Search Results (248)

Invasive plant species are increasingly recognized not only as ecological threats but also as potential sources of bioactive compounds with agricultural applications. However, the combined allelopathic and insecticidal potential of Ailanthus altissima’s different plant parts remains insufficiently explored. This study evaluated the bioactivity of different plant part (leaf, bark, and branch) extracts of A. altissima. Secondary metabolites were characterized by HPLC–DAD–MS, while ethanol extracts (0.5–5%) were tested on wheat (Triticum aestivum) seed germination, seedling growth, oxidative status, and on the survival and repellency of the rice weevil (Sitophilus oryzae). Biological responses were strongly plant part and concentration-dependent. Leaf extracts contained the highest phenolic levels, dominated by caffeoylquinic acids and quercetin derivatives, whereas bark and branch extracts showed lower but compositionally distinct profiles. Despite this, bark and branch extracts produced the strongest biological effects, inhibiting germination energy and root growth at higher concentrations, while leaf extracts stimulated seedling performance, including increased vigor index, while in insect bioassays, bark and branch extracts caused higher mortality and stronger suppression of rice weevil populations. This study provides new evidence that biomass extracts of the invasive species A. altissima represent a promising source of biologically active compounds with both allelopathic and insecticidal properties, highlighting its potential valorization as a plant-based biopesticide for sustainable pest management. Full article

Floodplain forests in central Amazonia are structured along a marked flooding gradient that influences species distribution, performance, and survival. This study evaluated the demographic structure, survival, and growth responses of two co-occurring tree species across contrasting várzea environments differing in inundation regimes. Field surveys quantified seedlings, juveniles, and adults in low- and high-floodplain forests, while a field experiment assessed survival and growth under conditions with and without interspecific interaction. Repeated-measures ANOVA revealed that temporal variation and forest type significantly affected growth parameters, with species-specific responses to flooding intensity. In the field experiment, mortality of Crateva tapia L. differed significantly among treatments (χ² = 24.96, p < 0.001), with the highest mortality observed in high-várzea (up to 75% under interspecific interaction), while Hura crepitans L. showed 100% survival across all treatments. Non-parametric analyses detected no significant treatment effects on selected morphological traits. The results support the stress-gradient hypothesis, suggesting that plant–plant interactions may shift along the flooding gradient, with facilitative processes becoming more relevant under higher stress conditions. Overall, differential flood tolerance appears to be a key driver of habitat preference and population structure in these Amazonian wetlands. Full article

Muskmelon (Cucumis melo) is a widely cultivated and economically important fruit crop that is severely affected by Fusarium wilt caused by Fusarium oxysporum f. sp. melonis (race 1.2) (Fom). Conventional management practices have shown limited effectiveness and pose environmental and health risks; therefore, sustainable and eco-friendly alternatives are required to manage this disease. In the present study, 23 endophytic fungal isolates belonging to eight genera were isolated from Ecballium elaterium and screened to determine antifungal potential against Fom using an in vitro antagonistic assay. Two endophytic isolates (Fusarium sp. EeR4 and Fusarium clavum EeR24) exhibited an inhibitory effect against Fom on quarter-strength PDA plates. In growth chamber experiments, F. clavum EeR24-colonized melon seedlings and significantly protected plants from wilting compared to non-colonized pathogen-challenged seedlings. Under greenhouse conditions, F. clavum EeR24 significantly improved morphological and physiological traits, including plant height, weight, number of leaves, membrane stability, photosynthesis, stomatal conductance, and transpiration, in Cucumis melo. Endophytic colonization improved catalase (56%), guaiacol peroxide (47%), and superoxide dismutase activity (25%), and increased flavonoid and phenolic content by 11–59% compared to non-colonized Fom-challenged plants. Lipid peroxidation significantly decreased by 37% and proline accumulation increased by 70% in colonized plants compared to non-colonized plants. Histochemical analysis also indicated that endophytic colonization considerably reduced the levels of H₂O₂, O₂⁻, malondialdehyde, and cell mortality in Fom-challenged plants. In addition, the culture filtrate and organic residues of F. clavum EeR24 inhibited the mycelial growth of Fom by 52–58%, respectively. Furthermore, a study on spatial colonization of the endophyte and the pathogen using GFP and RFP tagging indicated that both the endophyte and the pathogen simultaneously colonized the root tissues of C. melo; however, the endophyte significantly reduced the pathogenicity of Fom. These results suggest that endophytic F. clavum EeR24 may be developed as an effective biocontrol agent for the management of Fusarium wilt in melon plants under field conditions. Full article

Most cycad seeds germinate under the parent plant, and seedlings die before recruitment to the juvenile stage. Decomposition of the senesced organs releases the nutrients to influence nutrient cycling. The aim of this study was to quantify the soil nitrogen that accumulates from seedling turnover. Soil cores were collected beneath male and female trees of four Cycas species in five Philippine habitats from 2019 through 2025, with matching cores collected 5 m from the trees. Five to nine replications were employed depending on the habitat. One seedling was excavated beneath each tree in one location. Total nitrogen concentration was determined by dry combustion in soil and plant tissues, and total nitrogen content was calculated for seedlings. The soils beneath female trees contained more nitrogen than beneath male trees or away from cycad trees in every habitat. The highest nitrogen concentration within seedlings occurred in coralloid roots, but leaflets contained the most nitrogen pool, indicating rapid release of nitrogen during decomposition of the senesced seedling. No differences in rhizosphere nitrogen occurred in a 2017–2025 ex situ experiment using Cycas edentata, where seeds were sown beneath female and male trees. A second 2018–2025 experiment revealed that female trees provisioned with self-seeds did not differ in rhizosphere nitrogen compared with non-kin seeds. Nitrogen fixed by cyanobacteria endosymbionts of cycad seedlings and programmed seedling mortality combine to influence nitrogen cycling in soils beneath female trees over time. Full article

Phytophthora cinnamomi Rands, an oomycete pathogen of global relevance, is a major driver of cork oak (Quercus suber L.) decline and mortality in Mediterranean forests. Its management remains challenging in multifunctional landscapes where forestry and agriculture intersect, such as Mediterranean oak dehesas. Conventional fungicides are used against P. cinnamomi, but their negative environmental impacts underscore the need for alternative management in agroforestry systems. This study evaluated whether a commercially available microbial biostimulant, VESTA, enhances physiological performance and mitigates pathogen pressure in Q. suber. Seedlings were inoculated with P. cinnamomi and treated with the bioinoculant via fertigation or watering to substrate saturation, under controlled greenhouse conditions. Plant physiological parameters and soil oomycete inoculum concentrations were measured to assess treatment efficacy. Both application methods significantly improved physiological performance in inoculated and mock-inoculated plants. Photosynthesis, stomatal regulation, and water balance were most affected. Quantitative PCR analyses revealed a strong pathogen reduction, with DNA concentrations approximately tenfold lower in treated substrates (~0.001 ng mL⁻¹) than untreated controls (~0.011 ng mL⁻¹). Overall, the product enhanced Q. suber resilience by improving plant physiological responses and reducing pathogen abundance, supporting its potential as a bio-based tool for nurseries and restoration in Mediterranean ecosystems. Field studies are needed to validate these findings under natural variability and optimize long-term application strategies. Full article

Masson Pine (Pinus massoniana), an important afforestation species in southern China, is severely threatened by pine wilt disease caused by pine wood nematode (Bursaphelenchus xylophilus, PWN). To differentiate mortality induced by B. xylophilus from that caused by abiotic environmental factors, hyperspectral imaging and needle chlorophyll content were measured and analyzed for the early detection physiological changes in Masson pine seedlings under various environmental stressors. Four-year-old Masson pine seedlings were subjected to PWN inoculation, mechanical injury, drought, and waterlogging treatments. Hyperspectral reflectance and needle chlorophyll content of Masson pine were measured concurrently at 7-day intervals. The results showed that hyperspectral imaging responses varied among the stressors. Both PWN and waterlogging stress induced rapid mortality, with spectral changes observed as early as the 3rd week and reaching statistical significance by the 5th week. Under PWN infection, hyperspectral reflectance increased markedly in the 405–580 nm range, accompanied by a pronounced blue-shift of the red edge position (680–750 nm), while needle chlorophyll content declined sharply from approximately 0.8 mg g⁻¹ to 0.48 mg g⁻¹. Waterlogging stress produced a uniform increase in reflectance within the 500–580 nm range, with the hyperspectral curve gradually flattening, and needle chlorophyll content decreasing from 0.75 mg g⁻¹ to 0.6 mg g⁻¹. Conversely, drought-stressed seedlings exhibited only minor hyperspectral changes and maintained relatively stable chlorophyll levels, demonstrating the inherent drought tolerance of Masson pine. The RF and XGBoost models performed best in fitting the entire process of pine wood nematode infection and waterlogging stress, with all R² values greater than 0.69. The distinct hyperspectral imaging patterns under nematode infection and water-related stresses provide a reliable basis for early diagnosis and monitoring pine wilt disease in Masson pine stands. Full article

This study evaluated cherry tomato seedling production using pirapitinga RAS wastewater as the sole nutrient source in four substrate formulations: T1 (sand, gravel and coconut fiber), T2 (sand and gravel), T3 (gravel and coconut fiber), and T4 (sand and coconut fiber). No differences were observed for germination quality, germination percentage, seedling vigor index, germination vigor index, moisture content, total wet biomass, total dry biomass, or mortality. For small plants, leaf number (LN) was higher in T2 and lower in T4, while root length was greater in T3. The number of medium plants was higher in T3 and lower in T4; LN was higher in T1 and T2 and lowest in T3. For large plants, LN was higher in T1 and T2 and lower in T3; total length was higher in T1 and lower in T3 and T4. Visual differences in substrate water retention were observed: T4 exhibited rapid surface drying, T1 and T2 showed moderate moisture persistence, and T3 maintained surface water. Leaf yellowing was observed after 25 days, suggesting possible nutrient limitation or reduced nutrient availability at the measured pH. These findings indicate that substrate physical characteristics influence early seedling growth performance, whereas pirapitinga RAS wastewater can serve as a viable nutrient source. Full article

Reintroduction is increasingly used to support declining plant species, particularly epi-phytic orchids that display complex ecological requirements. We evaluated the seven-year performance of 123 asymbiotically propagated ghost orchid (Dendrophylax lindenii) seedlings that were reintroduced into a natural pond-apple/pop ash slough on the Florida Panther National Wildlife Refuge. Annual monitoring of this leafless epiphytic species assessed survival, root attachment, and reproduction, with respect to host tree bark texture, host tree species, and neighboring epiphytes. Eighteen individuals (15%) persisted after 83 months, and median survival time was 47 months. Reintroduced orchids near ferns experienced 2–4-fold higher mortality compared with those near mosses, lichens, or other ghost orchids, while survival exceeded 36% at 71 months for individuals placed adjacent to bryophytes. Despite flowering in up to 19% of surviving individuals, no seed capsule reached maturity, indicating that sexual reproduction remains a major bottleneck for population persistence. However, low reproductive output and gradual attrition suggest that reintroduction alone is unlikely to produce self-sustaining populations without addressing the likely genetic constraints, the possible pollinator service constraints, and microsite drivers of persistence. This study highlights the importance of extended monitoring and microsite selection strategies for leafless epiphytic orchid conservation. Full article

Soil conditioning can generate persistent plant–soil feedbacks (PSF) that influence plant performance under subsequent growth conditions, yet the role of soil inoculum volume in mediating these effects remains poorly understood. Here, we tested how inoculum volume influences the relative strength of a known positive PSF effect. We performed a plant–soil feedback experiment with Pinus radiata D. Don in two phases: one, a “conditioning phase”, and two, a “feedback phase”, where inoculum from the first phase was used in different dilutions to test the growth differences resulting from conditioning. To understand how inoculum volume affects subsequent growth in the feedback phase, seedlings (n = 12 per treatment) were grown in soil from phase one using different volumetric dilutions; 100% conditioned soil, 50% conditioned soil + 50% inert media, or 25% conditioned soil + 75% inert media. Positive plant–soil feedbacks were observed in undiluted soils: seedlings produced 40–65% greater biomass and experienced 50–70% lower mortality compared to the lowest inoculum treatment. However, this response varied with dilution; the strength of plant–soil feedbacks decreased with increasing dilution of inoculum. These findings highlight soil inoculum volume as an important, but often overlooked, factor in plant–soil feedback experiments and applied soil management. Our study provides experimental evidence that effective soil conditioning depends on both conditioning and a required minimum inoculum volume to confer measurable benefits to future plantings. Full article

Mangrove wetlands in northwestern Mexico have been highlighted due to their ecological relevance and ecosystem services. This study evaluated the mortality and natural regeneration of mangroves located in six coastal lagoons in Sinaloa, considering five plots each (400 m²), during a warm–strong (2015–2016) and cold–weak (2017–2018) El Niño–Southern Oscillation. The highest mean mortality was recorded in Huizache–Caimanero—the southern coastal lagoon—during the second stage (390 stems ha⁻¹; 22% corresponding to logging). While an increasing latitudinal (north–south) mortality trend was observed, differences between sites and stages were not statistically significant. Natural recovery was also observed due to higher abundance of seedlings, e.g., the largest increase from one stage to another was recorded in Santa María–La Reforma. Mortality and seedling regeneration are discussed in this study, particularly in relation to anthropogenic stressors, logging, and climate variability. Full article

Laser radiation constitutes a promising technological advancement within the integrated weed management toolbox but is hindered by low energy use efficiency. This study investigated the efficiency of a pulsed blue diode laser for controlling small weed seedlings and seeds under controlled conditions. Dose–response experiments were conducted on three grasses (Poa annua, Echinochloa crus-galli, Digitaria sanguinalis) and three dicotyledonous species (Solanum nigrum, Chenopodium album, Senecio vulgaris). For seedlings, the effects of species, growth stage (cotyledon, 2-leaf), and leaf wetness (dry, wet) were tested. For seeds, burial depth (0 mm, 2 mm) and imbibition status (non-imbibed, imbibed) were examined. Biological efficiency was assessed through plant survival, aboveground dry biomass, leaf area, and seed viability. Laser application caused significant, dose-dependent reductions in biomass accumulation and plant survival, with up to 100% mortality. Seedlings were most sensitive at the cotyledon stage and when foliage was dry, requiring up to 68 and 52% lower energy doses compared to older or wet targets, respectively. Species-specific responses were observed, with dicotyledonous species generally requiring 80 to 99% lower energy doses than grasses. Laser exposure was also effective in reducing the viability of non-imbibed, surface-exposed seeds, requiring up to 64 and 99% lower energy doses than imbibed or buried seeds, respectively. These results confirm that laser efficiency is strongly influenced by species traits, developmental stage, surface moisture, and seed water status. Optimising and tailoring laser parameters to these factors enhances weed control efficacy while maximising energy efficiency, improving the performance and sustainability of laser-based weeding. Full article

Increasing aridity and climate extremes are challenging the resilience of key Mediterranean species. Proxies that indicate plant water status, physiological condition and soil water availability are valuable tools for management planning. However, their reliability requires species-specific validation under dynamic environmental conditions. This study examined the relationship between predawn leaf water potential (Ψ_PD) and soil water potential (Ψ_S) in potted seedlings of two co-occurring Mediterranean evergreen oaks, Q. ilex and Q. suber, subjected to imposed soil drying under greenhouse conditions. We further quantified the occurrence and magnitude of predawn disequilibrium (PDD)—the mismatch between Ψ_PD and Ψ_S—and evaluated its association with soil water availability, plant water-status indicators, environmental factors, and physiological variables. In parallel, we assessed stomatal closure dynamics during the desiccation phase and characterised species-specific mortality patterns under progressive drought. Linear Mixed-Effects Models (LMMs), with pot identity included as a random factor, were fitted to assess the relationship between Ψ_PD and Ψ_S, as well as the occurrence of PDD and its potential drivers for each species. Stomatal conductance (g_s) responses to Ψ_S were evaluated using a paired t-test and an additional LMM. Finally, Generalised Linear Mixed-Effects Models (GLMMs) were used to analyse interspecific differences in mortality. We confirmed a tight relationship between Ψ_PD and Ψ_S, followed by a consistent PDD in both species, with magnitudes of 0.53 MPa for Q. ilex and 0.98 MPa for Q. suber, which increased significantly with drought severity. Our findings suggest that PDD under the studied conditions is primarily driven by soil water depletion and plant desiccation, as indicated by its negative correlation with water status parameters, as well as by its increase with progressive drought. Both oaks exhibited a water-saving strategy, with stomatal closure initiated around Ψ_S = −0.31 MPa (Q. ilex) and −0.42 MPa (Q. suber). Despite their physiological similarities, Q. suber showed higher mortality under imposed drought. These results encourage modelling the relationship between Ψ_PD and Ψ_S to accurately interpret plant and soil water needs in Mediterranean oaks, especially under soil water scarcity, and highlight species-specific responses critical for forest management and restoration under climate change. Full article

Goldenrod (Solidago gigantea Aiton) is a highly invasive species in Europe (e.g., Poland, Germany, and the Czech Republic) whose secondary metabolites can serve as potential sources of bioactive compounds. This study evaluated the phytochemical profile of S. gigantea extracts and evaluated their antibacterial, insecticidal, and phytotoxic activities. The extracts were found to be rich in flavonoids (TFC = 101 mg QE/g) and phenolics (TPC = 175 mg GAE/g), with chlorogenic acid and rutin as dominant constituents. Strong antibacterial activity was observed against Gram-positive bacteria, particularly Staphylococcus spp. (MIC₉₀ = 2.3 mg/mL; MBC = 5 mg/mL), while Gram-negative bacteria were less sensitive, with moderate susceptibility in Rhizobium radiobacter and Pseudomonas syringae. The extract exhibited fungistatic activity against all tested filamentous fungi, with Fusarium species being the most sensitive (49–56% growth inhibition at 10 mg/mL). Insecticidal assays demonstrated significant mortality of Tribolium confusum adults at 2.5–7.0 mg/mL and feeding inhibition at concentrations as low as 0.5 mg/mL. Seedling growth tests showed dose-dependent effects—from mild suppression to moderate stimulation, varying by plant species. Foliar application revealed both stimulatory and inhibitory effects, with the strongest biomass reduction in cress at 10 mg/mL (−45%). These findings indicate that S. gigantea extracts possess potent antibacterial, antifungal, insecticidal, and allelopathic activities. Their concentration-dependent effects on pathogens and plants highlight potential applications in sustainable agriculture, including natural crop protection and integrated pest management. Full article

Understanding the ecological processes that shape spatial patterns across different growth stages is crucial for revealing the mechanisms of species coexistence and community dynamics. This study investigates the spatial patterns and associations between the regeneration layer and the overstory layer in Quercus variabilis forests in northern China. Using spatial point pattern analysis, we analyzed the distribution of 2761 seedlings and 449 adult trees across twelve 20 × 20 m plots. Our results revealed a consistent pattern where seedlings exhibited significant spatial aggregation, best fitted by a simple Thomas process with an average cluster radius of 3.89 m calculated across all plots, while adult trees displayed a complete spatial random distribution. A marked reduction in local density from seedlings to adults, indicated by a self-thinning index greater than 1 in most plots, provided evidence for density-dependent mortality during stand development. However, bivariate analysis detected no significant spatial association or mark correlation between adult trees and seedlings in most plots, suggesting limited interaction between these layers after initial seedling establishment. These findings demonstrate a clear transition from clustered regeneration to randomly distributed adults, which is consistent with the potential roles of dispersal limitation, habitat filtering and competition processes, with implications for the management and conservation of temperate Quercus forest ecosystems. Full article

Conservation of the gallery forest in Berenty Reserve is becoming increasingly urgent. Any deterioration threatens its increasingly rare lemur species. Following a trial planting programme started in 2016 on three plots, with measurement of seedling growth in 2017 and 2018, we returned in 2025 to measure the changes in height, canopy cover and stem diameter. Key insights were that growth had accelerated markedly after 2018. Trees in the forest can be divided into three main species groups—upper canopy, lower canopy and dryland species—but we found scant relationship between species growth and their eventual canopy height, which could have consequences for future planting schemes and management. The plots in the mid-forest showed the highest growth rates. Mortality of seedlings was highest on the riverside plot, but there was also wild recruitment from the forest. The plots by the river and in the mid-forest received the largest number of recruits. The chief problem for the study was that we were only in Berenty for short periods and could not oversee ongoing activities in the plant nursery and in the forest. Consequently, there were problems arising from nursery treatment, unrecorded replanting and difficulties tracking the growth of individuals across years. Future work, based on our results, will focus on identifying and planting species best suited for recovery on the varied sites. Overall, temporal depth is essential for making appropriate restoration decisions based on long-term ecological functioning. Full article