Considerable Seasonal Variation Research Articles

Seasonality of bioirrigation by the maldanid polychaete Clymenella torquata and related oxygen dynamics in permeable sediments

Benthic organisms in coastal sediments affect elemental cycling and control benthic-pelagic coupling through particle reworking and ventilation of their burrows. Bioirrigation and associated porewater advection create intermittently oxic regions within sediments. The spatio-temporal patterns of such biogenic redox oscillations likely respond to seasonal factors, but quantitative information on the seasonality of bioirrigator behaviors and associated redox dynamics is scarce. We examined bioirrigation by the maldanid polychaete Clymenella torquata and its impacts on sediment oxygenation patterns in permeable sediments using high-resolution planar optode oxygen imaging. In sediment mesocosms with reconstructed summer-collected sediment, the durations of pumping and resting varied inversely with temperature. The average durations of pumping and resting increased from 4 min/4 min at 21 °C, to 6 min/6 min at 12 °C, to 15 min/14 min at 5 °C. In intact cores collected in summer, irrigation patterns (3.5 min/3.5 min) were similar to those observed at 21 °C during the temperature ramp. Pumping and resting durations in intact cores collected in winter at 6 °C averaged 9 min/26 min, significantly different from patterns at comparable temperatures in the temperature ramp. Pumping patterns strongly affected the temporal patterns of redox dynamics in surrounding sediments. In addition, temperature strongly affected burrow irrigation depth (exclusively within the top ∼10 cm at 21 °C, and down to ∼20 cm at 5–6 °C with an apparent transition at ∼15 °C), indicating that the zone with dynamic redox conditions migrates vertically on a seasonal basis. The differences in pumping patterns between in- and out-of-season experiments and the effect of temperature on irrigation depth underscore the importance of conducting experiments with bioturbators in-season and at field temperatures. The observed seasonal differences in bioirrigation patterns and associated spatio-temporal redox dynamics suggest that rates and pathways of redox-sensitive diagenetic processes and benthic chemical fluxes in permeable sediments likely show considerable seasonal variation.

Seasonal expressions of nerve growth factor (NGF), and its receptor TrkA and p75 in the scent glands of muskrats (Ondatra zibethicus).

NGF, also known as nerve growth factor, is crucial for the survival and differentiation of the nervous system, in addition to being involved in a number of non-neuronal systems. The aim of this work was to investigate the immunolocalization and expression patterns of NGF, its receptor, tyrosine kinase receptor A (TrkA), and p75 in the scent glands of muskrats (Ondatra zibethicus) throughout the breeding and non-breeding seasons. The scent gland mass showed considerable seasonal variations, with higher values during the breeding season and comparatively lower levels during the non-breeding season. While no immunostaining was observed in the interstitial cells, NGF, TrkA, and p75 were immunolocalized in the scent glandular cells and epithelial cells during both breeding and non-breeding seasons. NGF, TrkA, and p75 protein and mRNA expression levels were higher in the scent glands during breeding season compared to the non-breeding season. Circulating levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), and T in the scent gland were all significantly higher throughout the breeding season. The relative levels of the hormones in the plasma and the scent glands as well as NGF, TrkA, and p75 were positively associated with each other. Additionally, transcriptome analysis of the scent glands revealed that differentially expressed genes may be linked to steroid biosynthesis, the estrogen signaling pathway, and neurotransmitter transmembrane transporter function. These results suggest a potential role for NGF, TrkA, and p75 in controlling seasonal variations in the muskrats' scent gland functioning.

Temporal variations in the surface aragonite saturation state of the Yellow Sea: Observations at the Socheongcho Ocean Research Station during 2017–2022

Accurately constraining the natural variability of the carbonate system is essential for evaluating long-term changes in coastal areas, which result from the absorption of anthropogenic CO2. This is particularly important given the significant variation in physical and biological processes in these regions. In this regard, the analysis of surface carbonate chemistry in the Yellow Sea was conducted using discrete seawater samples obtained from the Socheongcho Ocean Research Station (37.423°N, 124.738°E) between 2017 and 2022. Our bottle data and sensor pH measurements revealed considerable seasonal variations of aragonite saturation state (ΩAR), typically ranging from 1.6 to 3.9. These variations are particularly pronounced during the summer and early winter. Our dataset serves as a baseline for understanding the long-term changes in ocean acidification in the Yellow Sea, the complex biogeochemical processes in coastal areas, and their impact on ocean acidification.

Assessing seasonal variation and trends in rainfall patterns of Madhya Pradesh, Central India

Abstract Climate change is a worldwide problem caused by various anthropogenic activities, leading to changes in hydroclimatic variables like temperature, rainfall, riverine flow, and extreme hydrometeorological events. In India, significant changes are noted in its natural resources and agriculture sectors. In this study, we analysed the long-term spatio-temporal change in rainfall patterns of Madhya Pradesh, Central India, using Indian Meteorological Department high-resolution gridded data from 439 grid points. The coefficient of variance analysis showed low variability in annual and monsoon rainfall but significant variability in pre-monsoon, post-monsoon, and winter seasons, indicating considerable seasonal variation. Pre-monsoon rainfall exhibited an increasing trend (0.018 mm annually), while annual, monsoon, post-monsoon, and winter rainfall showed decreasing trends. Change point analysis identified shifts in rainfall patterns in 1998 (monsoon, annual), 1955 (pre-monsoon), 1987 (post-monsoon), and 1986 (winter). Spatio-temporal distribution maps depicted irregular rainfall, with some areas experiencing drastic declines in precipitation after 1998. The maximum average annual rainfall reduced from 1,769 to 1,401 mm after 1998 affecting water availability. The study's findings highlight a significant shift in Madhya Pradesh's seasonal rainfall distribution after 1998, urging researchers and policymakers to address water-intensive cropping practices and foster climate resilience for a sustainable future in the region.

Seasonal Variations in Physico-Chemical Parameters of Manakudy Estuary, Southwest Coast of India

The present study was carried out to determine the seasonal variations in physico-chemical characteristics of water in Manakudy estuary Southwest coast of India, from June 2020 to May 2022. The study revealed that the physico-chemical parameters like temperature, hydrogen ion concentration, salinity, dissolved oxygen, nutrients like nitrate, nitrite, ammonia and total phosphorous exhibited considerable seasonal and spatial variations. The study showed that the Manakudy estuary is in a good state of health.

Characterization of rain microphysics on the leeside of the Western Ghats

AbstractThis study evaluates the performance of four impact‐type disdrometers installed at the Indian Institute of Tropical Meteorology, Pune, located on the leeside of the Western Ghats (WG). Further, seasonal variation of rain microphysical properties is studied during premonsoon (March–May), monsoon (June–September), postmonsoon (October–November), and winter (December–February). The four disdrometers exhibit comparable raindrop size distribution (DSD) patterns, though negligible differences are found at smaller drop diameters. The DSD shows higher concentrations of smaller (large‐size) drops during monsoon (premonsoon and postmonsoon). Principal component analysis revealed three distinct modes of DSD characteristics. Monsoon DSDs are associated with a group of numerous smaller drops allied with shallow storm heights (warm rain). The premonsoon and postmonsoon DSDs are clustered in a group where ice‐based processes dominate, resulting in higher median drop diameters (D0) and smaller normalized intercept parameters (Nw). The fitted gamma DSD model indicates higher mass‐weighted mean diameter (Dm) during premonsoon, and higher intercept parameter during monsoon, whereas postmonsoon and winter have intermediate values. DSD stratified with rain rate shows that the Dm values increase with an increase in rain rate during winter, monsoon and postmonsoon, whereas in premonsoon, Dm increases initially and then decreases. Higher Dm and lower Nw are observed during convective rain in all seasons. The fitted slope–shape parameter relationships show a considerable seasonal variation. The DSD on the WG's leeside is notably different from the windward slopes and other WG locations. Different microphysical and dynamical mechanisms lead to seasonal differences in DSD characteristics. In monsoon, a considerable volume of water vapour advected from the Arabian Sea promotes the formation of raindrops through collision–coalescence processes, which may result in a higher proportion of smaller and midsized raindrops. The deeper clouds during premonsoon and postmonsoon indicate mixed‐phase processes, which lead to mid and large‐sized raindrops.

Predicting residential water and electricity usage profiles with a temporal histogram model

The temporal histogram model and synthesiser that is presented in this paper statistically models the unique usage behaviour of electricity or hot water usage for individual residential households. These can be used to model behaviour and do simulations for demand management and planning. The model takes into consideration both seasonal variations and weekday differences and the synthesiser autonomously generates hourly synthetic profiles. We use 1,200 household electricity profiles, each spanning over one year, and 77 hot water usages, each spanning at least one month for each season, to obtain the results. The results showed that the model can accurately characterise the usage behaviour for a household and accurately predict future usage. The model also has a novel capability to model the relationship between usages at different times of the day, which further increases its usefulness in city-wide utility planning. This reduced hourly prediction errors by 19.6% for electricity usage and 25.0% for hot water usage when the first twelve hours of a day are known. This model can be used as an effective tool for demand-side management strategies and providing insight into utility planning in cities.

Seasonal Succession of Fungal Communities in Native Truffle (Tuber indicum) Ecosystems.

Truffles are a rare underground fungus and one of the most expensive, and sought-after kitchen ingredients in the world. Microbial ecology plays an important role in the annual growth cycle of truffles, but fungal communities in native truffle ecosystems are still largely unknown, especially for Tuber indicum from China. In this study, the spatial and temporal dynamics of soil physicochemical properties and fungal communities were described associated with four T. indicum-producing plots (TPPs) and one non-truffle-producing plot in four successive growing seasons. A total of 160 biological samples were collected, 80 of which were used for the determination of 10 soil physicochemical indices and 80 for Illumina-based analysis of the fungal microbiome. Soil physicochemical properties and fungal communities exhibited considerable seasonal variation. Ascomycetes, Basidiomycetes, and Mucormycoides dominated. The core microbiome work on the microecological changes in TPPs, and the identified core members contribute to the seasonal succession of communities. The genus Tuber occupies a central position in healthy TPPs. There was a strong correlation between soil physicochemical properties and fungal communities. The genus Tuber showed a positive correlation with Ca, Mg, and total nitrogen, but a negative correlation with total phosphorus and available potassium. This study describes the complex ecological dynamics of soil physicochemical indices and fungal communities occurring during the annual cycle of Tuber indicum, and highlights the succession of core communities in truffle plots, which contribute to better protection of native truffle ecosystems and control of mycorrhizal fungal contamination in artificial truffle plantations in China. IMPORTANCE The spatial and temporal dynamics of soil physicochemical properties and fungal communities associated with four Tuber indicum-producing plots and one non truffle producing plot in four different growing seasons are described. Soil physicochemical properties and fungal communities exhibited considerable seasonal variation. This study examines the complex ecological dynamics of soil physicochemical indices and fungal communities occurring during the annual cycle of Tuber indicum and highlights the succession of core communities in truffle plots, which contributes to better protection of native truffle ecosystems and control of mycorrhizal fungal contamination in artificial truffle plantations in China.

Length–weight relationship and seasonal variations in diet composition of whiting (Merlangius merlangus) in the South-eastern Black Sea

ABSTRACT The sex ratio, length–weight relationship (LWR) and diets based on stomach contents of whiting (Merlangius merlangus) were investigated in the south-eastern Black Sea, Turkey. A total of 3507 females (7.5–24.0 cm), 1602 males (9.4–20.0 cm), and 78 unidentified sex (5.5–16.5 cm) whiting were caught during monthly sampling from February to December 2017. The sex ratio was dominated by females, and their ratio (♀:♂, 1:0.46) significantly deviated from 1:1. The LWR indicated a negative allometric growth for males, while females had a positive allometric growth pattern. The stomach content analysis based on the relative importance index (IRI%) indicated exclusively piscivorous diets dominant by Sprattus sprattus and Engraulis encrasicolus made up more than 91 IRI% of the total diets of M. merlangus. The modified Costello-Amundsen’s graphical analyses evinced the specialized feeding strategy of M. merlangus throughout this study. The contribution of these two preys to the diets of M. merlangus showed considerable seasonal variations that were totally dependent on their abundance. Sprattus sprattus contributed to more than 98% of the total diets during June, July and August, while in the following months, E. encrasicolus appeared to take its position. Based on fish size, a general trend of a rise in prey diversity was found with increasing fish size. Also, the contribution of S. sprattus tended to decrease with increasing predator size, which is replaced by a rise in E. encrasicolus contribution. Hence, larger M. merlangus predominantly fed on E. encrasicolus while smaller size predators preferred to feed on S. sprattus.

The Effect of Spring Barley Fertilization on the Content of Polycyclic Aromatic Hydrocarbons, Microbial Counts and Enzymatic Activity in Soil.

Soil-dwelling microorganisms play an important role in the environment by decomposing organic matter, degrading toxic compounds and participating in the nutrient cycle. The microbiological properties of soil are determined mainly by the soil pH, granulometric composition, temperature and organic carbon content. In agricultural soils, these parameters are modified by agronomic operations, in particular fertilization. Soil enzymes participate in nutrient cycling and they are regarded as sensitive indicators of microbial activity and changes in the soil environment. The aim of the present study was to determine whether PAH content in soil is associated with the microbial activity and biochemical properties of soil during the growing season of spring barley treated with manure and mineral fertilizers. Soil samples for analysis were collected on four dates in 2015 from a long-term field experiment established in 1986 in Bałcyny near Ostróda (Poland). The total content of PAHs was lowest in August (194.8 µg kg-1) and highest in May (484.6 µg kg-1), whereas the concentrations of heavier weight PAHs was highest in September (158.3 µg kg-1). The study demonstrated that weather conditions and microbial activity induced considerable seasonal variations in PAHs content. Manure increased the content of organic carbon and total nitrogen, the abundance of organotrophic, ammonifying and nitrogen-fixing bacteria, actinobacteria and fungi and enhanced the activity of soil enzymes, including dehydrogenases, catalase, urease, acid phosphatase and alkaline phosphatase.

Influence of location, season and time of day on the spectral composition of ambient light: Investigation for application in myopia.

Given the possible role of spectral composition of light and myopia, this study aimed at investigating the variation in the spectral composition of ambient light in different (a) outdoor/indoor locations, (b) time of a day and (c) seasons. The spectral power distribution (SPD), categorised into short (380-500 nm), middle (505-565 nm) and long wavelengths (625-780 nm), was recorded using a handheld spectrometer at three outdoor locations ('open playground', 'under shade of tree' and 'canopy') and three indoor locations ('room with multiple windows', 'closed room' and 'closed corridor'). Readings were taken at five different time points (3-h intervals between 6:30 and 18:00 hours) on two days, each during the summer and monsoon seasons. The overall median SPD (IQR [25th-75th percentile] W/nm/m2 ) across the three outdoor locations (0.11 [0.09, 0.12]) was 157 times higher than that of the indoor locations (0.0007 [0.0001, 0.001]). Considerable locational, diurnal and seasonal variation was observed in the distribution of the median SPD value, with the highest value being recorded in the 'open playground' (0.27 [0.21, 0.28]) followed by 'under shade of tree' (0.083 [0.074, 0.09]), 'canopy' (0.014 [0.012, 0.015]) and 'room with multiple windows' (0.023 [0.015, 0.028]). The relative percentage composition of short, middle and long wavelengths was similar in both the outdoor and indoor locations, with the proportion of middle wavelengths significantly higher (p< 0.01) than short and long wavelengths in all the locations, except 'canopy'. Irrespective of variation in SPD values with location, time, day and season, outdoor locations always exhibited significantly higher spectral power than indoor locations. The relative percentage composition of short, middle and long wavelengths of light was similar across all locations. These findings establish a foundation for future research to understand the relationship between spectral power and the development of myopia.

Quantitative metaproteomics reveals composition and metabolism characteristics of microbial communities in Chinese liquor fermentation starters.

Daqu, the Chinese liquor fermentation starter, contains complex microbial communities that are important for the yield, quality, and unique flavor of produced liquor. However, the composition and metabolism of microbial communities in the different types of high-temperature Daqu (i.e., white, yellow, and black Daqu) have not been well understood. Herein, we used quantitative metaproteomics based on data-independent acquisition (DIA) mass spectrometry to analyze a total of 90 samples of white, yellow, and black Daqu collected in spring, summer, and autumn, revealing the taxonomic and metabolic profiles of different types of Daqu across seasons. Taxonomic composition differences were explored across types of Daqu and seasons, where the under-fermented white Daqu showed the higher microbial diversity and seasonal stability. It was demonstrated that yellow Daqu had higher abundance of saccharifying enzymes for raw material degradation. In addition, considerable seasonal variation of microbial protein abundance was discovered in the over-fermented black Daqu, suggesting elevated carbohydrate and amino acid metabolism in autumn black Daqu. We expect that this study will facilitate the understanding of the key microbes and their metabolism in the traditional fermentation process of Chinese liquor production.

Influence of circadian rhythms and seasonal and annual variations on acute myocardial infarction incidence

Background/Aim: Acute myocardial infarction (AMI) is a consequence of complete coronary artery occlusion. There is a considerable seasonal variation in the incidence of AMI. The aim of the study was to establish a circadian and seasonal pattern of AMI. Methods: A retrospective observational study was conducted, using the database of the Institute of Emergency Medical Service of the City of Novi Sad. The study included 982 patients, both male and female, diagnosed with AMI (I.21 - ICD-10 code) in the period between 15 March 2018 and 14 March 2022. Data were classified according to the time of the day, days of the week, quarters and months. Data were analysed by using descriptive statistical methods, Mann-Whitney U test, Chi-squared test and Fisher's exact test. Results: AMI most frequently occurred between 6 am and 2 pm (389; 39.6 %). A statistically significant incidence of AMI was calculated for the periods between 6 am and 2 pm (ch2 = 39.69; p &lt; 0.001) and between 2 pm and 10 pm (ch2 = 28.06; p &lt; 0.001). Most cases of AMI were noted on Monday (153; 15.6 %) and in January (93; 9.5 %). The highest incidence of AMI was in the period between 15 March 2021 and 14 March 2022 (304; 31.0 %), while the lowest incidence was noted between 15 March 2019 and 14 March 2020 (190; 19.3 %). Conclusion: Circadian, seasonal and annual rhythm may have a significant impact on the incidence of AMI. This fact can have an important role in the prevention, timely recognition and adequate treatment of acute coronary disease.

Morfološka i reproduktivna morfologija Cystoseira foeniculacea f. tenuiramosa (Phaeophyceae, Fucales) u Strunjanskoj laguni (Tršćanski zaljev, sjeverni Jadran)

The results of a study on morphological features and reproductive phenology of the brown alga Cystoseira foeniculacea f. tenuiramosa (Ercegović) A. Gómez Garreta, M.C. Barceló, M.A. Ribera &amp;amp; J. Rull Lluch from the marine lagoon of Strunjan (Gulf of Trieste), are reported. Based on monthly samplings carried out during one year period, it was observed that this species shows considerable seasonal morphological variations. The Strunjan marine lagoon appears to be the only location of the Slovenian coast where population of this taxon occur. Based on the high associated biodiversity, we propose the inclusion of this population in the conservation management plans in the area.

Seasonal differences in raindrop size and causative microphysical processes in continental, orographic and oceanic regions of the Indian subcontinent

Global precipitation measurement dual-frequency precipitation radar observations during 2014–2021 are used for the first time to infer the dominant microphysical processes responsible for the seasonal variations in mass-weighted mean diameter (Dm) in different regions of the Indian subcontinent. Seasonal differences in mean Dm estimated using stratified rain rates for deep systems is pronounced in continental and Western Ghats, while marginal in maritime and Myanmar coast regions. The mean Dm values are larger in pre-monsoon (PM) than in other seasons in all the regions due to prevalence of deepest storms and evaporation. Seasonal differences in Dm observed at the near-surface are originated at raindrop formation altitude (1.5 km below the 0 °C isotherm) and are magnified during the descent of raindrops due to more evaporation in PM over the Arabian Sea, Western Ghats, and Myanmar coast. Raindrop size show contrasting features at the formation altitude and at the near surface in southwest monsoon (SWM) and northeast monsoon (NEM) over Bay of Bengal, foothills of Himalayas, Northwest India, and southeast peninsular India. The breakup of raindrops in NEM results in small Dm at the near surface in NEM than in SWM over the Bay of Bengal and southeast peninsular India. Higher occurrence of convection over Western Ghats, evaporation over foothills of Himalayas and northwest India in NEM results in large Dm values than in SWM. Dm values of shallow rain show considerable seasonal variations over the Arabian Sea and Western Ghats and marginal differences in the Bay of Bengal and Myanmar coast.

Improved modeling of canopy transpiration for temperate forests by incorporating a LAI-based dynamic parametrization scheme of stomatal slope

The ecosystem-level conductance-photosynthesis models, which represent a linearly coupled relationship between canopy stomatal conductance (Gs) and CO2 assimilation, have been increasingly used for modeling transpiration (Tc). As a key parameter in these models, the slope parameter (G1) has been observed to vary considerably over the seasons in the field, but is often parametrized with a biome-specific temporally constant G1, resulting in large potential uncertainty. Here we hypothesized that G1 varies with leaf area index (LAI) phenology and soil water content (SWC) seasonality, and accurate characterization of G1 seasonality offers an avenue to improve Tc modelling. To test these hypotheses, we first investigated the seasonality of Eddy flux-derived G1 and then explored its relationship with satellite-derived LAI and field-observed SWC seasonality at 12 temperate forest FLUXNET sites across the Northern Hemisphere. Last, we cross-compared the two schemes of model parameterization of G1 for modeling Tc: (1) a constant G1 (FIX) and (2) a dynamic G1 parameterized using the selected variables (DYN). Our results show G1 displays considerable seasonal variations across all sites, with a minimum value in mid-summer. Further variance partitioning analysis demonstrates that the seasonal variations in G1 show direct linkages with LAI phenology rather than SWC seasonality likely associated with leaf aging and ontogeny development. Last, we found relative to the FIX model, the DYN model (using LAI for G1 parameterization) significantly reduced the model uncertainty in terms of RMSE by 24.6 ± 11.8% and 32.0 ± 8.7%, respectively for Gs and Tc at a daily scale. These results collectively improve our understanding of the dynamic pattern and proximate controls of G1 seasonality, and highlight the effectiveness of using remote sensing-derived LAI phenology for improved characterization of G1 seasonality that ultimately contributes to the improved process model simulations of the seasonal dynamics of Gs and Tc across temperate forest landscapes.

Temporal distribution, accumulation, speciation and ecological risk of heavy metals in the sediment of an urban Lagoon catchment at Xiamen in China

ABSTRACT The present study investigated the temporal distribution, accumulation, speciation and potential ecological risk of heavy metals in the sediment of an urban Yundang Lagoon catchment (YLC) at Xiamen in China. Total heavy metals concentration of Cr, Mn, Ni, Cu, Zn, As, Cd and Pb showed a significant seasonal variation in the sediment. Therefore, the average total metals concentration of Cr, Mn, Ni, Cu, Zn, As, Cd and Pb was 61.95, 529.95, 28.03, 64.95, 351.22, 10.29, 1.38 and 56.30 mg/kg for spring; 66.78, 501.22, 30.55, 67.72, 326.42, 10.91, 0.89 and 58.12 mg/kg for summer; 64.87, 472.80, 24.09, 66.26, 323.40, 5.51, 0.64 and 58.68 mg/kg for autumn; 82.36, 1589.05, 27.27, 82.64, 369.31, 11.79, 0.60 and 562.24 mg/kg for winter, respectively. Temporal metals speciation indicates a considerable seasonal variation of metal fraction concentrations. Igeo values have indicated considerable seasonal variation of pollution sources in the sediment of YLC. The temporal pollution load index indicates that winter sediment has the highest pollution load than other seasons.

Monthly and seasonal variations in the surface carbonate system and air–sea CO2 flux of the Yellow Sea

Surface carbonate chemistry in the Yellow Sea was investigated based on discrete seawater samples collected from 2017 to 2020 at the Socheongcho Ocean Research Station (S-ORS; 37.423°N, 124.738°E). Records of carbon parameters, including seawater CO2 partial pressure (pCO2), revealed considerable seasonal variations, with amplitudes comparable to those observed across the western part of the Yellow Sea. The study site acted as a modest sink (−0.13 mol C m−2 yr−1) for atmospheric CO2. Biological processes (primary production and respiration) and physical conditions (temperature and degree of stratification) determined seawater pCO2, which fluctuated on an intraseasonal timescale between oversaturated and undersaturated with respect to atmospheric pCO2. Variation in pCO2 was significant in summer, depending on the biological carbon drawdown and tidal mixing-induced upwelling (increased pCO2 up to ~1000 μatm). The intraseasonal variability in seawater pCO2 may bias estimated air–sea CO2 fluxes, if measurements with a coarser (seasonal) time resolution are used.

The Influence of the Partitioning of Sugars, Starch, and Free Proline in Various Organs of Cyclamen graecum on the Biology of the Species and Its Resistance to Abiotic Stressors

The geophyte Cyclamen graecum is native to the eastern Mediterranean. Its beautiful flowers with upswept pink petals appear during early autumn, after the summer drought period and before leaf expansion in late autumn. The floral and leaf development alternates with their cessation in early winter and late spring, respectively. Ecophysiological parameters and processes underlining the life-cycle of C. graecum have not previously been published. Seasonal fluctuations of sugars, starch, and free proline have been investigated in tubers, leaves, pedicels, and petals, as well as petal and leaf water status. At the whole plant level, the seasonal co-existence of leaves and flowers is marked by an elevated soluble sugar content, which was gradually reduced as the above-ground plant parts shed. The sugar content of petals and pedicels was lower than that of leaves and tubers. Leaf starch content increased from late autumn to spring and was comparable to that of tubers. The starch content in petals and pedicels was substantially lower than that of tubers and leaves. In tubers, monthly proline accumulation was sustained at relatively constant values. Although the partitioning of proline in various organs did not show a considerable seasonal variation, resulting in an unchanged profile of the trends between tubers, leaves, and flowers, the seasonal differences in proline accumulation were remarkable at the whole plant level. The pronounced petal proline content during the flowering period seems to be associated with the maintenance of floral turgor. Leaf proline content increased with the advance of the growth season. The values of leaf relative water content were sustained fairly constant before the senescence stage, but lower than the typical values of turgid and transpiring leaves. Relationships of the studied parameters with rainfall indicate the responsiveness of C. graecum to water availability in its habitat in the Mediterranean ecosystem.

Understanding seasonal variation in ambient air quality and its relationship with crop residue burning activities in an agrarian state of India.

In India, Indo-Gangetic Plains (IGP) is becoming the hotspot of air pollution due to increasing anthropogenic activities such as rapid industrial growth, infrastructure development, transportation activities, and seasonal practice of crop residue burning. In the current study, seasonal variation in ambient air quality for 14 parameters, i.e., particulate matter (PM), trace gases, and volatile organic compounds (VOCs), along with meteorological parameters, was studied in 21 districts of the Haryana state for year 2019, situated in IGP. To analyze spatial variation of pollutants, ambient air quality data of 23 continuous ambient air quality monitoring stations were divided into three zones based on ecology and cropping pattern. All the zones showed annual mean PM10 and PM2.5 concentrations much higher than national ambient air quality standards. Annual mean PM10 concentration (±standard deviation) in Zones-1, 2, and 3 was 156±86, 174±93, and 143±74 μg m-3, whereas for PM2.5 was 71±44, 85±54, and 78±47 μg m-3. The results showed a considerable seasonal variation in the concentration of all pollutants. Most of the pollutants peak in the post-monsoon season, followed by winters in which crop residue burning predominates in many parts of the Haryana. PM10 concentrations increased by 65-112% and PM2.5 concentrations increased by 131-147% in the post-monsoon season compared to monsoons. The post-monsoon season showed the highest concentration of PM10, NO, and toluene (Zone-1); and PM2.5, NH3, CO, and benzene (Zone-2); whereas in winters, SO2 (Zone-1); ethylbenzene, m,p-xylene, and xylene (Zone-2); and NO2 and NOx (Zone-3) showed the maximum pollution levels. The O3 concentration was highest in the pre-monsoon season (Zone-1). The satellite-based fire counts and PCA results show a significant influence of crop residue burning in the post-monsoon season and solid biomass burning in winters on Haryana's air quality. The study could help to understand seasonal variation in ambient air quality and the influence of factors such as crop residue burning in the IGP region, which could help to formulate season-specific control measures to improve regional air quality.