Vegetation Season Research Articles

Retrieving plant functional traits through time series analysis of satellite observations using machine learning methods

ABSTRACT Plant functional traits (e.g. leaf pigment and water contents, specific leaf area) serve as important indicators of plant condition, both within a given vegetation season and between years. Remote sensing-based methods allow for non-destructive and repeatable monitoring of the Earth’s surface and thus offer an efficient way to map and monitor these traits. In our study, we used a large database of ground survey data sampled at several contrasting phenological phases of vegetation to develop and compare different machine learning models trained to estimate selected plant functional traits at two different sites: mixed floodplain forest at Lanžhot and beech forest at Štítná, both in the Czech Republic. Empirical models were trained as predictors using 1) Sentinel-2 satellite data (a data set with higher spatial and spectral resolution), and 2) Harmonized Landsat Sentinel-2 (HLS) product (a data set with higher temporal resolution). The most successfully retrieved traits were chlorophyll and carotenoid content (R2 = 0.78 and 0.65, respectively). Although models trained with Sentinel-2 predictors proved to be slightly better in terms of validation statistics compared to HLS predictors, the HLS product may be preferable for some applications requiring analysis at a high frequency. The best-performing machine learning algorithm, canonical correlation forest, was then applied per pixel to all cloud-free images from the HLS product at both study sites for the years 2019–2021. This allowed us to create a time series of plant functional traits useful for observing differences between the two sites, as well as between growing seasons, and also to observe patterns of spatial behaviour using map outputs.

Chocolates enriched with seaweed: Sensory profiling and consumer segmentation

The idea of using macroalgae as a sustainable functional food is not new, however studies in the context of phycogastronomy are scarce. The aim of the current study was to develop three different types of chocolate enriched with marine macroalgae (seaweeds) and, through binary logistic regression models, outline their sensory profile (104–139 volunteers per sample), identify the profile of possible buyers and the sensory drivers of liking. The sensory characterization performed for each sample highlighted several attributes imparted by the added seaweeds, as the salty taste derived from kombu and the astringent stimuli and dehydrated fruits flavour note derived from nori. Moreover, together with the marine/ocean smell and vegetable flavour notes, results show there is a direct link between dried Portuguese sea lettuce and a distinctive green tea/matcha flavour. Significant differences were found among the purchase intent, flavour, and overall liking scores for each sample: milk chocolate with kombu and ruby chocolate with nori achieved a higher degree of acceptability by Portuguese consumers than white chocolate with sea lettuce. Along with the sensory drivers of liking uncovered, the preformed a priori and a posteriori consumer segmentation provided useful information for a better understanding of the associations between sensory perception, hedonic appraisal, chocolate consuming patterns and purchase intent of these innovative products. Results show that some macroalgae have the potential to be used in sweet formulations (chocolate) and this appears to be a good strategy to introduce macroalgae into Portuguese markets.

Vertical spread of Hymenoscyphus fraxineus propagules

Currently, the ash dieback causal agent Hymenoscyphus fraxineus is an established invasive pathogen in most European countries. Its potential to spread quickly among invaded forests is based on its propagules: airborne inoculum composed mainly of ascospores originated in apothecia growing on leaf litter infected during the previous vegetation season. The spread of the inoculum by air masses to distant areas is probable and depends on the availability of the ascospores in higher levels of air. Our study aimed to detect the inoculum in an infected area at heights of more than 20 meters. Our study was conducted in a municipal locality (Boršov nad Vltavou) with tens of infected ash trees (Fraxinus excelsior) in South Bohemia (SW Czechia). The infected trees surround an agricultural silo where five rotating arm spore traps (rotorods) were mounted for ten consequent 48h samplings during the peak of the sporulating season (17th July to 6th August 2020). The spore traps were mounted 48, 37, 25, 14 and 0,3 meters above ground. Samples were quantified by qPCR. Results clearly proved the ability of the spores to reach a height of 48 meters. Furthermore, H. fraxineus DNA was detected from all five spore traps during all ten samplings. Mostly, the amount of detected spores showed a decreasing trend with height, and varied a lot. During some of the samplings, higher spore concetrations were achieved at the top than at the lower traps, which can be explained by horizontal air transfer of the inoculum from other infected areas. Based on GLM analyses, higher spore concentrations were achieved during days without rain, lower air temperatures, after cloudy, humid and rainy weather without strong winds. A combination of rotorod ROTTRAP 52 with qPCR quantification proved to be an efficient technology for a study focused on the vertical spread of H. fraxineus propagules.

Tracing of contamination level of organochlorine pesticides in Bottle gourd (Lagenaria siceraria), Sponge gourd (Luffa aegyptiaca), Brinjal (Solanum melongena), Plum (Prunus domestica), Kiwi (Actinidia deliciosa) and Pineapple (Ananas comosus)

Fruits and vegetables have nutritional value, but they can also be source of toxic contaminants such as pesticide residues. The aim of this study was to estimate the contamination level of pesticide residues in summer season fruits and vegetables. The constant use of pesticides contaminated fruits and vegetables pose a major risk to community health. An electron capture detector was used in Gas chromatography analysis to monitor 20 organochlorine pesticides including α-chlordane, γ-chlordane, isomers of benzene hexachloride (α-BHC, β-BHC, γ-BHC, δ-BHC), 4,4’-DDT, 4,4’-DDE, 4,4’-DDD, aldrin, dieldrin, endrin, endrin aldehyde, endrin ketone, heptachlor, heptachlor epoxide, endosulfan-I, endosulfan II, endosulfan sulfate and methoxychlor in six types of fruits and vegetables (bottle gourd, sponge gourd, brinjal, plum, kiwi and pineapple) of summer season. It was found that plum and pineapple were found contaminated with 4,4’-DDD and other fruits and vegetables were found contaminated with more than one pesticides. During the tracing it was noticed that the estimated pesticides concentrations were lower than the (MRL) values but constant eating of infected pesticide fruits and vegetables may produce severe health complications. The findings of the present research showed that the existence of strict rules and observance of pesticide residues in fruits and vegetables is a basic need.

Collective Catering Activities and Official Controls: Dietary Promotion, Sustainability and Future Perspectives.

Ensuring safe meals with suitable hygienic-sanitary and nutritional features is an essential requirement to guarantee health in different settings. This study aims to evaluate the compliance of collective catering menus adopted in both school canteens and healthcare facilities in a regional area where specific guidelines have been issued, assessing many matters from food weight to single courses and from the use of wholegrain pasta and bread to the rotation of seasonal fruit and vegetables. Overall, 85 menus, edited by freelance professionals and endorsed by the Food Hygiene and Nutrition Service staff of the Local Health Authority, were assessed from 2018 to 2022, highlighting critical issues potentially attributable at a local level to the lack of complete knowledge of the existence of guidelines and official reference documents among nutrition professionals. Since the preliminary outcomes show non-compliance in both sectors investigated, it is essential to continue to strengthen the role of prevention departments entrusted with services dedicated to food and nutritional safety and promote joint official controls performed by healthcare workers and other professionals with different backgrounds in order to ensure safe food for the target population that use collective catering services. In school canteens and healthcare facilities, providing and administering food is an opportunity to promote health through a balanced diet and safe food and offers opportunities for the development of community well-being and the local economy in a sustainable manner, understood in economic, environmental and social terms.

Species Composition and Seasonal Abundance of Predatory Mites (Acari: Phytoseiidae) Inhabiting Aesculus hippocastanum (Sapindaceae)

Species of the family Phytoseiidae (Acari: Mesostigmata) inhabit a wide range of herbs, shrubs, and trees. Horse chestnut, Aesculus hippocastanum, is an important ornamental tree in Europe and, in addition to its importance for pollinators, it can serve as a host plant of these predatory mites. Little is, however, known about the factors affecting spatiotemporal variability in the density of phytoseiids on A. hippocastanum in an urban environment. We therefore assessed the species composition and the spatial and seasonal variability in the abundance of Phytoseiidae species in the city of České Budějovice, South Bohemia, Czech Republic. Compound-leaf samples were randomly collected from horse chestnut tree branches at eight sites, five times during the vegetation season in 2013. The mites were collected by washing technique and mounted on slides for identification. In total, 13,903 specimens of phytoseiid mites were found, and eight species were identified: Amblyseius andersoni, Euseius finlandicus, Kampimodromus aberrans, Neoseiulella tiliarum, Phytoseius macropilis, Paraseiulus talbii, Paraseiulus triporus, and Typhlodromus (Typhlodromus) pyri. The predominant species was E. finlandicus (96.25%). The mean number of mites per compound leaf was 2.53, 10.40, 23.54, 11.59, and 9.27 on the sampling dates in each month between May and September, respectively. The results further revealed that the mite abundance varied significantly among sampling sites and that it was negatively related to percentage of greenery area, intensity of greenery care, distance to water body, and density and age of horse chestnut trees, while it was positively related to air pollution index. The importance of leaf micromorphology for the attractiveness of A. hippocastanum to Phytoseiidae is discussed.

Comparison of СO<sub>2</sub> Content in the Atmosphere of St. Petersburg According to Numerical Modelling and Observations

Due to the increase in CO2 content in the Earth’s atmosphere, which is highly dependent on anthropogenic emissions of CO2, quality of emission estimation should be improved. Advanced experiment-based methods of the CO2 anthropogenic emission estimation are built on solution of an inverse problem using highly-accurate measurements of CO2 content and numerical models of transport and chemistry in the atmosphere. The accuracy of such models greatly determines errors of the emission estimations. In a current study temporal variations of column-average CO2 content in an atmospheric layer from surface to the height of ~70–75 km (XCO2) in the Russian megapolis of St. Petersburg during Jan 2019–Mar 2020 simulated by WRF-Chem model and measured by IR Fourier-transform spectrometer Bruker EM27/SUN are compared. The research has demonstrated that the WRF-Chem model simulates well the observed temporal variation of XCO2 in the area of St. Petersburg (correlation coefficient of ~0.95). However, using CarbonTracker v2022-1 data as chemical boundary conditions, the model overestimates XCO2 relative to the observations significantly during almost the whole period of investigation – systematic difference and standard deviation of the difference are 4.2 and 1.9 ppm (1 and 0.5%). A correction of the chemical boundary conditions which is based on analysis of a relation between near-surface wind direction and XCO2 variation notably decreases the systematic difference between the modelled and observed data (almost by a factor of 2). The XCO2 variation by the observations and modelling with uncorrected chemical boundary conditions are in a better agreement during vegetation season. Probably this is related to the compensation of the systematic difference by inaccuracies in estimated biogenic contribution. Hence, the reason of the still existing mean difference between the modelled and observed data can be inaccuracies in setting chemical boundary conditions for upper troposphere and in estimating how biosphere influences CO2 content.

Snow and vegetation seasonality influence seasonal trends of leaf nitrogen and biomass in Arctic tundra

AbstractClimate change, including both increasing temperatures and changing snow regimes, is progressing rapidly in the Arctic, leading to changes in plant phenology and in the seasonal patterns of plant properties, such as tissue nitrogen (N) content and community aboveground biomass. However, significant knowledge gaps remain over how these seasonal patterns vary among Arctic plant functional groups (i.e., shrubs, grasses, and forbs) and across large geographical areas. We used three years of in situ field vegetation sampling from an 80,000‐km2 area in Arctic Alaska, remotely sensed vegetation data (daily normalized difference vegetation index [NDVI]), and modeled output of snow‐free date to determine and model the seasonal trends and primary controls on leaf percent nitrogen and biomass (in grams per square meter) among Arctic vegetation functional groups. We determined relative vegetation phenology stage at a 500‐m spatial scale resolution, defined as the number of days between the date of the seasonal maximum NDVI and the vegetation field sampling date, and relative snow phenology stage (90‐m spatial scale) was determined as the number of days between the date of snow‐free ground and the sampling date. Models including relative phenology stage were particularly important for explaining seasonal variability of %N in shrubs, graminoids, and forbs. Similarly, vegetation and snow phenology stages were also important for modeling seasonal biomass of shrubs and graminoids; however, for all functional groups, the models explained only a small amount of seasonal variability in biomass. Relative phenology stage was a stronger predictor of %N and biomass than geographic position, indicating that localized controls on phenology, acting at spatial scales of 500 m and smaller, are critical to understanding %N and biomass.

Effects of Vegetation Belt Movement on Wildfire in the Mongolian Plateau over the Past 40 Years

The frequency and intensity of fires are increasing because of warmer temperatures and increased droughts, as well as climate-change induced fuel distribution changes. Vegetation in environments, such as those in the mid-to-high latitudes and high elevations, moves to higher latitudes or elevations in response to global warming. Over the past 40 years, the Mongolian Plateau has been arid and semi-arid, with a decrease in growing season vegetation in the southwest and an increase in growing season vegetation in the northeast. The northward movement of vegetation has brought fires, especially in the Dornod, Sukhbaatar, and Kent provinces near the Kent Mountains, and has become more obvious in the past 20 years. The occurrence of a dead fuel index (DFI) with high probability is distributed in northern Mongolia, the border area between China and Mongolia, and the forest-side meadow-steppe region of the Greater Khingan Mountains. These findings suggest that vegetation is moving northward because of climate change and this presents a challenge of future warming spreading fire northward, adding material to the study of the relationship between the northward movement of global vegetation and fires.

Air phyto-cleaning by an urban meadow – Filling the winter gap

Urban areas are characterised by polluted air which endangers the health and quality of life of city dwellers. Among the dangerous air contaminants is particulate matter (PM) and one of the main sources of PM in urban areas is road traffic. Studies have already shown that the air can be phyto-cleaned by plants, especially trees and shrubs. However, for safety reasons, planting trees and shrubs in some places is problematic, e.g. close to roads. These locations are usually occupied by lawns, which are plant communities of low ecological value. Unfortunately, too little attention has been paid so far to urban meadows. Therefore, this study (i) investigated for the first time the phyto-cleaning potential of an urban meadow all year round, including autumn–winter period, and (ii) compared the efficiency and mechanisms of PM phyto-cleaning by an urban meadow and lawn during the vegetative season. Plant material was harvested from urban meadow (in June, August, November and March) and lawns (in June and August) located by a busy road in Warsaw (Poland). PM was analysed in two categories (surface PM and in-wax PM) and two size fractions (fine: 0.2–2.5 µm, coarse: 2.5–10 µm). The results obtained suggested that accumulation of PM by urban meadow is possible even out of vegetative season. In autumn and winter, even though the meadow plants were physiologically not active, they still participated in air phyto-cleaning. Urban meadow phyto-cleaned air most effectively in summer when the vegetation was fully developed, and least effectively in autumn. During the vegetative season, the urban meadow accumulated more PM than lawns, mostly due to the greater height and complex structure. Therefore, urban meadow would appear to offer an promising solution to problem of phyto-cleaning of urban air in the immediate vicinity of roads throughout the year.

Aroma Components in Horticultural Crops: Chemical Diversity and Usage of Metabolic Engineering for Industrial Applications.

Plants produce an incredible variety of volatile organic compounds (VOCs) that assist the interactions with their environment, such as attracting pollinating insects and seed dispersers and defense against herbivores, pathogens, and parasites. Furthermore, VOCs have a significant economic impact on crop quality, as well as the beverage, food, perfume, cosmetics and pharmaceuticals industries. These VOCs are mainly classified as terpenoids, benzenoids/phenylpropanes, and fatty acid derivates. Fruits and vegetables are rich in minerals, vitamins, antioxidants, and dietary fiber, while aroma compounds play a major role in flavor and quality management of these horticultural commodities. Subtle shifts in aroma compounds can dramatically alter the flavor and texture of fruits and vegetables, altering their consumer appeal. Rapid innovations in -omics techniques have led to the isolation of genes encoding enzymes involved in the biosynthesis of several volatiles, which has aided to our comprehension of the regulatory molecular pathways involved in VOC production. The present review focuses on the significance of aroma volatiles to the flavor and aroma profile of horticultural crops and addresses the industrial applications of plant-derived volatile terpenoids, particularly in food and beverages, pharmaceuticals, cosmetics, and biofuel industries. Additionally, the methodological constraints and complexities that limit the transition from gene selection to host organisms and from laboratories to practical implementation are discussed, along with metabolic engineering's potential for enhancing terpenoids volatile production at the industrial level.

Influence of Living Mulch and Nitrogen Dose on Yield and Fruit Quality Parameters of Malus domestica Borkh. cv. ‘Sampion’

This study was conducted to estimate the yield, and to identify and quantify primary and secondary metabolites in fruit of Malus domestica Borkh. cv. ‘Sampion’ under two agrotechnical factors: the floor management (herbicide fallow and living mulch) and the dose of nitrogen (50, 80, 110, and 140 kg ha−1). Compared to herbicide fallow, living mulch did not decrease yield. Research showed a rich composition of phenolic and volatile organic compounds in apples, which varied with the evaluated factors, as well as with the weather conditions during the vegetation season. The precipitation deficit and high summer temperatures did not contribute to proper fruit growth and development and led to a higher content of phenolic compounds in the fruit flesh from trees in herbicide fallow compared to living mulch. Living mulch, which could be a factor regulating the availability of nitrogen to trees, stimulated the synthesis of anthocyanins, which was also potentiated by low average temperatures at harvest time, resulting in a large area of fruit skin red blush.

Feasibility and Response to the San Diego County, California, Supplemental Nutrition Assistance Program (SNAP) Agency Sending Food and Nutrition Text Messages to All Participants: Quasi-Experimental Web-Based Survey Pilot Study

The Supplemental Nutrition Assistance Program (SNAP) provides over 40 million Americans with money for food without typically providing participants with food or nutrition information. Educational SMS text messages can reach large numbers of people, and studies suggest SNAP participants appreciate nutrition education and have access to mobile phones. Using a pre-post intervention design, we assessed the feasibility of, and program satisfaction and outcomes resulting from, the San Diego County, California SNAP agency sending monthly food and nutrition education SMS text messages to all SNAP participants to increase fruit and vegetable purchasing and consumption. We developed and sent 5 behavioral science-informed SMS text messages with links to a project website in English and Spanish with information about selecting, storing, and preparing seasonal fruits and vegetables. The San Diego County SNAP agency sent monthly texts to ~170,000 SNAP households from October 2020 to February 2021. SNAP participants completed web-based surveys in response to a text invitation from the SNAP agency in September 2020 (baseline, n=12,036) and April 2021 (follow-up, n=4927). Descriptive frequencies were generated, and adjusted multiple linear mixed models were run on a matched data set of participants that completed both baseline and follow-up surveys (n=875) assessing pre- or postattitudes, behaviors, knowledge, and self-efficacy. We used adjusted logistic regression models to assess differences between the matched (n=875) and nonmatched (n=4052) participants related to experiences with the intervention (questions asked only at follow-up). After the intervention, matched participants reported significant increase in knowing where to get information about selecting, storing, and preparing fruits and vegetables (3.76 vs 4.02 on a 5-point Likert scale with 5=strongly agree, P<.001); feeling good about participating in SNAP (4.35 vs 4.43, P=.03); and thinking the CalFresh program helps them eat healthy (4.38 vs 4.48, P=.006). No significant pre- or postdifferences were found in fruit or vegetable consumption, though most participants at follow-up (n=1556, 64%) reported their consumption had increased. Among the sample that completed the follow-up survey only (n=4052, not including 875 participants who completed follow-up and baseline), 1583 (65%) and 1556 (64%) reported purchasing and eating more California-grown fruits and vegetables, respectively. Nearly all respondents appreciated the intervention (n=2203, 90%) and wanted it to continue (n=2037, 83%). SNAP can feasibly provide food and nutrition messages via text to participants. A monthly text campaign was well received by responding participants and improved some measures of their self-reported knowledge, self-efficacy, produce consumption, and perceptions of SNAP participation. Participants expressed interest in continuing to receive texts. While educational messages will not solve the complex food and nutrition challenges confronting SNAP participants, further work should employ rigorous methods to expand and test this intervention in other SNAP programs before considering to implement it at scale.

Vascular Cambium—Between the Hammer and the Anvil: A Tensile Stress Hypothesis on the Mechanism of Radial Growth of Broadleaved Trees

The vascular cambium is the main lateral meristem responsible for the secondary growth of trees. There are a number of explicit and implicit assumptions behind this statement which allow questions to be raised about the mechanism underlying the radial growth of trees. Based on the hypothesis of the diurnal strains of plant organs, it is anticipated that the process of radial growth can be understood as an adaptation to the cyclically changing mechanical stress in the radial direction generated by the phloem during the 24 h day cycle. This qualitative hypothesis treats cambium as a tissue subjected to nighttime stretching and daytime compression in the radial direction. The proposed osmo-mechanical hypothesis of the radial growth of vascular cambium links the daily change in water status and the considerable daily strains in the xylem and phloem with the radial net expansion of a tree trunk. We highlight transpiration as a major factor influencing the secondary growth of woody plants. Thus, we indirectly relate all the biotic (e.g., insect infestation, fungi infections, injuries, shadowing, intra- and interspecies competition, parasitism, symbiosis, etc.) and abiotic (e.g., humidity, water availability, wind, injuries, shadowing, day length in a vegetative season, altitude, temperature, insolation, etc.) processes influencing transpiration with radial growth. In the proposed hypothesis, we also infer that differences in the strains in phloem and xylem are the direct source of tensile stress, tensile stress relaxation, compressive stress, and compressive stress relaxation in the vascular cambium. This sequence appears to be crucial in understanding both the process of the radial growth of trees and the formation of differential wood patterns, within the same genotype as well as in different genotypes. It also provides arguments for the discussion on the mechanisms regulating processes in the vascular cambium. It points out the important role of the variable mechanical stresses in the radial, circumferential, and axial directions and their interference in the development of this lateral meristem. Thus, this hypothesis supports the concept of the epigenetic and systemic regulation of intrinsic wood patterns and tree forms by environmental factors. The hypothesis is focused exclusively on broadleaved trees and symplastic growth. This limitation of the scope is due to a concern for clarity. In this form, the hypothesis provides an alternative explanation for a pure process of radial growth and paves the way for a better interpretation of such phenomena as earlywood and latewood formation. At the same time, this approach to the vascular cambium provides answers to many questions related to the generation of the mechanical conditions necessary for the occurrence of intrusive growth between tangential cell walls; this is of fundamental importance for fusiform initials readjustment, vessel element and fibre formation, ring-porous wood formation, etc.

Soil Moisture Inversion in Grassland Ecosystem Using Remote Sensing Considering Different Grazing Intensities and Growing Seasons

Although vegetation community information such as grazing gradient, biomass, and density have been well characterized in typical grassland communities with Stipa grandis and Leymus chinensis as dominant species, their impact on the soil moisture (SM) inversion is still unclear. This study investigated the characteristics of a grassland vegetation community at different grazing gradients and growing seasons and its impact on SM inversion using remote sensing data. The water cloud model (WCM) was used for SM inversion, and both field and remote sensing data collected from 2019 to 2021 were used for calibration and prediction. The study found that the calibrated WCM achieved prediction results of SM inversion with average R2 values of 0.41 and 0.38 at different grazing gradients and growing seasons, respectively. Vegetation biomass and height were significantly correlated with vegetation indexes, and the highest model prediction accuracy was achieved for biomass and height around 121.1 g/m2 [102.3–139.9] and 18.6 cm [17.3–19.8], respectively. Generally, NDWI1 produced higher SM estimation accuracy than NDWI2. The growing season of vegetation also affects the accuracy of the WCM to retrieve SM, with the highest accuracy achieved in mid-growing season I. Therefore, the developed WCM with optimal height and biomass of vegetation communities can enhance the SM prediction capacity; it thus can be potentially used for SM prediction in typical grasslands.

Multiscale wood micromechanics and size effects study via nanoindentation

Wood as a material is a natural composite with a complex hierarchically arranged structure. All scale levels of wood structure contribute to its macroscopic mechanical properties. The nature of such characteristics and deformation modes differs radically at different scale levels. Wood macroscopic properties are well studied, and the relevant information can be easily found in the literature. However, the knowledge of the deformation mechanisms at the mesoscopic level corresponding to the cellular structure of early and late wood layers of annual growth rings is insufficient. It hinders building the comprehensive multiscale model of how wood mechanical properties are formed. This paper described the results of scanning of mechanical properties of softwood and hardwood samples, such as common pine, small-leaf lime, and pedunculate oak, by means of nanoindentation (NI). The NI technique allows varying the size of deformed region within a wide range by altering maximal load (Pmax) applied to the indenter so that one can repeatedly and non-destructively test wood structural components at different scale levels on the same sample without changing the technique or equipment. It was discovered that the effective microhardness (Heff) and Young's modulus (Eeff) decreased manifold with Pmax growing from 0.2 to 2 000 mN. This drop in Heff was observed when the locally deformed region grew, and resulting from Pmax increase generally follows the rule similar to the Hall-Petch relation for yield stress, strength, and hardness initially established for metals and alloys, though obviously in those cases the underlying internal mechanisms are quite different. The nature and micromechanisms of such size effect (SE) in wood revealed using NI were discussed in this study. At Pmax < 0.2 mN, the deformed area under the pyramidal Berckovich indenter was much smaller than the cell wall width. Hence, in this case, NI measured the internal mechanical properties of the cell wall material as long as free boundaries impact could be neglected. At Pmax > 200 mN, the indentation encompassed several cells. The measured mechanical properties were significantly affected by bending deformation and buckling collapse of cell walls, reducing Heff and Eeff substantially. At Pmax ≈ 1–100 mN, an indenter interacted with different elements of the cell structure and capillary network, resulting in intermediate values of Heff and Eeff. Abrupt changes in Heff and Eeff at annual growth ring boundaries allow accurate measuring of rings width, while smoother and less pronounced changes within the rings allow identification of earlywood and latewood layers as well as any finer changes during vegetation season. The values of ring width measured using NI and standard optical method coincide with 2%−3% accuracy. The approaches and results presented in this study could improve the understanding of nature and mechanisms lying behind the micromechanical properties of wood, help to optimize the technologies of wood farming, subsequent reinforcement, and utilization, as well as to develop new highly informative techniques in dendrochronology and dendroclimatology.

Linalool as a novel natural factor enhancing ginsenoside production in hairy root cultures of American ginseng

Ginsenosides are triterpenoid saponins, accumulated in root of Panax qiunquefolius. These secondary metabolites have numerous pharmacological properties such as: antimicrobial, antioxidant, anti-inflammation, anticancer. They have been found to regulate the functioning of the nervous and endocrine systems, thus maintaining homeostasis. Root harvesting for ginsenoside extraction for pharmaceutical industry destroys the entire plant, limiting its natural occurrence and impacts on wild populations of ginseng. The present study showed that hairy root cultures of P. quinquefolius, after using linalool as elicitor, can increase ginsenoside yield without the use of field-grown plants and independently of the vegetative season. The content of seven ginsenosides (Rb1, Rb2, Rb3, Rc, Rd, Rg1, Re) was determined. We found linalool to stimulate most studied saponin accumulation regardless of exposure time (24 and 72 h). Shorter time of elicitation and 0.1 µM linalool in medium proved to be optimum conditions to obtain the highest total saponin content (29% higher level than that of untreated roots) and Rg-group metabolites (2.28 fold higher amount than untreated roots). Ginsenosides, belonging to protopanaxadiol derivatives, were found to have different dynamics of their content changes depending on linalool concentration. The highest increase in untreated roots was noted for compound Rd. Therefore, elicitation with linalool can be an effective method of enhancing ginsenoside production in P. quinquefolium hairy root cultures cultivated in shake flasks.

Fine‐scale landscape phenology revealed through time‐lapse imagery: implications for conservation and management of an endangered migratory herbivore

AbstractClimate change modifies plant phenology through shifts in seasonal temperature and precipitation. Because the timing of plant growth can limit herbivore population dynamics, climatic alteration of historical patterns of vegetation seasonality may alter population trajectories in such taxa. Thus, sound management decisions may depend on understanding how plant growth varies across a landscape within and among distinct management units or protected areas. Here, we examine spatial variation in the timing of spring plant growth, measured using a network of automated time‐lapse cameras distributed across the range of endangered Sierra Nevada bighorn sheep (Ovis canadensis sierrae) in California, USA. We tracked greenness of individual plants across 2 years to compare spatial patterns of forage phenology in snowy and drought years. Green‐up timing was derived for individual plants across the camera network and compared with local estimates of green‐up timing from satellite data. Satellite‐derived estimates of green‐up timing showed strong correspondence with camera‐derived estimates in areas with dense vegetation cover and weak correspondence in areas with sparse vegetation cover. Daily time‐lapse imagery revealed consistent variation in green‐up timing across elevation, both among latitudinal zones and among individual plant species. Green‐up timing was earlier in 2020 than in 2019, reflecting differences in the end of the snowy season. Because bighorn forage seasonally on alpine species with a brief growing period, spring migration of bighorn may be linked to variation in snowmelt and plant growth across elevational gradients.

THE TURUCHAN PIKA (&lt;i&gt;OCHOTONA TURUCHANENSIS&lt;/i&gt; NAUMOV 1934, OCHOTONIDAE, LAGOMORPHA) PLAYING IN THE WILD

The adaptive functions and evolution of animal play remain unclear despite the great interest of researchers to these topics. One reason for this is thought to lie the deficiency of data on animal play in the wild, as well as on certain taxa. The latter include lagomorphs, as there is no information at all about the play in pikas (family Ochotonidae). This report describes some cases of play in the local population of the Turuchan pika on the Primorsky Mountain Ridge in the Irkutsky District of the Irkutsk Region (52.07 N, 105.16 E). During two vegetation seasons (May–September 2020–2021), we observed 14 individually marked pikas (6 males, 6 females, 2 subadults) for more than 150 hours by the ad libitum scoring of the focal animal behavior in the morning and in the evening. All behaviors were continuously recorded with a voice recorder. A total of 15 game episodes were registered in seven animals, of which 8 episodes were video recorded (32 frames per second). A subsequent frame-by-frame analysis of the videos allowed us to describe play behaviors more accurately and to evaluate their time parameters. Following Burghardt, we defined play behaviors as repetitive, but non-stereotypic activities that differed from the common activities and failed to contribute to current survival, initiated spontaneously by non-distressed animals. We found one element that was present in all episodes of an individual play, one we termed “jerk-uplifting”. A “jerk-uplifted” animal rose sharply on outstretched hind legs (sometimes jumps), while the head was thrown back, and the front legs were extended forward. Such a movement took an average of 0.54 ± 0.34 seconds. “Jerk-uplifting " could be accompanied by body twisted around the vertical axis. We analyzed 30 cases of “jerk-uplifting” of seven animals. In six cases, it was a single act; in the other 24 cases, “jerk-uplifting” occurred in a series of 2–4 acts, separated by intervals of several seconds. Of the seven playing pikas, four were adult males, two were adult females, and two were young animals. In 22 cases (73.3%), a “jerk-uplifted” animal had some object in its mouth: most often a bunch of lichens, but sometimes a bunch of grass or a dry stick. Only once after playing did the pika begin to eat lichens with which it was “jerk-uplifted”. “Jerk-uplifting” could alternate or end with sudden jumps and runs. Some motor activity preceded “jerk-uplifting” in all cases. Another form of individual play was noted twice: the animal jumped several times, breaking off the ground with all four paws and bending in the air, then, grabbing a dry branch with its teeth, fell on its back and rolled from side to side. Then, the pika dropped the branch and abruptly jumped up on four paws. Two episodes of social play were recorded. Once, an adult female and a young sexually mature male alternately scampered after each other, then the female hid behind a stone and jumped out at a running male. These actions were repeated several times with a change of the initiator, following which the animals parted in different directions. The second time, the same pikas followed each other with one jumping at the partner. Thus, for the first time, all three types of play (locomotor, object and social) were recorded for Lagomorpha in the wild. This was the first documented evidence of playing pikas that involved different sexes and ages. The play in pikas included elements (jumping, spinning, falling on the back) that were associated with a temporary loss of control.

Drying Kinetics and Performance Analysis of Thermal Storage-Based Hybrid Greenhouse Dryer for Uniform Drying of Tomato Flakes

Abstract This communication focuses on the experimental investigation of mixed heat storage-based hybrid greenhouse dryer. The proposed system is a combination of a solar air heater and a greenhouse dryer. Mixed heat storage material is applied on the bed of the dryer, which is a combination of paraffin wax and black-painted gravel. Tomato flakes were selected for drying in both hybrid system and natural sun drying. Tomato flakes were rehydrated up to 1.29% and 10.10% under hybrid and open modes. Daily drying efficiency for drying tomato flakes in the proposed dryer was 50.18%, while it was 30.02% for open mode. Effective moisture diffusivity was 0.8666 × 10−10 m2/s and 11.650 × 10−10 m2/s for open and hybrid modes. The solar drying process improved physicochemical properties of tomato flakes, resulting in a shelf life extension. This finding highlights the great potential for hybrid solar dryer in the food industry and suggests that it could emerge as an efficient postharvest conserving method for seasonal consumable vegetables and fruits, mostly in developing nations.