Variations In Climatic Factors Research Articles

Tree-growth synchrony index, an effective indicator of historical climatic extremes

BackgroundTree rings play an important role in reconstructing past climate. Growth differences among individual trees due to microclimatic conditions and local disturbances are averaged in developing tree-ring chronologies. Here, we addressed the problem of averaging by investigating growth synchrony in individual trees. We used tree-ring data of 1046 juniper trees from 32 sites on the Tibetan Plateau and 538 pine trees from 20 sites in the subtropical region of eastern China and calculated the tree-growth synchrony index (TGS).ResultsOur results showed that both the TGS index and tree-ring index could be indicators of interannual variation of climatic factors. The TGS index identified 20% more climatic extremes than tree-ring index over the last 50 years that high synchrony indicates extreme climate forcing in controlling forest growth.ConclusionsThe TGS index can identify extreme climatic events effectively than tree-ring index. This study provides a novel perspective for climate reconstruction, especially in the realm of tree growth response to extreme climate. Our findings contribute to understanding of the spatiotemporal dynamics and the causes of historical climate extremes and provide guidance for protecting trees from climate extremes in the future.

Spatial and Temporal Variations of Soil pH in Farmland in Xinjiang, China over the Past Decade

Soil pH is crucial for the quality of the farmland and crop growth. The objective of this study is to analyze the spatial and temporal variations of farmland soil pH in Xinjiang (XJ), and to provide a scientific basis for soil improvement and agricultural production optimization. Based on soil pH data from XJ farmland in two periods, 2008~2010 and 2019~2021, geostatistical methods and kriging spatial interpolation techniques were employed to analyze the spatiotemporal changes in soil pH and to investigate the relationship between relevant influencing factors and pH over more than a decade. The results indicate that the spatiotemporal distribution of soil pH in XJ farmlands is uneven. Between 2019 and 2021, the average soil pH was 8.11, generally being on the higher side, with a coefficient of variation (CV) of 3.85%, indicating minimal spatial variability. In the farmland soil of Southern Xinjiang (S-XJ), the average pH value was 8.17, significantly higher than that of Northern Xinjiang (N-XJ), which was 8.10, demonstrating a spatial pattern of “higher in the south, lower in the north”. Over the past decade, soil pH in XJ has significantly increased from 8.11 to 8.13, with a 0.05 unit increase in the north and a 0.01 unit increase in the south (p < 0.05). Regionally, Altay saw the largest increase of 0.22 units, while Bortala Mongol Autonomous Prefecture (Bortala) experienced the most significant decrease, dropping by 0.59 units. Furthermore, this study found that factors such as topography, nutrients, and irrigation methods all have certain influences on the spatial distribution of soil pH in XJ farmland, while variations in climate factors and fertilization levels may affect its long-term temporal changes. These research findings will provide new insights for adjusting and updating agricultural management measures related to soil pH regulation in XJ.

Exploring Sensitivity of Phenology to Seasonal Climate Differences in Temperate Grasslands of China Based on Normalized Difference Vegetation Index

The affiliation between vegetation phenology and seasonal climate (start and end times of the growing season, or SOS and EOS) provides a basis for acquiring insight into the dynamic response of terrestrial ecosystems to the effects of climate change. Although climate warming is an important factor affecting the advancement or delay of plant phenology, understanding the sensitivity of phenology to seasonal variation in climate factors (e.g., local air temperature, precipitation) is generally lacking under different climate backgrounds. In this study, we investigated the interannual variability of grassland phenology and its spatial variation in temperate regions of China based on satellite-derived products for the normalized difference vegetation index (NDVI) and weather data acquired from 2001 to 2020. We found that due to differences in local climate conditions, the effects of seasonal warming and precipitation on phenology were divergent or even opposite during the 20 years. The sensitivities of the start of growing season (SOS) to both spring temperature and last-winter precipitation was controlled by mean annual precipitation in terms of spatial variation. The SOS in the semi-humid (200–400 mm) region was most sensitive to spring temperature, advancing 5.24 days for each 1 °C rise in the average spring temperature (p < 0.05), while it was most sensitive to last-winter precipitation in arid regions (<200 mm), with SOS advancing up to 2.23 days for every 1 mm increase in the last-winter precipitation (p < 0.05). The end of growing season (EOS) was sensitive to autumn temperature, being delayed 10.13 days for each 1 °C rise in the average autumn temperature in regions with temperatures between −10 °C and −5 °C (p < 0.05). The uncertainty in the determination of the EOS could conceivably be greater than the determination of the SOS due to the dual effects of pre-autumn climate and growth constraints induced by declining fall temperatures. The effect of atmospheric warming on grassland phenology was lessened with increased atmospheric and soil aridity, suggesting that the interaction of regional drought and climate warming is an important source for local-to-regional differences and uncertainties in grass phenological response.

Short-Term Changes in Weather Conditions and the Risk of Acute Coronary Syndrome Hospitalization with and without ST-Segment Elevation: A Focus on Vulnerable Subgroups.

Background and Objectives: Acute coronary syndrome (ACS), a prevalent global cardiovascular disease and leading cause of mortality, is significantly correlated with meteorological factors. This study aims to analyze the impact of short-term changes in meteorological factors on the risk of ACS, both with and without ST-segment elevation, and to identify vulnerable subgroups. Materials and Methods: Daily ACS admissions and meteorological variables were collected from October 2016 to December 2021. A generalized linear model (GLM) with a Poisson distribution was employed to examine how short-term fluctuations in meteorological parameters influence ACS hospitalizations. Subgroup analyses were conducted to identify the populations most vulnerable to climate change. Results: Multiple regression analyses showed that short-term fluctuations in atmospheric pressure (≥10 mbar) and air temperature (≥5 °C) seven days prior increased the number of ACS hospitalizations by 58.7% (RR: 1.587; 95% CI: 1.501-1.679) and 55.2% (RR: 1.552; 95% CI: 1.465-1.644), respectively, notably impacting ST-segment elevation myocardial infarctions (STEMIs). The least pronounced association was observed between the daily count of ACS and the variation in relative air humidity (≥20%), resulting in an 18.4% (RR: 1.184; 95% CI: 1.091-1.286) increase in the risk of hospitalization. Subgroup analysis revealed an increased susceptibility among men and older adults to short-term variations in weather parameters. Conclusions: The findings indicate that short-term changes in weather conditions are associated with an increased risk of ACS hospitalizations, particularly STEMIs. Male and older adult patients exhibit heightened susceptibility to variations in climatic factors. Developing effective preventive strategies is imperative to alleviate the adverse consequences of these environmental risk factors.

Regional Analysis of Dominant Factors Influencing Leaf Chlorophyll Content in Complex Terrain Regions Using a Geographic Statistical Model

Chlorophyll is a vital indicator of vegetation growth; exploring its relationship with external influencing factors is essential for studies such as chlorophyll remote sensing retrieval and vegetation growth monitoring. However, there has been limited in-depth exploration of the spatial distribution of leaf chlorophyll content (LCC) and its influencing factors across large-scale areas with varying climates and terrains. To investigate the primary influencing factors and degrees of various environmental factors on LCC, this study employed the Geodetector Model (GDM) and the LCC satellite products in Sichuan Province in 2020 to investigate the impact of relationships between nine environmental factors (meteorology, topography, and vegetation types) and the ecosystem LCC at a regional scale. The results indicated the following: (1) Elevation (q-value = 49.31%) is the primary factor determining photosynthesis in Sichuan Province, followed by temperature (46.10%) and vegetation types (40.73%). The impact of topographical factors on LCC distribution is higher than that of meteorological factors and vegetation types in terrain with complex topography. The elevation effectively distinguishes the variations in climate factors and vegetation types. (2) Combining the influencing factors pairwise increased the combined q-values. The combination of elevation with other factors yielded the highest combined q-value. (3) The q-values for all influencing factors are higher in winter and spring and lowest in summer. Different influencing factors exhibited more substantial constraints on vegetation photosynthesis during winter and spring, significantly reducing influence during summer. (4) The different primary factors drive or constrain vegetation photosynthesis in different climate zones due to their distinct temperature and humidity characteristics. The findings of this study provide a basis for future research on vegetation change analysis and dynamic monitoring of vegetation LCC in different terrains.

Ecological Assessment of the Native Flora of Matta Kharari Village, Swat, Khyber Pakhtunkhwa, Pakistan

Plant species composition, diversity and distribution is a hierarchical expression of vegetation determined by different environmental factors. A study was conducted to document the floristic composition and biological spectrum of plant species of the Matta-Kharari region, Swat. The region has not been ecologically explored yet. We used quantitative ecological techniques for sampling plant species. Sixty-seven quadrats of 1x1 m2 for herbs, 5x5 m2 for shrubs and 10x10 m2 size for trees were established. Plant species data were analyzed using multivariate statistical techniques. We evaluated 76 plant species belonging to 42 families. Asteraceae and Rosaceae were the leading families with 8 species each, followed by Ranunculaceae, Lamiaceae and Moraceae with 4 species each. Among life form classes i.e., geophytes were dominant (13 species, 17.10 %), followed by therophytes (12 species, 15.87 %), nanophanerophytes (11 species, 14.47 %), and chamaephytes (10 species, 13.58 %). Moreover, Mesophylls (36.84 %) were the dominant leaf spectra class followed by nanophyll (30.26 %), microphyll (27.63 %), and megaphyll (2.63 %). The two-way cluster analysis classified the vegetation into three clusters. The detrended correspondence analysis shows the distribution of plants in a mixed array because the locations explored are characterized by similar climatic factors and vegetation. We elucidate that the variation in climatic factors and topography brings variation in vegetation. Understanding these responses at the life form and leaf spectra level will provide a better understanding and knowledge that how plant species and their communities or associations respond to changes in climate in the future. The current study could be utilized as a baseline for large-scale studies in the future.

Assessment of Changes in Climatic Variables in Hadeja-Nguru Wetlands

The study assessed the changes in climatic variables in Hadeja Nguru wetland. Parameters evaluated includes; variations in climatic variables over a 40-year window (1979-2019) Data on climatic variables on daily basis were obtained for a period 40years and Satellite imageries of the study area were officially downloaded from the United State Geological Survey website. Paired sample T-test and chi-square test of association were used in assessing the variation in climatic factors. Result showed that indicated sparse distribution as a major effect of climate change. Decreased in crops production, land shade, destruction of harvested crops, increase in insect population and shortened seed germination period were thought to be the consequences of reduction in rainfall, excessive rainfall, irregular rainfall pattern and increase in temperatures, Food scarcity, reduction in income due to depletion of crops were also pinpointed as impacts of climate change.. Maximum and minimum temperatures, precipitation, wind speed, relative humidity and solar intensity between 1979 and 2019 were 40.07 and 36.46, 1180.36mm and 58.18mm, 2.97m/s and 2.29m/s, 0.33g/kg and 0.22g/kg and 23.68w/m2 and 20.70w/m2 respectively. There was also a significant Chi-square value (33.481a) between respondents’ effect of climate change and increase in farm sizes. The paper concluded that there were fluctuations in climatic variables. There is the need to put in place right policies to protect and preserve wetlands to enhance their sustainability and resilience to climatic changes and variability.

Dust Storm Effect and Climatological Factors on Cardiovascular and Cerebrovascular Respiratory Diseases: A Literature Review

Background & Aims: Dust storms, which are considered natural occurrences, have harmed the global population’s health as a result of the broad increase in climate change. The most serious consequences of these alterations are cardiovascular, pulmonary, and cerebrovascular diseases. This review study focused on the effect of dust storms and climatic factors on mortality and morbidity in worldwide and assessed the prediction of these diseases based on changes in each of the meteorological factors and dust storms. Materials and Methods: For data collection, English literature was searched using keywords "dust storm" and "respiratory disorders" or "cardiovascular disease" or "cerebrovascular disease" in PubMed, Web of Science, and Scopus as databases, along with Google Scholar as engine search. The first step was to use statistics on the number of instances of cardiovascular, cerebrovascular, and respiratory diseases. The association between the occurrence of these diseases and variations in climatic factors underwent assessment. Results: Adverse repercussions could be noticed when dust storms were paired with changes in metrological parameters. More local information about the link of these diseases with dust storms and changes in metrological variables in the nation, as well as their capacity to anticipate them, is needed to prevent and reduce the health risk of these diseases. Conclusion: In areas prone to dust storms, the population will be prone to its effects and consequences. Thus, preventive measures are beneficial at the community level.

Quantifying the Spatio-Temporal Pattern Differences in Climate Change before and after the Turning Year in Southwest China over the Past 120 Years

In conjunction with Earth’s ongoing global warming, the Southwest China (SWC) region has become a fascinating case study on the control of local climate change. Moreover, an entire period of climate change may partially mask the patterns in some stages. Therefore, in this research, we investigated the spatial patterns of the significant turning years of climatic factor change, and determined the heterogeneity of the spatial patterns of climate change before and after the significant turning years. We used the long time-series of the CRU datasets (CRU_TS4.02) from 1901 to 2017 with a piecewise linear regression model to explore the significant turning-year distribution characteristics of inter-annual and inter-seasonal climate factor changes, and further describe and quantize the differences in the spatio-temporal patterns of climate factors before and after the significant turning years on the grid scale in SWC. Overall, the trends in temperature and precipitation factors in SWC were segmented over the last 120 years, with significant turning years with different regional and stepwise characteristics. In terms of timing, temperature and precipitation factors changed significantly in 1954 and 1928, respectively, and overall temporal variability (0.04 °C/(10 a) (p < 0.05), −0.48 mm/(10 a)) masked the magnitude or direction of variability (0.13 °C/(10 a) and 0.16 °C/(10 a) both at the level of p < 0.05 before the turning year, 19.56 mm/(10 a) (p < 0.05) and 1.19 mm/(10 a) after the turning year) around the watershed years. Spatially, the significant turning years were concentrated in the periods 1940–1993 (temperature) and 1910–2008 (precipitation), and the distribution pattern of the turning years was patchy and concentrated. The turning years of temperature factors were gradually delayed from east to west, and the variability of climate factors before and after the turning years exhibited significant shifts in location (e.g., temperature decreased from southeast to northwest before the turning year and increased after the turning year). After the turning year, the warming variability of the temperature factor increased, while the increasing variability of the precipitation factor decreased. Further integrated analysis revealed that the increase in variability of the climate factor after the turning year was mainly due to the increase in winter and autumn variability (0.05 °C/(10 a), 7.30 mm/(10 a) in autumn; and 0.12 °C/(10 a), 1.97 mm/(10 a) in winter). To the extent that this study provides a necessary academic foundation for efficiently unveiling the spatio-temporal variability properties of climate factors against the background of modern global climate change, more attention should be paid to the location and phase of the study.

Malaria, climate variability, and interventions: modelling transmission dynamics

Assessment of the relative impact of climate change on malaria dynamics is a complex problem. Climate is a well-known factor that plays a crucial role in driving malaria outbreaks in epidemic transmission areas. However, its influence in endemic environments with intensive malaria control interventions is not fully understood, mainly due to the scarcity of high-quality, long-term malaria data. The demographic surveillance systems in Africa offer unique platforms for quantifying the relative effects of weather variability on the burden of malaria. Here, using a process-based stochastic transmission model, we show that in the lowlands of malaria endemic western Kenya, variations in climatic factors played a key role in driving malaria incidence during 2008–2019, despite high bed net coverage and use among the population. The model captures some of the main mechanisms of human, parasite, and vector dynamics, and opens the possibility to forecast malaria in endemic regions, taking into account the interaction between future climatic conditions and intervention scenarios.

Climatic seasons and time of the day influence thermoregulation and testicular hemodynamics in Santa Inês rams raised under humid tropical conditions

This study evaluated the possible association between the diurnal variations of climatic factors during the rainy (RS) or less rainy (LS) seasons on the testicular hemodynamics and thermoregulatory responses of hair sheep rams raised in a humid tropical climate. Santa Inês rams (n = 6) underwent evaluation of general and testicular physiological parameters (heart and respiratory rates, internal and scrotal temperatures, internal-scrotal temperature gradient, scrotal distention, and color Doppler ultrasound evaluation of the spermatic cords and spectral analyses of testicular arteries) over six consecutive weeks per season at three separate times daily (morning = 8:00 a.m., noon = 12:00 p.m., and afternoon = 5:00 p.m.) during the RS and LS. Climatic air temperature and relative humidity data were recorded, and the temperature and humidity index (THI) was calculated. Higher thermal challenge was observed in LS relative to RS (air temperature = 28.0 vs. 30.9 °C; relative humidity = 84.1 vs. 69.9%; THI = 80.0 vs. 82.5; P < 0.05). In both seasons, respiratory rate and internal temperature were normal, demonstrating the animals’ adaptability. In RS, however, a higher scrotal temperature was recorded in relation to LS (35.0 vs. 34.7 °C; P < 0.05), with a gradual increase from morning to afternoon. Lower resistivity (0.40 vs. 0.64; P < 0.05) and pulsatility (0.55 vs. 1.14; P < 0.05) indices, and a higher rate of high-velocity blood flow of testicular arteries (71.1 vs. 60.6%; P < 0.05) were observed in RS compared to LS. The lowest correlations between testicular hemodynamic, physiological variables, and environmental parameters (P < 0.05) were observed in the morning. In conclusion, testicular thermoregulation and testicular hemodynamics were influenced by the climatic seasons and time of the day, being more efficient in the LS season and with less interference from environmental factors in the morning.

Spatiotemporal variation of irrigation water requirements for grain crops under climate change in Northwest China.

Clarifying the spatiotemporal variation of crop irrigation water requirement (IWR) under the background of climate change is an essential basis for water resource management, determining the irrigation quota and adjusting the planting structure. Using 61years of climate data from 205 stations in Northwest China, this study investigated the spatiotemporal variations of climatic factors and IWR during the growth period of five main grain crops (spring wheat, winter wheat, spring maize, summer maize, and rice) and explored the dominant climatic driving factors of IWR variation. Results showed that (1) the IWR of grain crops showed distinct differences. Rice was the highest water consumption crop (mean of 753.78mm), and summer maize was the lowest (mean of 452.90mm). (2) The variation trends and average values of IWR of different grain crops have spatial heterogeneity across Northwest China. For most crops, high values and increasing trends of IWR were mainly located in eastern Xinjiang, western Gansu, and western Inner Mongolia. (3) Tmax (maximum temperature), Tmin (minimum temperature), and Peff (effective precipitation) showed an increasing trend during the growth period of each grain crop, while U10 (wind speed at 10m height), SD (solar radiation), and RH (relative humidity) presented decreasing trends. (4) SD, Tmax, and U10 promoted the increase of grain crops' IWR, while Peff and RH inhibited it. The impacts of climatic factors on the grain crop IWR differed among different regions. Peff was the most influential factor to the IWR of all grain crops in most areas. Therefore, under the premise of a significant increase in T and uncertain precipitation mode in the future, it is urgent to take effective water-saving measures according to the irrigation needs of the region. To cope with the adverse impact of climate change on the sustainable development of agriculture in the northwest dry area, to ensure regional and national food security.

Anatomia foliar comparada de Palicourea rigida e Palicourea coriacea (Rubiaceae) ocorrentes no município de Diorama, Goiás, Brasil

This study aimed to perform a comparative anatomical study between Palicourea coriacea and Palicourea rigida (Rubiaceae), aiming to correlate possible anatomical changes to the variations of climatic factors found in the biome, and contribute to the taxonomic delimitation of the genus. The material was collected according to the usual recommendations in plant anatomy in an area of Cerrado sensu stricto, located in the municipality of Diorama – Goiás. We observed that the studied species share morphoanatomical diagnostic characteristics for the Rubiaceae family. However, some variations were found, such as styloid crystals, which were only found for species of the Psychotria genus, and which were considered a distinctive feature of the Psychotria genus. As styloid crystals were found in both P. coriacea and P. rigida, we suggest that it be used as a distinguishing feature of the tribe.

Assessment of changes in climatic variables in hadeja-nguru wetlands

The study assessed the changes in climatic variables in Hadeja Nguru wetland. Parameters evaluated includes; variation in climatic variables over a 40-year window (1979-2019) Data on climatic variables on daily basis were obtained for a period 40years and Satellite imageries of the study area were officially downloaded from the United State Geological Survey website. Paired sample T-test and chi-square test of association were used in assessing the variation in climatic factors. Result showed that indicated sparse distribution as a major effect of climate change. Decreased production in crops, land shade, damaged of harvested crops, increase in insect population, shortening the time of germinating seeds were thought to be the consequences of reduction in rainfall, excessive rainfall, irregular rain pattern and increase in temperatures respectively, Food scarcity, reduction in income due to depletion of crops were also pinpointed as impacts of climate change. Information on climate change and its impact were obtained majorly from radio, while major mitigating strategy for changing climatic variables. Maximum and minimum temperatures, precipitation, wind speed, relative humidity and solar intensity between 1979 and 2019 were 40.07℃ and 36.46℃, 1180.36mm and 58.18mm, 2.97m/s and 2.29m/s, 0.33g/kg and 0.22g/kg and 23.68w/m2 and 20.70w/m2 respectively. There was also a significant Chi-square value (33.481a) between respondents’ effect of climate change and increase in farm sizes. It is therefore concluded that there has been fluctuations in climatic variables. There is the need to put in place right policies to protect and preserve wetlands to enhance their sustainability and resilience to climatic changes and variability.

Assessment of Climate Change Impact on Maize Production in Serbia

Climate factors have an impact on plant life cycle, yield, productivity, economy and profitability of agricultural production. There are not a lot of studies on understanding of influence of climate factors variation on maize yield in agro-ecological conditions of Serbia. The aim of this paper is analysis of variation of climatic factors over a long-time period, as well as assessment of impact of the examined climate parameters on maize yield in two localities in the Republic of Serbia. For the analysis of climatic factors (temperature, precipitation, sunshine, humidity) in the region of Central Serbia and Vojvodina, the data of meteorological stations Kragujevac and Sombor during two thirty-year periods (1961–1990 and 1991–2020) were used. In order to determine the existence and strength of the relationship between the observed climatic factors and maize yield, a correlation analysis of these indicators for the period 2005–2020 years, was performed. In the period 1991–2020, the average values of temperature were annually increased for 0.046 °C in Kragujevac and for 0.05 °C in Sombor, and in the same period the average value of sunshine on an annual level was increased for 1.3 h in Kragujevac and for 5.01 h in Sombor, 2020 in comparison to average values in period of 1961–1990. The humidity was decline annually for 1.3 in Kragujevac and for 3.4 in Sombor in period 1991–2020 in comparison to average humidity in period of 1961–1990. The results of the correlation analysis showed that the maize yield was significantly lower in the years with expressed high temperatures and precipitation deficit. Based on these studies, established effect of climate change on maize yield and that this demand developing adaptation agricultural practice through creating maize hybrids and varieties with greater adaptability and improvement of agrotechnic measure.

Climate-driven vegetation greening further reduces water availability in drylands.

Climate change alters surface water availability (WA; precipitation minus evapotranspiration, P - ET) and consequently impacts agricultural production and societal water needs, leading to increasing concerns on the sustainability of water use. Although the direct effects of climate change on WA have long been recognized and assessed, indirect climate effects occurring through adjustments in terrestrial vegetation are more subtle and not yet fully quantified. To address this knowledge gap, here we investigate the interplay between climate-induced changes in leaf area index (LAI) and ET and quantify its ultimate effect on WA during the period 1982-2016 at the global scale, using an ensemble of data-driven products and land surface models. We show that ~44% of the global vegetated land has experienced a significant increase in growing season-averaged LAI and climate change explains 33.5% of this greening signal. Such climate-induced greening has enhanced ET of 0.051 ± 0.067 mm year-2 (mean ± SD), further amplifying the ongoing increase in ET directly driven by variations in climatic factors over 36.8% of the globe, and thus exacerbating the decline in WA prominently in drylands. These findings highlight the indirect impact of positive feedbacks in the land-climate system on the decline of WA, and call for an in-depth evaluation of these phenomena in the design of local mitigation and adaptation plans.

An updated biogeographic evaluation of endemism and conservation of small mammals from Chile

AbstractEcological factors such as temperature, precipitation, and vegetation type have been reported to influence biogeographic patterns (e.g., species distribution, richness, and endemism) in mammals. In Chile, these patterns only had been explored in selected mammal groups from certain localities. In this study, we describe and analyze biogeographic patterns for all small mammals (marsupials, armadillos, bats, rodents), reported until 2020, in different climatic and ecological regions from continental Chile. Using a compiled database of 89 species, we estimated their distributional similarity, described and characterized richness and areas of endemism using Bayesian and Parsimony Analysis of Endemism, and linked species distribution with conservation status according to the IUCN Red List. We found three similarity units of species distribution based on climate: Arid, Temperate, and Polar; higher richness and endemism in north and south-central Chile; two areas of endemism, one in north and one in south; and a hotspot in south-central Chile. Finally, species of greater conservation concern showed a similar and small distribution range. The concordance in the distribution of the species with Chilean climatic regions (as determined by precipitation and temperature) suggest that the spatial distribution of Chilean small mammals is influenced strongly by those abiotic factors. This also could explain the patterns of richness and endemism and, therefore species hotspots. Variations of climatic factors therefore should be considered in explaining biogeographic patterns and conservation plans of Chilean small mammal species, because species of greater concern tend to be associated and having similar distributional characteristics.

The Extremely Active 2020 Hurricane Season in the North Atlantic and Its Relation to Climate Variability and Change

The 2020 hurricane season in the North Atlantic basin was the most active on record, with 30 named tropical cyclones. In this study, climate trends in oceanic and atmospheric parameters (including the sea surface temperatures, ocean heat content, cloud cover, mid-level humidity, vertical wind shear, and sea level pressure) were used to model the tropical cyclone, hurricane, and major hurricane frequency in the post-satellite era (1966–2020). The relationships between storm frequency and climate variability factors (including the El Niño Southern Oscillation, the North Atlantic Oscillation, the Atlantic Multidecadal Oscillation, and the Atlantic Meridional Mode) were also examined. This was performed to determine the factors that exerted the greatest influence on the most active hurricane seasons on record. Mann–Kendall trend tests, Pearson’s correlations tests, stepwise Poisson linear regression models and spatial analysis techniques were used to identify the climate change and variability factors that best explained the tropical cyclone frequency in the North Atlantic. Our results show that hyperactive hurricane seasons, such as that of 2020, tend to be associated with higher cloud cover development, lower sea level pressure patterns, higher sea surface temperatures, positive phases of the Atlantic Multidecadal Oscillation and the Atlantic Meridional Mode, and weaker wind shear environments. Seasons with more major hurricanes had higher ocean heat contents and weaker wind shear environments. The 2020 and 2005 seasons had similar cloud cover and sea level pressure patterns, yet the wind shear was lower in 2020 than in 2005, which was associated with La Niña dominant conditions that could explain why 2020 surpassed 2005 in the total number of storms.

Identification and quantification of phytoprostanes and phytofurans in Acacia cyanophylla Lindl. seeds

Phytoprostanes and phytofurans are derived from peroxidation of α-linolenic acid (ALA) the main polyunsaturated fatty acid (PUFA) found in higher plants. These compounds are considered as excellent biomarkers of oxidative degradation and have demonstrated a wide range of biological activities (e.g. protection of neuronal cells against stress, anti-inflammatory). In the present work, these new active oxylipins, were detected for the first time in Acacia cyanophylla seeds collected in Tunisia from 7 ecotypes, using LC-MS/MS technology. The main PhytoP found was ent-9-L1-PhytoP, ranged from 3.30 ng/g (N-OB ecotype) to 19.14 ng/g (B-ZO ecotype). Three PhytoFs were detected with significantly higher values than PhytoPs. Multivariate analyses indicated a significant differentiation between compounds attributed to variation in climatic factors. This first complete PhytoP and PhytoF profile shows that Acacia cyanophylla Lindl. seeds could be as a new source of bioactive compounds for therapeutic and pharmaceutical applications.

Temporal variation in climatic factors influences phenotypic diversity of Trochulus land snails

Organisms with limited dispersal capabilities should show phenotypic plasticity in situ to keep pace with environmental changes. Therefore, to study the influence of environmental variation on the phenotypic diversity, we chose land snails, Trochulus hispidus and T. sericeus, characterized by high population variability. We performed long-term field studies as well as laboratory and common garden experiments, which revealed that temporal environmental changes generate visible variation in shell size and shape of these snails. Many shell measurements of T. hispidus varied significantly with temperature and humidity in individual years. According to this, the first generation of T. hispidus, bred in controlled laboratory conditions, became significantly different in higher spire and narrower umbilicus from its wild parents. Interestingly, offspring produced by this generation and transplanted to wild conditions returned to the ‘wild’ flat and wide-umbilicated shell shape. Moreover, initially different species T. hispidus and T. sericeus transferred into common environment conditions revealed rapid and convergent shell modifications within one generation. Such morphological flexibility and high genetic variation can be evolutionarily favored, when the environment is heterogeneous in time. The impact of climate change on the shell morphometry can lead to incorrect taxonomic classification or delimitation of artificial taxa in land snails. These findings have also important implications in the context of changing climate and environment.