Search Results (71)

Willow stands (Salix spp.) are an essential part of riparian ecosystems, as they sustain biodiversity and provide bioenergy solutions. The present review synthesizes the global scientific literature about the management of willow stands. In order to achieve this goal, we used a dual approach combining bibliometric analysis with traditional literature review. As such, we consulted 416 publications published between 1978 and 2024. This allowed us to identify key species, ecosystem services, conservation strategies, and management issues. The results we have obtained show a diversity of approaches, with an increase in short-rotation coppice (SRC) systems and the multiple roles covered by willow stands (carbon sequestration, biomass production, riparian restoration, and habitat provision). The key trends we have identified show a shift toward topics such as climate resilience, ecological restoration, and precision forestry. This trend has become especially pronounced over the past decade (2014–2024), as reflected in the increasing use of these keywords in the literature. However, as willow systems expand in scale and function—from biomass production to ecological restoration—they also raise complex challenges, including invasive tendencies in non-native regions and uncertainties surrounding biodiversity impacts and soil carbon dynamics over the long term. The present review is a guide for forest policies and, more specifically, for future research, linking the need to integrate and use adaptive strategies in order to maintain the willow stands. Full article

Land-based bioenergy systems are increasingly promoted for their potential to support climate change mitigation and energy security. Building on previous productivity and efficiency analyses, this study applies the MiscanFor and SalixFor models to evaluate land use energy intensity (LUEI) for Miscanthus (Miscanthus × giganteus) and willow (Salix spp.) under baseline (1961–1990) and future climate scenarios, and Business-as-Usual (B1) and Fossil Intensive (A1FI) scenarios, projected to 2060. The study also assesses the impact of biomass transport on energy use efficiency (EUE) and quantifies soil organic carbon (SOC) sequestration by Miscanthus. Under current conditions, Miscanthus exhibits a higher global mean LUEI (321 ± 179 GJ ha⁻¹) than willow (164 ± 115.6 GJ ha⁻¹) across all regions (p < 0.0001), with energy yield hotspots in tropical and subtropical regions such as South America, Sub-Saharan Africa, and Southeast Asia. Colder regions, such as Europe and Canada, show limited energy potential. By 2060, LUEI is projected to decline by 9–15% for Miscanthus and 8–13% for willow, with B1 improving energy returns in temperate zones and A1FI reducing them in the tropics. Global EUE for Miscanthus declines significantly (p < 0.0001) by 21%, from 15.73 ± 7.1 to 12.37 ± 5.2 as biomass transport distance increases from 50 km to 500 km. Mean SOC sequestration is estimated at 1.20 ± 1.46 t C ha⁻¹, with tropical hotspots reaching up to 4.57 t C ha⁻¹ and some cooler regions exhibiting net losses (–7.93 t C ha⁻¹). Climate change significantly reduces SOC gains compared to baseline (p < 0.0001), although differences between B1 and A1FI are not statistically significant. These findings highlight the importance of region-specific, climate-resilient biomass systems to optimize energy returns and carbon benefits under future climate conditions. Full article

Bee pollen (BP) is a very valuable bee product, and its value depends on its proteins, lipids, amino acids, carbohydrates, vitamins, minerals, and biologically active compounds such as phenolic compounds, which may change depending on the method of pollen preparation after collection and its storage conditions. Therefore, it is very important to determine when the decline in bioactive compounds in BP occurs during storage. The purpose of this study was to evaluate the changes in the content of ascorbic acid and phenolic compounds, and to determine the antioxidant activity of BP extracts depending on their preparation method and storage conditions over a 15-month period, with assessments conducted every 3 months. Dried pollen (at +28 °C on the first day and +35 °C on the second day) and frozen (−20 °C and −80 °C) BP samples were prepared. After 3 months of storage, there was no decrease of ascorbic acid in frozen BP; however, it decreased by 20% in dried BP (p < 0.05). It was determined that in frozen BP, the content of total phenolic compounds decreased by 12–14% (p < 0.05) after 6 months, and in dried BP, it decreased by 7% (p < 0.05) after 3 months. The levels of flavonoids decreased by 10–17% (p < 0.05) in BP after 6 months. Chlorogenic and p-coumaric acids have been observed as the most abundant phenolic acids in BP. During storage (the 6–15-month period), the strongest antiradical and reducing activity in vitro was estimated in the frozen (−80 °C) BP, which was 1.8–3.4-fold and 2.6–3.1-fold higher, respectively, compared to the dried BP extracts. In conclusion, significant results were obtained, showing better stability of phenolic compounds and ascorbic acid during storage in frozen BP compared to dried pollen. Melisopalynological analysis revealed a polyfloral pollen mixture, with Salix spp. and Brassica napus L. predominating in all samples, comprising 34.3% and 36.8%, respectively. Among these, Acer platanoides L., Malus domestica Borkh., and Taraxacum officinale L. were important minor pollens present in the samples examined. Full article

Catastrophic wind events play important but poorly documented roles in shaping bottomland hardwood forest structure and composition. The objective of this study was to survey a forested wetland area in Illinois, USA, twenty years following a severe tornado (wind speeds ranging from 333–418 km/h). Part of the damaged area had a subsequent salvage logging operation, and we compared the stand structure and composition of these damaged areas to adjacent reference sites. Stem density, basal area, and diversity differed significantly but slightly among disturbance types (p < 0.05). The density of Quercus spp. decreased in regenerated stands, while the density of Fraxinus pennsylvanica and invasive non-native species cover increased (p < 0.05). Salvage logging further increased the density of key bottomland taxa: Salix spp., Taxodium distichum, and Nyssa aquatica, as well as early successional species such as Liriodendron tulipifera (p < 0.05). Productivity did not differ between wind-impacted areas that were logged and not logged (p > 0.05). Recognizing the need for caution when informing management with case studies, this study highlights the value of delaying the assessment of even extreme wind disturbance impacts in hardwood forest recovery until the contribution of crown regrowth of severely wind-damaged trees, along with post-disturbance origin regeneration, can be ascertained. Full article

Qualitative and quantitative differences in the chemical composition between bee pollen originated from Castanea sativa (Türkiye and Slovenia), Salix spp. (Türkiye and Slovenia), and Quercus spp. (Türkiye) and androecia of Castanea sativa, Salix alba, and Quercus pubescens (apetalous trees) were evaluated for the first time by new high-performance thin-layer chromatography (HPTLC) and ultra-performance liquid chromatography (UPLC) methods using marker compounds. N¹,N⁵,N¹⁰-tricaffeoylspermidine was isolated, and its structure was elucidated by nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS). It was the main and the marker compound common to bee pollen (≈3–41 mg/g) and androecia (≈3–6 mg/g) samples. To the best of our knowledge, this is the first report of the identification of N¹,N⁵,N¹⁰-tricaffeoylspermidine in bee pollen originated from Salix spp. and androecia of C. sativa, S. alba, and Q. pubescens. The botanical origins of bee pollen were determined via phytochemical profiling using HPTLC-image analyses showing that bee pollen from the same botanical source had almost identical profiles regardless of collection location, geographical differences, and the bee race. In vitro tests and HPTLC-effect-directed analyses (EDAs) were performed to assess antioxidant and xanthine oxidase (XO) inhibitory activities of bee pollen, androecia, and N¹,N⁵,N¹⁰-tricaffeoylspermidine. HPTLC-EDA combined with image analyses was used for comparing the activities of bee pollen, androecia, N¹,N⁵,N¹⁰-tricaffeoylspermidine, and also other marker compounds (quercetin, myricitrin, hyperoside, quercitrin, isoquercitrin, and rutin). The remarkable bioactivity of N¹,N⁵,N¹⁰-tricaffeoylspermidine was for the first time evaluated by HPTLC-EDA and in vitro tests. This is the first study performing HPTLC-XO inhibitory activity analyses on the HPTLC NH₂ F_254S plates. Further bioactivity studies on botanically and chemically well-characterized bee pollen samples are needed to aid in the use of bee pollen-containing supplements in the prevention and treatment of diseases. Full article

Miscanthus (Miscanthus × giganteus) and Willow (Salix spp.) are promising bioenergy crops due to their high biomass yields and adaptability to diverse climatic conditions. This study applies the MiscanFor/SalixFor models to assess the sustainability of these crops under current and future climate scenarios, focusing on biomass productivity, carbon intensity (CI), and energy use efficiency (EUE). Under present conditions, both crops show high productivity in tropical and subtropical regions, with Miscanthus generally outperforming Willow. Productivity declines in less favourable climates, emphasising the crops’ sensitivity to environmental factors at the regional scale. The average productivity for Miscanthus and Willow was 19.9 t/ha and 10.4 t/ha, respectively. Future climate scenarios (A1F1, representing world markets and fossil-fuel-intensive, and B1, representing global sustainability) project significant shifts, with northern and central regions becoming more viable for cultivation due to warmer temperatures and extended growing seasons. However, southern and arid regions may experience reduced productivity, reflecting the uneven impacts of climate change. Miscanthus and Willow are predicted to show productivity declines of 15% and 8% and 12% and 7% under A1F1 and B1, respectively. CI analysis reveals substantial spatial variability, with higher values in industrialised and temperate regions due to intensive agricultural practices. Future scenarios indicate increased CI in northern latitudes due to intensified land use, while certain Southern Hemisphere regions may stabilise or reduce CI through mitigation strategies. Under climate change, CI for Miscanthus is projected to increase by over 100%, while Willow shows an increase of 64% and 57% for A1F1 and B1, respectively. EUE patterns suggest that both crops perform optimally in tropical and subtropical climates. Miscanthus shows a slight advantage in EUE, though Willow demonstrates greater adaptability in temperate regions. Climate change is expected to reduce EUE for Miscanthus by 10% and 7% and for Willow by 9% and 6%. This study underscores the need for region-specific strategies to optimise the sustainability of bioenergy crops under changing climate conditions. Full article

This study reveals patterns of yield and survival of short-rotation coppice (SRC) willow cultivars over eight rotations (1993–2019). Cultivars fell into four broad categories: commercial, released, stable, and decline. SV1, the singular cultivar that advanced to commercial deployments, had first-rotation yields of 8.9 Mg ha⁻¹ a⁻¹, peaking at 15.2 Mg ha⁻¹ a⁻¹ by the fourth. Mean yields from rotations 2–8 were still 36% above first-rotation yields, confirming the commercial potential for this cultivar over 26 years. The released group (four cultivars) had stable yields over six rotations (approximately 3 to 7 Mg ha⁻¹ a⁻¹), rising to match commercial yields (10 Mg ha⁻¹ a⁻¹) between the sixth and eighth rotation. Most of the cultivars were in the stable group that had relatively consistent yields over time. First-rotation yields in this group were approximately 5 Mg ha⁻¹ a⁻¹, and average yield increased by 23% for rotations 2–8. The two cultivars in the decline group were impacted by disease and browsing that lowered survival and growth. These findings are crucial for understanding willow systems’ potential over their full lifespan as a bioenergy crop, which is a crucial input into yield, economic, and environmental models. Full article

Soil salinization and alkalinization are pervasive environmental issues that severely restrict plant growth and crop yield. Utilizing plant growth-promoting rhizobacteria (PGPR) is an effective strategy to enhance plant tolerance to saline–alkaline stress, though the regulatory mechanisms remain unclear. This study employed biochemical and RNA-Seq methods to uncover the critical growth-promoting effects of Trichoderma spp. on Salix linearistipularis under saline–alkaline stress. The results showed that, during saline–alkaline stress, inoculation with Trichoderma sp. M4 and M5 significantly increased the proline and soluble sugar contents in Salix linearistipularis, enhanced the activities of SOD, POD, CAT, and APX, and reduced lipid peroxidation levels, with M4 exhibiting more pronounced effects than M5. RNA-Seq analysis of revealed that 11,051 genes were upregulated after Trichoderma sp. M4 inoculation under stress conditions, with 3532 genes primarily involved in carbon metabolism, amino acid biosynthesis, and oxidative phosphorylation—processes that alleviate saline–alkaline stress. Additionally, 7519 genes were uniquely upregulated by M4 under stress, mainly enriched in secondary metabolite biosynthesis, amino acid metabolism, cyanamide metabolism, and phenylpropanoid biosynthesis. M4 mitigates saline–alkaline stress-induced damage in Salix linearistipularis seedlings by reducing oxidative damage, enhancing organic acid and amino acid metabolism, and activating phenylpropanoid biosynthesis pathways to eliminate harmful ROS. This enhances the seedlings’ tolerance to saline–alkaline stress, providing a basis for studying fungi–plant interactions under such conditions. Full article

This research focuses on producing particleboards from the biomass of plantation willow (Salix viminalis L.) and poplar (Populus spp.), aiming to explore their feasibility as sustainable materials for various applications. Fast-growing willow and poplar are known for their rapid growth and suitability for energy production. They present an intriguing alternative as raw materials with added value for particleboard manufacturing. This study investigates the selected mechanical and physical properties of the produced particleboards, considering parameters such as density profile, bending strength, modulus of elasticity, internal bond, water absorption, thickness swelling, and screw withdrawal resistance. The research results were also compared between different mass shares of willow and poplar particles in the particleboards. The results show that the panels produced entirely from the tested alternative raw materials had a modulus of rupture of 21.7 N mm⁻² compared to 14.6 N mm⁻² for the reference panels, with an internal bond of about 2.02 N mm⁻² compared to 0.65 N mm⁻² for the reference panels. The thickness swelling after 24 h of soaking was about 24.2% compared to 42.2% for reference panels. The findings underscore the promising potential of willow and poplar-based particleboards as eco-friendly alternatives in the construction and furniture industries, contributing to resource efficiency and carbon emission reduction efforts. Full article

Soil organic matter (SOM) is essential for nutrient cycling and soil carbon (C) accumulation, both of which are heavily influenced by the quality and quantity of plant litter. Since SOM dynamics in relation to plant diversity are poorly understood, we investigated the effects of willow variety and mixture, and site on the soil C stocks, SOM chemical composition and thermal stability. Using pyrolysis-field ionization mass spectrometry (Py-FIMS), a method of stepwise thermal degradation in ultrahigh vacuum combined with soft ionization in a high electric field, followed by mass-spectrometric separation and detection of molecular ions, we analyzed SOM in the top 10 cm of soil from two 7-year-old experimental sites in Germany and Sweden. Monocultures and mixtures of two willow varieties (Salix spp.) belonging to different species were grown at the experimental plots. Overall, site had the strongest effect on SOM quality. The results showed significant variability across sites for willow identity and mixture effects on C accumulation and SOM chemistry. In the German site (Rostock), yearly soil C accumulation was higher (p < 0.05) for variety ‘Loden’ (1.0 Mg C ha⁻¹ year⁻¹) compared to ‘Tora’ (0.5 Mg C ha⁻¹ year⁻¹), whilst in the Swedish site (Uppsala), both varieties exhibited similar soil C accumulation rates of around 0.6 Mg C ha⁻¹ year⁻¹. Willow variety identity significantly affected SOM quality at both sites, while mixing had minor effects. Our findings emphasize the significance of site-specific context and variety and species identity in shaping soil C accumulation in willow plantations. Full article

This open-field small-plot long-term experiment was set up between 2011 and 2021 with willow (Salix triandra × S. viminalis ‘Inger’), grown as a short rotation coppice energy crop in Nyíregyháza, Hungary. The sandy loam Cambisol was treated with wastewater solids (WS) in the form of municipal sewage sludge compost (MSSC, 2011, 2013, and 2016), municipal sewage sediment (MSS, 2018), and with willow ash (WA, 2011, 2013, 2016, and 2018). Control plots remained untreated since 2011. All soil treatments significantly enhanced the uptake or accumulation of potentially toxic elements (PTEs) in the leaves of willows. During June 2019, 53 weeks after the last soil treatments, MSSC + MSS-, WA-, and MSSC + MSS + WA-treated willows leaves had 14–68% more As, 17–48% more Ba, 31–104% more Cr, 4–12% more Cu, 6–15% more Mn, 18–218% more Pb, and 11–35% more Zn compared to the untreated control. Significantly higher Mn and Zn concentrations were measured in the MSSC + MSS + WA treatments than in the MSSC + MSS treatments. The assumption that WA reduces the accumulation of PTEs in willow leaves when applied together with MSSC and MSS was therefore only partially confirmed. The hypothesis of this study was that PTEs accumulated in the leaves would affect the microanatomical parameters of the leaves. Numerous positive changes were observed with the combined application of WS and WA. MSSC + MSS + WA treatment reduced the thickness of the mesophyll less than MSSC + MSS or WA treatments alone; the size of the cells building the palisade and spongy parenchyma and the extent of the main vein significantly increased. In the case of the combined treatment, the extent of the sclerenchymatous stock was smaller than in the control but larger than in WS- or WA-treated willow. The extent of the collenchymatous stock significantly increased compared to the control. Increases in the thickness of the adaxial epidermis and the number of stomata were statistically significant. However, the extent of the increases did not reach the extent of the increase experienced in the case of WS treatment, as the size of the stomata did not significantly decrease. Full article

(1) Background: Salix species occurring in Finland have not been well studied for their antimicrobial potential, despite their frequent use for lung and stomach problems in traditional medicine. Thus, twig extracts of three species of Salix that are found naturally in Finland and one cultivated species were screened for their antimicrobial properties against human pathogenic bacteria. S. starkeana and S. x pendulina were screened for antibacterial effects for the first time. (2) Methods: An agar diffusion and a microplate method were used for the screenings. Time-kill effects were measured using a plate-count and a microplate method. A DPPH-method using a qualitative TLC-analysis was used to detect antioxidant compounds in antimicrobial extracts. Metabolites from a S. myrsinifolia extract showing good antibacterial effects were identified using UPLC/QTOF-MS. (3) Results: A methanol extract of S. starkeana was particularly active against B. cereus (MIC 625 µg/mL), and a methanol extract of S. myrsinifolia showed good activity against S. aureus and B. cereus (MIC 1250 µg/mL) and showed bactericidal effects during a 24 h incubation of B. cereus. Moreover, a decoction of S. myrsinifolia resulted in good growth inhibition against P. aeruginosa. Our UPLC/QTOF-MS results indicated that proanthocyanidins (PAs), and especially the dimer procyanidin B1 (m/z 577) and other procyanidin derivatives, including highly polymerized proanthocyanidins, were abundant in S. myrsinifolia methanol extracts. Procyanidin B1 and its monomer catechin, as well as taxifolin and p-hydroxycinnamic acid, all present in S. myrsinifolia twigs, effectively inhibited B. cereus (MIC 250 µg/mL). (4) Conclusions: This study indicates that Finnish Salix species contain an abundance of antibacterial condensed tannins, phenolic acids and other polyphenols that deserve further research for the antibacterial mechanisms of action. Full article

An investigation of phenolic glycosides extracted from Salix germplasm revealed that arbusculoidin (benzyl 1-O-β-d-glucopyranosyl-1-hydroxy-6-oxo-2-cyclohexenyl carboxylate) and its enolic 6-glycoside isomer, isoarbusculoidin, are widespread across the Salix family. An analysis of natural hybrid species and progeny from a willow breeding programme demonstrated that the putative biosynthetic pathway leading to the salicinoid family of phenolic glycosides runs in parallel to a “benzyl”-based pathway to arbusculoidin. The introduction of a known Diels–Alder reaction trait from Salix dasyclados, as well as an acylation trait, into progeny containing both salicyl- and benzyl- pathways caused the formation of all possible hetero-cyclodimers from mixtures of reactive dienone (acyl)glycosides that participated in cross-over reactions. In addition to providing access to new analogues of the anti-cancer dimer miyabeacin, the analysis of the breeding progeny also indicated that these dienone (acyl)glycosides are stable in planta. Although the immediate biosynthetic precursors of these compounds remain to be defined, the results suggest that the (acyl)glycosylation reactions may occur later in the pathway than previously suggested by in vitro work on cloned UGT enzymes. Full article

The tree species Salix caprea shows high adaptability to different habitat conditions and is economically valuable as a woody crop for biomass production. Moreover, S. caprea is dependent on mycorrhizal fungi, which are crucial for its growth and adaptability in different environments. Hence, this study explores the ectomycorrhizal diversity of S. caprea by utilizing the taxonomy (morphotyping and a molecular approach using the ITS and LSU regions) and trait diversity (exploration types) at two test sites in Germany and Poland. In total, 19 ectomycorrhizal (EM) morphotypes of S. caprea were characterized. Seven taxa were identified at the species level (Hebeloma populinum, Cortinarius atrocoerulaeus, Inocybe hirtella, Laccaria cf. ochropurpurea, Tuber maculatum, Cenococcum geophilum, and Phialophora finlandia) and twelve at the genus level (Tomentella spp. 1–8, Hebeloma sp. 1, Inocybe sp. 1, and Tuber spp. 1–2). The EM colonization ranged from 14 to 28% of the fine root tips. At both test sites, the largest portion of the total EM colonization consisted of Thelephoraceae. The exploration types were classified as medium-distance smooth (Tomentella sp. 1–8 and L. ochropurpurea) and medium-distance fringe (C. atrocoerulaeus), while the other taxa were short-distance exploration types, highlighting their potential functional role in the adaptation and growth of S. caprea. Full article

Willow (Salix spp.) trees, found worldwide, contain secondary metabolites that are valuable as dietary supplements for animal feed and as antiparasitic compounds. We quantified secondary metabolites (phenolics, flavonoids, and salicylic acid) in ethanolic extracts from leaves and branches of three Salix acmophylla Boiss. genotypes and investigated their potential to inhibit Eimeria sp. sporulation, a major concern in ruminants. The total phenolic content of willow leaves and branches was similar in two of three different genotypes. The total flavonoid content of the branches was significantly higher than that of leaves of the same genotype; however, the salicylic acid content was significantly higher in leaves than in branches. Importantly, all extracts exhibited significant inhibition of Eimeria sporulation, where over 70% inhibition was obtained at concentrations as low as 750 mgL⁻¹. The sporulation inhibition by branch or leaf extracts exceeded 80% for leaves and 90% for branches at concentrations above 1250 mgL⁻¹. The study highlights the potential of using Salix extracts as bioactive compounds for biological control of coccidiosis in ruminants. We conclude that all parts and all investigated genotypes of S. acmophylla can provide secondary metabolites that act as a coccidiostat to treat Eimeria in goats. Full article