Search Results (37)

Pea (Pisum sativum L.) is an important temperate grain legume crop of high nutritional and agronomic value. Ascochyta blight, caused by a multi-species complex of necrotrophic fungi, remains a major constraint for pea production worldwide. This review synthesizes the available genetic, physiological and molecular knowledge on the pea–Ascochyta blight pathosystem, with emphasis on the genetic architecture of resistance, host defense mechanisms and the recent contributions from the omics disciplines. Current evidence indicates that genetic resistance to the various Ascochyta blight pathogens is incomplete and multicomponent, being associated with loci of small to moderate effect, with expression depending on organ, developmental stage and environment. Under field conditions, the observed phenotypes reflect the interaction between physiological resistance, plant architecture, phenology, canopy microenvironment and epidemic dynamics. Together, these factors bias phenotyping and limit the transferability of molecular markers. The practical value of these markers for use in marker-assisted selection (MAS) and genomic selection (GS) is presented and critically discussed. Future progress in breeding for Ascochyta blight resistance will depend on integrating molecular knowledge with a careful definition of ideotypes, well-calibrated phenotyping and multi-environment validation. Full article

Pinus yunnanensis, an endemic tree species in southwest China, is regarded as a suitable candidate for afforestation. However, long-term disturbances have led to forest degradation and structural simplification. This study evaluated taxonomic and phylogenetic alpha (α) and beta (β) diversity across three P. yunnanensis vegetation types: evergreen coniferous forests (ECFs), evergreen coniferous and broad-leaved mixed forests (ECMFs), and deciduous and coniferous broad-leaved mixed forests (DCMFs), aiming to identify their optimal ecological configurations. A total of 120 vascular plant species from 33 families and 55 genera were recorded, with Ericaceae, Fagaceae, Pinaceae, and Adoxaceae as the co-dominant families. In the tree layer, species richness was significantly higher in DCMFs than in ECFs (p < 0.05), likely due to improved winter light availability resulting from seasonal canopy shedding. Both ECMFs and DCMFs supported significantly higher phylogenetic α diversity than ECFs, indicating a broader evolutionary history and potentially greater functional resilience. In contrast, taxonomic β diversity was lower in ECFs, suggesting a more homogeneous species composition dominated by closely related shrubs. Among the vegetation types, the P. yunnanensis–Pinus armandii community in ECFs showed the highest species richness and a stable microenvironment, making it particularly suitable for ecological restoration at high altitudes. Within ECMFs, the P. yunnanensis–Lyonia ovalifolia community appeared to be the most optimal, potentially reducing competition and promoting species coexistence through resource complementarity. In DCMFs, the P. yunnanensis–Alnus nepalensis community, with its strong nitrogen-fixing capacity, emerged as the preferred configuration for restoring degraded forests at lower elevations. These findings suggest that future vegetation restoration projects centered on P. yunnanensis should adopt tailored combinations of vegetation types based on specific environmental conditions. Full article

Street greening is widely recognized as influencing resident well-being and housing prices, and street-view imagery provides a fine-grained data source for quantifying urban microenvironments. However, existing research predominantly relies on single indicators such as the Green View Index (GVI) and overall green coverage/volume lacking a systematic analysis of how the hierarchical structure of trees, shrubs, and grass relates to housing prices. This study examines the high-density block context of Tianjin’s six urban districts. Using the Street Greening Space Structure (SGSS) dataset to construct greening structure configurations, we integrate housing-price data, neighborhood attributes, and 13,280 street-view images from the study area. We quantify how “visibility and hierarchical ratios” are capitalized on in the housing market and identify auditable threshold ranges and contextual gating. We propose an urban–forest structural system centered on visibility and hierarchical ratios that links street-level observability to ecosystem services. Employing an integrated framework combining Geographical-XGBoost (G-XGBoost) and SHapley Additive exPlanations (SHAP), we move beyond average effects to reveal structural detail and contextual heterogeneity in capitalization. Our findings indicate that tree visibility G_TVI is the most robust and readily capitalized price signal: when G_TVI increases from approximately 0.06 to 0.12–0.16, housing prices rise by about 8%–10%. Hierarchical structure is crucial: balanced tree–shrub ratios and moderate shrub–grass ratios translate “visible green” into functional green. Capitalization effects are environmentally conditioned—more pronounced along corridors with high centrality and accessibility—and are likewise common in dense East Asian metropolises (e.g., Beijing, Shanghai, Seoul, and Tokyo) and rapidly motorizing cities (e.g., Bangkok and Jakarta). These patterns suggest parametric prescriptions that prioritize canopy-corridor continuity and keep ratios within actionable threshold bands. We translate these findings into urban greening strategies that prioritize canopy continuity, under-canopy permeability, and maintainability, providing sustainability-oriented, parameterized guidance for converting urban greening structure into ecological capital for sustainable cities. Full article

The prolonged retention of senescent branches and needles (canopy litter) in Cunninghamia lanceolata canopies is an evolutionary adaptation, yet its impacts on stand microenvironment and understory succession remain poorly quantified. To address this gap, we conducted a 5-year field experiment across six planting densities (1800, 2400, 3000, 3600, 4200, and 4800 trees·ha⁻¹), aiming to evaluate the effects of canopy litter removal on canopy structure, forest light environment, and understory biodiversity. Results demonstrated that leaf area index (LAI) and mean tilt angle of the leaf (MTA) significantly increased with density (p < 0.05), leading to marked reductions in photosynthetic photon flux density (PPFD) and light transmittance (T). Canopy litter removal significantly reduced LAI across all densities after 4–5 years (p < 0.05) and consistently enhanced PPFD and transmittance (p < 0.01). MTA and light quality parameters (red:blue and red:far-red ratios) both exhibited variable responses to litter removal, driven by density and time interactions, with effects diminishing over time. Understory vegetation diversity exhibited pronounced temporal dynamics and density-dependent responses to canopy litter removal, with increases in species richness (S), Simpson diversity (D), and Shannon–Wiener diversity (H), while Pielou Evenness (J) responded more variably. The most notable increase in species richness occurred in the 4th year, when 21 new species were recorded, largely due to the expansion of light-demanding bamboos (e.g., Indocalamus tessellatus and Pleioblastus amarus), heliophilic grasses (e.g., Lophatherum gracile) and pioneer ferns (e.g., Pteris dispar and Microlepia hancei). Correlation analyses confirmed PPFD as a key positive driver of all diversity indices (p < 0.01), whereas LAI was significantly negatively correlated with PPFD, light transmittance, and understory diversity (p < 0.01). These findings demonstrate that strategic management of canopy litter incorporating stand density regulation can improve understory light availability, thereby facilitating heliophilic species recruitment and biodiversity enhancement in subtropical coniferous plantations. Full article

Transpiration and canopy shading are the main ways that trees cool urban environments; this is crucial to human survival and improving urban livability in the context of global warming and rapid urbanization. So far, most studies focus on the combined cooling effect of transpiration and canopy shading, but their individual contributions have not been widely explored. Therefore, a quantitative framework was developed by carrying out a long-term field experiment and microenvironment simulations to investigate the cooling effect of a single Ficus concinna. The results show that the annual mean cooling effects of shading and transpiration are 0.17 ± 0.27 °C and 0.30 ± 0.13 °C, accounting for 21.2 ± 51.6% and 44.7 ± 26.3% of total cooling, respectively. Shade cooling demonstrates strong radiative dependence, reaching a peak of 0.63 °C with a cooling contribution of 77.1% during summer at noon due to solar radiation interception. In contrast, nighttime and winter conditions revealed shading-induced temperature increases up to 0.52 °C via longwave radiation reflection. By contrast, transpiration cooling demonstrated temperature dependence, which increased with air temperature and peaked at 1.03 °C (contributing 70.0% to the total cooling) before stomata closing. This mechanistic analysis quantitatively reveals that F. concinna provides cooling effects through a dynamic complementarity between transpiration and shading. These findings could offer a biophysically grounded basis for optimizing urban greening strategies and contribute to the theoretical advancement of nature-based urban climate solutions. Full article

To effectively address the issues of poor ventilation, light deficiency, increased pest and disease pressure, and declining fruit quality in closed-canopy walnut orchards, this study was conducted in a standard, densely planted ‘Xinwen 185’ walnut orchard. Three treatments were established: an unthinned control (CK), a 1-year thinning treatment (T1), and a 2-year thinning treatment (T2). All parameters were uniformly investigated during the 2023 growing season to analyze the effects of thinning on orchard population structure, microenvironment, leaf physiological characteristics, fruit quality, and yield. The results demonstrated that tree thinning significantly optimized the population structure: crown width expanded by 6.22–6.76 m, light transmittance increased to 27.74–33.64%, and orchard coverage decreased from 100% to 75.94–80.51%. The microenvironment was improved: inter-row temperature increased by 2.34–4.08 °C, light intensity increased by 5.38–25.29%, and relative humidity decreased by 2.15–3.30%. Furthermore, leaf physiological functions were activated: in the T2 treatment, the chlorophyll content in outer-canopy leaves increased by 15.23% and 12.45% at the kernel-hardening and maturity stages, respectively; the leaf carbon-to-nitrogen ratio increased by 18.67%; the net photosynthetic rate (Pn) during fruit expansion increased by 34.21–46.10%; and the intercellular CO₂ concentration (Ci) decreased by 10.18–10.31%. Fruit quality and yield were synergistically enhanced: single fruit weight increased by 23.39~37.94%, and kernel weight increased by 26.79–41.13%. The total sugar content in inner-canopy fruits increased by 16.50–16.67%, while the protein and fat content in outer-canopy fruits increased by 0.69–12.50% and 0.60–2.18%, respectively. Yield exhibited a “short-term adjustment and long-term gain” pattern: the T2 treatment (after 2 years of thinning) achieved a yield of 5.26 t·ha⁻¹, which was 20.38% higher than the CK. The rates of diseased fruit and empty shells decreased by 65.71% and 93.22%, respectively, and the premium fruit rate reached 90.60%. This study confirms that tree thinning is an effective measure for improving the growing environment and enhancing overall productivity in closed-canopy walnut orchards, providing a scientific basis for sustainable orchard management and increased orchard profitability. Full article

Canopy conductance (G_c) is an important biological constant for quantifying the water vapor flux at the canopy-atmosphere interface, reflecting the coupling strength between crop transpiration and microclimate. To elucidate how mulching modulates G_c dynamics under varying environments, we measured the transpiration of maize based on thermal equilibrium method from 2020 and 2021, synchronously recording solar radiation (R_s), temperature (T), relative humidity (RH), and vapor pressure deficit (VPD) under no-mulching (NM), transparent film (TFM), black film (BM), and straw mulching (SM) treatments in the North China Plain. The results showed that in the near-surface microenvironment, at early stages (seedling-jointing), compared to the NM treatment, TFM and BM treatments unexpectedly reduced temperature by 0.1–1.1% while increasing humidity by 0.2–4.0%, lowering VPD by 0.7–15.5%, contradicting presumed warming effects. During tasseling-filling stages, both plastic films elevated temperature by 3.5–5.2%, decreased humidity by 5.2–6.9%, and sharply increased VPD by 23.4–27.6%, inducing heat-VPD coupling stress. Throughout the entire growth period, SM treatment resulted in an initial increase followed by a decrease in temperature, but the decrease in humidity and increase in VPD occurred earlier and smoothly compared to film mulching treatment in the near-surface microenvironment. All treatments increased average temperature but decreased average humidity in the near-ground microenvironment throughout growth stages, ultimately leading to an increase in average VPD. In addition, all treatments increased G_c at noon by 10.3–81.2%. Under different solar radiation conditions, TFM, BM, and SM treatments increased the reference conductance (G_cR) but did not always increase G_c sensitivity to VPD (m). We propose a specific mulching strategy: Using black or transparent plastic film mulching in arid/cold regions and straw mulching in high-temperature and drought-prone/rain-fed agricultural areas can reconcile the trade-off between microclimate optimization and physiological adaptation, advancing precision water management in arid-prone croplands. Full article

Reliable source term prediction for hazardous pollutant puffs in urban microenvironments is challenging, especially for risk management under strict time constraints. Puff movement is highly stochastic due to atmospheric turbulence, intensified by complex urban canopies. This complexity, combined with time limitations, makes advanced computational modeling impractical. A more efficient approach is leveraging past and present data using Machine Learning (ML) techniques. This study proposes an ML-based method, enriched with simplified physical modeling, for source term estimation of unforeseen hazardous air releases in monitored urban areas. The Random Forest Regression, commonly used in meteorology and air quality studies, has been selected. A novel variable selection method is introduced, including the following: (a) a model-derived Exposure Burden Index (EBI) reflecting plume–morphology interactions; (b) a plume travel time indicator; (c) the standard deviation of input variables capturing stochastic behavior; and (d) the total dosage-to-mass released ratio at sensor locations as the target variable. The case study examines JU2003 field experiments involving SF₆ puffs released at street level in Oklahoma City’s urban core, a challenging scenario due to the limited number of sensors and historical data. Results demonstrate the approach’s effectiveness, offering a promising, realistic alternative to traditional computationally intensive methods. Full article

Mediterranean wood pastures are the result of traditional silvo-pastoral uses that shaped these ecosystems into a mosaic of trees and open grassland. This ecosystem structure is generally associated with increased soil fertility under tree canopies. However, the response of herbaceous plant functional types (PFTs)—grasses, legumes, and non-legume forbs—to these heterogeneous microenvironments (under the canopy vs. open grassland) remains largely unknown, particularly regarding carbon (C) and nitrogen (N) acquisition and use. Even less is known about how different tree species and environmental conditions influence these responses. In this study, we aim to assess how tree canopies influence carbon and nitrogen cycling by comparing the effects of traditional oak stands and pine plantations on herbaceous PFTs and soil dynamics. For that we use C and N content and natural isotopic abundances (δ¹³C and δ¹⁵N) as proxies for biogeochemical cycling. Our results show that ecosystem C and N patterns depend not only on herbaceous PFTs and the presence or absence of tree canopies but also on tree species identity and environmental conditions, including climate. In particular, pine-dominated plantations exhibited lower nitrogen availability compared to those dominated by oak, suggesting that oak stands may contribute more effectively to enhance soil fertility in Mediterranean wood pastures. Furthermore, the canopy effect was more pronounced under harsher environmental conditions, highlighting the role of trees in buffering environmental stress, particularly in arid regions. This suggests that changes in tree cover and tree species may drive complex changes in ecosystem C and N storage and cycling. Full article

Tree-lined spaces as informal communication areas and important pathways for pedestrians are the second largest zones on university campuses, and they have a large impact on the microclimate. At present, the effects of the spatial form for tree-lined boulevards on microclimates have not been investigated. Thus, this study applied experimental and simulation methods to investigate the effects of tree-lined boulevards on microclimates in hot summer and cold winter regions. The main meteorological parameters including air temperature, relative humidity, wind speed, and solar radiation of the boulevard were obtained by experiments. Furthermore, the experimental data as a boundary condition were input into ENVI-met software to investigate the effects of the aspect ratio and canopy diameter of double-row open-canopy boulevards on microclimate regulation. The results showed that when the aspect ratio was reduced from 1.5 to 0.9, the temperature and UTCI increased by 0.047 °C and 0.21 °C, while relative humidity decreased by 0.227%. Decreasing the aspect ratio can effectively improve the microenvironment. As the canopy diameter increased from 7 m to 11 m, the temperature and UTCI of the boulevard space decreased by 0.064 °C and 0.45 °C, while relative humidity increased by 0.245%. An increase in canopy diameter is unfavorable to the improvement of microclimates. This study aims to provide a scientific basis for the design and improvement of tree-lined boulevards on university campuses. Full article

The ‘Diaoganxing’ is the experimental material, with natural grass cover as the control, to compare the effects of 5 different mulching materials. The aim was to identify the most effective mulching type for improving orchard microenvironments and fruit quality. The results demonstrated that waterproof, breathable film and reflective film significantly enhanced orchard microenvironments and fruit quality (p ≤ 0.05). Specifically, the waterproof, breathable film effectively regulated soil temperature and moisture, reducing soil temperature by 4.60% and increasing soil moisture by 17.09% in the 0–60 cm soil layer. Meanwhile, the reflective film optimized light distribution in the mid-lower canopy, increasing light intensity by 161.04–208.71% and reflectance by 2.6–3.3 times. In terms of fruit quality, the reflective film accelerated ripening by 10 d, increased carotenoid content by 15.34%, and achieved a peel color index (CCI) of 6.23. On the other hand, the waterproof breathable film advanced maturation by 7 d and significantly improved vitamin C, soluble sugar, and soluble solids content by 23.26%, 30.77%, and 12.76%, respectively. This study provides a scientific basis for the efficient and high-quality production of apricots in southern Xinjiang through the use of mulching practices. Full article

Nitrogen fertilizer setback and planting density both affect wheat yield. However, the differences in winter wheat yield and its components, canopy structure, and microenvironment caused by N fertilizer setback at different planting densities are not clear. A two-year field experiment was conducted to investigate the most suitable planting density and N fertilizer setback combinations for winter wheat. Three planting densities of 3.3, 2.36, and 1.77 million plants·hm⁻², and two basal fertilizer/nodulation and fertilizer/spike fertilizer ratios of 6:4:0 and 4:3:3, respectively, were used in the experiment. The results of the two-year experiment showed that, under the same planting density, the yields of wheat with nitrogen fertilizer setback increased by 8.2%, 2.7%, and 2.8%, respectively; the total leaf area of the upper trifoliate leaves increased by 10.7–17.4%; and the leaf area index (LAI) increased by 5.4% and 5.3%, respectively. The results showed that the yield, the effective number of spikes, leaf area index, and vertical light interception of wheat at a density of 3.30 million plants·hm⁻² were higher than those of the other treatments. In both years of the experiment, the planting density of 3.30 million plants·hm⁻² with nitrogen fertilizer setback (basal fertilizer/nodulation fertilizer/spike fertilizer = 4:3:3) was the best. Therefore, a nitrogen application of 240 kg·hm⁻² and a planting density of 3.30 million hm⁻² with nitrogen fertilizer setback was found to be the best combination. Full article

Canopy FGF signaling regulator 2 (CNPY2) has emerged as a crucial player in cancer development by promoting cell proliferation, tissue repair, and angiogenesis. This review synthesizes the current understanding of CNPY2’s role in solid tumors, particularly renal cell carcinoma, prostate cancer, hepatocellular carcinoma, and non-small-cell lung cancer. CNPY2 modulates key pathways such as p53, MYLIP, NF-κB, and AKT/GSK3β, thereby driving tumor growth and progression. In renal cell carcinoma, CNPY2 paradoxically promotes tumor growth through p53 upregulation, while in hepatocellular carcinoma, CNPY2 drives cell cycle progression via p53 destabilization. In prostate cancer, it enhances tumor progression by stabilizing androgen receptors through MYLIP interaction, and in non-small-cell lung cancer, it contributes to chemoresistance and metastasis through NF-κB and AKT/GSK3β signaling. Additionally, CNPY2 influences the tumor microenvironment, impacting immune function and metastatic potential. As a potential biomarker, CNPY2 shows promise for cancer detection and prognosis, particularly when used in combination with other markers. Early therapeutic strategies, including siRNA and miRNA approaches, are under exploration, though challenges remain due to CNPY2’s expression in normal tissues and potential off-target effects. This review underscores the need for further research to fully elucidate CNPY2’s oncogenic mechanisms and develop targeted therapies. Improved understanding of CNPY2’s diverse roles may lead to novel diagnostic and therapeutic approaches in solid tumors. Full article

Logging operations change the forest environment by creating a heterogeneous canopy with a range of different microenvironments that differ mostly in light intensity and level of soil disturbance. In this study, the growth characteristics and architecture of beech (Fagus orientalis Lipsky) seedlings grown in three different microenvironments in terms of canopy and soil conditions were investigated. The experimental treatments (microenvironments) included skid trail (removal of canopy and compacted soil), winching corridor (natural canopy and compacted soil), felling gap (removal of canopy and natural soil), and comparison with the control area (canopy and soil in natural state). The results showed that the status of many growth and architectural indicators of seedlings is significantly less favorable than in the control area. These indicators include the length and biomass above and below ground, and the ratio of root length to stem length in the skid trails and winching corridors. The status of these indicators was, however, more favorable in felling gaps than in the control area. The seedling quality index decreased by −12.2% and −4.9% in skid trails and winching corridors, respectively, but increased by 2.4% in felling gaps compared to the control area. The growth characteristics and biomass of seedlings had a significant negative correlation (p < 0.01) with soil bulk density and penetration resistance and a significant positive correlation (p < 0.05) with soil porosity, moisture, and organic matter content. These results showed that the creation of a gap in the stand canopy due to the cutting of individual trees created a favorable micro-environment for the growth of seedlings, but the soil compaction caused by logging operations created an unfavorable micro-environment for these. Therefore, it is necessary to plan and execute the operation of extracting the cut trees in such a manner as to reduce the extent and severity of soil compaction with the goal of preserving and maintaining the stability of the forest ecosystem. Full article

Shading is an effective agronomic technique to protect tea plants from intense sunlight. However, there are currently very few studies on more effective shading methods to improve the quality of summer tea. In this study, ‘Longjing43’ plants were grown under four different shading treatments for 14 days, with no shading as the control. Among the four shading treatments, double-layer-net shadings had the most positive impact on the tea quality, resulting in higher levels of amino acids but lower levels of tea polyphenols. Additionally, double-layer-net shadings provided more suitable microenvironments for tea plants. The tea leaves in T4 (double nets 50 cm above the plant canopy) contained 16.13 mg∙g⁻¹ of umami and sweet amino acids, which was significantly higher than in other treatments. T4 had the lowest air temperature and the most suitable and stable soil water content. Interestingly, the ratio of red light to far-red light in T4 was only 1.65, much lower than other treatments, which warrants further study. In conclusion, the microenvironment induced by shading can greatly affect the tea quality, and double-layer-net shading is better for improving the quality of summer tea. Full article