Temperate Zone Research Articles

Molecular phylogeny and morphology reveal two new species of Conocybe (Bolbitiaceae, Agaricales) from southwest China

ABSTRACT Conocybe commonly occur as saprobes, are distributed in tropical, subtropical, and temperate zones worldwide. In the present study, two new species in Conocybe section Conocybe, viz. Conocybe qujingensis and Conocybe qujinguniversitatis, are proposed based on morphological investigations and phylogenetic analyses. Molecular analyses based on sequence data from the nuclear ribosomal ITS loci support the taxonomic position of the two new species in the genus Conocybe. We also provide illustrations, line drawings, comparisons with closely related taxa, and descriptions of the new taxa.

Comparative Analysis of Methods for Predicting Brine Temperature in Vertical Ground Heat Exchanger—A Case Study

This research was carried out to compare selected forecasting methods, such as the following: Artificial Neural Networks (ANNs), Classification and Regression Trees (CARTs), Chi-squared Automatic Interaction Detector (CHAID), Fuzzy Logic Toolbox (FUZZY), Multivariant Adaptive Regression Splines (MARSs), Regression Trees (RTs), Rough Set Theory (RST), and Support Regression Trees (SRTs), in the context of determining the temperature of brine from vertical ground heat exchangers used by a heat pump heating system. The subject of the analysis was a public building located in Poland, in a temperate continental climate zone. The results of this study indicate that the models based on Rough Set Theory (RST) and Artificial Neural Networks (ANNs) achieved the highest accuracy in predicting brine temperature, with the choice of the preferred method depending on the input variables used for modeling. Using three independent variables (mean outdoor air temperature, month of the heating season, mean solar irradiance), Rough Set Theory (RST) was one of the best models, for which the evaluation rates were as follows: CV RMSE 21.6%, MAE 0.3 °C, MAPE 14.3%, MBE 3.1%, and R2 0.96. By including an additional variable (brine flow rate), Artificial Neural Networks (ANNs) achieved the most accurate predictions. They had the following evaluation rates: CV RMSE 4.6%, MAE 0.05 °C, MAPE 1.7%, MBE 0.4%, and R2 0.99.

Symbiotic efficiency of Rhizobium leguminosarum sv. trifolii strains originating from the subpolar and temperate climate regions

Red clover (Trifolium pratense L.) is a forage legume cultivated worldwide. This plant is capable of establishing a nitrogen-fixing symbiosis with Rhizobium leguminosarum symbiovar trifolii strains. To date, no comparative analysis of the symbiotic properties and heterogeneity of T. pratense microsymbionts derived from two distinct geographic regions has been performed. In this study, the symbiotic properties of strains originating from the subpolar and temperate climate zones in a wide range of temperatures (10–25 °C) have been characterized. Our results indicate that all the studied T. pratense microsymbionts from two geographic regions were highly efficient in host plant nodulation and nitrogen fixation in a wide range of temperatures. However, some differences between the populations and between the strains within the individual population examined were observed. Based on the nodC and nifH sequences, the symbiotic diversity of the strains was estimated. In general, 13 alleles for nodC and for nifH were identified. Moreover, 21 and 61 polymorphic sites in the nodC and nifH sequences were found, respectively, indicating that the latter gene shows higher heterogeneity than the former one. Among the nodC and nifH alleles, three genotypes (I–III) were the most frequent, whereas the other alleles (IV–XIII) proved to be unique for the individual strains. Based on the nodC and nifH allele types, 20 nodC-nifH genotypes were identified. Among them, the most frequent were three genotypes marked as A (6 strains), B (5 strains), and C (3 strains). Type A was exclusively found in the temperate strains, whereas types B and C were identified in the subpolar strains. The remaining 17 genotypes were found in single strains. In conclusion, our data indicate that R. leguminosarum sv. trifolii strains derived from two climatic zones show a high diversity with respect to the symbiotic efficiency and heterogeneity. However, some of the R. leguminosarum sv. trifolii strains exhibit very good symbiotic potential in the wide range of the temperatures tested; hence, they may be used in the future for improvement of legume crop production.

Physiological and transcriptome analysis of acclimatory response to cold stress in marine red alga Pyropia yezoensis

Red macroalga Pyropia yezoensis is a high valuable cultivated marine crop. Its acclimation to cold stress is especially important for long cultivation period across winter in coasts of warm temperate zone in East Asia. In this study, the response of P. yezoensis thalli to low temperature was analyzed on physiology and transcriptome level, to explore its acclimation mechanism to cold stress. The results showed that the practical photosynthesis activity (indicated by ΦPSII and qP) was depressed and pigment allophycocyanin content was decreased during the cold stress of 48 h. However, the Fv/Fm and non-photochemical quenching increased significantly after 24 h, and the average growth rate of thalli also rebounded from 24 to 48 h, indicating a certain extent of acclimation to cold stress. On transcriptionally, the low temperature promoted the expression of differentially expressed genes (DEGs) related to carbohydrate metabolism and energy metabolism, while genes related to photosynthetic system were depressed. The increased expression of DEGs involved in ribosomal biogenesis and lipid metabolism which could accelerate protein synthesis and enhance the degree of fatty acid unsaturation, might help P. yezoensis thallus cells to cope with cold stress. Further co-expression network analysis revealed differential expression trends along with stress time, and corresponding hub genes play important roles in the systemic acquired acclimation to cold stress. This study provides basic mechanisms of P. yezoensis acclimation to cold temperature and may aid in exploration of functional genes for genetic breeding of economic macroalgae.

Climate change impacts on rainfall intensity–duration–frequency curves in local scale catchments

The increasing intensity and frequency of rainfall events, a critical aspect of climate change, pose significant challenges in the construction of intensity–duration–frequency (IDF) curves for climate projection. These curves are crucial for infrastructure development, but the non-stationarity of extreme rainfall raises concerns about their adequacy under future climate conditions. This research addresses these challenges by investigating the reasons behind the IPCC climate report’s evidence about the validity that rainfall follows the Clausius-Clapeyron (CC) relationship, which suggests a 7% increase in precipitation per 1 °C increase in temperature. Our study provides guidelines for adjusting IDF curves in the future, considering both current and future climates. We calculate extreme precipitation changes and scaling factors for small urban catchments in Barranquilla, Colombia, a tropical region, using the bootstrapping method. This reveals the occurrence of a sub-CC relationship, suggesting that the generalized 7% figure may not be universally applicable. In contrast, our comparative analysis with Illinois, USA, an inland city in the north temperate zone, shows adherence to the CC relationship. This emphasizes the need for local parameter calculations rather than relying solely on the generalized 7% figure.

Global impacts of fire regimes on wildland bird diversity

BackgroundFire is a natural disturbance that significantly impacts ecosystems and plays a crucial role in the distribution and preservation of biota worldwide. The effects of fires on bird diversity can be both positive, as they can create new habitats, and negative, as they can reduce nesting success. To fully understand the ecological implications of wildfires, we need to understand the spatial distribution of wildland bird diversity and fire regimes and how fire regimes affect wildland bird diversity ecosystems. Using data collected at a global scale, we examined effects of time-averaged fire regimes on the spatial diversity of wildland bird species. Initially, we used the MaxEnt algorithm to model the potential distribution of 1,115 wildland bird species over a 20-year period. We also processed satellite observations of burned areas (FIRECCI51) during the same period to estimate fire regime characteristics, including the average proportion of burnt vegetation, interannual variability in the burnt area, and fire intensity. Finally, the association between wild bird diversity and fire variables in each biome was determined through Spearman, Bonferroni, and Kruskal-Wallis statistics.ResultsOur findings revealed that (I) the most affected wildland bird communities are those found in tropical ecosystems, where the majority of fires occur; (II) high fire intensity values and a substantial proportion of burned vegetation have a positive impact on maintaining a diverse population of wildland birds in biomes characterized by savannah or grassland covers, as seen in temperate or tropical zones. Conversely, low fire intensity values and a smaller proportion of burned vegetation also promote greater diversity of wildland birds in boreal or temperate zones, and (III) in Mediterranean ecosystems, a clear association between wildland bird diversity and wildfires could not be established.ConclusionsThis research could help identify areas that are ecologically vulnerable to wildfires. It could also be useful in guiding regional studies aligned with developing sustainable landscape management practices and conserving priority ecological zones in tropical ecosystems.

Summer heat during spermatogenesis reduces in vitro blastocyst rates and affects sperm quality of next generation bulls.

Due to global warming seasonal heat stress is an increasing problem in temperate zones. Heat stress not only decreases fertility in females, but can also be detrimental to male fertility. We studied the effects of natural summer heat stress during spermatogenesis in Holstein bulls on semen quality parameters and on fertilization performance in vitro and possible intergenerational transmission of effects on the next male generation. Semen samples from young Holstein breeding bulls, referred to as F0 founders during this study, were collected during summer (F0 "summer" semen) and the following winter (F0 "winter" semen). Parameters such as ejaculate volume, sperm density, motility, thermoresistance, and in vitro blastocyst rates from these F0 semen samples were determined. In addition, after generation of offspring by artificial insemination, semen samples from F1 male offspring were collected and tested for the same quality and performance parameters to capture intergenerational effects. F1 bulls were raised together under identical conditions and semen was collected at about 1 year after birth. The data showed that in vitro blastocyst rates of F0 "summer" semen samples were lower compared with "winter" semen, whereas blastocyst rates of F1 semen samples did not show significant differences. However, whereas F0 semen samples did not indicate significantly different quality parameters we found that motility of F1 semen samples showed significant differences with higher values when collected from bulls generated with F0 "winter" semen. From our data, we conclude that (i) natural summer heat stress during spermatogenesis can affect in vitro fertility parameters and (ii) the observed effects on sperm motility of F1 semen samples suggest intergenerational paternal transmission.

Long-term changes in vegetation and land use in mountainous areas with heavy snowfalls in northern Japan: an 80-year comparison of vegetation maps

Comparison of old and new vegetation maps is an effective way to detect vegetation dynamics. Recent developments in computer technology have made it possible to accurately compare old paper vegetation maps with current digitized vegetation maps to reveal long-term vegetation dynamics. Recently, a 1:50,000 scale vegetation map of the Hakkoda Mountains in northern Japan, located in the ecotone of cool temperate and subalpine forests in northern Japan under an East Asian monsoon climate, from 1930 was discovered. We compared the 1930s vegetation map with the most recent 2010 vegetation map to test the following hypotheses: 1) the occurrence of upward expansion of the upper limit of cool-temperate deciduous forests, and 2) whether designation as a national park in 1936 would have reduced forestry and land use, expanded beech forests, and cool-temperate deciduous forests. To compare vegetation changes, 67 types of vegetation legends for the 1930 and 2010 maps were unified to 21 based on plant species composition. Consequently, vegetation has changed substantially over the past 80 years. 1) In the subalpine zone above 1,000 m, the coniferous forest area decreased by half. In the cool temperate zone below 1,000 m, the area of beech forests increased 1.48 times, and some of them could be shifted upwards, replacing subalpine fir forests in the lower part of the subalpine zone. 2) In areas below 700 m, deciduous oak forests once used as thickets were almost halved. Instead, climax and beech forests expanded. However, we also found that even after the area was declared a national park, oak forests were cleared and converted to commercial forests such as cedar plantations, cattle ranches, and horse pastures in some areas. These results will be useful for future ecosystem and biodiversity research/conservation and will provide baseline information for climate change adaptation policies.

A systematic review of factors influencing habitat connectivity and biodiversity along road and rail routes in temperate zones

This systematic review, part funded by Network Rail Ltd (UK), considers the role of transportation corridors in habitat connectivity within temperate climates, through verge habitat, surrounding matrix, movement along and across the corridor, the wider landscape context and management practices. PICO terms were developed for the bibliographic search on 15/11/22 using Web of Science (all databases), yielding 168 studies for review. The risk of bias was minimised by excluding non-peer reviewed papers. Large and exotic taxa were excluded due to a focus on temperate zones, as were studies on invasive species and climate change where the primary focus was not ecological connectivity. Emergent themes were used to structure the paper. Results indicate that transportation corridors have significant potential for habitat connectivity, especially for generalist and open-specialist species, which favour early to mid-successional habitats. However, physiology is a key determinant in dispersal ability. Vegetation management should consider representative communities rather than individual species. Gaps exist in the range of taxa studied, understanding of seasonal variations and lifecycle stages supported in verges, survival factors such as predation and disease and changes to community structure. Rail environments are under-represented and there is limited knowledge on the relative impacts of vegetation management regimes.

Eurasian drylands are both evolutionary cradles and museums of Nitrariaceae diversity

AbstractAimDrylands cover about 41% of Earth's land surface and are home to fragile biota with high levels of endemism. Two hypothetical models, i.e., cradle and museum, have been proposed to account for present‐day species diversity in an ecoregion or biome. We investigated macroevolutionary patterns to test these two different models in Nitrariaceae, a characteristic component of the Eurasian dryland ecosystem. We also used this family to explore the intercontinental disjunct distribution pattern between the deserts of Eurasia and western North America, known as the Madrean–Tethyan disjunction.LocationDrylands in the Northern Hemisphere.TaxonNitrariaceae (Sapindales, Angiosperms).MethodWe sampled all 16 of the currently recognized extant species of Nitrariaceae and 59 species from the eight other families of Sapindales. A fossil‐calibrated phylogeny was generated using 12 fossil constraints. The ancestral range and climate niche of Nitrariaceae were reconstructed, and diversification rates were estimated.ResultsThe most recent common ancestor of Nitrariaceae likely inhabited arid habitats with low rainfall in the temperate zone in the Late Cretaceous, which geographically corresponds to present‐day Central Asia. The western North American Peganum mexicanum split from its Central Asian sister group at approximately 39 Ma. Net diversification rates of Nitrariaceae experienced a significant increase around 11 Ma. Within Sapindales, at least seven arid species originated markedly prior to the Miocene.Main ConclusionsThe North Atlantic land bridge and global cooling climate in the Late Eocene might have driven the formation of the present‐day disjunct distribution of Nitrariaceae between arid Central Asia and western North America. Nitrariaceae originated in the Late Cretaceous and exhibited long‐term climate niche conservatism, but experienced a rapid diversification in the late Miocene of Eurasia in response to orogenetic and climatic changes. These findings suggest that Eurasian drylands serve as both evolutionary cradles and museums for the diversity of Nitrariaceae and likely for other arid‐adapted lineages.

Karst landforms as microrefugia for soil Collembola: Open versus forested dolines

Enclosed surficial karst dolines are geomorphologically diverse habitats with the potential to strongly shape community structure and the distribution of functional groups of organisms. Forest habitats in karst landscapes are characterized by lower soil temperatures and microclimatic fluctuations compared to open habitats; therefore, they may provide favorable conditions for cold-adapted/psychrophilic species, which are highly vulnerable to climate warming. We compared the diversity and structure of soil Collembola communities at sites along microclimatic gradients in open and forested karst dolines. The effect of topography and related environmental conditions on the distribution of ecological groups of soil Collembola was analyzed, and the function of the dolines as potential climate refugia for psychrophilic arthropods was assessed. The karst dolines revealed significant habitat heterogeneity, including warm plateaus and S-facing slopes and colder and wetter bottoms and N-facing slopes. The inner sites of the dolines had an overall higher abundance and species richness compared to the plateau sites. Nonmetric multidimensional scaling ordination revealed a clear delimitation of Collembola communities in terms of warmer and cooler sites in the open dolines, while the forested dolines did not reveal such a clear pattern. The studied dolines showed a potential to serve as microrefugia in the context of global climate change. Dolines could support the long-term persistence of at least some species such as cold-adapted species. Karst dolines in the temperate zone play a key role in maintaining biodiversity; therefore, they should be central in biodiversity conservation programs.

Snow Contamination by Metals and Metalloids in a Polar Town: A Case Study of Nadym, Russia.

Snow composition depends on the long-range transport of pollutants. This article examines aspects of snow composition in the town of Nadym in Western Siberia. During fieldwork conducted in 2021 and 2022, we determined dust load, concentrations and ratio of dissolved and suspended forms of metals and metalloids (MMs). Moreover, we analyzed air mass trajectories using the HYSPLIT model, and the results showed that industrial regions of the southern Urals, southeastern Siberia, and Kazakhstan were the sources of MMs. Content of the insoluble fraction was increased by 23-fold in Nadym. The dust load in Nadym was higher than that in urban communities situated in the temperate zone, even though this town is relatively small in population and has little industrial infrastructure. This significant increase in dust load led to a ten- to 100-fold increase in the content MMs. Local soils (Fe, Al), vehicles (W), building dust (Mg, Ca), and anti-icing agents (Na) were found to be the sources of pollution. We found that the high dust load is caused by meteorological factors, such as temperature inversion and a large number of calm days, which reduce the dispersion of pollution. This case study demonstrates that winter air quality in polar settlements can be worse than that in urban areas in the temperate zone, even with few local sources of pollution. Furthermore, the trend toward an increase in the number of windless days, such as observed in Siberia as a result of global climate change, increases the risk of anthropogenic pollution of the atmosphere of polar cities.

An inexpensive artificial snake hibernaculum built using readily available plumbing supplies

Artificial snake hibernacula are anthropogenic structures used by snakes in temperate zones to survive harsh winter conditions. Artificial hibernacula can be intentionally created for various purposes including herpetoculture, research, habitat enhancement and conservation, or to offset development impacts. Here we present a design for an artificial snake hibernaculum for research use that was convenient (manually installed) and cost-effective ($91 CAD ea.). The hibernaculum was made of HDPE and ABS plumbing hardware, and measured ∼160 cm long by ∼10 cm wide. Our design was multi-chambered, descended to the groundwater table, and was modelled after the burrowing crayfish burrows used as overwinter refugia by snakes in our study area. Installation was completed using a manual soil auger in areas with soil depths of ∼115 cm. Removable components would allow easy ingress and egress of snakes, and threaded caps would facilitate monitoring via borescope camera. Dataloggers were used in 4 unoccupied hibernacula during one hibernation period, and results demonstrated that hibernacula supported a low mean air temperature and a high mean relative humidity. The hibernacula also provided a substantial buffer against extreme outside temperature and humidity. Further testing may demonstrate the suitability of our hibernaculum design for herpetoculture or conservation purposes.•Installed using a manual soil auger in areas with soil depths of ∼115 cm•Removable components allow for safe and easy ingress/egress of wild-caught or captive-reared snakes•Removable cap and simplified shape facilitate health monitoring of snakes via borescope camera

Studying the Optimization, Characterization, and Antioxidant Activities of Phenolic Extracts Extracted from Rhus chinensis Mill. Leaf using Microwave-assisted Extraction System with Glycerol as a Green Solvent

Background: The leaves of Rhus chinensis Mill., a common deciduous tree found in the mild temperate zone of Asia, have many medicinal effects, including antioxidant properties. Objectives and Methods: This study aims to optimize the conditions for extracting phenols from Rhus chinensis Mill. (RCM) using a microwave-assisted extraction system with glycerol (MAEG) via response surface methodology (RSM). It also aims to compare the extraction efficacy of decoction and MAEG methods in terms of the bioactive compounds and antioxidant activities of the extracts obtained through them, identify bioactive compounds in both extracts via ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOFMS/ MS), and determine the cytotoxicity and cellular antioxidant activity of MAEG extract. Results: Temperature and glycerol concentration significantly affected the total phenolic content (TPC) of the extracts. The validated value of TPC was 84.11 ± 4.28 mg GAE/g for the sample obtained under the optimal conditions of 12.76 min at 54.08°C and 34.48% glycerol concentration. MAEG extract exhibited higher antioxidant properties compared to the decoction extract. Different phenolic compounds in the extracts were tentatively identified by LC-QTOF. MAEG concentrations from 1 mg/mL to 7.5 mg/mL were considered non-cytotoxic to NIH/3T3 fibroblasts. Furthermore, the cell viability of NIH/3T3 fibroblasts increased after being treated with MAEG extract (from 2.5 mg/mL to 7.5 mg/mL) and subjected to H2O2- induced oxidative stress compared to H2O2 treatment alone. Conclusion: Finally, MAEG can be used as a novel green extraction method for obtaining bioactive compounds for cosmetic and medicinal applications.

Sexual Cycle of the Mediterranean Pond Turtle, <i>Mauremys leprosa</i> (Testudines: Geoemydidae) in West Central Morocco

We studied the reproductive cycle of male and female Mauremys leprosa in central Morocco. The cycle for males starts in the spring with warming temperatures and the beginning of the dry-season with testicular enlargement and a decrease in epididimydes size accompanied by sperm production. The epididymis contains sperm mainly in winter, spring and summer. Females exhibited follicular enlargement from November reaching a peak in February when a maximum follicle size of 38.5 mm was observed. Ovulation appears to begin in April or May and oviductal eggs were present in our samples from April – July. Suspected mating activity occurred from January – March when environmental temperatures were lowest and the wet-season peaked. Sexual activity was coincident with the onset of maximum storage of sperm in the epididymis. The overall reproductive cycle of this species is similar to that of other Temperate Zone turtles with the exception that mating occurs in the winter, not in the spring and fall. Winter mating may be a response to the wet-season Mediterranean climates. Rain connects isolated pools in ephemeral rivers and streams in Morocco that form during the dry season, thus providing greater opportunities for access to mates.

Standing dead wood stocks in forest stands of Middle Dnieper region (Forest-Steppe of Ukraine)

Standing dead wood is an important component of forest ecosystems of temperate zone. The aim of the article is to study the forestry and ecological features of the distribution of standing dead wood stocks in forest stands of Middle Dnieper region (Forest-steppe of Ukraine). The study was carried out based on State forest inventory data of the part of territory of state forest enterprise with a total area of 24558.6 ha in northern part of Cherkasy region. According to forest inventory data standing dead wood was found on area of 3439.4 ha or 14.0% of the total forest area. The average standing dead wood volume was the highest in forests of nature conservation, scientific, historical and cultural purposes (13.0 m3∙ha–1), somewhat lower — in forests with commercial purpose (11.0 m3∙ha–1), in protective, and recreational and health-improving forests (9.8 m3∙ha–1). Standing dead wood was found in the forest stands of 15 tree species with a total stock of 34660 m3. In those forests the average volume of by tree species ranging from 5.0 m3∙ha–1 up to 20.0 m3∙ha–1, in general for all tree species — 10.1 m3∙ha–1. In the stands of the prevailing tree species — Scots pine (Pinus sylvestris L.), black locust (Robinia pseudoacacia L.) and Common oak (Quercus robur L.) the average volume of standing dead wood was 10.4, 9.0 m3∙ha–1 and 7.5 m3∙ha–1, respectively. In the stands of the first two specified tree species, a tendency to increase the average volume of standing dead wood with an increase in the age of the stand was revealed. Standing dead wood was found in 17 out of 32 forest types that are represented in the forest fund of the studied object, with an average volume of 5.7 m3∙ha–1 (fresh eroded hornbeam dibrova) to 22.4 m3∙ha–1 (damp black alder hrud). In general, standing dead wood stocks are low, which may be caused by forestry activities (cutting). The data we obtained are important for research into the peculiarities of the formation of woody detritus stocks in the forests of Middle Dnieper region of Ukraine and nature protection functions of dead wood.

Epigenetic variation in early and late flowering plants of the rubber-producing Russian dandelion Taraxacum koksaghyz provides insights into the regulation of flowering time

The Russian dandelion (Taraxacum koksaghyz) grows in temperate zones and produces large amounts of poly(cis-1,4-isoprene) in its roots, making it an attractive alternative source of natural rubber. Most T. koksaghyz plants require vernalization to trigger flower development, whereas early flowering varieties that have lost their vernalization dependence are more suitable for breeding and domestication. To provide insight into the regulation of flowering time in T. koksaghyz, we induced epigenetic variation by in vitro cultivation and applied epigenomic and transcriptomic analysis to the resulting early flowering plants and late flowering controls, allowing us to identify differences in methylation patterns and gene expression that correlated with flowering. This led to the identification of candidate genes homologous to vernalization and photoperiodism response genes in other plants, as well as epigenetic modifications that may contribute to the control of flower development. Some of the candidate genes were homologous to known floral regulators, including those that directly or indirectly regulate the major flowering control gene FT. Our atlas of genes can be used as a starting point to investigate mechanisms that control flowering time in T. koksaghyz in greater detail and to develop new breeding varieties that are more suited to domestication.

Detection of two species of non-indigenous freshwater snails in Arctic Siberia

ABSTRACT Some species of freshwater gastropods, known for their adaptability and resilience, have gained attention globally as invasive species. However, to date, only one invasive population of freshwater snails has been documented beyond the Arctic Circle. In this study, we report the discovery of two non-indigenous species, Planorbella duryi (Wetherby, 1879) and Physella acuta (Draparnaud, 1805), north of 69°N in the Norilsk Industrial District (Central Siberia). Their identification was based on morphological features and COI gene sequences. Both species are native to the temperate and subtropical zones of North America and may have entered the Arctic Asian reservoirs through aquarium introductions. The distribution of these populations is constrained to areas affected by thermal pollution, and their further spread into pristine reservoirs of Northern Siberia is unlikely.

Machine Learning-Based Estimation of Daily Cropland Evapotranspiration in Diverse Climate Zones

The accurate prediction of cropland evapotranspiration (ET) is of utmost importance for effective irrigation and optimal water resource management. To evaluate the feasibility and accuracy of ET estimation in various climatic conditions using machine learning models, three-, six-, and nine-factor combinations (V3, V6, and V9) were examined based on the data obtained from global cropland eddy flux sites and Moderate Resolution Imaging Spectroradiometer (MODIS) remote sensing data. Four machine learning models, random forest (RF), support vector machine (SVM), extreme gradient boosting (XGB), and backpropagation neural network (BP), were used for this purpose. The input factors included daily mean air temperature (Ta), net radiation (Rn), soil heat flux (G), evaporative fraction (EF), leaf area index (LAI), photosynthetic photon flux density (PPFD), vapor pressure deficit (VPD), wind speed (U), and atmospheric pressure (P). The four machine learning models exhibited significant simulation accuracy across various climate zones, reflected by their global performance indicator (GPI) values ranging from −3.504 to 0.670 for RF, −3.522 to 1.616 for SVM, −3.704 to 0.972 for XGB, and −3.654 to 1.831 for BP. The choice of suitable models and the different input factors varied across different climatic regions. Specifically, in the temperate–continental zone (TCCZ), subtropical–Mediterranean zone (SMCZ), and temperate zone (TCZ), the models of BPC-V9, SVMS-V6, and SVMT-V6 demonstrated the highest simulation accuracy, with average RMSE values of 0.259, 0.373, and 0.333 mm d−1, average MAE values of 0.177, 0.263, and 0.248 mm d−1, average R2 values of 0.949, 0.819, and 0.917, and average NSE values of 0.926, 0.778, and 0.899, respectively. In climate zones with a lower average LAI (TCCZ), there was a strong correlation between LAI and ET, making LAI more crucial for ET predictions. Conversely, in climate zones with a higher average LAI (TCZ, SMCZ), the significance of the LAI for ET prediction was reduced. This study recognizes the impact of climate zones on ET simulations and highlights the necessity for region-specific considerations when selecting machine learning models and input factor combinations.

The dynamic landscape of chromatin accessibility and active regulatory elements in the mediobasal hypothalamus influences the seasonal activation of the reproductive axis in the male quail under long light exposure

BackgroundIn cold and temperate zones, seasonal reproduction plays a crucial role in the survival and reproductive success of species. The photoperiod influences reproductive processes in seasonal breeders through the hypothalamic-pituitary-gonadal (HPG) axis, in which the mediobasal hypothalamus (MBH) serves as the central region responsible for transmitting light information to the endocrine system. However, the cis-regulatory elements and the transcriptional activation mechanisms related to seasonal activation of the reproductive axis in MBH remain largely unclear. In this study, an artificial photoperiod program was used to induce the HPG axis activation in male quails, and we compared changes in chromatin accessibility changes during the seasonal activation of the HPG axis.ResultsAlterations in chromatin accessibility occurred in the mediobasal hypothalamus (MBH) and stabilized at LD7 during the activation of the HPG axis. Most open chromatin regions (OCRs) are enriched mainly in introns and distal intergenic regions. The differentially accessible regions (DARs) showed enrichment of binding motifs of the RFX, NKX, and MEF family of transcription factors that gained-loss accessibility under long-day conditions, while the binding motifs of the nuclear receptor (NR) superfamily and BZIP family gained-open accessibility. Retinoic acid signaling and GTPase-mediated signal transduction are involved in adaptation to long days and maintenance of the HPG axis activation. According to our footprint analysis, three clock-output genes (TEF, DBP, and HLF) and the THRA were the first responders to long days in LD3. THRB, NR3C2, AR, and NR3C1 are the key players associated with the initiation and maintenance of the activation of the HPG axis, which appeared at LD7 and tended to be stable under long-day conditions. By integrating chromatin and the transcriptome, three genes (DIO2, SLC16A2, and PDE6H) involved in thyroid hormone signaling showed differential chromatin accessibility and expression levels during the seasonal activation of the HPG axis. TRPA1, a target of THRB identified by DAP-seq, was sensitive to photoactivation and exhibited differential expression levels between short- and long-day conditions.ConclusionOur data suggest that trans effects were the main factors affecting gene expression during the seasonal activation of the HPG axis. This study could lead to further research on the seasonal reproductive behavior of birds, particularly the role of MBH in controlling seasonal reproductive behavior.