Monsoon Climate Research Articles

Breeding evaluation of the common buckwheat accessions (<i>Fagopyrum esculentum</i> Moench) obtained with the use of copper and zinc ions

Relevance. Employing new biotechnological methods in the breeding of buckwheat, including the screening of forms with tolerance to copper and zinc ions, might increase the adaptability of genotypes and allow the creation of promising starting material for further breeding.Methods. The research on common buckwheat with tolerance to copper and zinc ions and breeding evaluation of the obtained accessions were conducted at FSBSI «FSC of Agricultural Biotechnology of the Far East named after A.K. Chaiki» in 2020–2023. The research object was 10 accessions obtained from buckwheat varieties Kitavasesoba (Japan) and Izumrud (Russia) and hybrid Izumrud×Kitavasesoba, whose microshoots and seeds were exposed to copper and zinc ions. Released variety Izumrud was used as the standard. The method of cell and tissue culture in vitro as well as the germination of seeds in concentrated solutions of copper and zinc salts in vivo were employed.Results. In the conditions of the monsoon climate of Primorsky Krai, a three-year test of 10 buckwheat samples obtained under the influence of copper and zinc ions in culture in vitro and in vivo was carried out. As a result of the study, three samples were selected for further selection (No. 989, 1013, 783), which are characterized by a complex of economically valuable traits: high seed productivity (6.5–7.1 g), stress resistance, genetic flexibility, high mass of 1000 seeds (37.8–44.8 g), a combination of high mass of 1000 kernels (27.4–33.1 d) with low film content (23.3–25.5%), and two samples (No. 997, 1005) with an increased content of rutin in fruits (7.1–7.7 mg / 100 g).

Urban vegetation cooling capacity was enhanced under rapid urbanization in China

The cooling capacity of urban vegetation, which forms “urban cooling islands” (UCI), can play an important role in mitigating urban heat islands (UHI). However, the spatiotemporal changes in UCI intensity at the national scale have not been fully explored under rapid urbanization in China. In this study, based on 23,081 Landsat images from the Google Earth Engine, spatiotemporal UCI was obtained for 320 cities in China from 2000 to 2018 and correlated with meteorological and urbanization parameters to uncover the factors driving UCI changes. The direct and indirect effects of the driving factors on UCI were investigated using structural equation modeling. Our results showed that China experienced 12.38%, 181.23%, 83.6%, and 22.63% increases in population density, gross domestic product (GDP), the impervious surface, and leaf area index (LAI), respectively, between 2000 and 2018. Furthermore, we found more rapid urbanization in the temperate continental climate (TCC) zone than in the temperate monsoon climate (TMC) and subtropical monsoon climate (SMC) zones in China. The national averaged UCI was 2.47 °C, with the largest UCI recorded in small cities and TCC zones. From 2000 to 2018, over 70% of cities showed an increasing trend in UCI intensity, mainly concentrated in TMC and megacities. At the national scale, the increase in UCI was likely explained by a combination result of the intensified wind speed, decrease in urban areas, and enhanced LAI. We also identified that the driving mechanisms of UCI were very different in different climatic zones. In TCC, precipitation had a major impact on UCI intensity at a threshold of 78.92 mm. In TMC and SMC, in addition to temperature, urbanization factors significantly influenced UCI. The main factors in TMC were LAI, with a specific threshold of 1.15. These results deepen the understanding of UCI formation and provide new insights into the regional adaptation of urban vegetation to mitigate urban heat waves.

Habitat characteristics, population structure, distribution, and regeneration status of Taxus wallichiana in South Vietnam

Abstract. Hop NV, Xiong CC, Quy NV, Luong NT. 2023. Habitat characteristics, population structure, distribution, and regeneration status of Taxus wallichiana in South Vietnam. Nusantara Bioscience 15: 179-188. Taxus wallichiana Zucc. is an endangered plant species with high economic value, making it threatened to extinction. Biological information about this species is therefore essential for its conservation. This study is aimed to assess the habitat characteristics, population structure, distribution, and regeneration status of T. wallichiana in South Vietnam. Vegetation surveys were conducted from 2016 to 2021 in three regions in Lam Dong Province. The study revealed that it was distributed in regions with monsoon climate with a total extent of ??379.57 ha, with habitats located on the hillside, narrow shelves, dissected terrain, high slope, on feralite soil with light brown to yellow, red, the soil layer thickness over 0.3 m and in clusters or streaks. The study recorded 634 trees with a diameter at breast height (DBH)?25 cm and 137 trees with 6 cm ?DBH<25 cm. The trees were found primarily at 1401-1500 m above sea level in a mixed broadleaved-coniferous forest. The growth indicators of DBH and overall height (Hvn) developed strongly, but the stand volume was low owing to low tree density. The exponential function was the most suitable for simulating the relationship between Hvn and DBH. Seven thousand six hundred and seventy-three regenerating young individuals were recorded with low density. The density of the regenerating trees decreased as the tree height increased. The finding of this study suggests that T. wallichiana faces the danger of extinction, so solutions are required to conserve and develop this threatened species.

Geographical and morphological changes of conifers in Yunnan, China during the Cenozoic in response to climatic changes

Yunnan province, known as a hot spot of plant diversity, is located in Southwest China and on the southeastern margin of the Qinghai-Tibet Plateau. Today, there are four families, 21 genera and 56 species of conifers found in Yunnan. Three families, 15 genera and 44 species of fossil conifers have been reported from the Cenozoic in Yunnan. In this study, we investigated the fossil conifers from the Cenozoic in Yunnan and their corresponding living species and evaluated the distribution and climatic conditions of the extant genera. Based on this analysis, paleoclimates of the fossils were reconstructed to determine the migration patterns of these conifers in response to climatic changes caused by the uplift of the Qinghai-Tibet Plateau. Our analyses show that the cooling trend led to a southward expansion and migration of conifers to warm and humid climate areas since the early Oligocene. In addition, the drought tendency led to the disappearance of certain conifer species from Yunnan, and the strengthening monsoon climate resulted in the migration of conifers eastward to eastern China or coastal areas, westward to western Yunnan, southeast Tibet and northern Myanmar and northward to dry and cold North China and North Korea. Likely adaptive morphological changes also occurred among the conifer species. The study also revealed that the diversity and composition of conifers in Yunnan have changed significantly since the early Oligocene with the uplift of the Qinghai-Tibet Plateau and climatic changes and that the extant lineages of Yunnan conifers appeared in the late Miocene.

Paleofire dynamics in response to climate change during late Miocene derived from microcharcoal records in the Weihe Basin

The Weihe Basin, situated in the central part of Shaanxi Province between the Qinling and Weibei Mountains, falls under the influence of the Asian monsoon system. The basin's thick and continuous Cenozoic sedimentary layers offer a valuable repository for investigating environmental changes within a typical monsoon climate. Based on previous chronological research, our study delved into the microcharcoal concentration (MCC) of the samples extracted from Bahe Formation. This analysis aimed to reconstruct the paleo-fire and drought history during the late Miocene, shedding light on the region's evolutionary trajectory. Our findings unveil five distinct peaks in the microcharcoal record, occurring at approximately 9.9–9.7 million years ago (Ma), ∼9.5 Ma, ∼8.1 Ma, ∼7.6 Ma, and 7.4–7.2 Ma. These peaks signify high-frequency fire events, primarily taking place during periods of aridity. The combustion of broadleaved and coniferous trees was the predominant source of fuel for fires during 9.9–9.7 Ma, ∼9.5 Ma and ∼8.1 Ma, with elevated temperatures acting as the principal ignition catalyst. In contrast, the subsequent two fire events (∼7.6 Ma, and 7.4–7.2 Ma) coincided with drier climatic conditions, featuring xerophytic herbs s as the primary biomass. Drought emerged as the pivotal driving force behind these fire occurrences in this phase. The microcharcoal records of the Bahe Formation reveal a noteworthy pattern: the MCC during the latter two periods surpassed that of the initial three, indicating an escalated frequency of fires during dry intervals. This trend signifies a transition towards a dry and cold climate post ∼8.0 Ma. The expansion of grasslands and the occurrence of drought events since the late Miocene (∼8.0 Ma) can be attributed to the weakening of the Asian Monsoon. In summary, our investigation of microcharcoal concentration in the Bahe Formation provides valuable insights into the late Miocene paleo-fire and drought dynamics. By deciphering the interplay between vegetation, climate, and fire occurrences, our study contributes to a more comprehensive understanding of the environmental evolution within the Weihe Basin under the influence of the Asian monsoon system.

The Influence of Winter Snowpack on the Use of Summer Rains in Montane Pine Forests Across the Southwest U.S.

AbstractA two decade‐long megadrought, with likely anthropogenic causes, has impacted forest growth and mortality across the southwestern U.S. Given this event, and the future likelihood of similar climate challenges, it is important to understand how different water resources are used by semi‐arid forests in this region. Within the geographic domain of the North American Monsoon climate system, we studied seasonal water‐use in eight different Pinus ponderosa montane forests distributed across a climate gradient with varying contributions from winter and summer precipitation. We collected oxygen isotopes from precipitation, soil, and xylem water during two contrasting hydrologic years to determine how trees differentially use winter versus summer precipitation sources. Most trees switched from using snowmelt water as the primary source during the early‐summer hyper‐arid period, to monsoon rainwater during the late‐summer. However, during the low snowpack year, which represents the most common climate phenomenon during the megadrought, trees at all sites used less summer rain when compared to the higher snowpack year, demonstrating a drought‐induced antecedent influence of winter precipitation on the uptake of summer rain. A possible mechanism to explain the antecedent effect is an earlier snow disappearance during the low snowpack year weakening hydrologic connectivity within the soil profile, decreasing the soil infiltration of summer rains. However, in years with higher snowpack, the snow lasts longer, and this can improve the hydrologic connectivity within the soil profile. As a result, there is more infiltration of summer rains into the soils. This can enhance the maintenance of active shallow fine‐root biomass during the period when snowpack disappears, and monsoon rains have yet to arrive. These findings provide insight into how the seasonal interactions between major seasonal climate systems influence forest tree water use in the face of an extreme megadrought.

Identifying Temperature and Moisture Controls on Fe Oxide Origins

AbstractMagnetism, redness, and Fe oxides are indicators of pedoclimatic conditions. However, uncertainties with observing how Fe oxides form within soils has led to debates about relationships between magnetic mineral assemblages, temperature, and rainfall. To address these issues, Fe oxides from the equatorial tropics of Kenya were examined in Pliocene soils that developed under orbital forcing of the monsoon. Results demonstrate that with warm‐wet monsoons, ferrimagnetic production was increased and correlated with hematite concentrations, in accordance with expectations that ferrimagnetic and hematite minerals codevelop from amorphous Fe oxides. With cool‐dry monsoons, hematite concentrations increased but ferrimagnetic production decreased and decoupled from hematite development. These findings suggest that decreased rainfall rather than temperature change favored the dehydration step required to catalyze hematite enrichment within soils. This study explains Fe oxides origins under variable monsoonal climates and recognizes moisture changes in comparison to temperature as stronger controls on the production of soil‐formed hematite.

Divergent rainforest tree microbiomes between phases of the monsoon cycle, host plants and tissues.

The Australian Monsoon Tropics (AMT) contain some of the most biodiverse forests on the continent. Little is known about the dynamics of rainforest plant microbiomes in general, and there have been no community-level studies on Australian rainforest endophytes, their seasonality, tissue and host specificity. We tested whether community composition of tropical tree endophytes (fungi and bacteria) differs: (i) at different points during a monsoon cycle, (ii) between leaf and stem tissues, (iii) between forest microclimates (gully/ridge), and between (iv) host plant species, and (v) host plant clade, using amplicon sequencing of the bacterial 16S and fungal ITS2 gene regions. Results indicated that the composition of rainforest plant microbiomes differs between wet and dry seasons, which may be explained by physiological shifts in host plants due to annual climate fluctuations from mesic to xeric. Endophyte microbiomes differed between leaves and stems. Distinct fungal communities were associated with host species and clades, with some trees enriched in a number of fungal taxa compared to host plants in other clades. Diversity of bacterial endophytes in plant stems increased in the dry season. We conclude that the microbiomes of tropical plants are responsive to monsoonal climate variation, are highly compartmentalised between plant tissues, and may be partly shaped by the relatedness of their host plants.

On the successful acclimatization of the Colorado potato beetle Leptinotarsa decemlineata (Say, 1824) (Coleoptera: Chrysomelidae) in Primorsky kray

The successful naturalization of the Colorado potato beetle in Primorsky Kray is limited by the monsoon climate, namely unstable fluctuating weather conditions with periodic catastrophic precipitation. The most of potato fields are located in the bottomlands of rivers or in close proximity to water bodies and a drastic increase in the runoff due to excessive simultaneous rainfall leads to the flooding of agricultural lands and the elimination of the fodder plants. The Colorado potato beetle is an oligophage and can not switch to alternative food sources during these periods. Moreover, beetles that enter diapause under these conditions die because of flooding and cold injury. Despite this fact, the pest remains a threat to the potato production in the region and can cause significant damage in case of repeated invasions during periods with more favorable conditions.

Total and cause-specific mortality attributable to cold spells in China: A multicity and multicounty study

Climate change has resulted in an increase in the frequency and intensity of extreme cold weather events, but few multicity or multicounty researches have explored the association between cold spells and mortality risk and burden. We collected daily data on climate, sociodemographic factors and mortality in 18 cities/counties across 11 geographical regions for the period of November to March 2014–2018. A distributed lag nonlinear model was used to examine the association between cold spells and mortality after adjustment for confounding factors. Twelve definitions of cold spells were used. Multi-meta regression analysis was applied to pool the impacts over different regions. Cold spells were significantly associated with all-cause mortality at lag 0–21 (CRR:1.38, 95%CI:1.21,1.57). In addition to respiratory diseases and circulatory system diseases, digestive, endocrine and nervous system diseases and injury were also affected by cold spells. The magnitude of the impacts of cold spells on mortality varied among the diseases investigated, with the highest risk estimate found for influenza and pneumonia (CRR: 2.00, 95%CI: 1.45, 2.76) and the lowest estimate found for injury (CRR: 1.26, 95%CI: 1.09,1.46). The fraction of all-cause mortality attributable to cold spells was 2.31% (95%CI: 0.90%, 3.46%). Among the regional differences, the attributable burden of all-cause mortality was higher in rural areas and subtropical monsoon climate zone, with attributable fractions of 2.85% (95%CI: 1.23%, 4.11%) and 3.36% (95%CI: 0.55%, 5.35%), respectively. Cold spells increased mortality from a range of diseases. Women, older adults and residents of rural areas and subtropical monsoon climate zone were more vulnerable to cold spells impacts. The findings may help to formulate preventive strategies and early warning response plans to reduce mortality burden of extreme cold events.

Multimodal climate change prediction in a monsoon climate

Abstract The uncertainty in the climate projection arising from various climate models is very common, and averaging such results poses a risk of underestimation or sometimes overestimation of impact in magnitude and frequency. Further, the performance of various climate models in monsoon degrades drastically due to the skewed nature. Under these circumstances, the performance of the climate model in the monsoon and non-monsoon periods is critical for accurate assessment. A multimodal approach has been used in the present work to quantify the uncertainty involved in the climate model using reliability ensemble averaging (REA). Based on AR6 of IPCC, the ensemble of 26 global climate models (GCMs) was used to evaluate the model performance and possible change in seasonal precipitation in four cities with distinct climate conditions, namely, Coimbatore, Rajkot, Udaipur, and Siliguri. The results show that non-monsoon and monsoon rainfall are expected to increase in all the regions. Most of the models perform poorly in simulating monsoon climate, especially in the monsoon period and are highly inconsistent spatially. The study also finds that the model performance is largely linked to the ratio of natural variability and mean.

High-Resolution National-Scale Mapping of Paddy Rice Based on Sentinel-1/2 Data

Rice has always been one of the major food sources for human beings, and the monitoring and planning of cultivation areas to maintain food security and achieve sustainable development is critical for this crop. Traditional manual ground survey methods have been recognized as being laborious, while remote-sensing technology can perform the accurate mapping of paddy rice due to its unique data acquisition capabilities. The recently emerged Google Earth Engine (GEE) cloud-computing platform was found to be capable of storing and computing the resources required for the rapid processing of massive quantities of remote-sensing data, thereby revolutionizing traditional analysis patterns and offering unique advantages for large-scale crop mapping. Since the phenology of paddy rice depends on local climatic conditions, and considering the vast expanse of China with its outstanding geospatial heterogeneity, a zoning strategy was proposed in this study to separate the monsoon climate zone of China into two regions based on the Qinling Mountain–Huaihe River Line (Q-H Line), while discrepant basic data and algorithms have been adopted to separately map mid-season rice nationwide. For the northern regions, optical indices have been calculated based on Sentinel-2 images, growth spectral profiles have been constructed to identify phenological periods, and rice was mapped using One-Class Support Vector Machine (OCSVM); for the southern regions, microwave sequences have been constructed based on Sentinel-1 images, and rice was mapped using Random Forest (RF). By applying this methodological system, mid-season rice at 10 m spatial resolution was mapped on the GEE for the entire Chinese monsoon region in 2021. According to the accuracy evaluation coefficients and publicly released local statistical yearbook data, the relative error of the mapped areas in each province was limited to 10%, and the overall accuracy exceeded 85%. The results could indicate that mid-season rice can be mapped more accurately and efficiently on a China-wide scale with relatively few samples based on the proposed zoning strategy and mapping methods. By adjusting the parameters, the time interval for mapping could also be further extended. The powerful cloud-computing competence of the GEE platform was used to map rice on a large spatial scale, and the results can help governments to ascertain the distribution of mid-season rice across the country in a short-term period, which would be well suited to meeting the increasingly efficient and fine-grained decision-making and management requirements.

Loess microstructure indication indexes for the study of palaeoclimatic conditions in northwest China

AbstractThe Loess Plateau of China, located to the west of the Liupan Mountains and north of the Qinling Mountains stretching across the Yellow River, is the main loess deposit area in Northwest China. The loess in the northwest of China has deposits with large thickness and extensive distribution. Scanning electron microscopy (SEM) and energy spectrum analysis of loess have been performed to study the relationship between the loess microstructures and the forming climates Era. The relevant indexes were evaluated including the sand‐dropping speed (Vn), certain sedimentary depths (hn sand particle volume (Vd) and element ratios of Ca/Fe, K/Al, Si/Al and Ca/Mg. The microstructure indexes of loess accumulation and evolution reflect paleoclimate conditions and time scales to a certain extent. The important discovery is the microscopic sand‐dropping speed (Vn) and the sedimentary depth hn) calculation method of different sedimentary ages. These indices are compared with the record of major aeolian‐forming climates from the Guliya ice core, and provide a reliable benchmark for studying climate change It also can be used as important indicators of monsoonal change and environmental evolution reconstruction. The index of sand sedimentation speed (Vn) got from loess microstructure could reflect sand‐dropping speed and loess deposition course. According the article can serve as new indicators of climatic changes of different forming loess layers. It can also be concluded that the climatic indexes obtained from loess microstructure can reflect climate conditions of loess forming. The loess forming climatic parameters are synchronous correspond to Tengger Desert and Guliya ice core for studying climate change, then microscopic parameters can also be used for preliminary analysis of loess climate formation and has be found corresponding evidence, and the loess climatic parameters correspond to the other two indexes. The analysis of loess microstructure indexes is very useful in researching climate change. Loess microstructure indexes can find new indicators and information about the monsoon climate evolution and paleoclimate changes.

Contrasting hydrological responses to climate change in two adjacent catchments dominated by karst and nonkarst

Karst systems are well-known for their special features, such as epikarst zone and quick flow, compared to other hydrological systems. However, few studies explored the difference in hydrological responses to climate change between karst and nonkarst catchments. In this paper, two adjacent catchments dominated by karst and nonkarst in Southwest China (subtropical monsoon climate) were selected to investigate their different hydrological behaviors under future climates. To account for potential model structure uncertainties, three different karst hydrological models and three traditional catchment models were used to simulate these two catchments. The results demonstrate that different models yield comparable streamflow simulations within each catchment, allowing for the focus to be on the impact of climate change and catchment hydrological characteristics. The karst-dominated catchment is modeled to have larger actual evapotranspiration (AET) than the nonkarst-dominated catchment under similar climate conditions, with the AET of the former being more sensitive to changes in precipitation and potential evapotranspiration. These differences are primarily due to the presence of the epikarst in the unsaturated zone of the karst system, which can store more infiltration rainwater for evapotranspiration. Both catchments are expected to experience a wetter projection in the wet season and a drier projection in the dry season in the future. However, the karst-dominated catchment will face a drier climate with a significant increase in precipitation in just two months (July and August). Additionally, because of a higher sensitivity of monthly AET to climate change, the karst-dominated catchment will experience a greater monthly discharge reduction in the first two wet months (April and May), a relatively lower discharge increase in other wet months, and a lower monthly discharge in dry months, while the monthly discharge of the nonkarst-dominated catchment increases in the wet season and decrease in the dry season. Furthermore, the karst-dominated catchment will have a much lower annual discharge than the nonkarst-dominated catchment, particularly during extremely dry years in the future period due to its larger AET consumption. These all suggest that the karst-dominated catchment will be more vulnerable to droughts. Overall, due to the drier climate and the different hydrological backgrounds of the karst-dominated catchment, it is expected to have much drier hydrological conditions in the future compared to the nonkarst-dominated catchment.

Historical biogeography and evolutionary diversification of Lilium (Liliaceae): New insights from plastome phylogenomics

Here, we infer the historical biogeography and evolutionary diversification of the genus Lilium. For this purpose, we used the complete plastomes of 64 currently accepted species in the genus Lilium (14 plastomes were newly sequenced) to recover the phylogenetic backbone of the genus and a time-calibrated phylogenetic framework to estimate biogeographical history scenarios and evolutionary diversification rates of Lilium. Our results suggest that ancient climatic changes and geological tectonic activities jointly shaped the distribution range and drove evolutionary radiation of Lilium, including the Middle Miocene Climate Optimum (MMCO), the late Miocene global cooling, as well as the successive uplift of the Qinghai-Tibet Plateau (QTP) and the strengthening of the monsoon climate in East Asia during the late Miocene and the Pliocene. This case study suggests that the unique geological and climatic events in the Neogene of East Asia, in particular the uplift of QTP and the enhancement of monsoonal climate, may have played an essential role in formation of uneven distribution of plant diversity in the Northern Hemisphere.

Assessing Spatial Variation and Driving Factors of Available Phosphorus in a Hilly Area (Gaozhou, South China) Using Modeling Approaches and Digital Soil Mapping

Soil fertility plays a crucial role in crop growth, so it is important to study the spatial distribution and variation of soil fertility for agricultural management and decision-making. However, traditional methods for assessing soil fertility are time-consuming and economically burdensome. Moreover, it is hard to capture the spatial variation of soil properties across continuous geographic space using the conventional methods. As key techniques of digital soil mapping (DSM), spatial interpolation techniques have been widely applied in soil surveys and analysis in recent years, since they can predict soil properties at unknown points in continuous space based on limited sample points. However, further research is needed on spatial interpolation models for DSM in regions with variable climates and complex terrains, which are characterized by strong spatial variation in both environmental variables and soil fertility. In this study, taking a typical hilly area in a subtropical monsoon climate, i.e., Gaozhou, Guangdong Province, China, as an example, the performances of four popular spatial interpolation models (Random Forest (RF), Ordinary Kriging, Inverse Distance Weighting, and Radial Basis Function) for digital soil mapping on available phosphorus (AP) are compared. Based on RF, the spatial variation and its driving factors of the AP of Gaozhou are then analyzed. Furthermore, by selecting three typical truncation lines from different directions, the correlations between environmental variables and AP in different spatial positions are demonstrated. The root mean square error (RMSE) results of the above four models are 32.01, 32.08, 32.74, and 33.08, respectively, which indicate that the RF has a higher interpolation accuracy. Based on the mapping results of RF, the minimum, maximum, and mean values of AP in the study area are 38.90, 95.24, and 64.96 mg/kg, respectively. The high-value areas of AP are mainly distributed in forested and orchard areas, while the low-value areas are primarily found in urban and cultivated areas in the eastern and western regions. Vegetation and topography are identified as the key factors shaping the spatial variations of AP in the study area. Furthermore, the spatial heterogeneity of the influence strength of altitude and EVI is revealed, providing a new direction for further research on DSM in the future, i.e., spatial interpolation models considering the spatial heterogeneity of the influence of environmental variables.

The Dichotomy of Wet and Dry Trends Over India by Aerosol Indirect Effects in CMIP5 Models

AbstractAerosol‐cloud interactions, also known as aerosol indirect effect (AIE), substantially impact rainfall frequency and intensity. Here, we analyze NEX‐GDDP, a multimodel ensemble of high‐resolution (0.25°) historical simulations and future projections statistically downscaled from 21 CMIP5 models, to quantify the importance of AIE on extreme climate indices, specifically consecutive dry days (CDD), consecutive wet days (CWD), and simple daily intensity index (SDII). The 21 NEX‐GDDP CMIP5 models are classified into models with reliable (REM) and unreliable (UREM) monsoon climate simulated over India based on their simulations of the climate indices. The REM group is further decomposed based on whether the models represent only the direct (REMADE) or the direct and indirect (REMALL) aerosol effects. Compared to REMADE, including all aerosol effects significantly improves the model skills in simulating the observed historical trends of all three climate indices over India. Specifically, AIE enhances dry days and reduces wet days in India in the historical period, consistent with the observed changes. However, by the middle and end of the 21st century, there is a relative decrease in dry days and an increase in wet days and precipitation intensity. Moreover, the REMALL simulated future CWD and CDD changes are mostly opposite to those in REMADE, indicating the substantial role of AIE in the future projection of dry and wet climates. These findings underscore the crucial role of AIE in future projections of the Indian hydroclimate and motivate efforts to accurately represent AIE in climate models.

Spatio-temporal variation of bacterial community structure in two intertidal sediment types of Jiaozhou Bay

The intertidal sediment environment is dynamic and the biofilm bacterial community within it must constantly adapt, but an understanding of the differences in the biofilm bacterial community within sediments of different types is still relatively limited. The semi-enclosed Jiaozhou Bay has a temperate monsoon climate, with strong currents at the mouth of the bay. In this study, the structure of the bacterial community in Jiaozhou Bay sediment biofilms are described using high-throughput 16 S rRNA gene sequencing and the effects of temporal change and different sediment environment types are discussed. Alpha diversity was significantly higher in sandy samples than in muddy samples. Sandy sediments with increased heterogeneity promote bacterial aggregation. Beta diversity analysis showed significant differences between sediment types and between stations. Proteobacteria and Acidobacteria were significantly more abundant at ZQ, while Campilobacterota was significantly more abundant at LC. The relative abundances of Bacteroidetes, Campilobacterota, Firmicutes, and Chloroflexi were significantly higher in the muddy samples, while Actinobacteria and Proteobacteria were higher in the sandy samples. There were different phylum-level biomarkers between sediment types at different stations. There were also different patterns of functional enrichment in biogeochemical cycles between sediment types and stations with the former having more gene families that differed significantly, highlighting their greater role in determining bacterial function. Bacterial amplicon sequence variant variation between months was less than KEGG ortholog variation between months, presumably the temporal change had an impact on shaping the intertidal sediment bacterial community, although this was less clear at the gene family level. Random forest prediction yielded a combination of 43 family-level features that responded well to temporal change, reflecting the influence of temporal change on sediment biofilm bacteria.

Earliest fossil pollen records of endemic African Sclerosperma palms and the palaeoecological aspects of the genus

Palm diversity in present-day Africa is much less than in other tropical regions such as the Americas and Southeast Asia but comprises several endemic genera, including Sclerosperma. The origin and evolution of this small Arecaceae genus are still enigmatic, and every new fossil discovered helps fill the void in its palaeophytogeographic history. In this article, we report five different pollen morphologies assigned to Sclerosperma from the earliest Late Eocene (early Priabonian) of southeast Kenya, Africa. These pollen grains represent the earliest fossil records of Sclerosperma so far and add a new geographic region and time slot to the palaeophytogeographic history of this genus. The morphological variability observed in the fossil pollen suggests that the diversification within Sclerosperma was already underway by the onset of the Priabonian, c. 37 Ma. Detailed analysis of the distribution of the three extant Sclerosperma species shows that this genus occurs only under Equatorial/Tropical climates with MTCM ≥18 °C, such as fully humid Rainforest (Af), Monsoonal (Am), and winter dry Savannah (Aw) climates. Sclerosperma is also conservative when it comes to vegetation biomes and only occurs in three different but closely related biomes, the Tropical & Subtropical Moist Forests Biome, the Tropical & Subtropical Grasslands, Savannahs & Shrublands Biome, and the Mangroves Biome. No current outliners pinpoint to a wider ecological tolerance of this genus in the geological past. This suggests Sclerosperma to be an exceptionally reliable taxon for palaeoclimate estimations and when assigning palaeofloras to major vegetation biomes.

Improvement of technological processes of cultivation of vegetable crops in the Far East. Review

The results of the selection work of the Primorsky vegetable experimental station, work in the field of seed production of vegetable crops are presented, the characteristics of the negative processes occurring in the arable soils of the region and their removal by the developed ridgeridge technology of cultivation by technical means with a wide base are given. A comparative characteristic of the former and the wide-row version in terms of energy consumption and fuel consumption is givenAuthors´ Contribution: All authors contributed to the planning and setting up the experiment, aswell as in the analysis of experimental data and writing of the article.Based on the results of the selection work of the Primorsky Vegetable Experimental Station for the period 1993-2023, the station bred and released 56 varieties and hybrids of 19 main vegetable crops. The experience of the Primorsky branch of the Federal scientific vegetable center allows organizing production at a modern level, taking into account the rich experience of other regions of Russia. In conditions of monsoon climate and soils of heavy granulometric composition, with a general lack of heat, their fertility is negatively affected by a large number of external factors. To grow vegetables, a set of measures is needed for serious drainage and irrigation reclamation (creation of polder systems with the laying of systematic plastic drainage) against the backdrop of ridge-ridge cultivation technology, fine irrigation system). The developed wide-cut technology and a set of machines make it possible to introduce a resource-saving technology that saves energy costs and fuel.