoor flat-panel membrane photobioreactor to treat the effluent of an anaerobic membrane bioreactor. Influence of operating, design, and environmental conditions.

As microalgae have the ability to simultaneously remove nutrients from wastewater streams while producing valuable biomass, microalgae-based wastewater treatment is a win-win strategy. Although recent advances have been made in this field in lab conditions, the transition to outdoor conditions on an industrial scale must be further investigated. In this work an outdoor pilot-scale membrane photobioreactor plant was operated for tertiary sewage treatment. The effects of different parameters on microalgae performance were studied including: temperature, light irradiance (solar and artificial irradiance), hydraulic retention time (HRT), biomass retention time (BRT), air sparging system and influent nutrient concentration. In addition the competition between microalgae and ammonium oxidising bacteria for ammonium was also evaluated. Maximum nitrogen and phosphorus removal rates of 12.5 ± 4.2 mgN·L-1·d-1 and 1.5 ± 0.4 mgP·L-1·d-1, respectively, were achieved at a BRT of 4.5 days and HRT of 2.5 days, while a maximum biomass productivity of 78 ± 13 mgVSS·L-1·d-1 (VSS: volatile suspended solids) was reached. While the results obtained so far are promising, they need to be improved to make the transition to industrial scale operations feasible.

Measuring thermal conductivity of green-walls components in controlled conditions

This study is the first stage of a larger multidisciplinary research program about the environmental performances and functions of green walls in urban ecosystems. It aims to determine how green-walls contribute to the thermal insulation of buildings by measuring the thermal conductivities of green-walls’ components in controlled conditions. The study focused on complex green-wall systems, i.e. with a structure containing substrate in opposition with green-walls based on climbing plants. The four substrates were materials found in commercial substrate combinations. To compare, the thermal conductivities on two plants are carried out. In dry conditions, they showed conductivities of 0.062 W/m °C for sphagnum moss (Sphagnum cristatum), 0.060W/m °C for outdoor planting mix, and 0.105 W/m °C for clay balls and 0.051 W/m °C for substrate from a green-wall. Vegetation conductivities were also measured for ivy (Hedera helix) and Virginia creeper (Parthenocissus quinquefolia). As expected, conductivities were quite high (between 0.220 and 0.274 W/m °C). With the building thermal simulation, green-walls are technically able to improve buildings’ insulation.

The potential of culinary vegetable oils as herbicides in organic farming: the effect of oil type and repeated applications on plant growth

This study tested the herbicidal effects of raw and processed culinary oils (rapeseed oil, sunflower oil, olive oil, flax/linseed oils) on nine plant species (poppy, white clover, alyssum, lupin, buckwheat, mustard, oats, perennial ryegrass, tall fescue). Oils were also tested on weeds that naturally emerged from farm soil. Plants were coated with oil using a pressurized hand pump, then maintained in a glasshouse or outdoor plant facility until harvested approximately 5 weeks after oil application. All the oils tested caused a decrease in plant dry matter compared with water-sprayed control treatments, although there was some inconsistency in herbicidal effects among plant species, trials and growing conditions. Spraying plants with rapeseed oil on multiple occasions tended not to be more phytotoxic than only a single spraying. Raw or organic oils were not consistently more phytotoxic than processed versions of the same oil type. There was some evidence that negative effects of oils on plant growth were more apparent under warmer conditions. The results suggest that culinary oils could reduce the biomass of weeds in an environmentally friendly way that is permissible to organic growers. However, the herbicidal activity of these oils appears low, and the quantities required to obtain substantial weed control may not be economically viable in all instances.