Willow Cuttings Research Articles

The Influence of Contamination from Concrete Materials on the Growth and Accumulation of Metals within an Invasive Weed (Salix spp.)

Urban riparian vegetation is frequently dominated by invasive weeds, whose growth is often attributed to the elevated nitrogen and phosphorous in urban waters and soils. However, less recognition is given to other urban contaminants that may influence riparian vegetation. Previous studies have indicated that the dissolution of concrete modifies water and soil geochemistry and potentially enhances the growth of invasive species. This study investigated the relationship between urban water quality and the growth of an invasive urban riparian weed, willow (Salix spp.), to examine the contribution and influence of concrete materials. The study used water from endangered upland peat wetlands within and adjoining the Greater Blue Mountains World Heritage Area, many of which are in urban catchments and suffer degradation from water pollution and invasive weeds. In this study, willow cuttings were grown in a laboratory using four water treatments: pristine (non-urban), urban, and non-urban water exposed to two different concrete materials. The urban and concrete-exposed water treatments were associated with increased plant growth measures in addition to increased concentrations of barium and strontium that bioaccumulated in plant tissue.

Nature-based bank protection measures improve benthic macroinvertebrates in a stream draining an agriculturally dominated watershed

Increased bank erosion is one of the most significant threats to agricultural stream ecosystems. However, it is challenging to ascertain whether bank restoration measures positively affect in-stream habitats and aquatic communities. This study evaluated three nature-based bank protection measures' short-term (2-year) effects on aquatic physical habitat quality and benthic macroinvertebrate communities in a headwater stream in agricultural areas. The results demonstrate that nature-based bank protection measures can significantly improve the quality of aquatic physical habitat in streams. The TPRW (timber piles + riprap + willow cuttings) and WTRW (waste tires + riprap + willow cuttings) measures exhibited the most pronounced improvement in the quality of aquatic physical habitat in streams. The diversity of benthic macroinvertebrates was the highest in the TPRW reach, and the seasons significantly affected the density of benthic macroinvertebrates. The Shannon-Wiener diversity index and Margalef's richness index were the most consistent with the changing trend of physical habitat quality and are effective indicators of the ecological effects of stream restoration measures in our study area. In this study area, TPRW is the preferred measure for streambank restoration of agricultural streams, and WTRW is the alternative measure. However, the ecological effects of WTRW need to be monitored over a more extended period to identify whether there is potential ecotoxicity in the process of weathering and decomposition.

Multiyear trajectories of stream and riparian responses to beaver dam analogs on a low‐gradient channel lacking woody riparian vegetation

Beaver‐based restoration techniques seek to assist with the recovery of stream systems that have been damaged, degraded, or destroyed. In addition to reintroducing beaver, restoration practitioners have sought to mimic the influence of beaver dams on stream processes by building beaver dam analogs (BDAs). Stream restoration has been criticized for a lack of extended monitoring and a dearth of empirical evidence for the efficacy of BDAs. Here, we extend early and previously reported 1‐ to 2‐year monitoring of five BDAs on a low‐gradient stream lacking woody riparian vegetation to 3–6 years, depending on the parameter examined. BDAs raised groundwater near the stream and did not affect water temperatures during the duration of monitoring. Consistent with elevated groundwater levels, riparian willow cuttings grew 2.8–9.6 times more when planted near BDAs than far from BDAs, which was more than the 1.3‐ to 1.4‐fold difference after the first growing season. In contrast, a short‐term association between BDAs and willow survival disappeared in the long term. Likewise, sediment aggradation above the upstream BDA 1 year after construction reversed completely 4 years later, probably due to structural damage during high flows that could not be repaired until flows abated. Annual peak flow levels explained over 80% of the variation in the number of structures requiring annual repair. Our results suggest that BDA‐based restoration should account for both the costs of structure maintenance during project planning and the importance of long‐term monitoring during project assessment.

Responses of growth and photosynthesis to alkaline stress in three willow species

Investigating differences in resistance to alkaline stress among three willow species can provide a theoretical basis for planting willow in saline soils. Therefore we tested three willow species (Salix matsudana, Salix gordejevii and Salix linearistipularis), already known for their high stress tolerance, to alkaline stress environment at different pH values under hydroponics. Root and leaf dry weight, root water content, leaf water content, chlorophyll content, photosynthesis and chlorophyll fluorescence of three willow cuttings were monitored six times over 15 days under alkaline stress. With the increase in alkaline stress, the water retention capacity of leaves of the three species of willow cuttings was as follows: S. matsudana > S. gordejevii > S. linearistipularis and the water retention capacity of the root system was as follows: S. gordejevii > S. linearistipularis > S. matsudana. The chlorophyll content was significantly reduced, damage symptoms were apparent. The net photosynthetic rate (Pn), rate of transpiration (E), and stomatal conductance (Gs) of the leaves showed a general trend of decreasing, and the intercellular CO2 concentration (Ci) of S. matsudana and S. gordejevii first declined and then tended to level off, while the intercellular CO2 concentration of S. linearistipularis first declined and then increased. The quantum yield and energy allocation ratio of the leaf photosystem II (PSII) reaction centre changed significantly (φPo, Ψo and φEo were obviously suppressed and φDo was promoted). The photosystem II (PSII) reaction centre quantum performance index and driving force showed a clear downwards trend. Based on the results it can be concluded that alkaline stress tolerance of three willow was as follows: S. matsudana > S. gordejevii > S. linearistipularis. However, since the experiment was done on young seedlings, further study at saplings stage is required to revalidate the results.

Integrating histology and phytohormone/metabolite profiling to understand rooting in yellow camellia cuttings

Vegetative propagation through cutting is a widely used clonal approach for maintaining desired genotypes. However, some woody species have difficulty forming adventitious roots (ARs) with this approach, including yellow camellia (YC) C. nitidissima. Yellow camellias, prized for their ornamental value and potential health benefits in tea, remain difficult to propagate clonally due to this rooting recalcitrance. As part of the efforts to understand YC cuttings’ recalcitrance, we conducted a detailed investigation into AR formation in yellow camellia cuttings via histology and endogenous phytohormone dynamics during this process. We also compared YC endogenous phytohormone and metabolite phytohormone profiles with those of easy-to-root poplar and willow cuttings. Our results indicate that the induction of ARs in YC cuttings is achievable through auxin treatment, and YC ARs are initiated from cambial derivatives and develop a vascular system connected with that of the stem. During AR induction, endogenous hormones showed a dynamic profile, with IAA continuing to increase starting 9 days after auxin induction. JA, JA-Ile, and OPDA showed a similar trend as IAA but decreased by the 45th day. Cytokinin first decreased to its lowest level by the 18th day and then increased. SA largely exhibited an increasing trend with a drop on the 36th day, while ABA first increased to its peak level by the 18th day and then decreased. Compared to poplar, YC cuttings had a low level of IAA, IAA-Asp, and OPDA, and a high level of cytokinin and SA. Metabolite profiling highlighted significant down-accumulation of compounds associated with AR formation in yellow camellias, such as citric and ascorbic acid, fructose, sucrose, flavonoids, and phenolic acid derivatives. Our study reveals the unfavorable endogenous hormone and metabolite profiles underlying the rooting recalcitrance of YC cuttings, providing valuable knowledge for addressing this challenge in clonal propagation.

Perfluoroalkyl substances exposure alters stomatal opening and xylem hydraulics in willow plants

Climate change and pollution are increasingly important stress factors for life on Earth. Dispersal of poly- and perfluoroalkyl substances (PFAS) are causing worldwide contamination of soils and water tables. PFAS are partially hydrophobic and can easily bioaccumulate in living organisms, causing metabolic alterations. Different plant species can uptake large amounts of PFAS, but little is known about its consequences for the plant water relation and other physiological processes, especially in woody plants. In this study, we investigated the fractionation of PFAS bioaccumulation from roots to leaves and its effects on the conductive elements of willow plants. Additionally, we focused on the stomal opening and the phytohormonal content. For this purpose, willow cuttings were exposed to a mixture of 11 PFAS compounds and the uptake was evaluated by LC-MS/MS. Stomatal conductance was measured and the xylem vulnerability to air embolism was tested and further, the abscisic acid and salicylic acid contents were quantified using LC-MS/MS. PFAS accumulated from roots to leaves based on their chemical structure. PFAS-exposed plants showed reduced stomatal conductance, while no differences were observed in abscisic acid and salicylic acid contents. Interestingly, PFAS exposure caused a higher vulnerability to drought-induced xylem embolism in treated plants. Our study provides novel information about the PFAS effects on the xylem hydraulics, suggesting that the plant water balance may be affected by PFAS exposure. In this perspective, drought events may be more stressful for PFAS-exposed plants, thus reducing their potential for phytoremediation.

STUDY OF THE UNLOADING AND SELECTION PROCESS OF ENERGY WILLOW CUTTINGS FOR THE CREATION A PLANTING MACHINE

The article highlights the problems of ensuring continuous unloading of energy willow cuttings from slotted bunkers. During the free discharge of rod-like bodies, such phenomena as crypt formations, distortions, pinching occur, which stop the discharge under the action of gravity. Finding such parameters, under which the system will work evenly and without stops, will make it possible to automate many processes related to working with such material, in particular, when developing a piecemeal selection mechanism for a planting machine. The study revealed and analyzed the possible forms of vaults that are formed during unloading from creating obstacles to movement. As a hopper model, for unloading cuttings, a slotted hopper in the form of two walls located at angles to the horizontal plane is considered. These walls form an unloading slot with adjustable width of the unloading window and an adjustable tilt angle. During the study, vaults were recorded, which are formed at different parameters of the bunker during free unloading. As research has shown, in order to ensure uninterrupted unloading of cuttings, there is such a width of the unloading window of the hopper, which will ensure uniform pouring of cuttings without crypt formations and stops associated with this process. The analysis of continuous discharge of rod-like material established that for cuttings of energy willow, the width of the window, which ensures continuous discharge, is 8-12 cm.

THE DISTRIBUTION OF CASH EXPENSES FOR THE CREATION OF BIOENERGY WILLOW PLANTATIONS IN UKRAINE

The economic cost analysis of creating energy willow plantations in Ukraine is provided in the present paper. The experience of creating bioenergy willow plantations at scientific and industrial institutions in Ukraine has been used in the paper. The purpose of this scientific work is to conduct an analysis of the structure of cash expenses for the creation of bioenergy willow plantations based on the experience of various institutions of Ukraine. The analysis is based on a technological map created during the study on drained peat lands at Panfyly Research Station. Analyzing the cost structure by category, the data obtained during the creation of bioenergy willow plantations of Salix Energy LLC and the Institute of Bioenergy Crops and Sugar Beet were also taken into account. After analyzing all the technology stages of growing bioenergy willow, it was revealed that the most expensive is the second stage associated with the preparation for planting and planting willow cuttings in the context of the pricing policy in Ukraine. In general, more than 60% of all expenses fall upon the first year of cultivation. According to the experience of Ukrainian institutions, the cost structure will have a significant shift towards planting material - 55-60%. The remaining costs are distributed during the use of equipment in the field, which constitute 26-30% and transportation costs respectively are 12-19%.

Formation of the above-ground biomass of willow under the influence of varietal characteristics and the type of planting material

Purpose. To reveal the regularities of the formation of the energy willow above-ground biomass structure and evaluate the qualitative and quantitative indicators of the biomass components under the effect of varietal characteristics and the type of planting material.
 Methods. Field experiments were conducted at the experimental field of the Institute of Bioenergy Crops and Sugar Beet (Ksaverivka 2, Kyiv region) located in the zone of unstable moisture in the central part of the Right Bank Forest Steppe of Ukraine in 2019–2022. Cuttings and shoots were harvested in autumn and stored in various ways until planting. In the spring, after planting the shoots in the open ground, the biometric parameters of plants were determined: plant height, stem diameter and the number of stems. The measurements were taken on the same day every month during the three years of the experiment. Two willow varieties were used in the experiment: Salix triandra L. variety 'Panfylska' and S. viminalis L. variety 'Zbruch'.
 Results. The intensity of growth of the above-ground biomass of willow, which also depends on the yield of planting material (cuttings or shoots), was determined by plant height, stem diameter and the number of stems. These indicators were higher in 'Zbruch' compared to 'Panfylska'. Thus, in the second year of vegetation, on the first date of measuring (in spring), the plant height of 'Panfylska' variety was 136.3 cm, while in autumn. on September 21, it was 242.8 cm. In 'Zbruch', the indicators were higher by 12.4 and 13.5 cm, respectively. A similar dependence was found when planting shoots. It should be noted that within one variety, no regular and reliable difference in plant height depending on the type of planting material was found. In the third year of vegetation, a similar dependence of plant height on varietal characteristics was obtained. On average, in 2021–2022, when planting willow cuttings of 'Zbruch' variety, plant height was 276.1 cm in the spring, while in 'Panfylska' it was 20 cm lower (256.1 cm). In autumn, plant height was higher in 'Zbruch' also by 20 cm. Depending on the year of vegetation, the increase in plant height was the greatest in the first year of vegetation compared to the second and third years. Weather conditions during the growing season affected the height of plants; However, in all years of the research it was higher when planting cuttings and shoots of 'Zbruch' compared to 'Panfylska'. No significant influence of variety and the type of planting material on the stem diameter and the number of stems was found in all years of the research.
 Conclusions. Plant height and diameter of stem in dynamics depended on varietal characteristics. In 'Zbruch' variety, when planting cuttings and shoots, the increase in plant height and stem diameter was higher compared to 'Panfylska' both at the beginning of the growing season and in autumn. During the three years of vegetation, varietal characteristics and the type of planting material (cuttings and shoots) showed no significant difference in the plant height, stem diameter and the number of stems.

Collembola Communities, 20 Years After the Establishment of Distinct Revegetation Treatments in a Severely Eroded Area in South Iceland

Several restoration methods have been developed to aid ecosystem development from highly degraded Icelandic deserts into fully vegetated functional ecosystems. Despite the critical role of soil biota in many key ecosystem processes, the effect of restoration efforts on soil biota has rarely been explored. We took advantage of a large-scale restoration field experiment, to study the effect of distinct revegetation treatments on the taxonomic and functional composition of Collembola communities. Soil samples were taken from plots (one ha. each), that had received functionally distinct revegetation treatments; i: grass + fertilizer, ii: birch seedlings, iii: willow cuttings, iv: lupine and v: control. We were able to show that different revegetation treatments led to the establishment of distinct collembola communities in terms of density and taxonomic and functional composition, 20 years after the revegetation process had started. Life-forms were responsive to revegetation treatment, which suggests that the treatments had induced successional trajectories that lead to distinct habitat conditions, especially with respect to abiotic stress. In contrast to literature, eu-edaphic species were dominating in plots, which were exposed to high levels of disturbance and fluctuations in abiotic conditions. Further research is needed to unravel, to which extent resource supply and abiotic habitat conditions steer Collembola community development across successional trajectories.

Dual inoculation with rhizosphere-promoting bacterium Bacillus cereus and beneficial fungus Peniophora cinerea improves salt stress tolerance and productivity in willow

Utilization of rhizosphere microorganisms to improve plant growth and salt tolerance has recently attracted widespread attention. The growth and salt tolerance of willows inoculated with Bacillus cereus JYZ-SD2 and Peniophora cinerea XC were studied under different salt stress conditions. The results showed that the chlorophyll content of willow cuttings inoculated with the XC strain increased significantly by 51.27%. After salt stress of willow cuttings inoculated with B. cereus JYZ-SD2 and P. cinerea XC (solely or in combination), the amount of sodium in the roots from the epidermis to the pericycle decreased and the content of sodium in the pericycle was significantly lower than that of the uninoculated willow, while the proportion of potassium increased. Willow cuttings inoculated with microorganisms showed increased activity of SOD and POD. At the salt concentration of 100 mmol/L, the highest SOD activity was found in B. cereus JYZ-SD2-inoculated willows, with 59.88% increase compared to uninoculated willows; the highest POD activity was found in P. cinerea XC and B. cereus JYZ-SD2 co-inoculated willows, with 51.05% increase compared to uninoculated willows. The Na-K-ATPase and Ca-Mg-ATPase activities of inoculated P. cinerea XC willow cuttings were also 59.38% and 60% higher than that of uninoculated willows, respectively. The qPCR analysis showed that the expression of vp2 gene in the microorganism-inoculated willow leaves was always higher than that in willow alone. The expression of vp2 gene in P. cinerea XC-inoculated willow cuttings was 270.81% higher than that in uninoculated willows. Further observation of the ultrastructure of root cells under salt stress revealed that most of the vesicles in the root tip cells of willow were intact and secreted phagocytic vesicles to absorb sodium ions in the cytoplasm. This study shows that the combined beneficial fungi and rhizosphere-promoting bacteria inoculation technology as a practical biotechnological approach to enhance the growth of willows in salt-affected soils.

Effect of Ozonated Water Soaking on Adventitious Root Formation of Willow (Salix koreensis) Cuttings

본 연구는 버드나무의 생물학적 녹화 공법시 삽수 발근의 효율을 높이기 위해 오존수 농도 및 처리시간을 구명하기 위해 수행되었다. 오존발생기를 사용하여 오존수 농도 1, 5, 10, 15, 20ppm에서 5분, 2시간 침지처리를 하여 주차별 지상부의 변화를 관찰하고 부정근 개수와 길이를 측정하였다. 그 결과, 20ppm의 오존수를 2시간 처리와 1ppm의 오존수를 5분 동안 처리하면 지상부에 영향을 미쳐 잎이 고사하고, 부정근 발근이 이루어지지 않은 현상을 볼 수 있었다. 따라서 부정근의 외관, 개수, 길이 등을 고려해 볼 때, 버드나무 삽수에서 부정근 발근과 측지 발생이 이루어진 조건은 오존수를 따라 5분은 10－15ppm, 2시간은 5ppm을 처리하는 것이 적합하다고 사료된다.

Investigation of the process of gravitational unloading of energy willow cuttings in conditions of static and dynamic arch formations

Investigation of the process of gravitational unloading of energy willow cuttings in conditions of static and dynamic arch formations

Effects of one dark septate endophytic fungal and two Helotiales strains on the growth of plane-leaved willow (Salix planifolia) cuttings on iron ore waste rock

Plants maintain beneficial mutualistic relationships with the mycobiont communities found in their rhizosphere, leading to an increase in plant productivity and health. In nutrient-depleted substrates like mine tailings, mycobiont inoculation is often recommended to help restore a successful plant cover. Our 15-week greenhouse experiment aimed to assess the individual effects of a dark septate endophyte (Phialocephala fortinii C.J.K. Wang & H.E. Wilcox #4 (KX611529)) and two Helotiales strains (Rhizoscyphus ericae (D.J. Read) W.Y. Zhuang & Korf #22 (EU221877) and Meliniomyces sp. #1 (KT275679)) on the growth of plane-leaved willow (Salix planifolia Pursh) cuttings on sterilized and unsterilized waste rock. Rhizoscyphus ericae increased shoot biomass of cuttings on sterilized waste rock, whereas Meliniomyces sp. had a positive effect on cuttings grown on unsterilized waste rock. However, P. fortinii strain had no effect on the survival rate, shoot production, and biomass production of S. planifolia cuttings. This study demonstrates that controlled inoculation with ecologically well-adapted mycobionts could promote plant establishment and productivity on abandoned waste rock and could be an efficient and integrated biotechnological approach for ecological restoration of Canadian mining boreal ecosystems.

Could the Content of Soluble Carbohydrates in the Young Shoots of Selected Willow Cultivars Be a Determinant of the Plants’ Attractiveness to Cervids (Cervidae, Mammalia)?

Ten willow cultivars grown in experimental plots were evaluated for performance, attractiveness to foragers, and the content and composition of soluble carbohydrates. The survival of willow cuttings in a thicket and in browse plots differed subject to cultivar, soil quality, and soil moisture content. The number of stump sprouts varied considerably, from 1.1 shoots in the weakest soils in Słonin, Poland, to 3.43 in the plot in Czempin, Poland. Browse plots were established in 2017. They were cut, and fencing was removed in early spring of 2019. Young shoots (10 cm shoot tip with buds, preferably eaten by animals) were sampled for analyses of soluble carbohydrates as potential attractors for foraging cervids. All willow cultivars contained the same soluble carbohydrates: glucose, fructose, galactose, sucrose, myo-inositol, galactinol, and raffinose. Total carbohydrate content ranged from 21.31 (S. amygdalina 1045) to 69.37 mg/g−1 DM (dry matter) (S. purpurea). Glucose was the predominant soluble sugar in the shoots of all willow cultivars, excluding S. viminalis. The fructose content of the shoots was approximately twice lower than their glucose content in all willow cultivars. Smaller differences were observed in the content of myo-inositol, which ranged from 4.61 (S. amygdalina 1045) to 8.26 mg/g−1 DM (S. fragilis cv. Kamon/Resko). The phloem of all willow species contained small quantities of galactinol and trace amounts of raffinose. Weak negative correlations were noted between total carbohydrate content, the content of glucose, fructose, and galactose vs. the attractiveness of willow shoots to foraging cervids. The remaining carbohydrates that occurred in smaller quantities in willow shoots were not correlated with their attractiveness to cervids.

Addition of recyclable biochar, compost and fibre clay to the growth medium layer for the cover system of mine tailings: a bioassay in a greenhouse

Mine closures require landscape reclamation to reduce the environmental risks of tailings fields. However, information about the feasibility of recyclable waste materials as a growth medium layer for the cover systems of mine tailings and their effects on vegetation restoration and reforestation success is scant especially in the boreal climate. This study examines the use of various recyclable by-products in improving vegetation success on reclaimed mine tailings. The physical and chemical properties of two wood biochar types, fibre clay, compost, tailings soil and forest till soil as well as their effects as growth media on the growth of several plant species during one growing period in a greenhouse were examined. Marked differences in the properties (e.g. pH, element concentrations, water retention) as well as in plant growth among the growth media were found. Fresh non-oxidized tailings soil showed high salt contents and electrical conductivity which together with fine soil texture provided the poorest or nonexistent plant growth. Fibre clay was the coarsest and driest material and also showed poor plant growth. Root and shoot growth was greatest in pure compost. All media without compost additive showed relatively poor growth which indicates the lack of nitrogen. The results suggest that forest till soil and biochar are the most suitable growth media for the cover systems of mine tailings when added with compost or another nitrogen source. Scots pine container seedlings, willow cuttings and sown red clover showed to be the most feasible plant species to be grown on boreal tailings covers.

Using willow microcuttings for ecological restoration: An alternative method for establishing dense plantations

This experimental study presents an innovative method for establishing a willow (Salix spp.) shrub vegetation cover on disturbed sites in North America. Willow microcuttings of Salix miyabeana ‘SX61’, S. eriocephala ‘S25’ and S. purpurea ‘Fish Creek’ were selected to test the potential of shortened willow cuttings. We evaluated the effect of three factors related to microcutting assemblages (monoculture and polyculture), the presence or absence of a companion herbaceous plant and two types of substrate (same soil, but one with compost and one without). The objectives were to assess 1) the potential growth of willow microcuttings in open site conditions, 2) the influence of soil amendments on the establishment of willow microcuttings and 3) the influence of diversity on biotic resistance. The results showed a greater establishment rate, stem height and number of shoots per microcutting without the presence of an herbaceous plant. The plots planted without compost showed better establishment rates, especially those in the polyculture plots. The presence of compost increased the production of number of shoots per microcutting and tended to increase stem height. The presence of an herbaceous plant was related to higher plant cover, but no relationship with biotic resistance was observed. Although willow cover did not significantly affect relative growth of undesirable tree species seedlings (Betula populifolia and Acer rubrum), we observed that plant cover tended to reduce the relative growth rate. Consequently, this preliminary test of using microcuttings as an alternative approach to establishing a dense shrub cover showed good potential to restore disturbed sites and limit tree encroachment in open sites, reducing environmental and economic costs.

Short-Term Stream and Riparian Responses to Beaver Dam Analogs on a Low-Gradient Channel Lacking Woody Riparian Vegetation

As ecosystem engineers, beavers (Castor canadensis) influence biogeomorphology and riparian vegetation. Streams with historic beaver removal and grazing often become incised, thereby altering stream and riparian processes. Anthropogenic structures that mimic beaver dams called beaver dam analogs (BDAs) may reverse incision by reintroducing historic processes. To understand BDAs as a process-based restoration tool, monitoring is needed across a range of watershed and stream conditions, but monitoring lags behind implementation. We constructed five BDAs in Central Oregon, on a low-gradient stream to test whether it may transport sufficient sediment to favor streambed aggradation behind BDAs. The stream also lacks woody riparian vegetation, and we examined how water temperatures and restoration plantings respond to BDAs where woody riparian vegetation is absent. We monitored structure integrity, aggradation, water temperature, groundwater, and vegetation for 1–2 yr after structures were installed. BDAs retained flows equally whether they were constructed from on-site juniper or off-site willow. During high flows, three structures failed and were rebuilt using improved design. After one year, aggradation of sediment above the two structures that survived flooding was negligible at one structure and high (33.7 m3) at the other. Groundwater levels rose 18–30 cm up to 135 m upstream of BDAs and 12 m into the floodplain. We found no evidence that BDAs raised stream temperatures. Within six months, willow cuttings planted near BDAs exhibited 1.3 times more growth than those on unimpounded locations. Overall, BDAs promoted a restoration trajectory on a low-gradient stream lacking woody riparian vegetation.

Calculation algorithm for the dynamic coefficient of vibro-viscosity and other properties of energy willow cuttings movement in terms of their unloading from the tanker

When we design the automated systems of unloading materials from the tankers, especially when we construct the automated tool for planting an energy willow, there is a need to create the movement model and to study its characteristics. The combination of cuttings, unloaded from the tanker, can be represented as the flow of a two-phase pseudo liquid. Then the process of unloading itself can be modelled on the basis of methods of hydrodynamic multiphase systems. The main characteristics that affect the process of unloading are highlighted in the deduced equation. The effective coefficient of vibro-viscosity and the calculation algorithm for the dynamic coefficient of vibro-viscosity in terms of cuttings oscillatory motion influenced by gravity field and harmonic vibrations is given in the study.

Ecological and geochemical impact of an underground colliery waste discharge to a river

This study investigated the impact of mine wastewater disposal to a nearby river (the Bargo River). Mean electrical conductivity (EC) increased in surface waters below the mine discharge, rising more than six times from (219.5 μS/cm) upstream to 1551 μS/cm below the waste inflow. River pH increased from 7.12 (upstream) to 8.67 (downstream). The mine discharge strongly modified the ionic composition of the river. The mean concentration of several metals in the river were increased due to the mine wastewater. Nickel increased from 1.0 μg/L (upstream) to 32 μg/L (downstream). Zinc increased from 3.5 μg/L (upstream) to 23.5 μg/L (downstream). Our study also assessed the biological uptake of pollutants by growing weeping willow (Salix babylonica) cuttings in mine wastewater and contrasting to ‘control’ cuttings grown in river water from upstream of the mine. After growing in the laboratory for several weeks, the cuttings accumulated metals, dominated by barium, strontium and lithium. Results from the study constituted one of the most detailed geochemical and ecological studies investigating the impact of the coal mine waste discharge to an Australian river. Recommendations are suggested for improved regulation of the mine discharge to reduce its wastewater environmental impact.