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Symbiotic nitrogen (N) fixation (SNF) by legumes and their rhizobial partners is one of the most important sources of bioavailable N to terrestrial ecosystems. While most work on the regulation of SNF has focussed on abiotic drivers such as light, water and soil nutrients, the diversity of rhizobia with which individual legume partners may play an important but under-recognized role in regulating N inputs from SNF. By experimentally manipulating the diversity of rhizobia available to legumes, we demonstrate that rhizobial diversity can increase average SNF rates by more than 90%, and that high rhizobial diversity can induce increased SNF even under conditions of high soil N fertilization. However, the effects of rhizobial diversity, the conditions under which diversity effects were the strongest, and the likely mechanisms driving these diversity effects differed between the two legume species we assessed. These results provide evidence that biodiversity–ecosystem function relationships can occur at the scales of an individual plant and that the effects of rhizobial diversity may be as important as long-established abiotic factors, such as N availability, in driving terrestrial N inputs via SNF. [ABSTRACT FROM AUTHOR]

Featured Application: Biochars from broom and gorse presented appropriate properties for use as fuels for energy production and pose no risks from an environmental perspective due to their low PAH content. These biochars are rich in carbon and have a low ash content. However, future investigations are needed to optimize and better understand their use in energy production and other potential uses, for example, as reductant materials in carbothermic reduction processes. Biochar (BC), which can be produced from several feedstocks, has been widely studied. However, the BC derived from highly pyrolytic shrubs, such as broom and gorse, has been less frequently used and only partially characterized. These wastes, when used for the preparation of biochar, can fix carbon and contribute to environmental conservation, helping to achieve sustainable development objectives. Eight biochars from broom and gorse were produced and fully analyzed, providing a more complete and novel description, with new insights for assessing their utilization. The aims of this study were to elucidate the effects of feedstock, pyrolysis temperature, and residence time on biochar properties and to assess the adequacy of these biochars as fuel. Elemental and proximate analyses and estimations of the lower and higher heating values were performed, and physical and chemical properties, as well as several other related energy indices, were determined. The experimental results showed that the temperature was a key factor in the properties of the biochars, while residence time was less important. The BCs obtained from the two feedstocks did not show important effects on the properties, which is consistent with the fact that they are woody legumes. These biochars had a high carbon content and were thermally stable. The BCs also had a high calorific value and suitable energetic properties. Additionally, their PAH contents were low, indicating that the use of these biochars would be safe. In conclusion, broom- and gorse-derived biochars can be considered as renewable fuels for green energy production. [ABSTRACT FROM AUTHOR]

Biochar (BC), which can be produced from several feedstocks, has been widely studied. However, the BC derived from highly pyrolytic shrubs, such as broom and gorse, has been less frequently used and only partially characterized. These wastes, when used for the preparation of biochar, can fix carbon and contribute to environmental conservation, helping to achieve sustainable development objectives. Eight biochars from broom and gorse were produced and fully analyzed, providing a more complete and novel description, with new insights for assessing their utilization. The aims of this study were to elucidate the effects of feedstock, pyrolysis temperature, and residence time on biochar properties and to assess the adequacy of these biochars as fuel. Elemental and proximate analyses and estimations of the lower and higher heating values were performed, and physical and chemical properties, as well as several other related energy indices, were determined. The experimental results showed that the temperature was a key factor in the properties of the biochars, while residence time was less important. The BCs obtained from the two feedstocks did not show important effects on the properties, which is consistent with the fact that they are woody legumes. These biochars had a high carbon content and were thermally stable. The BCs also had a high calorific value and suitable energetic properties. Additionally, their PAH contents were low, indicating that the use of these biochars would be safe. In conclusion, broom- and gorse-derived biochars can be considered as renewable fuels for green energy production.

Background. Complex interactions between fuel structure and fire substantially affect fire spread and spatial variability in fire behaviour. Heterogeneous arrangement of the fuel coupled with variability in fuel characteristics can impact heat transfer efficiency, preheating of unburned fuel and consequent ignition and spread. Aim. Study the influence of pre-burn fuel structure (canopy height, spatial arrangement) on fire behaviour (rate of spread, flame residence time) derived from high-resolution video of a prescribed gorse fire. Method. Rate of spread and flame residence time are calculated and mapped from high-resolution overhead visible-spectrum video, and compared with the Canopy Height Model derived from pre-burn Light Detection and Ranging (Lidar) scans. Results. Geospatial analytics can provide precision observations of fire behaviour metrics. Rates of spread under high wind conditions are influenced by local changes in canopy height and may be more dependent on other fuel characteristics, while flame residence time is better correlated with canopy height. Conclusions. These observational technology and spatio-temporal analytical techniques highlight how detailed fire behaviour characteristics can be derived from these data. Implications. The results have implications for wildfire modelling and Wildland--Urban Interface (WUI) building design engineers, as the reported dataset is suitable for model validation and the analysis contributes to further understanding of gorse fire hazard. [ABSTRACT FROM AUTHOR]

Invasive species control management involves a large amount of plant material. The present work evaluated the allelopathic potential of the invasive species Ulex europaeus L. (Fabaceae) or 'Gorse' and its possible use as a bioherbicide, taking advantage of the extracted plant material after control measures, particularly needed in invaded areas. Specifically, we investigated the efficacy of dried plant material from U. europaeus in the control of the adventitious plants, Lolium multiflorum Lam. and Lolium rigidum Gaud., using the Avena sativa L. crop as a case study. We only used vegetative plant parts because it is essential to avoid the dispersion of U. europaeus with its use, especially in invaded areas. A greenhouse pot experiment was conducted, using activated carbon (AC). The target species (L. multiflorum, L. rigidum and A. sativa) were subjected to a mixture of organic substrate with U. europaeus mulch applied pre-emergence and a subsequent application of aqueous extracts from the mulch. Emergence, height and biomass of the target species were determined. After 2 months, we also tested a possible legacy effect of the substrate on the germination of the target species. We noticed a negative effect of U. europaeus mulch on the emergence of L. rigidum, which can be attributable to the allelopathic compounds released from U. europaeus mulch because the effect was non-significant in presence of AC. Conversely, no effect on L. multiflorum or A. sativa was produced by mulch treatments. Nevertheless, the combination of U. europaeus mulch and its extracts demonstrated a phytotoxic effect on the biomass of the crop species A. sativa, and a fertilizing effect on the weeds L. multiflorum and L. rigidum, which is why this use is discouraged. With our results we cannot recommend the use of U. europaeus as a bioherbicide in oat crops, but this study emphasizes the capability of U. europaeus to structure plant communities through the chemic- and bio-properties of its tissues that modifies the soil environment. [ABSTRACT FROM AUTHOR]

Invasive plant species are a global environmental threat since they affect native species and can modify ecosystems, which negatively impacts human health and world economics. The aim of this preliminary study was to synthesize and characterize a new lignin-based biopolymer from gorse (Ulex europaeus), a globally widespread invasive plant. The lignin extraction was carried out through base/acid and solvent-based methodologies to compare the reaction yield. Subsequent polymerization of the extracted lignin was performed by glycine condensation in a 70% 1,4-dioxane solution with H2O2 and CaCl2 as catalysts. The extraction and polymerization products were characterized by Fourier-transform infrared spectroscopy. Thermal and stability properties of the new biopolymer were determined by thermogravimetric analysis, differential scanning calorimetry, and a soil burial test. The alkaline extraction process of lignin resulted in a higher yield than the process using an organic solvent. In comparison to the extracted lignin, the novel biopolymer showed different absorption bands that are characteristic of tensions and flexions of alkenes, amine, and amide groups. Additionally, thermal properties revealed peaks corresponding to decomposition and dehydration reactions, endothermic processes and a glass transition temperature of ≈259 °C. Potential biodegradation was observed. A new polymeric, possibly cross-linked, thermally stable material with a potentially high degree of crystallinity was synthesized from a renewable raw material, which might contribute to the gorse management according to the concept of novel ecosystem, as well as the reduction in contamination by other polymeric materials.

Most botanical species contain various types of bioactive compounds. This study focusses on the extraction and identification of bioactive compounds from Calicotome spinosa (Gorse), including flavones, α-linolenic acid and sugar. During the investigation of gorse flowers, leaves and bark, flavones were isolated from the bark and leaves. Calicotome spinosa showed a total isoflavonoid content of 1.5% from the bark of gorse and 1.3% from the leaves. To find the best conditions for flavone extraction, samples of Calicotome spinosa were extracted with different solvents (methanol, water and acetonitrile). Methanol was found to be a suitable solvent to selectively extract flavone. An unsaturated cis fatty acid (α-linolenic acid, C18:3 ∆9, 12, 15) was identified as the principal component of the triacylglycerol fraction from the flowers. Hydrolyses process conditions were used to study Gorse wood. The results indicated that the wood of gorse is not a suitable substance for making paper. The extracted bioactive compounds were analysed using NMR, GCMS, UV, TLC and Fibre Analyser techniques. The extracted compounds offered uses as antioxidants and agricultural chemicals in addition to other benefits. [ABSTRACT FROM AUTHOR]

The widespread invasive success of Ulex europaeus, a thorny shrub native to NW Europe, remains to be understood from a functional perspective. According to the Enemy Release Hypothesis (ERH), lower pressure by vertebrate herbivores in the invaded areas should lead to lower investment in (costly) physical defenses, allowing plants to invest more in growth and/or reproduction. While U. europaeus seedlings have spines, adult plants have thorns, which are the main photosynthetic tissue (leaves are reduced to small phyllodes). Therefore, reduced biomass investment in thorns could compromise photosynthesis and growth in the invaded range. We hypothesized that U. europaeus plants in invaded ranges should show a reduction in the defensive components of thorns (e.g., softer and less fibrous tissues), but not reduced biomass allocation. We compared U. europaeus plants from the invaded (Chile) and native (Spain) distribution ranges regarding: (i) spinescence traits (thorn length, width, biomass, slenderness and bending strength) in adult plants, (ii) thorn fiber content and digestibility (proxies for palatability) in adult plants, and (iii) spine density in seedlings grown in a common garden. As expected, plants in the invaded range showed larger thorns, which contained less cellulose, were slenderer and easier to bend than those from plants in the native range. Likewise, seedlings from the invaded range showed lower spine density and more diameter growth, thus supporting the ERH. We found functional changes in spinescence traits between distribution ranges consistent with the dual role of thorns in U. europaeus, and these changes may partly explain its invasiveness. [ABSTRACT FROM AUTHOR]

The main objective of this study was to examine the interactive effects of nutrient availability and understorey plants, including a nitrogen(N)-fixing shrub, on growth, physiology and survival of commercial maritime pines (Pinus pinaster Ait.). Three experimental sites within the Landes de Gascogne forest were installed in two wet moorlands (one dominated by gorse, a leguminous shrub and one by a perennial grass), and in one dry moorland dominated by ericaceous plants. In dry moorland, the ericaceous understorey increased pine mortality and decreased pine growth, suggesting a competition for water, the most limiting resource of this ecosystem. In wet moorland, a decrease in pine growth suggested a strong competition for soil resources, with or without phosphorus addition. In the other wet moorland dominated by gorse, pines responded to competition for light through stem elongation and self-pruning, but not by reducing growth. The intercropped gorse improved pine N-nutrition and trees acclimated to shrubs by growing more fine roots. Gorse had a positive effect on stomatal conductance during spring, while pine water status decreased moderately with increasing shrub competition during summer. Our results provide new understanding of the feasibility of using gorse as an intercropping N-fixing plant in managed forests, and revealed the structural and physiological trade-offs that exist between increasing N-availability and competition for water and light. [ABSTRACT FROM AUTHOR]

Ulex europaeus (Gorse) is one of the most invasive shrubs in the world, being now found in more than 50 countries where it economically and environmentally degrades the land. This highly versatile shrub can live more than 30 years and produce over 18,000 fertile seeds annually that can remain viable for over 30 years. Ulex europaeus spread is facilitated by its ability to germinate in a wide range of conditions, quick growth and maturing rate and several seed dispersal mechanisms. Despite extensive research and attempts at managing U. europaeus, current rates of control are not adequate to limit the species' competitiveness and impact on the environment. This has resulted in the species altering soil and landscape dynamics in areas of major invasion, inhibiting the growth of agricultural and native species, creating shelter for pest species and reducing the richness of competing species at a site, all of which contribute to the economic and environmental degradation of the land. This review highlights that herbicide application is the most successful technique used to control U. europaeus, although it has shown varying success across different climatic regions. In this regard, future research should investigate the possibility of integrating a range of techniques (competition, fire management, grazing, manual removal and mycoherbicides) to increase control success and reduce any potential risk of herbicide resistance. Further research is also required on the maintenance of longer‐term viable populations of biological control agents to limit the success of this invasive species. Bridging the identified research gaps will help to facilitate the improved long‐term management of U. europaeus and help land managers confidently to maintain sustainable land systems. [ABSTRACT FROM AUTHOR]

This paper explores the use of biochar obtained from the pyrolysis of Ulex Europaeus, an invasive species in the mountain ecosystems of Colombia, for the removal of total chromium from the water. The investigation was developed in two phases. First, the slow pyrolysis of Ulex Europaeus was carried out at varying temperatures (450, 550, and 650° C) to produce a biochar that was characterized by texture, surface area, and percent yield. In the second phase, the biochar then was used to test the removal of chromium from natural water samples collected from the Upper Bogotá River Basin. The removal of chromium with a commercial activated carbon also was assessed as a control. Finally, measurements of total chromium collected were used to evaluate biochar removal efficiencies. The biochar produced at both 550° C and 650° C was found to remove over two times the amount of chromium compared the activated carbon, demonstrating that biochar from Ulex Europaeus is an effective sorbent for total chromium. [ABSTRACT FROM AUTHOR]

Invasive plant species are a global environmental threat since they affect native species and can modify ecosystems, which negatively impacts human health and world economics. The aim of this preliminary study was to synthesize and characterize a new lignin-based biopolymer from gorse (Ulex europaeus), a globally widespread invasive plant. The lignin extraction was carried out through base/acid and solvent-based methodologies to compare the reaction yield. Subsequent polymerization of the extracted lignin was performed by glycine condensation in a 70% 1,4-dioxane solution with H2O2 and CaCl2 as catalysts. The extraction and polymerization products were characterized by Fourier-transform infrared spectroscopy. Thermal and stability properties of the new biopolymer were determined by thermogravimetric analysis, differential scanning calorimetry, and a soil burial test. The alkaline extraction process of lignin resulted in a higher yield than the process using an organic solvent. In comparison to the extracted lignin, the novel biopolymer showed different absorption bands that are characteristic of tensions and flexions of alkenes, amine, and amide groups. Additionally, thermal properties revealed peaks corresponding to decomposition and dehydration reactions, endothermic processes and a glass transition temperature of -259 °C. Potential biodegradation was observed. A new polymeric, possibly cross-linked, thermally stable material with a potentially high degree of crystallinity was synthesized from a renewable raw material, which might contribute to the gorse management according to the concept of novel ecosystem, as well as the reduction in contamination by other polymeric materials. [ABSTRACT FROM AUTHOR]

Most botanical species contain various types of bioactive compounds. This study focusses on the extraction and identification of bioactive compounds from Calicotome spinosa (Gorse), including flavones, α-linolenic acid and sugar. During the investigation of gorse flowers, leaves and bark, flavones were isolated from the bark and leaves. Calicotome spinosa showed a total isoflavonoid content of 1.5% from the bark of gorse and 1.3% from the leaves. To find the best conditions for flavone extraction, samples of Calicotome spinosa were extracted with different solvents (methanol, water and acetonitrile). Methanol was found to be a suitable solvent to selectively extract flavone. An unsaturated cis fatty acid (α-linolenic acid, C18:3 ∆9, 12, 15) was identified as the principal component of the triacylglycerol fraction from the flowers. Hydrolyses process conditions were used to study Gorse wood. The results indicated that the wood of gorse is not a suitable substance for making paper. The extracted bioactive compounds were analysed using NMR, GCMS, UV, TLC and Fibre Analyser techniques. The extracted compounds offered uses as antioxidants and agricultural chemicals in addition to other benefits.

The use of allelopathic foliage incorporated into the soil as a bioherbicidal amendment is a promising weed management strategy which allows combining a cocktail of allelochemicals at low effective individual concentrations. In previous studies, the herbicidal potential of Ulex europaeus and Cytisus scoparius has been argued to be mediated by volatile organic compounds (VOCs). The present work undertakes for the first time the potential involvement of phenolic acids and flavonoids in the herbicidal bioactivity of both shrub species. Such compounds are those most likely to be released to soil water when the allelopathic foliage is incorporated into the soil. By dose-response in vitro bioassays of aqueous extracts, the flowering foliage of both shrub species was shown to release water-soluble compounds capable of inhibiting the germination and/or early growth of two agricultural weeds: Amaranthus retroflexus and Digitaria sanguinalis. Far from expected, such phytotoxicity was enhanced when the aqueous extracts were applied to fresh soil. Via HPLC-DAD, 11 and 17 phenolic compounds were identified from U. europaeus and C. scoparius aqueous extracts, respectively, some of them cited for the first time in both species. The phenolic acids trans-cinnamic, p- coumaric, and ferulic, when were separately assayed in vitro at 1 mM, resulted phytotoxic to one or other target weed and physiological processes. However, except for the caffeic acid and vanillin, the phenolic acids lost effectiveness when applied at lower concentrations (0.1 or 0.01 mM). Otherwise, it was noteworthy that the flavonoids luteolin, ellagic acid, kaempferol, and naringenin were only phytotoxic when applied at low concentrations (≤0.1 mM). The proven herbicidal efficiency of the shrub foliage was argued to derive from the phytotoxicity of the water-soluble compounds assayed, and maybe from the combined or synergistic action with the VOCs emitted from the fresh plant material. Image, graphical abstract • First-ever report of the herbicidal potential of Ulex europaeus aqueous extract. • First-ever report of the herbicidal potential of Cytisus scoparius aqueous extract. • Novel phenolic profiles identified and quantified by HPLC-DAD. • Phenolic acids and flavonoids underlie the phytotoxicity of the aqueous extracts. • Luteolin, ellagic acid, kaempferol, and naringenin were only phytotoxic at ≤0.1 mM. [ABSTRACT FROM AUTHOR]

The behavior of the gorse extract has been investigated as a new corrosion inhibitor by weight-loss measurements, potentiodynamic polarization curves, electrochemical impedance spectroscopy and scanning electron microscopy. Weight-loss measurements showed an increase in inhibition efficiency (IE) with the immersion time and the concentration of the extract. At 800 mg L−1, the extract IE ranged from 72.5% to 93.8% for 2 and 48 h, respectively. The Ea decreased slightly with the addition of the extract, characterizing the chemical adsorption by the molecules present in the extract on the surface. The measurements of electrochemical impedance spectroscopy showed an increase in Rct and a decrease in Cdl, reaching 96.6% of IE at 1600 mg L−1. The polarization curves indicated that the gorse extract served as an adsorption inhibitor, reducing both the anodic and cathodic current density. The high-molecular-weight fraction isolated from the gorse extract also showed high inhibition efficiencies.

Ulex europaeus is one of the most abundant and aggressively invasive plants on the world. Its fibres, which can be isolated using an alkaline pulping process, have been successfully thermo-pressed into high-density fibreboards without any type of binder. The influence of the bioorganic and crystalline components on the product was investigated using crystallographic, thermo-analytical, and mechanical techniques. Cellulose was predominantly an Iβ polymorph, more common in hardwood, but the composition of the material was typical of softwood. Both the crystallinity in the fibres and the average domain size of cellulose increased during thermo-pressing. Notwithstanding that the residual lignin was present in a small amount, this promoted the cohesion of fibres by improving hydrolysis and adhesion properties. The best overall properties were observed in the pressed products of 1030 ± 38 kg/m3, showing an elastic modulus of 4.31 ± 0.26 GPa, with a modulus of rupture of 26.5 ± 1.3 MPa. These results serve as the basis to transform the invasive species into a fully non-toxic added-value resource.

Background and Aims Large, persistent seed banks contribute to the invasiveness of non-native plants, and maternal plant size is an important contributory factor. We explored the relationships between plant vegetative size (V) and soil seed bank size (S) for the invasive shrub Ulex europaeus in its native range and in non-native populations, and identified which other factors may contribute to seed bank variation between native and invaded regions. Methods We compared the native region (France) with two regions where Ulex is invasive, one with seed predators introduced for biological control (New Zealand) and another where seed predators are absent (La Réunion). We quantified seed bank size, plant dimensions, seed predation and soil fertility for six stands in each of the three regions. Key Results Seed banks were 9–14 times larger in the two invaded regions compared to native France. We found a positive relationship between current seed bank size and actual plant size, and that any deviation from this relationship was probably due to large differences in seed predation and/or soil fertility. We further identified three possible factors explaining larger seed banks in non-native environments: larger maternal plant size, lower activity of seed predators and higher soil fertility. Conclusions In highlighting a positive relationship between maternal plant size and seed bank size, and identifying additional factors that regulate soil seed bank dynamics in non-native ranges, our data offer a number of opportunities for invasive weed control. For non-native Ulex populations specifically, management focusing on ' S ' (i.e. the reduction of the seed bank by stimulating germination, or the introduction of seed predators as biological control agents) and/or on ' V ' (i.e. by cutting mature stands to reduce maternal plant biomass) offers the most probable combination of effective control options. [ABSTRACT FROM AUTHOR]

Nitrate pollution is a global issue threatening the health and function of many lowland freshwater ecosystems. Quantifying nitrate loads and instream attenuation associated with land use is a critical requirement for improving freshwater management. One often overlooked nitrate source in catchments is invasive N-fixing trees such as Ulex europaeus (European gorse). This study compared nitrate concentrations in conjunction with stable isotope analyses (nitrate δ15N and δ18O) to investigate the effects of catchment gorse cover on stream nitrate export relative to three other land uses. These were regenerating native forest, low-intensity (dry-stock) and high-intensity (dairying) agriculture. We tested two hypotheses: (1) gorse is a regionally significant nitrate source; (2) instream nitrate attenuation is land-use dependent. The study was conducted in 24 reaches across six small, mixed land-use coastal catchments located on Banks Peninsula, New Zealand. Our results demonstrated that gorse-dominated stream reaches had significantly higher nitrate concentrations than all other land uses. Within the gorse-dominated reaches, nitrate concentration was significantly correlated with upstream catchment gorse cover. Furthermore, nitrate oxygen and nitrogen stable isotope compositions demonstrated that elevated nitrate concentrations in gorse streams were associated with decomposition of dead gorse foliage. The isotope data revealed sub-catchment-scale land-use-specific patterns of nitrate attenuation within streams. All three anthropogenic land uses (gorse, dry stock and dairy) showed distinctly different N-cycling from native-forested reaches where nitrate was efficiently cycled with evidence for highly localised nitrification. Stable isotope data demonstrated that overall nitrate attenuation became less efficient with higher nitrate loads. Our research demonstrates the significant impact N-fixing plants have on nitrate concentrations and instream attenuation. Quantifying the effects of N-fixing plants on water quality is an important step in achieving globally significant goals of sustaining ecosystem health and (sub)catchment-scale nutrient management. [ABSTRACT FROM AUTHOR]

Abstract Species presently considered as invasive were often deliberately introduced. Which factors led them from being desired to being denounced and what trajectory did such a transition follow? Using the case of common gorse (Ulex europaeus) on Reunion Island, the aims of this study were first, to identify and describe the different status that were attributed to this species since its introduction; and second, to discern the factors that influenced their emergence and decline in the public sphere. Five types of status were identified for common gorse in Reunion (useful, nationalistic, indigenized, noxious weed, and invasive), each peaking at a certain time, and then reverting to a low-key presence. The emergence and dissemination of each status in the public sphere depends on how well the various narratives proposed about the plant by networks of legitimate actors match the socio-technical landscape, as well as on how these narratives appear within legal and institutional frameworks. In addition, translating a status into actions of management can bolster its trajectory in the public sphere. Lastly, the decline of a status can be explained by a gradual desynchronization between its cognitive, normative and/or instrumental dimensions and the local socio-technical landscape. Highlights • Invasive species moved from being desired or neutral to being denounced. • In Reunion Island, various status were attributed to gorse over time. • Networks of actors play a key role in the emergence of a status in the public sphere. • Changes in status depend on socio-technical factors at local and global scales. [ABSTRACT FROM AUTHOR]

In our previous studies, the phytotoxicity of Ulex europaeus (gorse) and Cytisus scoparius (Scotch broom) was demonstrated in vitro and argued to be caused by the release of volatile and water-soluble compounds from fresh plant foliage. In light of these positive results, there was a need to test the effects ex vitro. In this work, gorse and Scotch broom were used as soil amendments in pot experiments in a glasshouse by incorporating slashed plant material into the soil at a ratio of 1% w/w on a dry mass basis. The phytotoxic effects on the emergence and early growth of maize and five accompanying weed species were analyzed, as were the effect on soil fertility and soil community-level physiological profiles. Thirty days after incorporation, significant decreases in weed density of 32.2% and 59.5% were found for gorse and Scotch broom soil amendments, respectively. Gorse soil amendment was notably effective impairing the establishment of Amaranthus retroflexus and diminishing the plant height of Digitaria sanguinalis and Portulaca oleracea. Scotch broom soil amendment was capable of significantly inhibiting the emergence of D. sanguinalis, Convolvulus arvensis, P. oleracea, and A. retroflexus, with a notable reduction of weed biomass. No undesirable side effects on maize crop or soil quality, including microbial activity, were detected. Our results suggest that the incorporation of gorse and Scotch broom foliage is promising for pre-emergent weed control in maize; however, field trials that support and expand these glasshouse results are essential.

The phytotoxic potential of the legume shrubs Ulex europaeus L. (gorse) and Cytisus scoparius (L.) Link. (Scotch broom) is studied in this work for the first time. On the basis of their richness in active principles, the previous evidence of biological activity, and the abundance of biomass in their native range and invaded areas, a question arose: can U. europaeus and C. scoparius be considered as potential sources of natural herbicides for sustainable agriculture? By means of volatile bioassays, the flowering fresh plant material of both shrub species was shown to produce and emit volatile organic compounds (VOCs) able to inhibit the germination and/or early growth of two agricultural weeds: Amaranthus retroflexus and Digitaria sanguinalis. Novel complete VOCs profiles from the volatile extracts of the shrub species were obtained by GC and GC/MS. A total of 20 compounds were identified from U. europaeus flowering biomass, theaspirane and eugenol, among others, being described in gorse for the first instance. The chemical profile of C. scoparius yielded 28 compounds and was rich in oxygenated monoterpenes such as terpinen-4-ol, verbenol, α-terpineol, and verbenone, which were also identified in this species for the first time. Using dose-response bioassays with pure compounds, these VOCs were argued to be involved in the phytotoxicity observed for the plant materials, even at very low concentrations. The phytotoxic effects were predominantly irreversible, particularly for D. sanguinalis, since the seeds exposed to the VOCs produced damaged seedlings, were unable to recover germination capacity after removing the phytotoxin or, when recovered, produced unviable seedlings. Our results extend the interest of the abundant U. europaeus and C. scoparius for the obtention of natural products with bioherbicide potential, or to be used as allelopathic biomass in the development of new sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

Aims: Effects of root water status on root tensile strength and Young’s modulus were studied in relation to root reinforcement of slopes.Methods: Biomechanical properties of woody roots, Ulex europaeus, were tested during progressive dehydration and after thirty-day moisture equilibration in soil with contrasting water contents. Root diameter, water content and water loss were recorded and root water potential versus water content relation was investigated. Tensile stresses induced by root contraction upon dehydration were measured.Results: Root tensile strength and Young’s modulus increased abruptly when root water content dropped below 0.5 g g−1. The strength increase was due to root radial and axial contraction induced by root water potential drop. Diameter decrease and strength gain were the largest for thin roots because of the relatively larger evaporative surface per volume of thin roots. Largely negative water potentials in dry soil induced root drying, affecting root biomechanical properties.Conclusion: Root water status is a factor that can cause (inappropriately) high strength values and the large variability reported in literature for thin roots. Therefore, all root diameter classes should have consistent moisture for fair comparison. Testing fully hydrated roots should be the routine protocol, given that slope instability occurs after heavy rainfall. [ABSTRACT FROM AUTHOR]

Invasive plant species can substantially alter the soil fertility of the ecosystems they invade, and in doing so have the potential to reduce the suitability of the soil for native species. Even after removal of the invader these alterations can inhibit the reestablishment of native species. We evaluated the impact of invasion by the leguminous shrub Ulex europaeus on soil properties on Mauna Kea, HI. We also investigated the effect of efforts to remove U. europaeus and restore native ecosystems in the study area; where the efforts included bulldozing the U. europaeus and planting introduced Cryptomeria japonica to compete with regenerating U. europaeus. Mauna Kea supports a strong rainfall gradient and substantial associated variation in soil properties. We use statistical models to extract the effect of invasion and restoration from the influence of rainfall. We found U. europaeus decreases soil pH, calcium content, base saturation, and labile phosphorus. Restoration efforts over an 11-year period restored the soil’s calcium and phosphorus content to levels comparable to those found in uninvaded soils on Mauna Kea, demonstrating that the effects of U. europaeus on soils are reversible. [ABSTRACT FROM AUTHOR]

Summary: Exotic woody plants are often used by native organisms, but may also be targets of expensive control justified by nature conservation. We determine the use of a weed of national significance, Gorse (Ulex europaeus L.), by native mammals, birds, reptiles and vascular plants in pastoral areas in an Australian biodiversity hotspot. Large numbers of fauna species were observed using Gorse within our 43 × 1 ha sample sites in riparian, woodland and pasture vegetation. Gorse cover and/or height positively influenced: the detection of mammals as a whole in an interaction with visibility at 50–75 cm above ground, but not their species richness or individual species abundances; bird abundance, but not richness; and, reptile richness but not abundance. In terms of flora, Gorse cover and/or height positively affected: non‐native plant species richness and the height and fecundity, but not the richness, of native grasses and forbs—but Gorse cover negatively influenced the height of native herbs. The only species of conservation significance using Gorse were three mammals, only one of which, the Tasmanian Pademelon (Thylogale billardieri), was sufficiently common to analyse. Its abundance had no relationship with Gorse cover or height. Even in the wider context of complementary work, there is no strong threatened species conservation justification for retaining Gorse thickets in the Northern Midlands pastoral landscape. Equally, expending scarce conservation resources to remove Gorse, as is taking place, is unlikely to achieve any threatened species conservation outcome but may help reduce long‐term loss of native animal and plant species. [ABSTRACT FROM AUTHOR]

The behavior of the gorse extract has been investigated as a new corrosion inhibitor by weight-loss measurements, potentiodynamic polarization curves, electrochemical impedance spectroscopy and scanning electron microscopy. Weight-loss measurements showed an increase in inhibition efficiency (IE) with the immersion time and the concentration of the extract. At 800 mg L−1, the extract IE ranged from 72.5% to 93.8% for 2 and 48 h, respectively. TheEadecreased slightly with the addition of the extract, characterizing the chemical adsorption by the molecules present in the extract on the surface. The measurements of electrochemical impedance spectroscopy showed an increase inRctand a decrease inCdl, reaching 96.6% of IE at 1600 mg L−1. The polarization curves indicated that the gorse extract served as an adsorption inhibitor, reducing both the anodic and cathodic current density. The high-molecular-weight fraction isolated from the gorse extract also showed high inhibition efficiencies. [ABSTRACT FROM PUBLISHER]

A key determinant of wildfire behaviour is the flammability of constituent plants. One plant trait that influences flammability is the retention of dead biomass, as the low moisture content of dead material means less energy is required to achieve combustion. However, the effect of the dead-to-live ratio of fuel on plant flammability has rarely been experimentally quantified. Here we examine the nature of the relationship between dead fuel accumulation and flammability in Ulex europaeus (common gorse). Shoots with varying proportions of dead material were ignited in a purpose-built plant-burner. Three components of flammability were measured: sustainability (flame duration), consumability (proportion burnt biomass) and combustibility (maximum temperature). While flame duration and proportion burnt biomass had a positive linear relationship with the proportion of dead material, the response of maximum temperature was positive but non-linear. All three flammability components were reduced to a single variable using principal components analysis; this had a non-linear relationship with the proportion of dead material. The response of maximum temperature to dead material plateaued at 39%. These findings have implications for the management of habitats invaded by gorse; to mitigate fire hazard associated with gorse, stands should be kept at a relatively young age when dead fuel is less prevalent.

Ulex europaeus is one of the most abundant and aggressively invasive plants on the world. Its fibres, which can be isolated using an alkaline pulping process, have been successfully thermo-pressed into high-density fibreboards without any type of binder. The influence of the bioorganic and crystalline components on the product was investigated using crystallographic, thermo-analytical, and mechanical techniques. Cellulose was predominantly an Iβ polymorph, more common in hardwood, but the composition of the material was typical of softwood. Both the crystallinity in the fibres and the average domain size of cellulose increased during thermo-pressing. Notwithstanding that the residual lignin was present in a small amount, this promoted the cohesion of fibres by improving hydrolysis and adhesion properties. The best overall properties were observed in the pressed products of 1030 ± 38 kg/m3, showing an elastic modulus of 4.31 ± 0.26 GPa, with a modulus of rupture of 26.5 ± 1.3 MPa. These results serve as the basis to transform the invasive species into a fully non-toxic added-value resource. [ABSTRACT FROM AUTHOR]

In 1986 the paths of two men crossed - one who had started a Trust fund to purchase land for conservation and the other who was looking for land to test his hunches about forest regeneration. The two joined forces and the subsequent 30 years saw a growth in both the Trust and the forest such that today it is a 1,500 ha regrowth rainforest with a network of indefatigable supporters. [ABSTRACT FROM AUTHOR]

Aims The study of the adaptive potential of the germination patterns of invading species enables us to identify some traits linked with their capacity to colonize new sites, and to gain a better understanding of their area of distribution. The aim of this study is to determine the germination pattern of Ulex europaeus, a cosmopolitan invasive species, in relation to temperature and to explore its potential evolution and invasiveness in a tropical region, following its introduction from Europe. Methods We studied the germination pattern of U. europaeus (the common gorse) to test both physical dormancy and germination capacity within the range of temperatures found in the native and invasive regions. To understand its germination pattern and its evolution, the rate and the speed of germination, as well as the percentage of seeds that became mouldy during the experiment, have been compared between a native habitat, France and a habitat into which it has been introduced, the tropical island of La Reunion. Important Findings The results show that gorse seeds germinate in large quantities, possess the ability to germinate under a wide range of temperatures and they confirm the physical dormancy of the seeds (caused by seed coat impermeability). The decrease in germination from 25°C upwards, coupled with an increase in the rate of moulding help to explain its restricted distribution at altitude in tropical environments. For scarified seeds, we have not detected any difference between the two regions, neither in the percentage of germinated seeds, nor in the percentage of mouldy seeds. However, seeds from Reunion germinate faster at 20°C than seeds from France and a greater number of seeds from Reunion are able to germinate without scarification (10-60% for Reunion versus 0-10% for France). These results suggest that while preserving the advantages of the native habitat, in Reunion gorse develops a strategy which favours the rapid occupation of new sites. [ABSTRACT FROM AUTHOR]

The seed density of Ulex europaeus was established on borders of invasive scrub thickets to the south of the Eastern Hills of Bogota. Through the direct counting method, seed abundance was established at six sampling points in an altitudinal gradient between 2.300 and 3.200 meters altitude, and for four soil depth ranges of 0 to 20 cm. Variable seed densities were established for the six sampling points between 109 and 3.384 seeds m-2. With regard to depth, the highest seed density was in the range of 0 to 5 cm for all sites sampled. Among the sampling points, significant differences were found in the number of seeds at different altitudes (p = 0,0416) and depth ranges evaluated (p=0,0392). There is a high potential at the edges of scrub for the extension of the invaded areas, by activation of the seed bank of the invasive species, suggesting the need for a priority strategy for the control of these border areas in the framework of ecological restoration processes in high Andean ecosystems. [ABSTRACT FROM AUTHOR]

Green compost is seen as one of the best solutions for peat replacement in growing media and for increasing their sustainability. However, the poor quality of many composts has restricted their use as substrate components. The EU Ecolabel may be awarded to products and services that have a reduced environmental impact throughout their life cycle. It is voluntary and ensures certain aspects of the origin and quality. The primary aim of this work was to obtain a gorse compost-based substrate fulfilling the requirements for award of the eco-label. Forest biomass consisting mainly of gorse was composted in dynamic piles with or without irrigation (I) at the beginning and with or without addition of 5% v/v poultry manure (PM). There were thus four different composting treatments that were designated PM0I, PM5I, PM5 and PM0. Temperature, moisture, pH and the C/N ratio of the composting biomass were monitored over a period of nearly 10 months. The resulting composts were characterized in physical, chemical and biological terms, and evaluated for compliance with the requirements of the European Union eco-label for growing media. All composts were found to be mature, stable and pathogen-free. All of them were suitable for use as growing media, exhibiting a high aeration and drainage capacity, little water retention and adequate level of available nutrients. In general they also met the requirements of the EU eco-label, although not all were weed seed-free, which was possibly the sole unfulfilled EU eco-label requirement. [ABSTRACT FROM AUTHOR]

The screening and quantification of the main phenolic compounds in leaves and flowers of Ulex europaeus (gorse) was carried out by high-performance liquid chromatography with electrospray ionization mass spectrometric detection (HPLC-ESI–MS n ) after ultrasound-assisted extraction with methanol. About 98% of compounds corresponded to flavonoids, distributed as flavonols, flavones, isoflavones and flavanones. Flavonols were mainly quercetin glucosides; most of the found flavones were apigenin derivatives and the isoflavone group was dominated by glycitin. The flavanone group was composed mainly of liquiritigenin derivatives, substances usually found in liquorice ( Glycyrrhiza ssp) and associated with high pharmacological relevance; in Ulex they represent about 25% of total polyphenols content. Phenolic acids and saponins were also detected, as minor components. In vitro antioxidant activity (nitric oxide, superoxide assays, ABTS and DPPH assays) of leaves and flowers, and their inhibitory effects towards digestive enzymes related to carbohydrate metabolism (α-glucosidase and α-amylase) were also studied. [ABSTRACT FROM AUTHOR]

Microwave hydrodiffusion and gravity (MHG) extraction of Ulex europaeus was proposed for the production of extracts. The extraction time and yield and the antioxidant and sensorial properties of the extracts were significantly affected by the irradiation power. MHG treatment at 100 W during 76 min provided optimum yields and the extracts showed the highest reducing power and antiradical activity. The extraction time could be reduced in relationship to that needed with steam distillation (153 min) to reach comparable extraction yields and retaining the antioxidant properties. The flower extracts from the two tested technologies showed similar color (colorless) and olfactometric characteristics (floral and ripe fruity aroma). [ABSTRACT FROM AUTHOR]

Woody nitrogen (N) fixers are known to fix atmospheric N at very high rates. However, N leached from woody N fixers is rarely accounted for in catchment nutrient budgets. We conducted a scoping study to determine the potential impact of the invasive N fixer gorse (Ulex europaeus) on water quality in an agricultural catchment in New Zealand. With current gorse cover (596 ha) our model-based leaching estimates suggest that gorse accounts for 1.7%-2.4% of total N leaching in the catchment. This is equivalent to leaching from 1200-1800 ha of pasture (averaged across both dry stock and dairy land uses). In our worst-case scenario, with gorse covering over 5000 ha, we estimate that N leaching from gorse would account for 12%-25% of the catchment total. The expected increase in N leaching under this scenario is equivalent to leaching for 9000-14000 ha of pasture, suggesting that gorse could significantly constrain capacity for agricultural expansion or intensification if a cap on N loads is imposed in the catchment. These results show that leaching from gorse is probably much higher than currently assumed. Further, land use policies aiming to abandon marginal land may cause a net increase in leaching if large areas of abandoned land are colonised by gorse. [ABSTRACT FROM AUTHOR]

The ABO blood group system is the most important blood group system in clinical practice. The relationship between Plasmodium falciparum and ABO blood groups has been studied for many years. This study was undertaken to investigate the abilities of different blood group erythrocytes to support in vitro growth of P. falciparum parasites. P. falciparum parasites of four different strains (3D7, 7G8, Dd2 and RKL9) were co-cultured with erythrocytes of blood group 'A', 'B', 'O' (n = 10 for each) and 'O(h)' (Bombay group) (n = 7) for 5 days. Statistically significant differences were observed on the fourth day among the mean percent parasitemias of 'O', non-'O' ('A' and 'B') and 'O(h)' group cultures. The parasitemias of four strains ranged from 12.23 to 14.66, 11.68 to 13.24, 16.89 to 22.3, and 7.37 to 11.27 % in 'A', 'B', 'O' and Bombay group cultures, respectively. As the expression of H antigen decreased from 'O' blood group to 'A' and 'B' and then to Bombay blood group, parasite invasion (percent parasitemia) also decreased significantly (p < 0.01) and concomitantly, indicating the association of parasite invasion with the amount of H antigen present on the surface of erythrocyte. Thus, the question arises, could H antigen be involved in P. falciparum invasion? To evaluate erythrocyte invasion inhibition, 'O' group erythrocytes were virtually converted to Bombay group-like erythrocytes by the treatment of anti-H lectins extracted from Ulex europaeus seeds. Mean percent parasitemia of lectin-treated cultures on the fourth day was significantly lower (p < 0.05) than that of non-treated cultures and was found to be similar with the mean percent parasitemia demonstrated by the Bombay group erythrocyte cultures, thus further strengthening the hypothesis. [ABSTRACT FROM AUTHOR]

Fusarium circinatum is a quarantine pathogen in numerous countries that causes important economic losses in forest nurseries and mature pine trees. Alternatives to chemical control of plant diseases such as suppressive composts and the use of biological control agents in growth media can reduce the incidence and spread of disease. In this work, four gorse composts obtained from forest cleaning green wastes and reference compost prepared from the organic fraction of solid urban waste were studied as environmentally sustainable peat substitutes. Their ability to suppress the effects of mating types M1 and M2 of the pathogen F. circinatum on Pinus radiata was evaluated in the presence or absence of the biocontrol agent Trichoderma asperellum strain T34. One of the gorse composts was more suppressive than the reference compost (15% and 55% of disease incidence, respectively). The former had a low EC, moderate amounts of P, Ca, Mg and K, and high levels of NH 4 + , as well as moderate levels of Ca, B and oligotrophic actinomycetes, the highest levels of total fungi, moderate levels of Trichoderma spp. and the lowest levels of Fusarium spp. Adding T34 to the moderately suppressive and non-suppressive composts decreased pre- and post-emergence incidence of the disease by up to 50%. In conclusion, one gorse compost decreased the incidence of F. circinatum disease when used as a growth medium for P. radiata seedlings. T. asperellum strain T34 further reduced the incidence of disease and improved the health of pine seedlings grown in moderately non-suppressive composts. [ABSTRACT FROM AUTHOR]

Taste signals are received by taste buds. To better understand the taste reception system, expression patterns of taste-related molecules are determined by in situ hybridization (ISH) analyses at the histological level. Nevertheless, even though ISH is essential for determining mRNA expression, few taste bud markers can be applied together with ISH. Ulex europaeus agglutinin-1 (UEA-1) appears to be a reliable murine taste bud marker based on immunohistochemistry (IHC) analyses. However, there is no evidence as to whether UEA-1 can be used for ISH. Thus, the present study evaluated UEA-1 using various histochemical methods, especially ISH. When lectin staining was performed after ISH procedures, UEA-1 clearly labeled taste cellular membranes and distinctly indicated boundaries between taste buds and the surrounding epithelial cells. Additionally, UEA-1 was determined as a taste bud marker not only when used in single-colored ISH but also when employed with double-labeled ISH or during simultaneous detection using IHC and ISH methods. These results suggest that UEA-1 is a useful marker when conducting analyses based on ISH methods. To clarify UEA-1 staining details, multi-fluorescent IHC (together with UEA-1 staining) was examined, resulting in more than 99% of cells being labeled by UEA-1 and overlapping with KCNQ1-expressing cells. [ABSTRACT FROM AUTHOR]