Methods to model wet snow accretion on structures are developed and improved, based on unique records of wet snow icing events as well as large datasets of observed and simulated weather. Hundreds of observed wet snow icing events are logged in detail in an icing database, most of which include an estimate of the mean and maximum diameter of observed icing on overhead power conductors. Observations of weather are furthermore available from a dense network of weather stations. The existing models for wet snow accretion on a standard cylinder are updated with realistic values for the terminal fall speed of wet snowflakes together with a snowflake liquid fraction–based criterion to identify wet snow. The widely used parameterization of the sticking efficiency is found to strongly underestimate the accretion rate. A calibrated parameterization of the sticking efficiency is suggested on the basis of long-term statistics of observed and modeled wet snow loads. Application of the improved method is demonstrated in a high-resolution simulation for a case of observed widespread and intensive wet snow icing in south Iceland. The results form a basis for mapping the climatology of wet snow icing in the complex terrain of Iceland as well as for preparing operational forecasts of wet snow icing and severe weather for overhead power transmission lines in complex terrain.

Background: The study examined the impact of varying the concentrations of zinc (Zn) on plant responses, particularly on photosynthetic and oxidative metabolic processes. This investigation aimed to distinguish between the beneficial and harmful effects of Zn on plants, highlighting significant nutrient supply concerns. Methods: The investigation methods were centered around non-invasive methods, such as biophoton emission (delayed fluorescence—DF, ultra-weak bioluminescence—UWLE), fluorescence induction (F_v/F_m) measurements, chlorophyll content estimation (SPAD) and vegetation index (NDVI) determination. Furthermore, the analytical determination of lipid oxidation (MDA level) and antioxidant capacity (FRAP) as well as gene expression studies of the antioxidative enzymes glutathione reductase (GR), glutathione S-transferase (GST) and lipoxygenase (LOX) for essential Zn and nonessential cadmium (Cd) were also carried out in order to clarify toxic symptoms through different Zn investigation approaches. Results: It was possible to identify a metabolic enhancement from 1000 µM; however, stress symptoms from the 2000 µM Zn treatment were noted for both the investigated photosynthetic and oxidative processes. The outcomes of this research contribute to the improvement of Zn mineral-supplementation technology, which is essential for maize growth, and the optimization of agricultural practices.

High temperature induces oxidative processes in wheat, the alleviation of which is promising using biostimulants. Priming has been used for enhancing stress tolerance of seedlings. However, the usage of biostimulants for priming is an unexplored area under either normal or stress conditions. Therefore, the aim of our study was to evaluate the heat stress alleviation capability of differentially applied biostimulant treatments on wheat seedlings. The investigation included stress parameters (fresh/dry weight ratio, chlorophyll content estimation, antioxidant capacity and lipid oxidation) combined with biophoton emission measurement, since with this latter non-invasive technique, it is possible to measure and elucidate in vivo stress conditions in real-time using lipid oxidation-related photon emissions. We confirmed that a single biostimulant pretreatment increased antioxidant capacity and decreased biophoton release and lipid oxidation, indicating the reduction of the harmful effects of heat stress. Therefore, biophoton emission proved to be suitable for detecting and imaging the effects of heat stress on wheat seedlings for the first time. Two-way analysis of variance (ANOVA) revealed that biostimulant (p = 4.01 × 10⁻⁷) treatments, temperature (p = 9.07 × 10⁻⁸), and the interaction of the two factors (p = 2.07 × 10⁻⁵) had a significant effect on the overall count per second values of biophoton emission, predicting more efficient biostimulant utilization practices, even for seed priming purposes.

Biophoton radiation also referred to as ultra-weak photon emission (UPE) is used to denote a spontaneous and permanent photon emission associated with oxidative processes in cells and seems to universally occur in all living systems as a result of the generation of reactive oxygen species (ROS) that are produced under stress conditions. The measurement of this biophoton emission allows for a non-invasive approach in monitoring phenological stages throughout plant development which has direct relevance in agriculture research. In this study, the emission of photons emanating from sunflower (Helianthus annuus, L.) plants exposed to biotic and abiotic stress has been investigated. In healthy plants raised under controlled growth conditions UPE was low whereas in stressed individuals it considerably increased; particularly upon water stress. The kinetics of the signal is shown to reveal an exponential decay with characteristic dynamics, which appears to reflect different physiological states concomitantly setting in upon stress. The dynamics of the signal decay is shown to vary according to the type of stress applied (biotic vs. abiotic) hence suggesting a putative relationship between the kinetic traits of change in the signal intensity-decay and stress. Intriguingly, the determination of the change in the intensity of biophoton emission that ensued in a short time course was possible by using the initial biophoton emission intensity. The predictability level of the equations demonstrated the applicability of the model in a corroborative manner when employing it in independent UPE-measurements, thus permitting to forecast the intensity change in a very accurate way over a short time course. Our findings allow the notion that albeit stress confers complex and complicated changes on oxidative metabolism in biological systems, the employment of biophoton imaging offers a feasible method making it possible to monitor oxidative processes triggered by stress in a non-invasive and label-free way which has versatile applications especially in precision agriculture.

The accidentally introduced ragweed leaf beetle ( Ophraella communa ) is a most promising biological control agent for common ragweed ( Ambrosia artemisiifolia ), which herbivore has already emerged in several areas of the Palearctic region. The aim of our study was to model the expansion of O. communa and the number of generations in the various Palearctic regions. Furthermore, our objective was to determine the effect of the prevailing wind on the direction of its spread and to ascertain the relationship between the green biomass production of ragweed and individual numbers of this leaf beetle. According to our meta‐analytical findings, the advancement of O. communa is continuous in the Palearctic areas. This phytophagous insect invades new habitats, which are occupied by A. artemisiifolia , and spreads quickly. The stable populations of O. communa seem to be strictly linked to the presence of its primary host, A. artemisiifolia . We show that the rapid spread of this insect is due to the combination of wind direction and topography features, which was reinforced by our analysis. O. communa possesses uniformly multivoltine populations in its Palearctic habitats. So, insects possessing facultative diapause are able to colonize northern areas depending on the presence of their host, which statement is based on the processing of 143 East‐ and 68 West‐Palearctic records According to our investigations, the mass appearance of this phytophagous insect coincided with the assimilation peak of its main host, common ragweed.

The herb layer plays a significant role in maintaining forest functions, and its community composition is determined by various abiotic factors and biotic interactions. This study attempted to investigate the interspecific plant–plant biotic interactions using a functional traits approach. Specifically, the effects of a dominant species coverage on the functional diversity of coexisting species in the temperate forest understory were studied. Species coverage and soil moisture data were collected using a 1 m² quadrat couplet (2 × 1 m²) from six sites alongside a 20 m linear transect encompassing a cover gradient of Allium ursinum in southwest Hungary. Major plant functional dimensions i.e., aboveground, and clonal functional traits were considered. Linear and nonlinear mixed models to quantify the effects of biotic interaction on the functional diversity of every single trait and multiple traits were employed. Both aboveground traits and clonal traits of persistent clonal growth organs responded positively to the A. ursinum L., cover gradient. The coexistence of understory species in the presence of a monodominant species seems to be mainly influenced by aboveground traits as compared to the clonal traits suggesting, a role of niche differentiation. The consistent impact of A. ursinum coverage on coexisting species dynamics highlights a need for similar in-depth studies in various forest settings.