Early Spring Period Research Articles

Thermal performance of solar dryer using bio-composite insulation material based on date palm waste for drying of hot chili: experimental investigation in Algerian Sahara

This paper investigates the thermal efficiency of solar dryers using different insulation materials, focusing on a bio-composite derived from discarded date palm residues. The current study introduces this sustainable material, created from local palm waste, as insulation material in Solar Air Heaters (SAHs) for agricultural products drying purposes. Thus, two SAH models are designed, fabricated and compared for their thermal efficiencies: the first one used the bio-composite (Model A) as insulation material and the second one is equipped with a polystyrene sheet in the rear insulation (Model B). The thermal performance of these models are assessed, alongside the drying kinetics of Algerian chili at different maturity stages under the climate of Biskra, Algeria. A local product that we aim to promote (Arab chili), widely used in southern Algeria during the harvest period in summer and early spring. It is generally grown using traditional techniques despite its very delicious taste, while (Gazelle’s horn) chili is grown in greenhouses throughout the year. Although the polystyrene-insulated SAH shows slightly better thermal efficiency, the bio-composite model achieves satisfactory drying temperatures, drying chili in 5 hours and 30 minutes.

Predator biomass affects west–east shifts in Barents Sea capelin (Mallotus villosus) spawning ground use

AbstractSpawning locations of migratory fish influence the environmental and oceanographic fate of eggs and larvae. However, we have an incomplete understanding of how and why realized spawning locations vary. We quantified the yearly variation in spawning location for Barents Sea capelin (Mallotus villosus) within the recognized spawning areas along the coast of northern Norway and Murman. Furthermore, we tested whether water temperature, sea ice cover, predation and capelin fisheries are associated with spawning locations. Estimated spatial variation in spawning longitude used data from Soviet‐Russian ichthyoplankton surveys from 1959 to 1993 and a bootstrap procedure. The mean spawning area along the coast was then calculated by combining larvae observations with backtracking a larvae drift model from potential spawning areas. We fitted a generalized additive model (GAM) to assess the effects of environmental conditions on these drift‐corrected spawning longitudes. Capelin's mean yearly spawning location varied substantially across the study period. An increase in immature cod biomass, a major predator of capelin, during the spawning migration period in winter and early spring corresponds to more eastward capelin spawning. The eastward shift in mean spawning longitude seems to reach an eastern limit at high immature cod biomass. Sea temperature, sea ice cover and capelin fisheries were not associated with mean capelin spawning longitude. We show that the realized spawning areas for capelin are related to cod biomass, potentially through cod predation depleting and/or acting as a migration barrier for mature capelin.

Soil nutrient availability and understorey composition beneath plantations of ecto- and arbuscular mycorrhizal Chilean native trees

Background and aimsSeveral lines of evidence indicate that arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) associations can have different effects on soil nutrient dynamics. Some lineages of ECM fungi can extract N from organic matter, with varying impacts on decomposers, soil carbon pools, mineral N availability, and plants that lack ECM. However, these effects are not always observed, and it is not clear how they are mediated by environmental factors.MethodsWe used Plant Root Simulator probes to compare soil availability of a wide range of nutrients beneath replicated 30-yr old plantations of Chilean Nothofagus (ECM) and Cupressaceae (Austrocedrus, Fitzroya: AM) on a lowland temperate site. Probes were buried for two 8-week periods in early spring and late summer. We also compared understorey composition beneath plantations, to test for evidence of different successional trajectories beneath Nothofagus and Cupressaceae.ResultsSoil organic carbon, total N and total phosphorus did not differ significantly between Nothofagus and Cupressaceae stands. Redundancy analysis revealed significant effects of both plantation type (Nothofagus vs. Cupressaceae) and season on overall mineral nutrient availability. Mineral N availability did not differ significantly between Nothofagus and Cupressaceae plots, but pH and calcium availability were significantly lower beneath Nothofagus. Manganese (Mn) was much more available beneath Nothofagus stands, which might reflect abundant Mn-peroxidase, a key enzyme involved in breakdown of lignin by ECM fungi. Understorey composition varied considerably between individual plantations, but did not differ significantly between Nothofagus and Cupressaceae plantations.ConclusionsDespite an overall effect on the stoichiometry of nutrient availability, we found little evidence of modification of the local N cycle by ECM fungi, or of divergent regeneration patterns beneath AM and ECM plantations. This might reflect the relatively N-rich character of this site, and/or mycorrhizal effects being counteracted by leaf trait differences between Chilean Cupressaceae and Nothofagus species.

Study on spring drought in cold and arid regions based on the ANOVA projection pursuit model

Due to the influence of snow cover and soil freeze–thaw processes in the early spring, the characteristics of spring drought in cold regions are different from those in other regions. This paper takes Qiqihar, a cold and semiarid grain production area in Northeast China, as the study area. Based on factors such as snow cover in the early spring period and precipitation, temperature, evapotranspiration, and soil moisture during the spring sowing period, a projection pursuit model with analysis of variance (ANOVA PPM) was used to analyze the spatiotemporal variation characteristics of regional spring drought. For the ANOVA PPM, based on the grouping of the projection points, local aggregation is measured by the mean square within groups, and overall dispersion is measured by the mean square between groups, thus achieving comparability and balance between overall dispersion and local aggregation. The spatial analysis of spring drought showed that, from a spatial perspective, there were significant spatial differences in spring drought in different subregions, and spring drought was closely related to latitude, with significant differences occurring at different latitudes. The northern region is relatively light, while the central and southern regions are more severe. From a temporal perspective, there are significant differences in spring droughts between different decades (1980 s, 1990 s, 2000 s and 2010 s). Overall, spring drought first intensifies and then decreases.

Comparative Study of the Effect of Pollen Substitute Diets on Honey Bees during Early Spring.

The nutritional quality of a colony significantly affects its health and strength, particularly because it is required for population growth in the early spring. We investigated the impact of various artificial pollen substitute diets on colony performance in the Republic of Korea during early spring, a critical period for colony health and growth. The colonies were provided with different diets, including the commercial product Megabee (positive control), our developed diet Test A, and four upgraded versions (Diet 1, Diet 2, Diet 3, and Diet 4) of Test A. The negative control group received no supplementary feed. Over 63 days, we observed 24 experimental colonies and assessed various parameters at the colony and individual levels. The results revealed that Diet 2 had the highest consumption and had the most positive impact on population growth, the capped brood area, colony weight, honey bees' weight, and vitellogenin levels. These findings suggested that Diet 2 is most attractive to honey bees and thus holds great promise for improving colony maintenance and development during the crucial early spring period.

The efficiency of nuisance relief by filtering facepiece respirators used by workers exposed to agricultural odours.

The study aimed to evaluate the effectiveness of filtering facepiece respirators (FFRs) in reducing odour nuisances in agricultural work environment. Additionally, an assessment was conducted on the microbiological contamination of FFRs and the functionality of Time4Mask application in enhancing workplace safety. Two types of FFRs were used for the study: with absorbing properties and reference ones. The research was carried out in 6 livestock rooms during a 1-week period in early spring (February-March 2021) on a farm in central Poland. The microclimate conditions (thermoanemometer), and particulate matter concentrations (laser photometer) were assessed. Additionally, the odour content in the studied rooms and the breathing zone of FFR users (gas chromatography with mass spectrometry) were evaluated. The number of microorganisms on the respirators was determined (cultivation method), followed by their identification (biochemical tests, taxonomic keys). Breakthrough curves were determined for both FFR types to assess absorption capabilities. The average temperature in the livestock rooms was about 13°C, relative humidity - 53%, air flow velocity - 0.21 m/s, and particulate matter concentration - 0.216 mg/m3. A significant variety of odorants was found in the environment and the breathing zone under the FFRs. Bacterial counts ranged between 2.4 × 101 and 2.6 × 102 CFU/cm2, fungi between 3.2 × 100 and 5.4 × 101 CFU/cm2, xerophilic fungi from 4.4 × 100 to 4.0 × 101 CFU/cm2, mannitol-positive staphylococci between 1.6 × 101 and 1.0 × 102 CFU/cm2, and haemolytic staphylococci from 2.2 × 101 to 4.5 × 101 CFU/cm2, depending on the respirator type. Respirators were colonized by bacteria from the genera: Bacillus, Staphylococcus, actinobacteria Streptomyces sp., and fungi: Candida, Absidia, Aspergillus, Mucor, and Penicillium. Respirators with absorbing properties had over 8-times longer breakthrough time than reference ones. Respirators with activated carbon effectively improved work comfort when exposed to odours. Due to growth of microorganisms in the respirator materials, periodic replacement is necessary. It is crucial to provide workers with information about the safe-use time of respirators, considering environmental conditions. This is achievable using modern IT tools like Time4Mask application. Med Pr Work Health Saf. 2023;76(5):363-75.

INFLUENCE OF PREDECESSORS ON THE FORMATION OF INDIVIDUAL PRODUCTIVITY OF SPRING TRITICALE VARIETIES

Ukraine's agricultural production is dominated by winter crops, with winter wheat accounting for the largest area. At the same time, due to dynamic climate change and unstable weather conditions in the autumn-winter and early spring periods, there is a need to reseed significant areas of winter crops every year. Spring triticale is one of the insurance crops. Due to its high productivity and unpretentiousness to growth and development conditions, its cultivation on large areas can contribute to a significant increase in food grain production. In the current conditions of reforming the agricultural sector of Ukraine's economy, as well as climate warming, there is an urgent need to develop agrotechnological methods that would ensure the efficient use of crop rotations in general. One of the methods to increase the efficient use of arable land in modern business conditions is to grow crops that produce less costly and competitive products. Triticale meets these requirements best of all. Modern varieties, in particular those of Ukrainian breeding, are characterized by high physical properties, and in terms of grain quality and technological properties of flour are not inferior, and in some respects even superior to bakery wheat. Thanks to this, spring triticale can be grown as a major food crop. To date, many technological methods have been developed that ensure sufficiently high grain yields of this crop both in irrigated and non-irrigated farming. However, the technology of triticale cultivation in the context of climate change remained insufficiently developed and studied. In particular, such important elements of the technology as triticale varieties, precursors and doses of mineral fertilizers have not been determined. Therefore, the study of the peculiarities of growth and development of high-yielding varieties of spring triticale and the introduction of basic methods of growing the crop, establishing the effect and interaction of the variety and mineral fertilizers, which significantly affect the yield and quality of grain, sowing and yielding qualities of seeds in the conditions of the Right-Bank Forest-Steppe are relevant, which determined the choice of the topic of the master's thesis. On average, over two years of research, the influence of different precursors was also significant in the cultivation of spring triticale. Thus, the most mineral fertilizers significantly influenced the formation of grain yield of spring triticale varieties, namely increased it, but a significant increase in yield - 1.58 t/ha was obtained only when N30P60K60.+ N30 was applied in the earing phase. Thus, the highest grain yield of the studied spring triticale varieties was obtained in the most favorable year of 2019 - 6.48 t/ha, in 2020 it was 5.99 t/ha, which is 0.49 t/ha less. The yield of the spring triticale variety Boriviter in 2019 was the highest and amounted to 6.48 t/ha, respectively, in 2020 it was 5.47 t/ha and on average for two years of research did not exceed 5.97 t/ha.

TWO-YEAR FLOWER CULTURES IN THE COLLECTION OF THE BOTANICAL GARDEN OF BILA TSERKVA NATIONAL AGRARIAN UNIVERSITY

The article presents the results of the analysis of the collection of two-year-old flowering ornamental plants in the Botanical garden of Bila Tserkva national agrarian university. It was established that the biennial collection includes 17 species belonging to 15 genera and 10 families. The largest number of species is represented by the family Brassicaceae Burnett. – Brassica oleracea L. var. Acephala DC., Erysimum perovskianum Fisch.hort., Hesperis matronalis L., Lunaria biennis L. The collection presents species that have not only decorative, but also medicinal, fodder, and tanning properties. Diditalis grandiflora contains poisonous glycosides. Alcea rosea has ethnographic significance and belongs to amulet plants.
 The morphometric indicators of biennials by height and their flowering periods were analyzed. It was established that 41,2% of the collection of biennials of the Botanical Garden of the Bila Tserkva NAU belongs to low-growing species, medium-sized and tall plants are represented by the same number of species, which is 29,4% each. The largest number of species in the collection is represented by the group of summer-flowering biennials, 47,1%, late-spring-flowering ones make up 29,4%, and early-flowering ones – 23,5% of species. 
 Most biennials are cultivated in open ground to decorate flower beds, only a few to create seasonal bouquets and phytocompositions. Thanks to the plasticity of biennials, which is manifested in non-standard sowing dates, relative frost resistance and early spring and early summer flowering periods, biennials reduce the costs of growing seedlings and care for them after planting in a permanent place, provide an annual change in the design of flower beds and fill the flowerless periods of early spring and early summer. Biennials are suitable for creating borders, flower beds, rabatoks, lawns, carpets, ribbons, for decorating flowerbed groups and balconies, container culture. Tall species can be used as a background for the entire composition. Varietal diversity of Bellis perennis L., Brassica oleracea L. var. Acephala DC, Dianthus caryophyllus L. var. Grenadine hort, Dianthus barbatus L., Viola wittrockiana Gams. allows you to create monoculture flower beds with a wide color palette.

Adaptability of early flowering ornamental peach cultivars

To assess the adaptive potential of very early, early and early-medium flowering cultivars of ornamental peach, their frost resistance taking into account the rate of microsporogenesis, susceptibility to blossom blight, leaf curl and powdery mildew were assessed in connection with their use in breeding and landscaping. According to the results of freezing, it was revealed that the early-middle flowering cultivars subgroup showed greater frost resistance. When exposed to -16 °C in February, the number of live buds in different cultivars varied from 0 to 42 % in 2020 and from 13.64 to 95.65 % in 2021, because they were at later stages of development. The temperature of -10°C in March 2020 had a significant detrimental effect on the opened buds and blossoming buds of most genotypes. The maximum percentage of live buds (48.08-64.21 %) was noted in cultivars at the stage of the appearance of sepals. Frost -3°C at the end of March 2019 before flowering was weak: the number of live buds varied between 79.22-100 % in many cultivars. Three early-flowering cultivars with the highest frost resistance of generative buds (Lel, Frezi Grant and Ruthenia) were identified during February freezing and 3 cultivars (Lel, Miraisikl 2/4 and Ruthenia) during March freezing. Their use in regions with similar frosts in the late winter and early spring periods does not significantly reduce the ornamental value of plants. An assessment of susceptibility to the main fungal diseases showed that early-flowering cultivars are most sensitive to the causative agent of blossom blight. The cultivar Snezhnaya Koroleva showed the least susceptibility to the three studied pathogens, to two pathogens – Lel, Zhisele (to blossom blight and leaf curl) and Lyubava (to blossom blight and powdery mildew). This allows them to be more widely used in landscaping and, depending on breeding tasks, to be used in breeding as sources of tolerance.

Estimating Early Summer Snow Depth on Sea Ice Using a Radiative Transfer Model and Optical Satellite Data

Sea ice regulates the overall energy exchange and radiation budget of the Arctic region, and understanding this relationship requires an accurate determination of snow depth. However, methods for deriving snow depth have a large error through the annual winter and early spring periods due to the potential complexity of surface melting during early summer. In this study, we explore the potential of retrieving snow depth during the early summer using optical satellite imagery of the sea-ice cover. Measurements using VIS/IR (visible and infrared) usually feature much higher spatial resolution than L-band satellite data and can provide additional surface melting and leads information; in addition, considering the snow grain size–snow surface temperature interaction, there is co-variability between the observed sea-ice surface broadband albedo using an optical satellite sensor, the sea-ice surface temperature, and the retrieval target of snow depth on the spatial scale of optical imagery samples. We applied a surface classification procedure to optical satellite imagery and introduce an approach to derive snow depth from optical satellite imagery and ice surface temperature data using two solar radiation transfer models: the Delta-Eddington solar radiation model, which is the shortwave radiative scheme of the Los Alamos sea-ice model, and a simplified snow albedo scheme, which is tuned to the observational data of buoys. The snow depth was inversed from the model simulation results using a lookup-table-based method. For comparison with the observational data, using the Delta-Eddington solar radiation model, about 55% of the differences are below 5 cm, and thicker snowpack has a larger bias; using the simplified snow albedo scheme, a mean difference of 4.1 cm between retrieval and measurements was found, with 93% of the differences being smaller than 5 cm. This approach can be applied to optical satellite imagery acquired under clear-sky conditions and can serve as an addition to overcome the limitations of existing methods.

Drought Stress Affects the Reproductive Biology of Avena sterilis ssp. ludoviciana

Avena sterilis ssp. ludoviciana (hereafter, A. ludoviciana) is considered the most difficult-to-control winter weed in the Northern Grains Region (NGR) of Australia. The abundance of this weed has increased after the adoption of the no-tillage conservation agriculture (NTCA) approach, which does not bury seeds deep in the soil profile. In addition, the increasing frequency and intensity of drought stress events during the late winter to early spring period in the NGR may modify this weed’s persistence mechanisms, which may further impact crop production. The present study focused on plant maturity time and seed production, dormancy, and longevity of four NGR A. ludoviciana biotypes in relation to the severity of drought stress over 2 consecutive years. Plants of all four A. ludoviciana biotypes were grown under 100% plant available water capacity (PAWC) until panicle initiation. At panicle initiation, very mild (80% PAWC), mild (60% PAWC), moderate (40% PAWC), and severe (20% PAWC) drought stresses were imposed on plants and continued through to maturity; an additional subset of plants were maintained at 100% PAWC through to maturity (control). Plants exposed to severe drought stress matured 24 days earlier than control plants, and produced 34% fewer filled seeds, with seeds having a 42% lower mass, 70% less dormancy, and shorter predicted longevity of at least 2 years compared to the seeds produced on control plants. All reproductive traits were less affected when the severity of the drought stress was decreased. The increasing frequency of drought stress in combination with the widely adopted practice of NTCA favours seeds of A. ludoviciana to undergo rapid germination in the following autumn/winter NGR planting season. However, effective control of A. ludoviciana remains a challenge in the NGR due to this weed’s genetic variability with respect to its response toward the seasonal variability of the NGR.

Observations on the Foraging Behaviors of Commercial Bumble Bee Colonies in Prunus avium Orchards

Prunus avium blooming period starts in early spring. The uncertain climatic conditions in this period can cause mis-pollination syndromes. It could be directly because of the frozen days or non-forgeable conditions for the possible pollinators or indirectly the poor quality of surrounding habitat and lack of pollinators. When wild pollinators are scarce owing to one of these reasons, introduction of commercial pollinators can be a solution to ensure pollination. Within this context, commercial bombus colonies were chosen as insurance for the pollination of sweet cherries. In the blooming period of Prunus avium, for two years-with totally 120 transect observations, the daily foraging activities of these bumblebees were investigated in Sultandağı-Afyonkarahisar. Before the settlement of the hives in the field, trees were marked with different colored stripes every 10 meters which makes it possible to follow how far the bumblebees fly and forage in the field. Starting at 7:00, 9:00, 11:00, 14:00, 16:00, and 18:00, six times a day, with transect observations, the number of the foragers on cherries was recorded. The average number of flowers they visit per minute was calculated. The plants blooming simultaneously with cherry trees in the trial area were determined. Pollen preferences of foragers were examined with their cobicular pollen loads. The actual foraging range was found as 10-40 meters away from the hives, the maximum activities were recorded before the noon. The average number of visited flowers per minute for bumblebees was ~ 8 flowers. Taraxacum spp. and Lamium spp. pollen were found, but cherry preference was determined to be almost 90%. It is still an uncommon agricultural practice to use commercial bumble bees in open fields, especially for the plants which have very early blooming periods in early spring, it is thought that they are very good manageable pollinator agents according to their foraging capacities.

Экологические факторы, определяющие естественную и антропогенную инвазию борщевика Сосновского Heracleum sosnowskyi Manden., меры борьбы с ним (обзор)

This review analyzes the problem of invasion of Heracleum sosnowskyi Manden. under the influence of various environmental factors. Particular attention is paid to abiotic, biotic and anthropogenic factors. The influence of these factors on invasiveness is considered on specific examples. It has been established that among abiotic factors, temperature, humidity, light, wind speed and direction, duration and depth of snow cover, terrain, and elemental composition of the soil play the main role in the distribution of H. sosnowskyi. The totality of abiotic factors generally determines the confinement of H. sosnowskyi to areas of a cool humid climate. Increased humidity, the presence of snow cover, low positive temperatures in the autumn-winter and early spring periods create conditions for seed stratification, which ensures the viability of hogweed. Various interspecific interactions, along with other environmental factors, make a significant contribution to the invasiveness of H. sosnowskyi. The determining biotic factor in the case of this species is competition for resources. However, despite the allelоpathic activity of hogweed, it can be the object of parasitic invasion of some plant species, for example, vines of Echinocystis lobata (Michx.) Torr. & A. Gray. The introduction of H. sosnowskyi into natural phytocenoses depends on their density, it is also closely related to pollinators and phytophages. The connection of the plant with soil microbial communities is noted, which have both positive and negative effects on the invasion of H. sosnowskyi. Among anthropogenic factors, the greatest contribution to the invasiveness of H. sosnowskyi is made by the movement of soils contaminated with viable seeds of this plant during construction, the transfer of seeds with various modes of transport. Deforestation plays a significant role in the invasiveness of H. sosnowskyi, during which the structure and composition of vegetation changes. The distribution of hogweed is due not only to environmental factors acting in combination, but also to its high adaptability to various environmental conditions. In this regard, in order to determine the method of combating H. sosnowskyi, it is important to take into account not only the effectiveness of measures, but also the role of environmental factors that determine the viability of this plant.

WIND FACTOR IN SPATIAL AND TEMPORAL DYNAMICS OF WIND EROSION WITHIN VOLYN REGION

The analysis of the wind factor as a factor of wind erosion of Polissia soils is highlighted. The highest intensity of wind erosion in the Polissya zone is observed in the spring and autumn periods, when the density of vegetation cover is the lowest during the year and there is no snow cover. The temporal dynamics of the wind regime forms certain patterns, which determines the formation of the corresponding clusters of months of the year as indicators of the temporal regularity of the wind regime and clusters of administrative districts as indicators of the spatial regularity of the wind regime. The early spring period is the least long (two months), which allows it to be interpreted as transitional. This interpretation explains the inclusion in this cluster by the dynamic features of August as also the transition period from the summer wind regime to the autumn one. The winter period is characterized by an extremely strong wind regime, the lowest wind intensity is observed in the summer-autumn period. The transitional early spring period is characterized by an intermediate level of wind load, but the greatest variability of indicators, which also emphasizes the transitional nature of this time stage of the year. It was established that the maximum value of the wind factor for these areas is observed in winter and is 3,57 m3 s−3, and the minimum is observed in August and is 2,3 3,57 m3 s−3. The central and eastern regions (Manevytskyi, Kovelskyi and Rozhishchenskyi) also form a homogeneous subzone, the peculiarity of which is that the duration of strong winds in the winter period is somewhat shorter compared to the northwestern regions. The highest wind load is observed in the winter months, and the lowest at the end of summer. Geographically, the north-western and south-eastern regions of the region experience the greatest wind load. In terms of time, three consecutive periods can be distinguished: winter, early spring, and summer-autumn.

GIS-Based Geopedological Approach for Assessing Land Suitability for Chestnut (Castanea sativa Mill.) Groves for Fruit Production

The identification of mountainous areas suitable for chestnut stands for fruit production (CSFP) is raising increasing interest among researchers. This work aimed to (i) identify the areas suitable for CSFP shown in a land suitability map easy to read by land planners, and (ii) propose a remote-sensing-based methodology able to identify the lands currently under cultivation for CSFP. This study was conducted using the QGIS software for the Municipality of Castel del Rio, Emilia-Romagna Region, Italy. To obtain the land suitability map, topographic, lithological, and pedological data were acquired, and the areas located between 200 and 1000 m of altitude, with north exposition, a slope < 20°, sandstone-based lithology, and soils with dystric features were selected. The currently cultivated areas for CSFP were identified through remote-sensing images of the early spring period, which were delineated and georeferenced. The findings showed that only 10% of the whole study site area can be considered suitable for CSFP. Further, most of the currently cultivated CSFP (59%) are in non-suitable areas characterised by high slope gradients. The methodology applied in this study can easily provide detailed information about the suitable areas for CSFP and the areas currently cultivated with chestnut, thus allowing accurate land-use planning and land conservation.

Sclerochronological and geochemical study of the carpet shell Ruditapes decussatus in archaeological contexts: A potential tool for season of collection and coastal paleo-temperature

Specimens of the carpet shell Ruditapes decussatus from the Mesolithic shell midden (6th millennium BC) of Beg-an-Dorchenn (Brittany, France) were studied in order to assess their period of collection as well as provide some insight on Paleo-temperature reconstructions. Cross sectioned shells display very clear growth structures allowing an assessment of a growth rhythm of 2 increments per lunar day. From this temporal framework, daily growth increments and winter annual growth breaks were characterized. Our results show the R. decussatus shells were typically collected in the early spring period. Chemical analyses of shell carbonates were also performed to assess a preliminary range of potential sea temperature data from oxygen isotopes values (δ18Oshell). δ18Oshell shows seasonal variations but do not record the whole seasonal temperature range as R. decussatus have a growth break during winter. However, results show predicted SSTs within the range of expected values. Thus, R. decussatus is particularly suited for paleo-environmental reconstructions at high temporal resolution such as seasonal timescales. Additional sclerochronological and chemical research on additional carpet shells and also other mollusk species from Beg-an-Dorchenn or other Mesolithic shell middens along the European Atlantic coast should be considered. Such studies will contribute to the understanding of the seasonal occupation patterns of the last hunter-gatherers of the European Atlantic coast as well as the climate variability at the Mesolithic-Neolithic transition.

Assessment of the grassland carrying capacity for winter-spring period in Mongolia

The grassland ecosystems of Mongolia are among the most sensitive to global climate change because of the arid and semiarid climate. As a key source of primary productivity for livestock, the quantification of the carrying capacity in grassland for the winter and early spring period is crucial for sustainable livestock management and livelihoods of herders in Mongolia. In this study, we used remote sensing data and ancillary data to propose a framework to estimate the aboveground biomass(AGB) and the carrying capacity of grassland (GCC) using the Google Earth Engine (GEE) environment. We analysed the spatial and temporal changes in the GCC for the winter-spring period in Mongolia during 2000–2020, and the grassland carrying status index for winter-spring period (GCSIW) was proposed to reflect grassland utilization and livestock carrying status over the past 21 years. Our study demonstrated the effectiveness of AGB and GCC estimation using the Carnegie-Ames-Stanford Approach (CASA) model with the root-to-crown ratio method within the GEE environment. The AGB model validation showed good performance with an R2 of 0.67–0.71 and RMSE of 22.91–28.94 g/m2. Significant increases in AGB and GCC over the 21 years were found in Mongolian grasslands and most provinces. The average GCSIW increased significantly during 2000–2020 in the whole country and all provinces, indicating the increasing stocking density and the overexploited status of grassland in recent years. The multiregression analysis further showed that the dramatic increase in livestock populations contributed 87.5% and 55%-99% to the variations in the GSCIW for the grassland and seventeen provinces, respectively. These results will be useful and helpful in supporting sustainable grassland management and the sustainable livelihoods of herders in Mongolia.

Diurnal variations in primary and secondary organic aerosols in an eastern China coastal city: The impact of land-sea breezes

The land-sea breeze circulation significantly impacts the atmospheric transport of organic aerosols in coastal regions. However, the links between organic aerosols and land-sea breezes remain poorly understood. In this study, organic marker compounds for biomass burning, primary biological aerosols, biogenic and anthropogenic secondary organic aerosols (SOA) in fine particles from a coastal city in East China were analysed using gas chromatography–mass spectrometry. Land-sea breeze circulations were identified to explore their potential influence on organic molecular compositions. Organic marker compounds showed obvious diurnal/seasonal patterns. Surprisingly, due to the combined influence of weakened East Asian monsoons and land-sea breezes, all detected organic markers decreased except α/β-pinene SOA markers during land-sea breeze periods in early autumn; whereas, all the organic markers increased except α/β-pinene SOA markers, pollen and plant debris markers during land-sea breeze periods in early spring. Furthermore, the reaction pathway and aging of biogenic SOA were also related to land-sea breezes. During the land-sea breeze periods, the ratios of 2-methylglyceric acid (2-MGA) to 2-methyltetrols increased in early autumn, indicating that more isoprene-derived SOA generated from the high-NOx (nitrogen oxides) pathway when the land-sea breezes occurred; while the ratios decreased in early spring, this may be related to the chemical transformation of 2-MGA to 2-MGA sulfates. Changes in the ratio of monoterpene SOA markers demonstrate that monoterpene SOA was relatively aged during sea breeze periods, while it was fresher when the land breeze occurred. Although boundary layer height, emissions, gas/particle partitioning, etc. are important reasons for the diurnal variations of organic aerosols, night/day ratios of molecular markers increased obviously when land-sea breezes occurred in both early autumn and early spring. Our results provide new insights into the shift in the chemical composition of organic aerosols over coastal areas that are influenced by land-sea breezes.

Prospects for the introduction of fodder species Artemisia into culture

In many desert communities, the basis of pasture ecosystems are species of the genus Artemisia, which are edifiers of plant communities in the vast territories of the Central Asia desert zone. Sagebrush pastures with a diverse set of plant species and life forms are used in desert animal husbandry all year round. Artemisia spp. is good fodder pastures plants. Green twigs contain 16.9% protein, 4.4% fat, 39% nitrogen-free extractives. Artemisia diffusa, А. turanica are common on desert graybrown and gray-earth soils with different granulometric composition, Artemisia halophila has a narrow ecological area confined to saline soils. The fodder mass of Artemisia spp. serves as the main type of sheep fodder and is especially appreciated in the autumn, winter and early spring periods. As a result of irrational use, the natural sagebrush pastures of deserts are degraded and need to restore their fodder productivity. All three wild–growing species – Artemisia turanica, Artemisia diffusa, Artemisia halophyla in culture conditions accelerate the passage of phenological phases in the process of ontogenesis. Individuals of species populations of sagebrush develop faster in cultural conditions than in natural sagebrush communities. In the culture conditions the process of ontogenesis, skeletal axes of the shrub are laid at the base of the maternal shoots in young individuals, in the second or third year of life, the tested species of sagebrush form a morphologically full-fledged life form of a semishrub with a feed productivity 3-5 times higher than the yield of natural pastures. In the conditions of Artemisia spp. culture, they grow well and quickly. Many individuals enter the fruiting season in the first year of life.

Оценка разных систем содержания гиссарских овец, сложившихся в Таджикистане в последнее время

The article provides an assessment of the different systems of keeping Hissar sheep that have developed in the farms of Tajikistan in recent years. The first system is the year-round pasture keeping of Hissar sheep in winter and early spring periods on valley and foothill pastures, and in summer and early autumn - in the mountains on alpine and subalpine pastures. The second system is the pasture keeping of Hissar sheep only in summer and early autumn in the mountains, and in other periods - stable and semi-stable keeping. Pasture maintenance is practically absent. The third system is the year-round stable or semi-stable keeping of Hissar sheep.