Search Results (321)

How do microorganisms in litter and soil affect litter decomposition in a temperate forest? Here, we conducted an 18-month laboratory experiment to assess the decomposition of pure Robinia pseudoacacia, pure Platycladus orientalis, and mixed R. pseudoacacia–P. orientalis litters under four treatments, namely “no microbe” (NM), “litter microbes” (LM), “soil microbes” (SM), and “litter and soil microbes” (LM + SM). Results demonstrated that, compared with SM, LM significantly enhanced the litter weight-loss rate and elevated the potential activities of lignocellulolytic enzymes at 180 days, and this was accompanied by lower cellulose and hemicellulose contents. Structural equation modeling indicated that microorganisms may directly or indirectly influence weight mass loss, partly by regulating these potential enzyme activities that are associated with changes in the litter organic matter composition. Across three forest stands, microbial treatments significantly affected litter decomposition. The standardized direct path coefficients linking microorganisms to the litter-mass-loss rate from highest to lowest were LM + SM, LM, and SM, indicating a synergistic effect between LM and SM that promotes decomposition through coordination. Taxonomically, most bacterial genera differed significantly among microbial treatments, whereas most fungal genera did not. Notably, the standardized direct path coefficient linking bacteria to litter mass loss was larger than that for fungi in both the SM and LM + SM groups. Additionally, field decomposition was faster than in the laboratory, with distinct microbial communities, verifying the environmental modulation of decomposers and the home-field advantage. This study clarifies microbial mechanisms underlying litter decomposition and provides a theoretical basis for forest ecosystem stability and sustainable management. Full article

The Yellow River floodplain relies on plantations for ecological restoration, yet the key factors influencing soil microbial communities remain poorly elucidated. In this study, we investigated soil microbial communities under four representative stand types (Populus tomentosa monoculture (PP), Salix matsudana monoculture (PS), Populus tomentosa-Robinia pseudoacacia mixed plantation (MPR), and Salix matsudana-Populus tomentosa mixed plantation (MSP)) in this region. Using high-throughput sequencing, we compared the soil microbial community composition and diversity across stands, and combined soil physicochemical measurements to evaluate the relationships between community variation and soil factors. The results indicated that soil physicochemical properties differed significantly among stand types, except for available phosphorus. Bacterial α-diversity was highest in MPR, whereas fungal α-diversity was highest in MSP. Variation in microbial community structure (β-diversity) was primarily explained by soil organic carbon, total nitrogen, pH, water content, and electrical conductivity, as indicated by redundancy analysis and Mantel tests. The dominant bacterial phyla were Acidobacteriota, Pseudomonadota (formerly Proteobacteria), and Actinomycetota, while the dominant fungal phyla were Ascomycota, Basidiomycota, and Mortierellomycota. These findings demonstrate significant variation in soil microbial communities among plantation types and highlight the important role of soil physicochemical properties in shaping microbial community composition. Full article

Obolodiplosis robiniae (Haldeman) is a specialist herbivore of Robinia pseudoacacia L., and its infestation is closely associated with tender leaf tissues. The ability of gravid females to recognize suitable host tissues is essential for successful oviposition and subsequent population development. Here, we assessed whether leaf age affects the host-selection behavior of O. robiniae and whether volatile organic compounds are associated with this process. Laboratory oviposition assays were used to compare egg deposition on tender leaves and mature leaves of R. pseudoacacia, and Y-tube olfactometer bioassays were performed to evaluate female responses to odors from the two leaf ages. Volatiles released from healthy tender leaves and mature leaves were collected using dynamic headspace sampling and characterized by thermal desorption–gas chromatography–mass spectrometry. Principal component analysis, orthogonal partial least squares discriminant analysis, and variable importance in projection scores were used to compare volatile profiles between leaf ages. Gravid females deposited significantly more eggs on tender leaves than on mature leaves in both choice and no-choice assays. Females also showed a significant olfactory preference for tender-leaf odors when directly offered a choice between volatiles from tender leaves and mature leaves, with 76.47% of responding individuals selecting tender-leaf odors and 23.53% selecting mature-leaf odors. Chemical profiling identified 28 volatile compounds across the two leaf ages, and their composition and relative abundance differed markedly. Among shared compounds, (Z)-3-hexen-1-ol and α-farnesene differed significantly between tender leaves and mature leaves. Multivariate analyses further identified several candidate compounds contributing to leaf age-related volatile differences. These results indicate that leaf age influences both oviposition behavior and odor-mediated host location in O. robiniae. Leaf age-dependent volatile blends may serve as important chemical cues associated with host selection by gravid females and provide a basis for future studies on volatile-mediated management strategies. Full article

Mining activities elevate environmental noise and represent a major disturbance in terrestrial ecosystems. Vegetation belts are often used as mitigation measures. This study evaluates the role of Robinia pseudoacacia L. forest plantations in reducing noise at the lignite complex of western Macedonia, in Greece. Field measurements of noise level (LAeq) were conducted inside and outside the plantations from spring to autumn during 2020 and 2021. Measurements were taken at five points across four sites differing in their distance from the noise source. Leaf Area Index (LAI) was recorded, and meteorological variables were measured concurrently. Linear mixed-effect models were used to assess the effects of forest presence, distance from source, climatic conditions, and LAI, while accounting for repeated measurements across sampling days and sites. Noise levels were significantly lower within plantations than outside, indicating that restored forest stands can act as buffers to mining noise. The distance of trees from the noise source and atmospheric conditions are also significant drivers of noise levels. These findings highlight the potential of post-mining plantations to provide an additional acoustic regulation service in restored industrial landscapes. Full article

Deltas are highly susceptible to biological invasions because of strong hydrological connectivity, frequent disturbance, and intense human use. Here, we synthesise coordinated monitoring observations and literature evidence on invasive alien plant species (IAS) recorded in four Black Sea riparian protected areas located across five countries, surveyed under the IASON/IASON+ initiatives (Danube Delta, Nestos Delta and Lake Vistonida, Kızılırmak Delta, Chorokhi Delta and Kolkheti National Park). Across the study sites, 17 IAS were documented, mainly represented by taxa native to North America and characterised by high propagule production and/or strong vegetative regeneration. Woody riparian invaders (e.g., Amorpha fruticosa, Robinia pseudoacacia, Acer negundo, Gleditsia triacanthos and Ailanthus altissima) exploited nutrient-rich floodplain soils and disturbances. In contrast, annual weeds (e.g., Ambrosia artemisiifolia, Sicyos angulatus and Xanthium orientale) remained associated with disturbed habitat edges. Aquatic dominance was confined to the Danube Delta, where Elodea nuttallii and Elodea canadensis formed dense submerged stands. Species were assigned to broad range expansion categories (slowly, moderately and rapidly spreading species) based on project observations and supporting records. We discuss shared invasion syndromes linked to reproductive and dispersal traits and outline management implications for Black Sea deltas, emphasising pathway prevention, early detection and rapid response for localised taxa, and sustained control combined with restoration for dominant invaders. Full article

Different host plants influence the nutritional and metabolic profiles of the fall webworm (Hyphantria cunea), a globally invasive pest. This study investigated the proximate composition, free amino acid and lipid profiles of its pupae from larvae reared on three distinct diets (Robinia pseudoacacia, Morus alba and Armeniaca sibirica). The results showed that pupal weight and size varied significantly with host plant. The pupae contained 64.94 ± 1.57% crude protein and 30.82 ± 0.53% crude fat (dry mass basis), with high levels of magnesium and calcium. A total of 82 free amino acids and their metabolites were identified, including all essential and non-essential amino acids. In addition, 1026 lipids were detected, with triacylglycerols as the predominant class. Notably, the levels of linoleic and α-linolenic acid were highest in the pupae fed on R. pseudoacacia. Among the three diet groups, the lipid species TG (16:0_16:2_20:5) was identified as a characteristic differential metabolite. These findings show that host-plant-induced nutritional variation reflects metabolic plasticity, which underlies the dietary adaptability and invasion success of this polyphagous pest and also suggestsits potential use as a feed ingredient. Full article

The growing demand for renewable energy, together with the need to mitigate climate change and promote more sustainable agriculture systems, has stimulated interest in energy crops. In this context, invasive alien plant species (IAPS), which have progressively colonized abandoned farmland, degraded ecosystems, and marginal areas, represent a key bioresource. IAPS have a dual nature combining high ecological invasiveness and fast growing rate with notable energetic potential. These aspects have generated a still ongoing debate among farm managers, ecologists, and policymakers regarding their role within the future bioeconomy. The present study provides a review of the IAPS black locust (Robinia pseudoacacia L.) on its real benefits as a source of bioenergy, ecological impact, and the management strategies adopted. We examine the trade-offs between containment efforts and use for renewable bioenergy production, particularly in marginal areas where few alternatives exist. This review highlights the need for stratified site-specific approaches that balance biodiversity conservation with bioresource exploitation. Finally, this study also contributes to the ongoing discussion on whether IAPS should be regarded primarily as a management challenge or a multifunctional bioresource, as in the production of bioenergy. Full article

Background: As a transcription factor superfamily unique to plants, WRKY plays broad roles in both secondary development and secondary metabolic processes. Robinia pseudoacacia is renowned for its durable and naturally durable heartwood, which holds significant commercial value. However, their potential association with heartwood formation remains largely unexplored. Results: Leveraging published genomic data from Robinia pseudoacacia, we conducted a comprehensive bioinformatics analysis that identified 85 WRKY transcription factors. An uneven distribution across 11 chromosomes was observed for the RpWRKY genes, which were systematically named RpWRKY1 to RpWRKY85 according to their genomic locations, as determined by chromosomal localization. By conducting a phylogenetic comparison between RpWRKY and AtWRKY (from Arabidopsis thaliana), the RpWRKY family was categorized into three primary clades (I, II, and III), wherein group II was additionally partitioned into subgroups designated IIa through IIe. Conserved structural features and motif patterns were observed among members of each subgroup. Purifying selection was suggested by collinearity analysis as the primary evolutionary driver of RpWRKY, leading to structural and functional diversification. Finally, four candidate genes (RpWRKY78, RpWRKY45, RpWRKY50, RpWRKY80) potentially involved in heartwood formation regulation were identified through analysis of xylem tissue-specific expression patterns. Conclusions: For this economically important tree species, the present study not only provides the first systematic characterization of RpWRKY but also identifies potential regulators of heartwood development. Thus, the present study lays the groundwork for subsequent research aimed at uncovering the molecular processes that regulate heartwood development. Full article

Black locust (Robinia pseudoacacia L.) has exceptional growth capacity in nutrient-poor environments and is therefore widely used for afforestation and land reclamation on degraded soils. However, drought stress can restrict sapling growth, which undermines the success of their establishment. The effect of a product containing two endophytic strains (Trichoderma afroharzianum P. Chaverri, F.B. Rocha, Degenkolb & Druzhinina TR04 and Trichoderma simmonsii P. Chaverri, F.B. Rocha, Degenkolb & Druzhinina TR05) was studied on a black locust sapling stand under severe drought in eastern Hungary. The two-year-old saplings were root-soaked before planting in sandy soil. The growth of Trichoderma-treated plants improved by late spring. Compared to the control trees, average height increased by 25.75%, and root collar diameter was 21.96% larger. Treated plants also showed 9.1% higher chlorophyll content and 11.1% Normalized Difference Vegetation Index (NDVI). The reduced intercellular CO₂ concentration, together with slightly lower stomatal conductance and increased transpiration rate, suggests tighter stomatal regulation and altered water-use dynamics under drought conditions. These responses indicate improved short-term drought acclimation rather than enhanced carbon assimilation capacity. Pre-planting inoculation with endophytic Trichoderma strains provides a sustainable method to enhance the early establishment and drought resilience of black locust, thereby increasing the efficacy of forest restoration by improving the survival of black locust on challenging degraded sites. Full article

Although silvopastoral systems are widely recognized to improve ecosystem services, empirical evidence regarding their long-term effects on herbaceous diversity during succession remains scarce. In 2011, we established a silvopastoral experiment in the low hilly area of western Henan Province, China. Four pure forest plots—poplar (Populus simonii, PS), oriental thuja (Platycladus orientalis, PO), Chinese cork oak (Quercus variabilis, QV) and black locust (Robinia pseudoacacia, RP)—were planted on natural wasteland, with perennial alfalfa (Medicago sativa, MS) intercropped to form silvopastoral systems (PS-MS, PO-MS, QV-MS, RP-MS), with a natural wasteland plot serving as the control (CK). In July 2024, we investigated the species density, richness, and aboveground biomass of herbaceous communities across all plots. Species composition differed significantly between MS and CK, PS-MS and PS, and PO-MS and PO. Silvopastoral systems and MS generally exhibited higher density, richness, and biomass than pure forests and CK. Furthermore, MS and silvopastoral systems showed uniform density and biomass across slope positions, whereas CK and pure forests had higher values downslope, along with shifts in relative biomass. Except for MS and PS-MS, all plots had higher species richness downslope. Soil nutrient properties were closely correlated with the biomass, richness, density, and functional groups. These findings indicate that silvopastoral systems can significantly increase herbaceous density, richness, and biomass and alter species composition, with the effects varying by the dominant tree species. Full article

Tree bark, an abundant by-product of the timber industry, represents a promising feedstock for sustainable construction. This study investigates the thickness swelling, water absorption, hygroscopicity and mechanical (compressive strength) properties of insulation panels produced from hardwood bark (Tilia spp. and Robinia pseudoacacia) via hydromechanical treatment and a wet-forming process. The panels were produced without added adhesives, relying on the formation of hydrogen bonds during the drying phase to ensure structural integrity. Both bark-based insulation boards (thermal conductivity coefficient 0.055–0.057 W/m·K) showed similar hygroscopic behavior, reaching equilibrium moisture contents of max. 25% at 93.9% RH. Water absorption after 24 h immersion was highly material-dependent; Tilia-based panels showed 57.11 ± 5.81%, and Robinia-based panels 320.61 ± 11.34%. Thickness swelling remained low (max. 6% for Robinia), showing significant orthotropic anisotropy. At 10% compressive strain, the Tilia and Robinia bark-based panels showed compressive strengths of 188 ± 14.6 kPa and 298 ± 18.1 kPa, accordingly. These findings demonstrate that hardwood bark can be successfully valorized into high-performance, binderless insulation, supporting circular economic strategies. Full article

The influence of growing site conditions on the chromatic properties of heartwood in black locust (Robinia pseudoacacia L.) cultivar ‘Nyírségi’ sampled from five regions of Hungary was investigated in this study. A total of 23 boards (average age of trees: 34.5 years) representing four site types were analyzed by instrumental colorimetry using the CIE Lab system. The overall average color coordinates were L* = 69.9 ± 4.0, a* = 4.0 ± 0.8, and b* = 27.4 ± 2.3. Significant chromatic differences were observed among site types proven by statistical analysis; however, no single site type consistently increased within-site color variability. Average total color differences (ΔE*) ranged from 3.94 to 6.31 across site types, corresponding to “noticeable” to “large” visual differences. Regionally, 89.1% of 55 specimen pairs exhibited clearly perceptible color variation (ΔE* > 2), with 61.8% classified as “large” (ΔE* > 5). Within-tree comparisons revealed ΔE* values of 3.72–3.75 under poor site conditions but <2.0 on good growing sites. The a* and b* components appear with measurable variations across all sites, while the characteristic yellow hue remains distinct and stable independent of site origin due to the high b* value. Full article

The flowers of Sophora japonica L. (SJF) and Robinia pseudoacacia L. (RPF) are edible and similar in appearance. The chemical constituents of SJF and RPF were compared by UPLC-Q-TOF-MS/MS and HPLC analysis in this study. A total of 29 and 19 constituents were identified in SJF and RPF, respectively. Flavonoid glycosides were the main constituents found in both flowers. The main aglycon moieties found in SJF were quercetin, kaempferol and isorhamnetin, whereas acacetin and kaempferol were the main ones found in RPF. Additionally, the content of flavonoids in SJF was significantly higher than that in RPF, as determined by HPLC. Rutin was the most dominant flavonoid in SJF with a content range of 72.31~88.15 mg/g, followed by quercetin (13.05~20.30 mg/g). Kaempferol-di(rhamnoside)-hexoside was the most dominant flavonoid in RPF with a content range of 25.94~30.00 mg/g. The distinct flavonoid profiles indicated the chemical non-equivalence of SJF and RPF. Therefore, RPF should not be considered a direct substitute for SJF in herbal medicine without further pharmacological and clinical validation. Full article

Light environments within plantation forests vary significantly with stand degradation. This study investigated how light-related factors change along degradation gradients in Robinia pseudoacacia L. (black locust) plantations and how these changes influence understory herbaceous vegetation and regeneration. An R. pseudoacacia plantation at the Zhongmu State-owned Forest Farm, ZhengZhou, China was studied across three degradation levels (least degraded, moderately degraded, and severely degraded). Integrated analyses were employed to assess light–vegetation relationships under different stand densities. The results indicated that canopy openness (CO), photosynthetically active radiation (PAR), and light transmittance increased significantly with increasing degradation severity, whereas the leaf area index (LAI) declined. Specifically, differences in LAI among degradation levels were observed in all density stands. CO, TDR, and PAR showed degradation-related differences in medium- and high-density stands, while other light variables varied under specific density–degradation combinations. Furthermore, herbaceous biomass declined, canopy cover showed a fluctuation trend, and species diversity increased. Significant correlations were observed between multiple light parameters and herbaceous attributes. Overall, variations in the light environment were closely associated with understory vegetation dynamics. Moderate degradation was linked to higher herbaceous diversity, whereas regeneration density exhibited a non-monotonic response across degradation levels, with the lowest value under moderate degradation rather than a continuous decline under severe degradation. Full article

Although plant restoration is essential for improving soil structure and stability, there are still few systematic assessments of its impacts across various restored vegetation species, especially in environmentally sensitive areas like the East Qinling Mountains. In order to provide a scientific foundation for optimizing restoration tactics and enhancing soil erosion control and ecosystem services in the area, this study attempts to assess the impacts of different recovered plant types on soil aggregate stability and to clarify the underlying mechanisms. The Pinus tabuliformis Carrière, Quercus variabilis Blume, Robinia pseudoacacia L., Pinus tabulaeformis-Quercus variabilis mixed forest, Platycladus orientalis (L.) Franco and abandoned grassland were the six vegetation types represented by the sixteen plots. Farmland was used as a control. Soil samples were taken from three depths (0–5 cm, 5–20 cm, and 20–40 cm) and evaluated for root biomass, soil organic matter (SOM), and water-stable aggregate dispersion. Mean weight diameter (MWD), fractal dimension (D), macroaggregate content of diameter > 0.25 mm (R_0.25), and percentage of aggregate disruption (PAD) were used to evaluate aggregate stability. One-way ANOVA, LSD multiple comparisons, and Spearman correlation analysis were among the statistical analyses. In comparison to grassland and farming, forested regions, particularly mixed forests, showed considerably higher proportions of macroaggregates (>0.25 mm) and superior aggregate stability (higher MWD and R_0.25, lower D and PAD). Increased litter and coarse root inputs, which encouraged big water-stable aggregates (WSAs) and reinforced their positive connection with SOM, were the driving forces behind this development. Robinia pseudoacacia L. and Platycladus orientalis (L.) Franco displayed the highest SOM concentration and root biomass (1201.45 and 679.66 g/m², respectively). At all depths, mixed forests showed the most stable soil structure. In contrast to agriculture, vegetation restoration dramatically changed the mechanical composition of the soil, increasing the differentiation of particle-size fractions across soil layers and decreasing the amount of surface clay. Soil aggregate stability is greatly enhanced by vegetation restoration, with mixed forests offering the greatest advantages because of their varied root systems and increased input of organic matter. These results emphasize how crucial it is to choose the right vegetation types for restoration efforts in order to improve soil structure, reduce erosion, and promote ecological sustainability in the East Qinling Mountains. Full article