Autumn Growth Research Articles

Stem Growth and Dehydration Responses of Mediterranean Tree Species to Atmospheric and Soil Drought.

Stem growth responses to soil and atmospheric drought are critical to forecasting the tree carbon sink strength. Yet, responses of drought-prone forests remain uncertain despite global aridification trends. Stem diameter variations at an hourly resolution were monitored in five Mediterranean tree species from a mesic and a xeric site for 6 and 12 years. Stem growth and dehydration responses to soil (REW) and atmospheric (VPD) drought were explored at different timescales. Annually, growth was determined by the number of growing days and hours. Seasonally, growth was bimodal (autumn growth ≈ 8%-18% of annual growth), varying among species and sites across the hydrometeorological space, while dehydration consistently responded to REW. Sub-daily, substantial growth occurred during daytime, with nighttime-to-daytime ratios ranging between 1.2 and 3.5 (Arbutus unedo ≈ Quercus faginea < Quercus ilex < Pinus halepensis in the mesic site, and Juniperus thurifera < P. halepensis in the xeric site). Overall, time windows favourable for growth were limited by soil (rather than atmospheric) drought, modulating annual and seasonal growth in Mediterranean species, and stems maintained non-negligible growth during daytime. These patterns contrast with observations from wetter or cooler biomes, demonstrating the growth plasticity of drought-prone species to more arid climate conditions.

Long-term warming and human-induced plankton shifts at a coastal Eastern Mediterranean site

Plankton are key ecological indicators for assessing the impacts of human-induced pressures like climate change and waste-water discharge. Here, 26 years (1988–2015) of biweekly in-situ chlorophyll-a concentration, mesozooplankton biomass and remotely-sensed sea surface temperature (SST) data are utilized to investigate long-term changes of plankton biomass and timing of growth (phenology) in relation to warming, in a coastal region of the Saronikos Gulf (Aegean Sea). A Waste-Water Treatment Plant (WWTP) was established in 1995, leading to decreased nutrient concentrations circa 2004. Overall, the results indicate an interplay between warming and changes in ecological status. During higher nutrient input (1989–2004), a temporal mismatch between zooplankton and phytoplankton, and a positive zooplankton growth—SST association, are evident. Conversely, in the warmer, less mesotrophic period 2005–2015, an earlier timing of zooplankton growth (related to copepod abundance) synchronizes with phytoplankton growth, including a secondary autumn growth period. Concurrently, an abrupt negative interannual relationship between SST and mesozooplankton, and a summer biomass decrease (linked with cladoceran abundance) are observed. This work provides evidence that current warming could alter plankton abundance and phenology in nearshore Eastern Mediterranean ecosystems, suggesting shifts in plankton community composition that could trigger potential cascading effects on higher trophic levels.

Life cycles and larval and pupal habitats of eleven Japanese Rhyacophila (Trichoptera) species at the mountain streams in central Honshu

The life cycles and microhabitats involved in aquatic stages of eleven Rhyacophila Stephens, 1836 species living in two neighboring Japanese mountain streams in Nara Prefecture, central Honshu, were investigated. Eight species had univoltine life cycles; seven species had spring to early summer emergence seasons. One species had an autumnal emergence. Four univoltine species had periods where no larvae or pupae were collected in aquatic stages, possibly a period of egg diapause. Three species had bivoltine life cycles, with early summer and autumn emergence seasons. Rhyacophila nipponica Iwata, 1927, R. manuleata AV Martynov, 1934, and R. shikotsuensis Iwata, 1927, in the nigrocephala species group Ross, 1956, have larvae which spend most of their larval stage in the hyporheos. The larvae of R. transquilla Tsuda, 1940, also inhabit the hyporheic zone, although the vertical microhabitat used by this species differed from the former three species. All four of these species have hyporheic larval stages, but in these species the first and final instar larvae reside on the surfaces of cobbles. The first instar larvae seem to live on stone surfaces immediately after hatching, and subsequently move to the interstices of sand. Final instar larvae live in the interstices of sandy bottom, and move to stone surfaces for pupation. Eleven species of the genus Rhyacophila had diverse life histories, microhabitat preferences, and experienced differing water temperature regimes during larval stages at the sites. Life history and habitat preference variation enhances the species richness of the genus and coexistence of species in upper stream of the Kinokawa River.

Patterns, timing, and environmental drivers of secondary growth in two physiologically distinct Mediterranean alpine shrub species

Alpine plants are particularly sensitive to climate change, and in the Mediterranean, less frequent winter cold and prolonged summer drought are expected to shift the growth patterns of species, altering their range and strategies to cope with these dual climatic stressors. However, adaptive strategies for drought and frost and their impact on performance of species are poorly explored, with critical timescales relevant for growth insufficiently reflected and a focus on a limited set of environmental drivers. Here, we explored the growth processes of two physiologically distinct Mediterranean alpine shrub species: Cytisus galianoi (green-stemmed species) and Astragalus granatensis (dimorphic species). By measuring the daily stem diameter changes of 26 specimens over six consecutive years (2015–2020) using dendrometers, as well as the corresponding soil temperature and soil moisture conditions, we identified bimodal annual growth patterns (i.e. two phases of growth), water-related timing of growth, and drought- and frost-related environmental constraints. By implementing correlation analyses, linear mixed effects models, and partial least-squares regression, we found pregrowth temperature and moisture drivers to be highly relevant for growth in both species, suggesting a temporal decoupling of growth and resource acquisition. However, the underlying mechanisms were contrasting. While the spring growth of C. galianoi was promoted by pregrowth winter conditions, the autumn growth of A. granatensis was promoted by pregrowth summer conditions. Thus, resource acquisition is likely to be optimized when the traits of species allow physiological activity at high gain and low costs, i.e. when adaptive mechanisms reduce resource consumption to cope with frost and drought. This is during winter for frost-tolerant green-stemmed species and during summer for drought-avoidant dimorphic species, leading to species-specific time windows of growth. Understanding these species-specific growth mechanisms contributes to answering the overarching question of when and how woody plants grow and helps in understanding their adaptability to future climate variability, particularly in sensitive alpine environments, where plant species are evolutionally adapted to physical peculiarities and reach their low-temperature limit.

Seed treatment affected establishment and yield in two pennycress lines

IntroductionOilseed pennycress (Thlaspi arvense L.) is an emerging biofuel crop for use in the aviation industry that has potential as a rotational crop in corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] cropping sequences. Ensuring autumn emergence of pennycress after early broadcast seeding is key because this practice may result in uneven spatial distribution due to the small seed size and variable germination, soil contact, and moisture availability. The objective of this research was to evaluate the impact of five seed treatments and enhancements on autumn establishment in two pennycress lines (MN106NS and tt8-t/ARV1) in broadcast seeding compared with no treatment.MethodsTested treatments were (i) gibberellic acid (GA) soak, (ii) fludioxonil fungicide, (iii) pelleting with diatomaceous earth and a commercial binder, (iv) fungicide plus pelleting, or (v) fungicide plus pelleting with GA added to the binder. Seeds were planted at nine sites in four U.S. states to assess establishment (stand counts and percentage canopy cover) in the autumn and spring and seed yield after maturity.ResultsThe MN106NS line had greater plants m−2 and percent green cover with treatments that included GA compared to the control. Line tt8-t/ARV1 had reduced stands when pelleted compared to the untreated, and establishment was unchanged when treated with GA compared to the untreated. Pelleting treatments without GA were not beneficial for stand establishment of either line. Seed yield for MN106NS was 20% greater than the untreated when treated with GA only or pelleted. Seed yield for tt8-t/ARV1 did not increase over the untreated with any treatment and was reduced by 20%–40% when pelleted.DiscussionThese results suggest minimal benefit of seed treatment and pelleting for the tested lines under broadcast seeding, though black-seeded lines may still benefit from GA treatment. Plant establishment and yield were negatively correlated with total precipitation post-planting, suggesting that excessive rainfall post-planting (&amp;gt;60 mm) may impede establishment when broadcast seeded.

Beneficial microbial consortium improves winter rye performance by modulating bacterial communities in the rhizosphere and enhancing plant nutrient acquisition.

The beneficial effect of microbial consortium application on plants is strongly affected by soil conditions, which are influenced by farming practices. The establishment of microbial inoculants in the rhizosphere is a prerequisite for successful plant-microorganism interactions. This study investigated whether a consortium of beneficial microorganisms establishes in the rhizosphere of a winter crop during the vegetation period, including the winter growing season. In addition, we aimed for a better understanding of its effect on plant performance under different farming practices. Winter rye plants grown in a long-time field trial under conventional or organic farming practices were inoculated after plant emergence in autumn with a microbial consortium containing Pseudomonas sp. (RU47), Bacillus atrophaeus (ABi03) and Trichoderma harzianum (OMG16). The density of the microbial inoculants in the rhizosphere and root-associated soil was quantified in autumn and the following spring. Furthermore, the influence of the consortium on plant performance and on the rhizosphere bacterial community assembly was investigated using a multidisciplinary approach. Selective plating showed a high colonization density of individual microorganisms of the consortium in the rhizosphere and root-associated soil of winter rye throughout its early growth cycle. 16S rRNA gene amplicon sequencing showed that the farming practice affected mainly the rhizosphere bacterial communities in autumn and spring. However, the microbial consortium inoculated altered also the bacterial community composition at each sampling time point, especially at the beginning of the new growing season in spring. Inoculation of winter rye with the microbial consortium significantly improved the plant nutrient status and performance especially under organic farming. In summary, the microbial consortium showed sufficient efficacy throughout vegetation dormancy when inoculated in autumn and contributed to better plant performance, indicating the potential of microbe-based solutions in organic farming where nutrient availability is limited.

Effects of Multi-Growth Periods UAV Images on Classifying Karst Wetland Vegetation Communities Using Object-Based Optimization Stacking Algorithm

Combining machine learning algorithms with multi-temporal remote sensing data for fine classification of wetland vegetation has received wide attention from researchers. However, wetland vegetation has different physiological characteristics and phenological information in different growth periods, so it is worth exploring how to use different growth period characteristics to achieve fine classification of vegetation communities. To resolve these issues, we developed an ensemble learning model by stacking Random Forest (RF), CatBoost, and XGBoost algorithms for karst wetland vegetation community mapping and evaluated its classification performance using three growth periods of UAV images. We constructed six classification scenarios to quantitatively evaluate the effects of combining multi-growth periods UAV images on identifying vegetation communities in the Huixian Karst Wetland of International Importance. Finally, we clarified the influence and contribution of different feature bands on vegetation communities’ classification from local and global perspectives based on the SHAP (Shapley Additive explanations) method. The results indicated that (1) the overall accuracies of the four algorithms ranged from 82.03% to 93.37%, and the classification performance was Stacking &gt; CatBoost &gt; RF &gt; XGBoost in order. (2) The Stacking algorithm significantly improved the classification results of vegetation communities, especially Huakolasa, Reed-Imperate, Linden-Camphora, and Cephalanthus tetrandrus-Paliurus ramosissimus. Stacking had better classification performance and generalization ability than the other three machine learning algorithms. (3) Our study confirmed that the combination of spring, summer, and autumn growth periods of UAV images produced the highest classification accuracy (OA, 93.37%). In three growth periods, summer-based UAVs achieved the highest classification accuracy (OA, 85.94%), followed by spring (OA, 85.32%) and autumn (OA, 84.47%) growth period images. (4) The interpretation of black-box stacking model outputs found that vegetation indexes and texture features provided more significant contributions to classifying karst wetland vegetation communities than the original spectral bands, geometry features, and position features. The vegetation indexes (COM and NGBDI) and texture features (Homogeneity and Standard Deviation) were very sensitive when distinguishing Bermudagrass, Bamboo, and Linden-Camphora. These research findings provide a scientific basis for the protection, restoration, and sustainable development of karst wetlands.

Yield tradeoffs of early corn harvest to enhance pennycress establishment

AbstractOilseed pennycress (Thlaspi arvense L.) establishment following grain corn (Zea mays L.) harvest in northern latitudes is challenging because of the short duration between corn harvest and soil freeze. The use of shorter season corn hybrids for a region may partly solve this challenge, but tradeoffs in reduced corn yield may be a concern. This study evaluated corn relative maturity (CRM) hybrids on pennycress establishment, seed and oil yields, and corn grain yield tradeoffs. The CRM hybrids ranged from 76‐ to 95‐day for northern sites (Morris and Rosemount, MN), and from 95‐ to 113‐day for the southern sites (Custar, OH, and Lexington, IL). The checks were full‐season corn (113‐ and 95‐day corn for the southern and the northern sites, respectively) harvested for silage. Pennycress plant density, green cover, and yield were generally greater when pennycress was seeded following silage corn due to early seeding and reduced corn stover. Pennycress seed yields ranged from 388 to 778, 641 to 834, 362 to 784, and 834 to 2038 kg ha−1 at Custar, Lexington, Morris, and Rosemount, respectively. The results showed that growing 86‐ and 105‐day grain corn in the northern and southern sites, respectively, facilitated timely pennycress establishment with little or no corn grain yield loss compared with full‐season hybrids. Developing pennycress varieties better suited for emergence under high corn stover or employing stover management practices to increase autumn emergence is suggested. Additionally, an economic analysis of the entire cropping sequence (corn–pennycress–soybean) is needed.

Bimodal and unimodal radial growth of Mediterranean oaks along a coast-inland gradient

Wood formation during the growing season is shaped by the intra-annual variability of climatic conditions. In the Mediterranean, the cambial activity is seasonally constrained by winter low temperature and summer drought, resulting in bimodal growth patterns. Although bimodal growth is an ecologically important adaptation of woody species to seasonally dry environments, its variability across space and among species remains unclear. We combined direct monitoring of intra-annual radial growth using dendrometers and xylogenesis micro-sampling with indirect wood formation modeling to assess growth bimodality for two coexisting oak species across six sites in North-Eastern Spain. We focused on species with two contrasting life strategies, evergreen with diffuse-porous wood (Quercus ilex) and winter deciduous with ring-porous wood (Q. faginea/Q. pubescens). Study sites spanned from oceanic areas with high autumn precipitation to dry continental inland regions. We hypothesized that growth bimodality reflects the interaction between local precipitation patterns and species-specific traits. Our results revealed cambial activity in autumn after summer quiescence across the entire region and for both oak species. However, growth bimodality and the relative contribution of the autumn growth peak to the total annual growth was geographically structured and species-specific. Growth was unimodal under continental and Atlantic conditions. By contrast, growth bimodality was significant along the Mediterranean coast, where precipitation showed a bimodal pattern. Moreover, evergreen Q. ilex showed more growth bimodality compared with deciduous Q. faginea/Q. pubescens at Mediterranean sites. Different intra-annual distribution of radial growth could facilitate coexistence of both oak species through temporal niche partitioning. The growth bimodality helps to compensate for reduced growth in summer by autumn cambial resumption and, therefore, the differences in its intensity between sites and species may determine divergent responses of forest ecosystems to ongoing climate change.

Effects of Spring Warming and Drought Events on the Autumn Growth of Larix kaempferi Seedlings

High temperatures and droughts following winter dormancy can negatively affect seedling growth and mortality. An open-field experiment was conducted to study the growth and mortality of Larix kaempferi seedlings in response to spring warming and drought treatments and to determine whether seedlings could regain their growth capability once the treatments were discontinued. In May 2020, 1-year-old seedlings were exposed to four treatments: control, warming-only, drought-only, and the combined warming and drought. Drought treatment reduced the seedling height and root collar diameter and increased the mortality rate. The combined warming and drought treatments had the highest mortality rates, followed by the drought, control, and warming treatments. However, after the cessation of the treatments, the combined warming and drought treatments increased seedling height, root collar diameter, and individual seedling biomass because the high mortality rate relaxed competition among seedlings. This suggests that the effects of low competition on the surviving seedlings may mitigate the negative effects of warming and drought on seedling growth. Our study demonstrates that despite the high mortality and decreased growth during the treatment period, seedlings subjected to combined high temperature and drought stress showed short-term high levels of growth compared to seedlings subjected to a single stress.

Influence of irrigation and weather conditions on the duration of interphase periods of winter wheat varieties

The autumn growth and development of plants depend on a complex of external factors: the average daily air temperature, the amount of precipitation, the humidity of the seed layer of the soil, nutrients, light, etc. If winter wheat is sown at a later date, there are risks that the plants will enter the winter not well developed. It is possible to accelerate the passage of interphase periods with the help of irrigation, which is a necessary agrotechnical measure in the Southern Steppe of Ukraine. The purpose of the research is to establish the influence of varietal characteristics, irrigation and weather conditions on the duration of interphase periods of winter wheat in the autumn period on an international scale. Experimental research was carried out during 2020-2021 on southern chernozem, on the basis of the Educational Scientific and Practical Center of the Mykolaiv NAU with two varieties of winter wheat. Field, laboratory and comparative calculation methods were used during the research. The establishment and conduct of experiments were carried out according to the methodology of the research case. Soil moisture was determined by the thermogravimetric method, and phenophases were determined simultaneously throughout the experiment. It was determined that irrigation for 1-2 days reduces the duration of the interphase period of BBCH 00-09; for 3 days – BBCH 10-12; for 11 days – BBCH 13-19; for 5-7 days – BBCH 20-22. In natural conditions (without irrigation), the duration of the interphase periods (from BBCH 00-09 to 20-22) of the growth and development of plants of the studied varieties of winter wheat in 2020 was 93-96 days, which is 23-25 days more than in 2021. In plants of the Ovid variety under conditions of natural moisture (without irrigation), the interphase periods came 1-3 days later than in the Duma Odeska variety, while under irrigation conditions there was no significant difference. The obtained scientific results of the research will contribute to the wider implementation of irrigation, which will ensure the rapid and full growth and development of winter wheat plants in the autumn period, which will further contribute to increasing the yield and gross harvest of grain

Photoperiod Control of Plant Growth: Flowering Time Genes Beyond Flowering.

Fluctuations in environmental conditions greatly influence life on earth. Plants, as sessile organisms, have developed molecular mechanisms to adapt their development to changes in daylength, or photoperiod. One of the first plant features that comes to mind as affected by the duration of the day is flowering time; we all bring up a clear image of spring blossom. However, for many plants flowering happens at other times of the year, and many other developmental aspects are also affected by changes in daylength, which range from hypocotyl elongation in Arabidopsis thaliana to tuberization in potato or autumn growth cessation in trees. Strikingly, many of the processes affected by photoperiod employ similar gene networks to respond to changes in the length of light/dark cycles. In this review, we have focused on developmental processes affected by photoperiod that share similar genes and gene regulatory networks.

Influences of Shifted Vegetation Phenology on Runoff Across a Hydroclimatic Gradient.

Climate warming has changed vegetation phenology, and the phenology-associated impacts on terrestrial water fluxes remain largely unquantified. The impacts are linked to plant adjustments and responses to climate change and can be different in different hydroclimatic regions. Based on remote sensing data and observed river runoff of hydrological station from six river basins across a hydroclimatic gradient from northeast to southwest in China, the relative contributions of the vegetation (including spring and autumn phenology, growing season length (GSL), and gross primary productivity) and climatic factors affecting the river runoffs over 1982–2015 were investigated by applying gray relational analysis (GRA). We found that the average GSLs in humid regions (190–241 days) were longer than that in semi-humid regions (186–192 days), and the average GSLs were consistently extended by 4.8–13.9 days in 1982–2015 period in six river basins. The extensions were mainly linked to the delayed autumn phenology in the humid regions and to advanced spring phenology in the semi-humid regions. Across all river basins, the GRA results showed that precipitation (r = 0.74) and soil moisture (r = 0.73) determine the river runoffs, and the vegetation factors (VFs) especially the vegetation phenology also affected the river runoffs (spring phenology: r = 0.66; GSL: r = 0.61; autumn phenology: r = 0.59), even larger than the contribution from temperature (r = 0.57), but its relative importance is climatic region-dependent. Interestingly, the spring phenology is the main VF in the humid region for runoffs reduction, while both spring and autumn growth phenology are the main VFs in the semi-humid region, because large autumn phenology delay and less water supply capacity in spring amplify the effect of advanced spring phenology. This article reveals diverse linkages between climatic and VFs, and runoff in different hydroclimatic regions, and provides insights that vegetation phenology influences the ecohydrology process largely depending on the local hydroclimatic conditions, which improve our understanding of terrestrial hydrological responses to climate change.

Working collection of crimson clover (Trifolium incarnatum L.) in the Ciscarpathia

Aim. To identify collection accessions – sources of valuable traits for using as starting material to create varieties of perennial grasses in Western Ukraine. Results and Discussion. The vegetable protein problem is one of the main issues facing scientists whose activities are related to agriculture, ecology and other areas of biology. The Ciscarpathia is a zone of natural meadows, hayfields and pastures, where a large number of plant species belonging to different botanical families grow. Among the natural vegetation on pastures, meadows and fallows, clover species are most often found. Trifolium incarnatum L. is an annual winter-spring plant. It is widely used in agriculture as a nitrogen-fixing cover crop. The crimson clover collection comprises 24 accessions. Some promising accessions that can be used as starting material in breeding for high productivity (green mass, hay and seeds), herbage capacity, resistance to diseases and pests were selected. Reference accessions and sources of economically valuable traits, which are actively involved in breeding, were singled out. During the study (2019-2021), accessions were investigated in detail for biological and morphological features. We evaluated the crimson clover collection for germinability, winter survival, flowering time, green mass per plant, and seed yield. The results showed that the crimson clover collection could be tentatively divided into 3 groups: early-ripening (70-79 days; 37.5%), mid-ripening (83-87 days; 50.0%) and late-ripening (92-94 days; 12.5%). Nine accessions (PFZ 00625, PFZ 02148, PFZ 01264, PFZ 01266, PFZ 01295, PFZ 01273, PFZ 01270, PFZ 02266, and PFZ 02265) ripened slightly earlier. They are potential parents to develop an early-ripening population. Three accessions (PFZ 02268, PFZ 02267, and PFZ 02073) ripened significantly later than all the others. Thus, these accessions are excellent candidates to develop a late-ripening population. Depending on the region and cultivation system, farmers may be interested in both early-ripening and late-ripening crimson clover. Conclusions. Literature review allowed us to note that the studied crimson clover accessions had several advantages when used in production, namely: they are annuals, have high vegetation rates and productive potentials. Crimson clover accessions showed particularly distinct differences in autumn emergence and flowering time, indicating greater diversity and potential for breeding. In contrast, winter survival, green mass per plant showed greater intra- and inter-year variations. Autumn emergence and winter survival were found to be positively correlated, and both traits were negatively correlated with green mass per plant. Some accessions were identified as highly effective in several key traits and are of particular interest as parents in further breeding: PFZ 02118, PFZ 01270, PFZ 02267, PFZ 02073, PFZ 02072, PFZ 01290.

Landsat Observations of Two Decades of Wetland Changes in the Estuary of Poyang Lake during 2000–2019

The stability of wetlands is threatened by the combined effects of global climate change and human activity. In particular, the vegetation cover status of lake wetlands has changed. Here, the change in vegetation cover at the estuary of Poyang Lake was monitored, and its influencing factors are studied to elucidate the dynamic change characteristics of vegetation at the inlet of this lake. Flood and water level changes are two of the main factors affecting the evolution of wetland vegetation at the estuary of Poyang Lake. Therefore, Landsat data from 2000 to 2019 were used to study the spatial and temporal variation in the Normalized Difference Vegetation Index (NDVI) in the vegetation cover area. Theil–Sen Median trend analysis and Mann–Kendall tests were used to study the long-term trend characteristics of NDVI. The response between NDVI and the explanatory variables at the estuary of Poyang Lake was quantified using regression tree analysis to study the regional climate, water level, and flood inundation duration. Results showed the following: (1) Vegetation in a large area of the study area improved significantly from 2000 to 2010 and only slightly from 2010 to 2019, and few areas with slight degradation of vegetation were found. In most of these areas, the vegetation from 2000 to 2010 exhibited a gradual change, from nothing to something, which started around 2004; (2) The main variable that separated the NDVI values was the mean water level in October. When the mean October water level was greater than 14.467 m, the study area was still flooded in October. Thus, the regional value of BestNDVI was approximately 0.3, indicating poor vegetation growth. When the mean water level in October was less than 14.467 m, the elevation of the study area was higher than the water level value, and after the water receded in October, the wetland vegetation exhibited autumn growth in that year. Thus, the vegetation in the study area grew more abundantly. These results could help manage and protect the degraded wetland ecology.

Characteristics of the COVID-19 Epidemiological Situation in the Russian Federation in 2020

Background.The COVID-19 epidemic in the Russian Federation, which began in March 2020, caused serious damage to health of the population and led to severe economic losses. By December 28, 2020, 3 078 035 cases of COVID-19 and 55 265 lethal outcomes were registered in the country. The population of all territorial subjects of the country is involved in the epidemic process of COVID-19. The severe epidemiological situation made it necessary to conduct an analysis to identify the factors that determine the high intensity of the epidemic process, as well as the population groups with the highest risk of SARS-CoV-2 infection.&#x0D; Aims to study the patterns of SARS-CoV-2 spread and the epidemiological features of the initial stage of the COVID-19 pandemic in the Russian Federation in 2020.&#x0D; Methods.An epidemiological analysis of the COVID-19 situation in the Russian Federation was carried out to determine the dynamics of morbidity, the gender proportion and age structure of patients, the proportion of hospitalized patients, the ratio of various forms of infection, the social and professional status of patients. Standard methods of descriptive statistics Microsoft Excel and STATISTICA 12.0 (StatSoft, USA) were used for statistical processing. The mean values were estimated with a 95% confidence interval [95% CI] (the exact Klopper Pearson method).&#x0D; Results.During the observation time (2020), several periods were identified in the dynamics of the new COVID-19 cases detection: the period of importation of SARS-CoV-2 and the increase in morbidity, the period of epidemic decline, the period of autumn growth, the period of sustained high incidence of COVID-19. It was found that people over 70 years of age are the group with the highest risk of infection and a more severe course of COVID-19. The presence of target contingents among social and professional groups of the population, which should include medical workers, retired person, employees of educational institutions, law enforcement agencies, transport, who require special attention and medical and social support, was shown.&#x0D; Conclusions.The analysis showed that the large-scale spread of COVID-19 requires in-depth epidemiological studies and the development of additional disease control measures, taking into account the dynamics of the incidence of this socially significant infection.

Climate windows of intra-annual growth and post-drought recovery in Mediterranean trees

Forests store large amounts of carbon as wood, but this storage potential depends on seasonal radial growth and how it is driven by climate. Therefore, we need a better understanding on how intra-annual radial increment rates determine growth responses to climate variability. There is a large gap of knowledge on the climate windows, i.e. the effective climatic time-window for tree growth, and predictors of intra-annual growth, particularly in seasonally dry biomes such as Mediterranean forests where growth may show several seasonal peaks. We described the radial increment rates of five tree species inhabiting mesic (Quercus ilex, Quercus faginea, Arbutus unedo) and xeric (Pinus halepensis, Juniperus thurifera) sites using dendrometers. Then, we related those rates and tree-ring width to climate data using correlations and model selection. All species presented bimodal patterns of radial increment rates with a major peak in spring and a minor peak in autumn, being this pattern most marked in Q. ilex, A. unedo and J. thurifera. Differences in climate-rates relationships were greater between species than between sites. Wet and cool conditions in winter and spring increased spring rates, but the climatic time-windows were longer in some species (Q. ilex, J. thurifera) and shorter in others (Q. faginea, P. halepensis). Similarly, wet and cool conditions also enhanced autumn rates in the xeric site, but warm conditions did it in the mesic site. Rainy autumn conditions reduced A. unedo rates. Climate-growth associations at intra- and inter-annual scales were consistent in species showing long intra-annual climatic time-windows such as Q. ilex. Our findings confirm the importance of wet winters and cool springs for radial growth in some species, and the relevance of autumn growth in A. unedo. Similar studies on intra-annual radial increment rates and climatic time-windows of forest growth and productivity can reveal which will be the species most impacted by drought.

Changing composition of SARS-CoV-2 lineages and rise of Delta variant in England.

BackgroundSince its emergence in Autumn 2020, the SARS-CoV-2 Variant of Concern (VOC) B.1.1.7 (WHO label Alpha) rapidly became the dominant lineage across much of Europe. Simultaneously, several other VOCs were identified globally. Unlike B.1.1.7, some of these VOCs possess mutations thought to confer partial immune escape. Understanding when and how these additional VOCs pose a threat in settings where B.1.1.7 is currently dominant is vital.MethodsWe examine trends in the prevalence of non-B.1.1.7 lineages in London and other English regions using passive-case detection PCR data, cross-sectional community infection surveys, genomic surveillance, and wastewater monitoring. The study period spans from 31st January 2021 to 15th May 2021.FindingsAcross data sources, the percentage of non-B.1.1.7 variants has been increasing since late March 2021. This increase was initially driven by a variety of lineages with immune escape. From mid-April, B.1.617.2 (WHO label Delta) spread rapidly, becoming the dominant variant in England by late May.InterpretationThe outcome of competition between variants depends on a wide range of factors such as intrinsic transmissibility, evasion of prior immunity, demographic specificities and interactions with non-pharmaceutical interventions. The presence and rise of non-B.1.1.7 variants in March likely was driven by importations and some community transmission. There was competition between non-B.1.17 variants which resulted in B.1.617.2 becoming dominant in April and May with considerable community transmission. Our results underscore that early detection of new variants requires a diverse array of data sources in community surveillance. Continued real-time information on the highly dynamic composition and trajectory of different SARS-CoV-2 lineages is essential to future control effortsFundingNational Institute for Health Research, Medicines and Healthcare products Regulatory Agency, DeepMind, EPSRC, EA Funds programme, Open Philanthropy, Academy of Medical Sciences Bill,Melinda Gates Foundation, Imperial College Healthcare NHS Trust, The Novo Nordisk Foundation, MRC Centre for Global Infectious Disease Analysis, Community Jameel, Cancer Research UK, Imperial College COVID-19 Research Fund, Medical Research Council, Wellcome Sanger Institute.

Effect of autumn vegetation conditions on overwintering of winter rye and wheat with different sowing dates

The research was carried out in order to study the effect of autumn vegetation conditions on the growth, development and overwintering of winter wheat and rye depending on different sowing dates. The work was performed in 2016–2019 in the conditions of the forest-steppe of the Ob region. The research material included the varieties of tetraploid winter rye Vlada and Tetra short and winter wheat varieties Novosibirskaya 40 and Novosibirskaya 3. Sowing was carried out on three dates: 1st – 23 August, 2nd – 31 August and 3rd – 7 September under bare fallow. The choice of the optimal sowing time creates favorable conditions for the growth and development of winter crops and their preparation for further overwintering. According to the studies, it was noted that the intensity of autumn shoot formation and plant growth to a greater extent depends on the duration of the autumn growing season. A decrease in the plant growth rate and formation of tillering shoots from the first sowing date to the third date was associated with a decrease in the sum of effective temperatures. When sowing on a later date, the sum of effective temperatures varied in the range of 90–197° over the years. Under these conditions, overwintering rate of winter rye remained at the level of 94–100%, while in winter wheat it decreased to 40%. The best option, which ensured the stability of winter resistance, was the second sowing date (August 31) with a sum of effective temperatures of 250-300°, whereby the plants formed 3–4 tillering shoots and the plant height reached 18–25 cm. Winter rye outperforms winter wheat in autumn growth rate, shoot formation and in the vegetation cone development.

Nitrogen Uptake Efficiency, Mediated by Fine Root Growth, Early Determines Temporal and Genotypic Variations in Nitrogen Use Efficiency of Winter Oilseed Rape.

Maintaining seed yield under low N inputs is a major issue for breeding, which requires thoroughly exploiting the genetic diversity of processes related to Nitrogen Use Efficiency (NUE). However, dynamic analysis of processes underlying genotypic variations in NUE in response to N availability from sowing to harvest are scarce, particularly at the whole-plant scale. This study aimed to dynamically decipher the contributions of Nitrogen Uptake Efficiency (NUpE) and Nitrogen Utilization Efficiency (NUtE) to NUE and to identify traits underlying NUpE genetic variability throughout the growth cycle of rapeseed. Three experiments were conducted under field-like conditions to evaluate seven genotypes under two N conditions. We developed NUE_DM (ratio of total plant biomass to the amount of N available) as a new proxy of NUE at harvest, valid to discriminate genotypes from the end of inflorescence emergence, and N conditions as early as the beginning of stem elongation. During autumn growth, NUpE explained up to 100% of variations in NUE_DM, validating the major role of NUpE in NUE shaping. During this period, under low N conditions, up to 53% of the plant nitrogen was absorbed and NUpE genetic variability resulted not from differences in Specific N Uptake but in fine-root growth. NUtE mainly contributed to NUE_DM genotypic variation during the reproductive phase under high-N conditions, but NUpE contribution still accounted for 50–75% after flowering. Our study highlights for the first time NUpE and fine-root growth as important processes to optimize NUE, which opens new prospects for breeding.