Effects Of Meteorological Factors Research Articles

Spatio-Temporal Changes of Vegetation Net Primary Productivity and Its Driving Factors on the Tibetan Plateau from 1979 to 2018

The Net Primary Productivity (NPP) of the Tibetan Plateau (TP) has undergone significant changes since the 1980s. The investigation of the spatiotemporal changes of NPP and its driving factors is of significant importance. Here, we analyze the spatial and temporal trends of Net Primary Production (NPP) and the effects of meteorological factors on the NPP change on the Tibetan Plateau (TP) using version 5.0 of the Community Land Model. The results showed that the average NPP was 256 (g C·m2·yr−1) over the past 40 years, with a continuously increasing trend of 2.38 (g C·m2·yr−1). Precipitation was the main factor affecting NPP changes, temperature had no significant effect on NPP changes, while radiation showed a negative trend. Changes in precipitation, temperature and radiation account for approximately 91%, 5.3%, and 3.8% of NPP variation, respectively. Based on grass coverage, we categorized alpine grasslands into three types: high, medium, and low coverage. Our findings indicate the NPP change of the high-coverage grasslands was mainly affected by precipitation, and then the temperature and radiation. Comparatively, the precipitation change is the driving factor of the increased NPP of low-coverage grasslands, but the temperature increase is the negative factor. Our studies have implications for assessing and predicting vegetation responses to future climate change.

Effects of Meteorological Factors on Asthma Hospital Visits in Haikou City, China

The effects of meteorological conditions on asthma in Haikou, a tropical city in China, are still unclear. This study aimed to determine the relationships between meteorological factors and the number of asthma hospital visits in Haikou. A Poisson generalized additive model combined with a distributed lag nonlinear model is used to model the nonlinear exposure–response relationship between the daily mean temperature and asthma hospital visits. The daily mean pressure and air quality are used as covariates and simultaneously control the mixed effects of holiday effects, weekend effects, and long-term trends. The results indicate that there is a significant statistical relationship between the daily mean temperature and asthma hospital visits, which shows an inverted J-shaped relationship. When the daily mean temperature is below the reference value (29.3 °C), the number of asthma patients increases considerably, and there is a marked lag in the prevalence of asthma. The longest lag is 9 days, and the most pronounced impact of the daily mean temperature on the number of asthma hospital visits can be found when the lag time is 1–4 days. When the daily mean temperature is 10 °C, the cumulative effect of the relative risk of asthma is 2.204, an increase of 120.4% (95% CI 1.294–3.755). If the daily mean temperature is below the 2.5th percentile value (14.8 °C), the relative risk significantly increases by more than 5.3% (95% CI 1.000–1.110), and the longest lasting impact time is 5 days. This indicates that increases in asthma hospital visits in Haikou, China, are significantly correlated with low-temperature weather. We suggest that preventive measures for asthma should take low-temperature weather into account. Additionally, we also found that extremely high temperatures have a certain impact on the increase in asthma hospital visits, but that the correlation is not significant.

Effects of meteorological factors on influenza transmissibility by virus type/subtype

BackgroundQuantitative evidence on the impact of meteorological factors on influenza transmissibility across different virus types/subtypes is scarce, and no previous studies have reported the effect of hourly temperature variability (HTV) on influenza transmissibility. Herein, we explored the associations between meteorological factors and influenza transmissibility according to the influenza type and subtype in Guangzhou, a subtropical city in China.MethodsWe collected influenza surveillance and meteorological data of Guangzhou between October 2010 and December 2019. Influenza transmissibility was measured using the instantaneous effective reproductive number (Rt). A gamma regression with a log link combined with a distributed lag non-linear model was used to assess the associations of daily meteorological factors with Rt by influenza types/subtypes.ResultsThe exposure-response relationship between ambient temperature and Rt was non-linear, with elevated transmissibility at low and high temperatures. Influenza transmissibility increased as HTV increased when HTV < around 4.5 °C. A non-linear association was observed between absolute humidity and Rt, with increased transmissibility at low absolute humidity and at around 19 g/m3. Relative humidity had a U-shaped association with influenza transmissibility. The associations between meteorological factors and influenza transmissibility varied according to the influenza type and subtype: elevated transmissibility was observed at high ambient temperatures for influenza A(H3N2), but not for influenza A(H1N1)pdm09; transmissibility of influenza A(H1N1)pdm09 increased as HTV increased when HTV < around 4.5 °C, but the transmissibility decreased with HTV when HTV < 2.5 °C and 3.0 °C for influenza A(H3N2) and B, respectively; positive association of Rt with absolute humidity was witnessed for influenza A(H3N2) even when absolute humidity was larger than 19 g/m3, which was different from that for influenza A(H1N1)pdm09 and influenza B.ConclusionsTemperature variability has an impact on influenza transmissibility. Ambient temperature, temperature variability, and humidity influence the transmissibility of different influenza types/subtypes discrepantly. Our findings have important implications for improving preparedness for influenza epidemics, especially under climate change conditions.

Effects of meteorological factors and groundwater depths on sap flow density of Populus euphratica in a desert oasis, Taklamakan Desert, China.

Accurate estimation of desert vegetation transpiration is key to regulating desert water resources of desert ecosystems. Sap flow density (SFD) can indirectly reflect a tree's transpiration consumption, and it has been affected by climate warming and groundwater depths in desert ecosystems. Sap flow responses to meteorological conditions and groundwater depths are further affected by tree of different sizes. However, how meteorological factors and groundwater depths affects tree sap flow among tree sizes remains poorly understand. In this study, a 50 × 50 m P. euphratica stand was selected as a sample plot in the hinterland of the Taklamakan Desert, and the SFD of P. euphratica of different sizes was measured continuously using the thermal diffusion technique from May to October of 2021 and 2022. The results showed that SFD of large P. euphratica was consistently higher than that of small P. euphratica in 2021 and 2022. and the SFD of P. euphratica was significantly and positively correlated with solar radiation (Rad) and vapor pressure deficit (VPD), and the correlation was higher than that of the air temperature (Ta) and relative humidity (RH), and also showed a strong non-linear relationship. Analysis of the hour-by-hour relationship between P. euphratica SFD and VPD and Rad showed a strong hysteresis. Throughout the growing season, there was no significant relationship between SFD of P. euphratica and groundwater depth, VPD and Rad were still the main controlling factors of SFD in different groundwater depths. However, during the period of relative groundwater deficit, the effect of groundwater depth on the SFD of P. euphratica increased, and the small P. euphratica was more sensitive, indicating that the small P. euphratica was more susceptible to groundwater changes. This study emphasized that Rad and VPD were the main drivers of SFD during the growing season, as well as differences in the response of different sizes of P. euphratica to groundwater changes. The results of the study provide a scientific basis for future modeling of transpiration consumption in P. euphratica forests in desert oases, as well as the regulation and allocation of water resources.

Experience from a light trap Lepidoptera survey in a populated settlement: effects of meteorological factors and changes in lunar phases

In the framework of the research, light trap Lepidoptera collections were carried out in the territory of a settlement (Velyki Berehy, Zakarpatska Oblast, Ukraine), which is bordered by nature reserves, forests, and agricultural areas, as well as by the remains of a large marsh (Szernye bog) that had been drained in the past. A Jermy light trap with a household LED bulb was used to capture the moths and butterflies. In addition to assessing the Lepidoptera fauna of the area, the study aimed to find out which species of Lepidoptera are attracted to energy-saving light bulbs commonly used in households in a settlement located in a habitat-diverse environment. In addition to the artificial light pollution conditions and other anthropogenic influences of the settlement, the direction and magnitude of the effects of temperature, relative humidity, cloud cover, wind speed, and moon phase parameters at the time of collection on the flight trends of nocturnal Lepidoptera species were also investigated. A total of 97 days of collecting between May 2018 and May 2019 resulted in the collection of 122 Lepidoptera species from 16 families. In terms of their ecological requirements, species were found in closed and open forest, forest edge, scrub, meadow, actively cultivated and abandoned agricultural areas, as well as in dry and wet areas. Several species considered being agricultural, forestry, or horticultural pests were identified, but not in abundance. Among the environmental variables, temperature variation showed a strong significant positive correlation with daily species numbers and abundance, while relative humidity, wind speed, cloud coverage and moon phases showed varying degrees of negative correlation, but were generally weak. The effects of the interactions of natural and man-made environmental influences on living organisms are difficult to assess objectively, but their research is of paramount importance for the long-term effective conservation of habitats of particular conservation value and for the preservation of their biodiversity.

Persistent Organic Pollutants and Suspended Particulate Matter in Snow of Eastern Siberia in 2009-2023: Temporal Trends and Effects of Meteorological Factors and Recultivation Activities at Former Industrial Area.

Suspended particulate matter (SPM), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCP) were studied in the snow cover at urban and suburban localities in the Irkutsk region, Eastern Siberia for their temporal variations in 2009-2023, daily deposition fluxes (DDFs), and effects of some meteorological factors, as well as the effects of different technogenic activities in the industrial area of the former organochlorine enterprises of Usol'ekhimprom. SPM loads at both stations were found to be at a low level of pollution. The levels of HCB, α + γ-HCH, and ∑p,p'-DDX were lower than Russian maximum permissible levels (MPLs) in drinking water, groundwater, and surface water for household drinking and cultural purposes. The sums of all organochlorine compounds studied in snow were higher than the MPL in freshwater water bodies for fishery purposes. The levels of the DDFs of HCHs, DDTs, and heptachlorinated PCB decreased, di- and trichlorinated PCB levels increased, and HCB levels changed at a polynomial line during 2009-2023. The change in the relative composition of PCBs was found as a result of recultivation activities at the industrial area of the former organochlorine enterprise of Usol'ekhimprom. The air humidity and temperature are the key meteorological factors affecting the DDFs of PCBs and OCPs.

Epidemiology, genetic characteristics, and association with meteorological factors of human metapneumovirus infection in children in southern China: A 10-year retrospective study

ObjectivesThis study aimed to determine the epidemiological and genetic features of human metapneumovirus (HMPV) infection in children in southern China, and the effect of meteorological factors on infection. Methods14,817 children (≤14 years) with acute respiratory tract infections from 2010 to 2019 were examined for HMPV and other respiratory viruses by real-time quantitative polymerase chain reaction. Full-length F gene of 54 positive samples were sequenced and subjected to phylogenetic analysis. The correlation between the HMPV-positive rate and meteorological factors was analyzed by linear regression analysis. ResultsHMPV was detected in 524 (3.5%) children, who were mostly younger than 1 year. The seasonal peak of HMPV prevalence mainly occurred in spring. Respiratory syncytial virus was the most common virus coinfected with HMPV (5.3%). Phylogenetic analysis revealed that the sequenced HMPV strains belonged to four sublineages, including A2b (1.9%), A2c (31.5%), B1 (50.0%), and B2 (16.7%). After adjusting for all meteorological factors, sunshine duration was inversely correlated with the HMPV-positive rate. ConclusionHMPV is an important respiratory pathogen that causes acute respiratory tract infections in children in southern China, particularly in children ≤5 years old. The prevalence peak of HMPV in this area appeared in spring, and the predominant subtype was B1. Meteorological factors, especially long sunshine duration, might decrease the HMPV prevalence.

Effect of Meteorological Factors and Air Pollutants on Daily Hospital Admissions for Ischemic Heart Disease in Lanzhou, China

Introduction: Meteorological factors and air pollutants are believed to be associated with cardiovascular disease. Ischemic heart disease (IHD) is a major public health issue worldwide. Few studies have investigated the associations among meteorological factors, air pollutants, and IHD daily hospital admissions in Lanzhou, China. Methods: We conducted a distributed lag nonlinear model on the basis of 5-year data, aiming at disentangling the impact of meteorological factors and air pollutants on IHD hospital admissions. All IHD daily hospital admissions recorded from January 1, 2015, and December 31, 2019, were obtained from three hospitals in Lanzhou, China. Daily air pollutant concentrations and meteorological data were synchronously collected from Gansu Meteorological Administration and Lanzhou Environmental Protection Administration. Stratified analyses were performed by sex and two age groups. Results: A total of 23,555 IHD hospital admissions were recorded, of which 10,477 admissions were for coronary artery disease (CAD) and 13,078 admissions were for acute coronary syndrome. Our results showed that there was a nonlinear (J-shaped) relationship between temperature and IHD hospital admissions. The number of IHD hospital admissions was positively correlated with NO2, O3, humidity, and pressure, indicating an increased risk of hospital admissions for IHD under NO2, O3, humidity, and pressure exposure. Meanwhile, both extremely low (−12°C) and high (30°C) temperatures reduced IHD hospital admissions, but the harmful effect increased with the lag time in Lanzhou, China, while the cold effect was more pronounced and long-lasting than the heat effect. Subgroup analysis demonstrated that the risk on CAD hospital admissions increased significantly in females and Conclusion: Our findings added to the growing evidence regarding the potential impact of meteorological factors and air pollutants on policymaking from the perspective of hospital management efficiency.

Estimation of the relationship between meteorological factors and measles using spatiotemporal Bayesian model in Shandong Province, China

BackgroundMeasles-containing vaccine (MCV) has been effective in controlling the spread of measles. Some countries have declared measles elimination. But recently years, the number of cases worldwide has increased, posing a challenge to the global goal of measles eradication. This study estimated the relationship between meteorological factors and measles using spatiotemporal Bayesian model, aiming to provide scientific evidence for public health policy to eliminate measles.MethodsDescriptive statistical analysis was performed on monthly data of measles and meteorological variables in 136 counties of Shandong Province from 2009 to 2017. Spatiotemporal Bayesian model was used to estimate the effects of meteorological factors on measles, and to evaluate measles risk areas at county level. Case population was divided into multiple subgroups according to gender, age and occupation. The effects of meteorological factors on measles in subgroups were compared.ResultsSpecific meteorological conditions increased the risk of measles, including lower relative humidity, temperature, and atmospheric pressure; higher wind velocity, sunshine duration, and diurnal temperature variation. Taking lowest value (Q1) as reference, RR (95%CI) for higher temperatures (Q2–Q4) were 0.79 (0.69–0.91), 0.54 (0.44–0.65), and 0.48 (0.38–0.61), respectively; RR (95%CI) for higher relative humidity (Q2–Q4) were 0.76 (0.66–0.88), 0.56 (0.47–0.67), and 0.49 (0.38–0.63), respectively; RR (95%CI) for higher wind velocity (Q2–Q4) were 1.43 (1.25–1.64), 1.85 (1.57–2.18), 2.00 (1.59–2.52), respectively. 22 medium-to-high risk counties were identified, mainly in northwestern, southwestern and central Shandong Province. The trend was basically same in the effects of meteorological factors on measles in subgroups, but the magnitude of the effects was different.ConclusionsMeteorological factors have an important impact on measles. It is crucial to integrate these factors into public health policies for measles prevention and control in China.

Effects of Meteorological Factors and Water-Nitrogen Management Techniques on Carbon Dioxide Fluxes in Wheat Fields in a Dry Semi-Humid Area

Effects of Meteorological Factors and Water-Nitrogen Management Techniques on Carbon Dioxide Fluxes in Wheat Fields in a Dry Semi-Humid Area

Effects of ambient temperature and relative humidity on preterm birth during early pregnancy and before parturition in China from 2010 to 2018: a population-based large-sample cohort study.

The progression of global warming and increase in instances of extreme weather have received considerable attention. We conducted a cohort study on women of childbearing age in Yunnan Province, examined the association between ambient temperature and humidity on preterm birth and evaluated the effects of extreme weather during early pregnancy and before parturition on preterm birth. We conducted a population-based cohort study on women of childbearing age 18-49 years who participated in National Free Preconception Health Examination Project (NFPHEP) in Yunnan Province from January 1, 2010, to December 31, 2018. Meteorological data, namely daily average temperature (°C) and daily average relative humidity (%), were obtained from China National Meteorological Information Center. Four exposure windows were explored: 1 week of pregnancy, 4 weeks of pregnancy, 4 weeks before delivery, and 1 week before delivery. We used a Cox proportional hazards model and adjusted the potential risk factors for preterm birth to obtain the effects of exposure to temperature and humidity on preterm birth among the stages of pregnancy. At 1 week of pregnancy and at 4 weeks of pregnancy, the association between temperature and preterm birth was U-shaped. The correlation between relative humidity and the risk of preterm birth was n-type at 1 week of pregnancy. The correlation between preterm birth and temperature and relative humidity at 4 weeks before delivery and at 1 week before delivery is J-shaped. Low temperature and low humidity were protective factors against preterm birth, whereas high temperature and high humidity were risk factors for preterm birth.The effects of high temperature and extremely high temperature were the strongest at 4 weeks before delivery, with HRs of 1.417 (95% CI: 1.362-1.474) and 1.627 (95% CI: 1.537-1.722), respectively. The effects of extremely low humidity and low humidity were strongest at 1 week before delivery, with HRs of 0.681 (95% CI: 0.609-0.761) and 0.696 (95% CI: 0.627-0.771), respectively. Temperature and relative humidity affect preterm birth differently for each pregnancy stage. The effects of meteorological factors on pregnancy outcomes such as premature birth should not be ignored.

Quantitative Analysis of Relationship Between Fruit Quality of ‘Fuji’ Apple and Environmental Factors: A Case Study of the Loess Plateau Production Region

The objective of this study was to investigate the effect of environmental factors (soil nutrition and meteorological factors) on fruit quality traits of ‘Fuji’ apples. ‘Fuji’ apple fruits, soil samples, and meteorological data were investigated from 66 commercial orchards covering 22 counties of the Loess Plateau region in China. Partial least squares regression (PLSR) and linear programming were combined to analyze the quantitative relationship between fruit quality and environmental factors. The effect of meteorological factors (55.99%) on fruit quality was greater than that of soil nutrition factors (44.01%) in the Loess Plateau apple-producing region of China. Optimum environmental factors for high-quality ‘Fuji’ apples in the Loess Plateau region were: soil organic matter (13.94–17.93 g ∙ kg−1), total N (0.77–1.03 g ∙ kg−1), available N (68.39–115.87 mg ∙ kg−1), P (62.39–124.67 mg ∙ kg−1), K (324.41–468.62 mg ∙ kg−1), Ca (6.54 mg ∙ kg−1), Fe (14.97 mg ∙ kg−1), Zn (1.55–2.72 mg ∙ kg−1), B (0.37 mg ∙ kg−1), and soil pH (7.98–8.20); mean annual temperature (18 ℃), total annual precipitation (431.2–713.8 mm), monthly mean temperature (19.9 ℃), lowest temperature (8.03 ℃), highest temperature (19.63 to 27.25 ℃), temperature difference between day and night (12.41 ℃), total precipitation (338.3–589.8 mm), relative humidity (56.57–82.41%), and sunshine percentage (36.96–55.87%) during the growing period (April–October).

How agricultural technologies and climatic factors affect India's crop production? A roadmap towards sustainable agriculture

AbstractThis study aims to explore the long‐term (LT) and short‐term (ST) effects of meteorological factors and technological advancement on major crop production, that is, wheat, and rice, in India from 1990 to 2020. For this purpose, the authors also used other important controlled variables, that is, agriculture employment (AE), agricultural credit (AC), and cultivated land (AUR/AUW). For the estimation of data series, the study employed robust econometric techniques, such as the ARDL, FMOLS, and CCR framework. Empirical results reveal the long‐term relationship among meteorological factors, agricultural technologies, and major crop production (wheat and rice). In the case of meteorological factors, rainfall (RF) and carbon emission (CO2) have a positive and negative impact on wheat and rice production, while the mean temperature is negatively related to rice production and positively related to wheat production. Whereas agricultural technologies, such as fertilizer usage and farm machinery, improve wheat and rice crop production. The long‐term (LT) estimated findings are confirmed by econometric techniques such as FMOLS and CCR. The government should adopt necessary measures to achieve sustainable production and develop resilient hybrid seeds of rice and wheat that are well‐suited to agro‐climatic conditions in order to mitigate environmental degradation.

Effect of Meteorological Factors on Yield Formation in Hulless Oats in Kirov Oblast

Effect of Meteorological Factors on Yield Formation in Hulless Oats in Kirov Oblast

The Effect of Meteorological Factors on the COVID-19 Pandemic in Northeast Turkiye.

Introduction Although various studies have been conducted on the relationship between meteorological factors and coronavirus disease 2019 (COVID-19), this issue has not been sufficiently clarified. In particular, there are a limited number of studies on the course of COVID-19in the warmer-humidity seasons. Methods Patients presenting to the emergency departments of health institutions and to clinics set aside for cases of suspected COVID-19 in the province of Rize between 1 June and 31 August 2021 and who met the case definition based on the Turkish COVID-19 epidemiological guideline were included in this retrospective study. The effect of meteorological factors on case numbers throughout the study was investigated. Results During the study period, 80,490 tests were performed on patients presenting to emergency departments and clinics dedicated to patients with suspected COVID-19. The total case number was 16,270, with a median daily number of 64 (range 43-328). The total number of deaths was 103, with a median daily figure of 1.00 (range 0.00-1.25). According to the Poisson distribution analysis, it is found that the number of cases tended to increase at temperatures between 20.8 and 27.2°C. Conclusion It is predicted that the numberof COVID-19 cases will not decrease with the increase in temperature in temperate regions with high rainfall. Therefore, unlike influenza, there may not be seasonal variation in the prevalence of COVID-19. The requisite measures should be adopted in health systems and hospitals to manage increases in case numbers associated with changes in meteorological factors.

The Effect of Environmental Factors on Mould Counts and AFB1 Toxin Production by Aspergillus flavus in Maize.

The toxins produced by Aspergillus flavus can significantly inhibit the use of maize. As a result of climate change, toxin production is a problem not only in tropical and subtropical areas but in an increasing number of European countries, including Hungary. The effect of meteorological factors and irrigation on mould colonization and aflatoxin B1 (AFB1) mycotoxin production by A. flavus were investigated in natural conditions, as well as the inoculation with a toxigenic isolate in a complex field experiment for three years. As a result of irrigation, the occurrence of fungi increased, and toxin production decreased. The mould count of fungi and toxin accumulation showed differences during the examined growing seasons. The highest AFB1 content was found in 2021. The main environmental factors in predicting mould count were temperature (Tavg, Tmax ≥ 30 °C, Tmax ≥ 32 °C, Tmax ≥ 35 °C) and atmospheric drought (RHmin ≤ 40%). Toxin production was determined by extremely high daily maximum temperatures (Tmax ≥ 35 °C). At natural contamination, the effect of Tmax ≥ 35 °C on AFB1 was maximal (r = 0.560-0.569) in the R4 stage. In the case of artificial inoculation, correlations with environmental factors were stronger (r = 0.665-0.834) during the R2-R6 stages.

The Effects of Meteorological Factors on Grain Yield of Foxtail Millet (Setaria italica Beauv.) under Different Water Supply Conditions

Meteorological factors have significant impacts on crop yield. To account for the impact of meteorological factors on foxtail millet (Setaria italica Beauv.) production in different water conditions, a total of 38 collected varieties were grown in nine seasons from 2011 to 2020 (except 2016) under well-watered (WW) and water-stressed (WS) conditions. The results showed that there was a large seasonal variation in GY; the variation ranged from 4.92 t ha−1 to 6.95 t ha−1 under the WW treatment and from 3.50 t ha−1 to 5.77 t ha−1 under the WS treatment. The impacts of meteorological factors on foxtail millet under the WW and WS treatments were different; sunshine duration during the whole stage, vegetative stage and reproductive stage had the greatest impact under the WW treatment, while under the WS treatment, sunshine duration and the diurnal temperature range during the whole stage and reproductive stage were the greatest impact factors on grain yield. This work could help us in high-yield foxtail millet cultivation and breeding.

A Review of Icing and Anti-Icing Technology for Transmission Lines

This paper reviews the application of various advanced anti-icing and de-icing technologies in transmission lines. Introduces the influence of snowing and icing disasters on transmission lines, including a mechanical overload of steel towers, uneven icing or de-icing at different times, Ice-covered conductors galloping and icing flashover of insulators, as well as the icing disasters of transmission lines around the world in recent years. The formation of various icing categories on transmission lines, as well as the effect of meteorological factors, topography, altitude, line direction, suspension height, shape, and electric field on ice-covered transmission lines, are all discussed in this study. The application of various advanced anti/de-icing technologies and their advantages and disadvantages in power transmission lines are summarized. The anti/de-icing of traditional mechanical force, AC/DC short-circuit ice melting, and corona effect is introduced. Torque pendulum and diameter-expanded conductor (DEC) have remarkable anti-icing effects, and the early investment resources are less, the cost is low, and the later maintenance is not needed. In view of some deficiencies of AC and DC ice melting, the current transfer intelligent ice melting device (CTIIMD) can solve the problem well. The gadget has a good effect and high reliability for de-icing conductors in addition to being compact and inexpensive. The application of hydrophobic materials and heating coatings on insulators has a certain anti-icing effect, but the service life needs further research. Optimizing the shed’s construction and arranging several string kinds on the insulators is advisable to prevent icing and the anti-icing flashover effect. In building an insulator, only a different shed layout uses non-consumption energy.

黄土高原植被覆盖与水热时空通径分析

PDF HTML阅读 XML下载 导出引用 引用提醒 黄土高原植被覆盖与水热时空通径分析 DOI: 10.5846/stxb202106081520 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 陕西省社会科学基金项目（2020D008）；陕西省自然科学基础研究计划项目（2021JM-513）；陕西省教育厅科学研究计划项目（21JK0475）；宝鸡文理学院研究生创新项目（YJSCX21YB03） Path analysis between vegetation coverage and climate factors in the Loess Plateau Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:探究黄土高原地区气象因子对植被覆盖的影响作用以丰富生态修复理论。基于黄土高原2001-2017年归一化植被指数（Normalized Difference Vegetation Index，NDVI）与气象数据，采用通径分析方法分别从时间和空间尺度上，分析黄土高原气温和降水对植被覆盖变化的直接及间接影响作用，为该地区生态建设提供科学依据。结果如下：黄土高原地区年际间植被明显波动增长，降水变化大体上与植被变化相似；降水整体较气温对植被覆盖变化的作用大。黄土高原植被与水热空间关系的最优分析尺度为80km，在80km空间尺度上，植被与气温有最大相关性，植被、降水由东南到西北递减，而气温分布规律不显著；降水整体呈现促进作用，气温的抑制作用较强，且空间差异明显。在时间与空间尺度上，植被主要受水热促进尤其是降水促进影响，且降水对植被生长的直接作用远大于通过气温的间接作用；不论生态区还是植被类型，气候因子作用均以促进类型为主，但存在明显差异。水热作用在时空尺度上具有明显空间差异性，不同地区影响植被变化的主控因子不同。 Abstract:Exploring the influence of climate factors on vegetation coverage in the Loess Plateau can enrich the ecological restoration theory. In order to provide a scientific basis for the ecological construction of the Loess Plateau, the direct and indirect effects of temperature and precipitation on vegetation were analyzed by using the path analysis, based on MODIS NDVI and corresponding meteorological data from 2001 to 2017. The findings are as follows the annual fluctuation growth of vegetation in the Loess Plateau were obvious, and the precipitation variation was like that of vegetation. Precipitation played a more important role than temperature overall. The maximum correlation between vegetation and temperature was found at the spatial scale of 80 km. At the spatial scale, vegetation and precipitation decreased from southeast to northwest, but the distribution of temperature was not significant. Precipitation presented a promoting effect on the whole while temperature mainly showed an inhibiting effect, and there was obviously spatial difference. On the temporal and spatial scale, vegetation was mainly affected by the promoting effect of climate factors, especially precipitation. The direct promoting effect of precipitation on vegetation is much greater than the indirect effect of temperature. Regardless of ecological areas or vegetation types on the Loess Plateau, the main effect of climate factors is promoting type, but there are obvious differences. On the spatial and temporal scales, the effects of meteorological factors obviously show the spatial difference. The main control factors affecting the vegetation are different in different regions, which has a theoretical guiding significance for the ecological management of the Loess Plateau and related problems in the process of management. 参考文献 相似文献 引证文献

Weather conditions affect pollinator activity, fruit set rate, and yield in Japanese apricot

Japanese apricot blooms in mid-winter, and thus severe weather conditions, including low temperatures, sometimes limit pollinator activity and consequently decrease fruit set rate and yield. Plant physiology is also affected by weather conditions. In this study, we aimed to evaluate the effect of pollinator activity on fruit set rate and yield, in comparison with the effects of meteorological factors. First, we conducted field experiments in 2021 and 2022 at Wakayama prefecture. The results showed that honey bee visitation increased as ambient temperature increased. Fruit set rate also increased under warm conditions when Japanese apricot was naturally pollinated by honey bees. In contrast, hand-pollinated flowers were not affected by ambient temperature. These results revealed that low temperature during the flowering period decreased pollinator visitation but did not affect plant fertilization ability. To compare pollinator activity with meteorological factors over a long period, including the pre- and post-flowering periods, we used a state-space model describing the time series of fruit set rate. The model using fruit set rate data and meteorological records over 15 years (2007–2021) at the Japanese Apricot Laboratory showed that the pre-blossom temperature and number of days suitable for pollination significantly affected the fruit set rate. Another model for the time series of fruit yield using the fruit yield records over 46 years (1976–2021) in Wakayama prefecture showed that fruit yield was affected by number of suitable pollination days, pre-blossom temperature, and sunshine duration before harvest. Moreover, the introduction of Western honey bees into orchards had considerable effects on fruit yield. These results indicate that pollinator activity (which is responsive to weather conditions) and pre-blossom temperature have a significant influence on fruit set rate and yield in Japanese apricot.