Search Results (975)

High-resolution yield forecasting is essential for advancing precision agriculture and improving the sustainability of wheat and barley production. While most previous studies focus on field-scale predictions, pixel-level approaches are needed to capture intra-field variability and support site-specific management. This paper evaluates the performance of machine learning models for 10 m resolution yield prediction using multi-temporal Sentinel-2 surface reflectance data across seven major cereal-producing regions in Spain. Yield monitor data from winter wheat and barley fields collected over five growing seasons (2020–2024) were combined with spectral bands and vegetation indices. Random Forest (RF) and XGBoost (XGB) models were trained at five phenological stages expressed as days before harvest (DBH) and validated using both internal (2020–2023) and independent external (2024) datasets. Model accuracy increased as harvest approached. In external validation, RF achieved the best performance for wheat (R² = 0.77; RMSE ≈ 697 kg · ha⁻¹), while XGB performed best for barley (R² = 0.86; RMSE ≈ 744 kg · ha⁻¹). Visible, red-edge, and SWIR bands were the most informative predictors, especially during grain filling and senescence. Results demonstrate the potential of multi-temporal Sentinel-2 data and machine learning for accurate, transferable, pixel-level yield forecasting in Mediterranean cereal systems. Full article

The occurrence of forest pests and diseases is synergistically driven by stand factors (canopy closure, stand density, DBH, etc.) and site factors (elevation, soil type, slope aspect, etc.). To evaluate the effect grade of site factors on the degree of occurrence of specific forest pests and diseases after their interaction with stand factors, and to further determine the infestation severity of specific pests and diseases in stands established on suitable forestlands post-afforestation, a novel forest pest–disease base index model is defined based on the fundamental principles governing the occurrence of forest pests and diseases in specific pure forest stands. The model mandates the selection of pure forest ecosystems and the establishment of standard plots, within which a comprehensive survey of all site factors, stand factors, and target pest and disease incidence is conducted. Through methods such as stepwise regression analysis, key stand factors that influence forest pest and disease occurrence are identified, and a functional relationship between these factors and the forest pest–disease index is established. The optimal model, known as the principal curve, is obtained by relating the key stand factors to the pest–disease index. By proportionally stretching this principal curve, a series of forest pest–disease base index curves, namely the forest pest–disease base index model, is generated. These curves represent different pest–disease base index levels from bottom to top, corresponding to different grades of site effects on forest pest and disease occurrence. Furthermore, a model linking the pest–disease base index and site factors is established to evaluate the potential occurrence of pests and diseases in suitable forestlands. Applied to pure Pinus densiflora stands in Kunyu Mountain, this model quantitatively assesses the grade of site effects on the degree of occurrence of P. densiflora blight and Cephalcia kunyushanica, thereby verifying feasibility and practical applicability. It not only provides theoretical and technical support for pest and disease prediction prior to artificial forest establishment and the determination of infestation severity in post-afforestation stands but also improves ecological regulation methods for forest harmful organisms. Full article

Outbreaks of Ips hauseri, a major bark beetle pest in Central Asian Picea schrenkiana forests, have intensified under climate warming and prolonged droughts. However, the reproductive behavior and gallery construction strategies of this species remain poorly understood, limiting our ability to predict its population dynamics. Here, we dissected 219 galleries from infested spruce trees in Hami, Xinjiang, during an outbreak period (2024–2025). We identified 11 distinct gallery morphologies, with harem size (number of females per male) ranging from one to seven. Gallery length was positively correlated with egg production. Reproductive output peaked at a harem size of five, beyond which both gallery dimensions and fecundity declined. Host tree diameter at breast height (DBH) significantly influenced gallery complexity, with larger trees supporting more maternal galleries. Upward-oriented galleries were longer and contained more eggs than downward ones. Intraspecific competition, mediated by gallery adjacency and spatial orientation, strongly affected offspring development. Our results demonstrate that I. hauseri exhibits flexible gallery architecture and reproductive adjustments in response to resource availability and competition—a behavioral plasticity that likely contributes to its outbreak potential. Monitoring gallery morphology and harem size could enhance early detection and population forecasting for this increasingly damaging forest pest. Full article

Heartwood proportion (HWP) and specific gravity (SG) are two important properties of Dalbergia retusa and Platymiscium curuense wood, which is considered to be of high value. The objective of this study was to establish which morphological and soil fertility parameters present the greatest influence on HWP and SG. For this, increment cores were extracted, and soil samples were collected. The results showed that D. retusa presented a lower HWP (22.65%) than P. curuense (28.75%), and D. retusa averaged a higher value (0.87) than P. curuense (0.63). The forward stepwise regression analysis for D. retusa showed that the magnesium content was the most important factor for SG, while for the HWP, the potassium content was the most important, followed by diameter at breast height (DBH). SG was most strongly influenced by total height in P. curuense, and HWP was most strongly influenced by DBH. Additional notable results showed that the SG of D. retusa was primarily determined by soil fertility conditions, whereas the SG of P. curuense was more strongly influenced by tree morphology. Meanwhile, the HWP in both species was mainly affected by DBH and total height, and to a lesser extent by soil fertility conditions. These results show that plantation management should be focused on trees with large diameters and HWP, since soil conditions demonstrated little effect on this property. Full article

The conservation and genetic improvement of rare and endangered tree species are crucial for sustainable forest management. Liriodendron chinense, a relict species with limited distribution in China, exhibits high cross-compatibility with Liriodendron tulipifera, providing opportunities for interspecific hybrid breeding. In this study, 29 Liriodendron hybrids were established in a progeny trial plantation in Fujian Province, China, and subjected to multi-year evaluation of tree height, diameter at breast height (DBH), and individual stem volume. Significant differences (p < 0.01) among hybrids and hybrid × replicate interactions were detected for all traits across all assessment years, with individual stem volume showing the highest phenotypic coefficient of variation (35.30–40.56%). The mean annual increment in tree height increased during the early years, peaking at 1.50 m in the fourth year. Broad-sense and narrow-sense heritabilities for growth traits were consistently high (0.4073–0.7253 and 0.3410–0.6501, respectively), and the ratio of narrow-sense to broad-sense heritability ranged from 0.64 to 0.99, supporting the feasibility of early hybrid and individual selection. At a 10% selection intensity, hybrids No. 39, No. 59, and No. 74 were identified as elite, with selection based on individual stem volume providing the highest predictive accuracy and genetic gain (26.54–34.69%). Individual selection at a 1% intensity yielded genetic gains of 95.55–107.12% for stem volume. These results demonstrate substantial potential for early and efficient genetic improvement in Liriodendron hybrids, providing a theoretical foundation for the selection and deployment of elite hybrids and individuals in subtropical forest plantations. Full article

Accumulation of stem non-structural carbohydrates (NSC) at heading is crucial for mitigating grain-setting defects in large-panicle rice. While traditional panicle nitrogen fertilizer application at the emergence of the fourth leaf from the flag leaf stage (TL4) may weaken stem sink strength, delaying application to the emergence of the third leaf from the flag leaf stage (TL3) significantly enhances NSC accumulation. This study aimed to elucidate the molecular mechanisms through which TL3 remodels stem sink strength to promote NSC storage. Using two large-panicle rice varieties (Huiliangyou 280 and Yangliangyou 228), we compared stem NSC dynamics under TL4 and TL3 treatments and integrated sugar-related metabolite profiling with transcriptome analysis during the critical NSC accumulation phase. The results showed that TL3 treatment significantly increased stem NSC content and NSC per spikelet at heading, leading to a higher percentage of filled grains. The period from 5 days before heading (DBH) to heading showed the highest NSC accumulation rate. At the molecular level, TL3 treatment specifically up-regulated eight key genes in the sucrose–starch metabolism pathway, increasing the activities of sucrose phosphate synthase, sucrose synthase, and ADP–glucose pyrophosphorylase, and thereby promoting the accumulation of sucrose, trehalose, and D-fructose. In summary, delaying panicle nitrogen application to TL3 enhances stem NSC storage by remodeling sink strength via coordinated regulation of the sucrose–starch metabolic network. Full article

Urban forests serve as representations of nature within city landscapes. Green Forest, spanning 5,198,412 square meters, has been incorporated into the Municipality of Timișoara’s public domain and designated as a forest park. This fact increased green space per capita and enriched biodiversity within Timișoara’s landscape architecture. This study explores the diversity of Green Forest trees and highlights their contribution to the urban landscape. Statistical methods, including comparative and linear relationships analyses, were employed to assess significant variations in the dendrometric parameters of the analyzed tree species: mean tree height, mean trunk diameter at breast height (DBH), tree age, and stand density. Principal Component Analysis (PCA) and cluster analysis were applied to uncover underlying patterns in the data. Using ArchiCAD and Lumion, high-quality 3D visual representations were developed for an ecological education area, an active recreation region, and a passive recreation area within Green Forest. Due to their morphological characteristics and phenotypic traits, the predominant tree species include Quercus robur, Quercus cerris, Quercus rubra, Fraxinus excelsior, Acer platanoides, Acer pseudoplatanus, Ulmus campestris, and Robinia pseudoacacia, which contribute to Timișoara’s urban aesthetic. Moreover, the results of the dendrometric analysis provide a foundation for further research in urban ecology. A key practical application of this study is landscape design renderings, which provide detailed and realistic visualizations to effectively communicate the design and functionality of Green Forest’s spaces. If implemented, these developments will encourage public engagement with nature, promoting mental and physical well-being within the community. Full article

Flooding and sea-level rise are recurrent challenges in Probolinggo Regency, driven by the anthropogenic degradation of mangrove forests. Although restoration initiatives are ongoing, the vegetation condition of natural mangrove forests remain poorly characterized. The aim of this study was to provide a baseline ecological assessment of natural mangrove forests across Probolinggo Regency by evaluating vegetation structure and carbon stocks. Using a purposive sampling method, species composition, vegetation height, and diameter at breast height (DBH) were measured in 33 plots across eight subdistricts. Avicennia marina and Rhizophora mucronata were the dominant species, with relative abundances varying spatially. Saplings represented the most abundant growth stage. Kraksaan subdistrict exhibited the highest Shannon–Wiener diversity index (H’ = 1.8), whereas Sumberasih had the lowest (H’ = 0.9). Species richness (R) ranged from low to moderate, evenness (E) was consistently high, and dominance (C) was low in all subdistricts. Carbon stocks were highest in Dringu (508.1 Mg C ha⁻¹) and lowest in Tongas (87.6 Mg C ha⁻¹). Overall, the natural mangrove forests in Probolinggo Regency appeared to be in an early to mid-successional stage because of past degradation, highlighting the need for continuous monitoring to support vegetation recovery and sustain ecosystem services. Full article

Identifying a metabolic rescue for mitochondrial toxins induced neurodegeneration is a promising therapeutic target. Dopaminergic neurons are high energy dependent neurons, owing to their metabolic functions, and this makes them vulnerable in conditions of bioenergetic failure and mitochondrial dysfunction. In this study, we explored the protective potential of sodium propionate, a short-chain fatty acid and metabolic precursor of succinate, against mitochondrial toxin-induced neurotoxicity in MN9D dopaminergic cells. Cells were treated with 200 µM sodium propionate after exposure to 1.5 µM rotenone or 10 µM antimycin A, and cell viability, intracellular ATP levels, reactive oxygen species (ROS) generation, and dopaminergic markers were assessed. Our results show that sodium propionate significantly attenuates mitochondrial toxin-induced loss of cell viability and ATP depletion while reducing oxidative stress and preserving the expression of enzymes involved in catecholamine biosynthesis pathway, including tyrosine hydroxylase (TH) and dopamine β-hydroxylase (DBH). These findings suggest that sodium propionate confers functional protection to dopaminergic neurons under mitochondrial toxin stress. Sodium propionate is proposed to act as a metabolic precursor to succinyl-CoA, thereby replenishing tricarboxylic acid cycle intermediates and supporting cellular metabolic homeostasis. Under Complex I inhibition (rotenone) and complex III inhibition (antimycin A), sodium propionate treatment was associated with preservation of cellular ATP levels. Across conditions, sodium propionate treatment was associated with improved cell viability, reduced oxidative stress associated signals, and preservation of dopaminergic function. Together, these data indicate that sodium propionate supports dopaminergic neuronal resilience through toxin-dependent metabolic and cellular stress modulating effects. Full article

To investigate the effects of long-term continuous rotary tillage incorporation (RT) on Fraxinus chinensis Roxb. plantations, this study compared 7- and 15-year-old stands subjected to RT since afforestation with their non-tilled counterparts (CK). Results demonstrated that RT significantly enhanced tree growth by synergistically improving soil nutrient availability, physical properties, and microbial community structure and function: (1) Compared with CK, RT increased diameter at breast height (DBH) by 28.89% in 7-year-old stands and 22.58% in 15-year-old stands, and tree height by 19.51% in 7-year-old stands and 25.00% in 15-year-old stands; (2) RT increased contents of soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP), rearranged the distribution patterns of soil particulate organic carbon (POC) and mineral-associated organic carbon (MAOC), and reduced soil bulk density (BD) and soil water content (SWC); (3) RT regulated microbial diversity, co-occurrence networks, and carbohydrate-degrading gene abundances, with more prominent effects in 15-year-old stands. This tillage practice is feasible and effective, and thus is recommended for application in F. chinensis plantation management, providing a scientific basis for refined and sustainable plantation management. Full article

Handheld personal laser scanning (PLS) systems are increasingly being tested in forest inventory as an efficient alternative to labor-intensive, time-consuming field-based methods. However, comparative evaluations across different PLS instrument classes and the influence of operator experience on estimation accuracy remain insufficiently explored. This study presents a controlled comparison of three handheld PLS instruments representing different performance and cost classes, namely professional-grade (high-end) and lower-grade (entry-level and open-source) systems, and evaluates the influence of operator experience on the accuracy of diameter at breast height (DBH) and tree height estimation. Data were collected in even-aged European beech stands using consistent acquisition and processing workflows. Tree attributes were independently estimated by operators with high, medium, and low experience and validated against reference measurements obtained from diameter tape and multi-scan terrestrial laser scanning. Accuracy was assessed using mean difference (bias) and root mean square error, and the effects of instrument type and operator experience were analyzed using one-way and two-factor repeated-measures ANOVA. Results show that instrument type is the dominant factor determining estimation accuracy. The high-end system produced the most accurate DBH and tree height estimates across all operator experience levels, whereas the entry-level and open-source systems yielded acceptable DBH accuracy but consistently underestimated tree height, particularly for taller trees. Operator experience had a secondary effect, improving DBH estimates when lower-grade instruments were used, but had little influence on tree height accuracy. Significant interaction effects indicate that operator influence depends on instrument class. These findings demonstrate that PLS can support operational forest inventory when instrument capabilities align with inventory objectives. High-end systems are currently optimal when reliable tree height estimation is required, whereas lower-grade systems may provide cost-effective solutions for inventories focused primarily on DBH. Full article

Greenhouse gases emitted by humans have exacerbated global climate change. Forests can effectively sequester atmospheric carbon dioxide through photosynthesis, and afforestation has been widely adopted worldwide to mitigate climate change. Cunninghamia lanceolata and Pinus massoniana, as major afforestation tree species, are extensively cultivated in southern China. However, the mechanisms by which climate, topography, biodiversity, forest structure, and forest growth status affect the productivity of these two species remain unclear. This study used forest inventory data from Lishui City combining the Biomod2 model with a structural equation model (SEM) to investigate the differential effects of biotic and abiotic factors on the productivity of the two tree species. The results showed that at the same diameter at breast height (DBH), the biomass of P. massoniana reached 384.67 kg, accounting for 188.75% of that of C. lanceolata (211.07 kg). The dominant climatic factors affecting C. lanceolata and P. massoniana were different; the most important climatic factors affecting C. lanceolata were Bio 17, Bio 15, Bio 05, Bio 08, and Bio 02, while those affecting P. massoniana were Bio 18, Bio 04, and Bio 01. Furthermore, the explanatory power of the structural equation model (SEM) optimized by the Biomod2 model was effectively improved. Biodiversity and forest growth factors were the most important biotic factors affecting C. lanceolata (p < 0.01), while structural diversity and forest growth factors were the most important biotic factors affecting P. massoniana (p < 0.05). Biodiversity and structural diversity exerted divergent effects on C. lanceolata and P. massoniana in different growth stages, exerting negative effects in the early growth stage and positive effects in the late growth stage. These outcomes were jointly driven by the selection effect and niche complementarity. This study recommends the forest management practices should select tree species based on local conditions. Full article

Black locust (Robinia pseudoacacia L.) breeding is an important component of plantation forestry in Central and Eastern Europe; however, clone trials are still mainly evaluated using conventional field surveys, and the application of high-resolution red-edge satellite indices at the intraspecific level remains rarely applied. As a result, less information is available on the phenological status of black locust clones derived from red-edge satellite data. This study evaluates a clone trial established in Eastern Hungary on slightly acidic Arenosol soil, assessing the growth performance and seasonal spectral dynamics of newly bred black locust clones during their fifth growing season by integrating field measurements with PlanetScope-derived Normalized Difference Red-Edge Index (NDRE) time series. Clone NK2 exhibited the most vigorous growth, reaching a mean height of 11.1 ± 0.15 m and a diameter at breast height (DBH) of 11.21 ± 0.19 cm, which were 35.4% greater in height and 19.0% larger in DBH than those (8.2 ± 0.12 m height, and 9.42 ± 0.23 cm diameter) of the control (‘Üllői’ cultivar). Clone PL251 also exceeded the control by 25.6% in height and 19.2% in DBH. Spectral analysis (NDRE value ± standard error) revealed marked differences in phenological development: in the early stage (April 15), NK1 and PL040 had the highest NDRE values (0.472 ± 0.020 and 0.461 ± 0.019), whereas NK2 showed delayed leaf emergence (0.398 ± 0.019). By June 21, PL251 had reached an NDRE value of 0.692 ± 0.013, which was higher than that of the control (0.673 ± 0.016). In mid-July, NDRE peaked for NK2 and NK1 (0.732 ± 0.012 and 0.731 ± 0.013), with ‘Üllői’ showing consistently lower values across the season. In the final stage, NK2 maintained the highest NDRE values (October 22: 0.618 ± 0.015; November 9: 0.466 ± 0.021), indicating prolonged photosynthetic activity, while NK1 and ‘Üllői’ declined earlier (e.g., November 9: 0.354 ± 0.018 and 0.390 ± 0.027, respectively). These findings highlight NK2 and PL251 as superior candidates for high-yield, climate-resilient tree plantations because of their strong growth and extended physiological activity. Full article

The dimension-balanced cycle (DBC) problem is new in graph theory, with applications such as 3D stereogram reconstruction. In a graph whose edges are partitioned into k dimensions, a cycle is dimension-balanced if edge counts across dimensions differ by at most one. When such a cycle is Hamiltonian, it is called a dimension-balanced Hamiltonian cycle (DBH). Since DBHs do not always exist, a relaxed notion—the weakly dimension-balanced Hamiltonian (WDBH) cycle—was considered, allowing a difference of up to three. We prove that WDBH always exists in any 3-dimensional toroidal mesh graph T_m,n,r for all positive integers m, n, and r. Full article

Sapium discolor is a valuable native species in southern China, valued for its rapid growth and vibrant foliage, and widely used in ecological restoration and landscaping. To identify superior propagation materials with fast growth and red leaves, regional open-pollinated progeny trials of 10 elite trees were established in Nanping, Sanming, and Zhangzhou (Fujian Province) in 2015. Growth (tree height and diameter) was monitored from 2015 to 2023, and leaf color (the proportion of red in leaf color) was assessed in 2024. The species showed early fast growth, with mean tree height and diameter at breast height (DBH) reaching 7.98 m and 9.99 cm at six years, then slowing. Family-level phenotypic variation was limited. ANOVA revealed highly significant differences among families for growth traits from 2016 onward and for leaf color in 2024. Broad-sense heritability was moderate for 2023 tree height (0.3839), DBH (0.1879), and 2024 leaf color (0.2102), with low narrow-sense heritability, indicating non-additive genetic effects. Clonal selection based on genotypic values achieved notable genetic gains, especially for growth. One superior clone combined improvements in height (13.1%), diameter (10.1%), and red coloration (8.3%). These results highlight the value of clonal selection and the need to consider genotype × environment interactions in breeding programs. Full article