Low-altitude Regions Research Articles

Assessment of Inter-relationship between Anemia and COPD In Accordance with Altitude.

Anemia, a common blood disorder has been analysed for the risk for chronic obstructive pulmonary disease (COPD), a predominant respiratory condition. The COPD patients have been found to have anemia due to inflammation, accounting for about 7.5-33%. To predict the influence of anemia in the COPD occurrence as well as to depict the role of change in altitudes in the occurrence of anemic as well as COPD. A total of 17 hematological parameters has been analysed in the anemic and COPD patients along with the control samples of low and high altitude regions and the significance of the results has been calculated. The hematological parameter comparison between anemia and COPD samples of two different altitudes showed highly significant variations (p<0.001) as well as slighter significant variations (p<0.01, p<0.05 and p<0.1) in most of the parameters as well as the prevalence of anemic condition among the COPD patients was significant. The considered hematological parameters shown to have a considerable influence in the occurrence of anemia and COPD as well as in the occurrence of anemia in COPD patients along with the change in altitudes.

Constructing High-Resolution (10 km) Daily Diffuse Solar Radiation Dataset across China during 1982–2020 through Ensemble Model

Diffuse solar radiation is an essential component of surface solar radiation that contributes to carbon sequestration, photovoltaic power generation, and renewable energy production in terrestrial ecosystems. We constructed a 39-year (1982–2020) daily diffuse solar radiation dataset (CHSSDR), using ERA5 and MERRA_2 reanalysis data, with a spatial resolution of 10 km through a developed ensemble model (generalized additive models, GAM). The validation results, with ground-based measurements, showed that GAM had a high and stable performance with the correlation coefficient (R), root-mean-square error (RMSE), and mean absolute error (MAE) for the sample-based cross-validations of 0.88, 19.54 Wm−2, and 14.87 Wm−2, respectively. CHSSDR had the highest consistency with ground-based measurements among the four diffuse solar radiation products (CERES, ERA5, JiEA, and CHSSDR), with the least deviation (MAE = 15.06 Wm−2 and RMSE = 20.22 Wm−2) and highest R value (0.87). The diffuse solar radiation values in China range from 59.13 to 104.65 Wm−2, with a multi-year average value of 79.39 Wm−2 from 1982 to 2020. Generally, low latitude and low altitude regions have larger diffuse solar radiation than high latitude and high altitude regions, and eastern China has less diffuse solar radiation than western China. This dataset would be valuable for analyzing regional climate change, photovoltaic applications, and solar energy resources. The dataset is freely available from figshare.

Altitudinal variation in life-history features of a Qinghai-Tibetan Plateau lizard.

Environmental changes along an altitudinal gradient can facilitate the differentiation of life-history features in ectothermic species, but little attention has been devoted to the reciprocal influence of altitude and alpine slope directionality on life-history variation. According to life-history theory, increased environmental stress causes a change in reproductive allocation from number to quality of offspring, as well as a stronger trade-off between size and number of offspring. To clarify the influence of environmental pressures on the life-history features of the Qinghai toad-headed lizard Phrynocephalus vlangalii along an altitudinal cline, we surveyed late pregnant females from 3 populations of low (2,600 m), middle (3,400 m), and high (3,600 m) elevations in the Dangjin Mountain of Gansu, China from July to October 2019, and compared their inter-population differences in maternal body size, reproductive characteristics, offspring growth, and locomotor performance. Because of lower temperatures, higher humidity, and lower light intensity caused by slope aspect and altitude, the middle-altitude region experienced stronger environmental stress than the high- and low-altitude regions. Our results showed that females were larger at middle- and high-altitude sites and smaller at the low-altitude site, following Bergmann's rule. We also found that females from low-altitude population gave birth earlier than those from the middle and high altitudes. Our results showed a shift in the offspring size-number trade-off of P. vlangalii in response to colder and harsher environments, with lizards from the alpine steppe (i.e. the middle- and high-altitude habitats) producing fewer but larger offspring than those from the warm steppe (i.e. the low-altitude habitat). Low-altitude juveniles grew faster than high-altitude ones, but at the same rates as middle-altitude juveniles. This result demonstrates that the growth of P. vlangalii was associated with temperature and light intensity. Our findings contribute to enhancing our understanding of the altitudinal variation in life-history features of plateau ectotherms and their phenotypic plasticity or local adaptation.

Pulmonary Capacity, Blood Composition and Metabolism among Coal Mine Workers in High- and Low-Altitude Aboveground and Underground Workplaces.

(1) Background: While previous studies revealed how underground mining might adversely affect the cardiopulmonary functions of workers, this study further investigated the differences between under- and aboveground mining at both high and low altitudes, which has received little attention in the literature. (2) Methods: Seventy-one healthy male coal mine workers were recruited, who had worked at least 5 years at the mining sites located above the ground at high (>3900 m; n = 19) and low (<120 m; n = 16) altitudes as well as under the ground at high (n = 20) and low (n = 16) altitudes. Participants’ heart rates, pulmonary functions, total energy expenditure and metabolism were measured over a 5-consecutive-day session at health clinics. (3) Results: Combining the results for both above- and underground locations, workers at high-altitude mining sites had significantly higher peak heart rate (HR), minimum average HR and training impulse as well as energy expenditure due to all substances and due to fat than those at low-altitude sites. They also had significantly higher uric acid, total cholesterol, creatine kinase and N-osteocalcin in their blood samples than the workers at low-altitude mining sites. At underground worksites, the participants working at high-altitude had a significantly higher average respiratory rate than those at low-altitude regions. (4) Conclusion: In addition to underground mining, attention should be paid to high-altitude mining as working under a hypoxia condition at such altitude likely presents physiological challenges.

"Economics of Oyster Mushroom (Pleurotus spp) Production in Bhagalpur District of Bihar"

"The mass population of India was vegetarian and attracted to mushroom consumption because they have contained more nutrients like vitamins, minerals, fibers, and medicinal value. The mushroom species (oyster, button, milky and paddy straw) was identified for cultivation in upper and hilly regions of the Indian states suitable for white button mushrooms and plain areas of lower altitude regions in favor of oyster ‘Dhingri’ (Plutorus sages Kaju) mushroom. Moreover, growers have doesn’t fully organize form of mushroom per unit sale in Bhagalpur &amp; territories market of Bihar as well as other states of India. The strategic economic problem of the net sown area was limiting shrink factors day by day due to increase the infrastructure alternate option is open but human population is pressurized for fulfilling the demand become inevitable to best alternative option to supplementary mushroom growing opportunity. Mushroom production in locale area under Bhagalpur district of Bihar was purposively studies of the fourteen each block and village panchayat with the help of snowball referral to subsequent respondents collected 71 complete lists enumerated then obtained sample size (Taro Yamane) 60 oyster growers and cumulative cube root frequency distribution techniques were used. The major variable costs of oyster mushroom that spawn cost was higher expenses followed by the human labour, chopped dry straw, plant protection and polythene bags. The overall farms of fresh oyster mushroom production were accounted to be on an average 16.90 Kg (m2) per square meter, which were varied to be on an average 18.48 Kg (m2) per square meter higher for large farms followed by 16.99 Kg (m2) per square meter of medium farm and 15.16 Kg (m2) per square meter for the small farm. The overall farm benefit-cost ratio (BCR) was estimated to be on average 1.31 which varied to 1.40 higher for large farms followed by 1.31 for medium farms and 1.19 for small farms. Further, the cost of oyster mushroom production per unit was decreased when the increase in the size of farms and vice-versa."

Geostatistical surfaces of climatological normals of mean air temperature in Minas Gerais.

Air temperature, a vital component for the terrestrial environment sustainability, can be used as an indicator and an important factor used in short- and long-term meteorological modeling at different scales. Temperature must be monitored on spatial and temporal scale with high precision. Terrain elevation can be used as the main influence factor depending on the measurement scale. In small and medium scales, factors related to local relief were modeled with geostatistics including external variables in temperature modeling. We aimed to evaluate the use of universal kriging in the modeling of air temperature in order to create temperature surfaces at each km[Formula: see text] in Minas Gerais State, Brazil using altitude, longitude and latitude covariates. The organized mean air temperature data of climatological normals of the National Institute of Meteorology were submitted to summary statistics, statistical regression and geostatistical analysis. Monthly and annual normals of the mean air temperature compensated for the period 1981 to 2010 were modeled using temperature as dependent variable and altitude, longitude and latitude as co-variables. Multiple regression modeling performed on temperature using altitude, longitude and latitude covariates determined significant parameters for monthly and annual mean air temperature global prediction. Relief and coordinates were used as external drift on variography and universal kriging with block for local temperature interpolation and prediction in order to generate 1-km moderate resolution surfaces of monthly and annual mean air temperature. Universal kriging determined smoothing effect of standard deviation of geospatial variation with prediction errors varying between 0.6 and [Formula: see text]C. Higher prediction error values were observed between June and August. Mean air temperature local prediction presented greater errors mainly in the lower altitude regions and in the colder months. In both monthly and annual temperature predictions, universal kriging with external drift enabled to circumvent the problem of performing spatial prediction from sparse punctual attribute data, conferring a temperature downscaling effect in Minas Gerais.

The Diversity Distribution and Climatic Niche of Samara Species in China.

Studying the distribution of samara species is of ecological and economic significance. This information helps us with understanding species dispersal mechanisms, evaluating the risk of invasive species, and the management of ecological forests. However, limited research has explored, on a large scale, the geographic distribution of samara species and their influential abiotic factors. Here, we use the distribution data of 835 vascular samara species and growth form data to explore their geographic patterns in China and the environmental determinants. We divided China into 984 grid cells and examined the relationship between the proportion of samara species and climate variables using both ordinary and spatial linear regressions for each grid cell. Total samara species richness is higher in southern China in low altitude regions and the proportion of woody samara species is significantly higher than that of herbaceous samara species. The proportion of woody samara species is higher in the northeast regions where precipitation is sufficient, winters are dry and mild, and temperature seasonality and land surface relief degree values are high. Annual precipitation and temperature seasonality are the most important climatic drivers for the distribution of woody samara species. In contrast, herbaceous samara species prefer to distribute to the areas where climate is warm and dry but have higher temperature seasonality. Temperature related variables (mean annual temperature, mean diurnal range, and temperature seasonality) are the most important drivers for the distribution of herbaceous samara species. Samara species can better adapt to climatic regions with large temperature fluctuations and dry winters. The present distribution patterns of samara species are formed by the combined adaptation of fruit traits and growth form to climate. This work contributes to predictions of the global distribution of samara species under future climate change scenarios and conservation and management for the samara species.

Molecular investigation of Babesia caballi in horses from the state of Rio de Janeiro, Brazil: Epidemiological aspects associated with the infection.

The epidemiological aspects of Babesia caballi infection were evaluated in 516 horse samples from Rio de Janeiro, Brazil. The presence and infestation level of ticks on horses, breed conditions, and animal management were evaluated on each farm through an epidemiological questionnaire. The gene that codes for rhoptry-associated protein-1 (RAP-1) of B. caballi was amplified by nested PCR (nPCR). Among the horses sampled, 17.2% (n=89/516) presented B. caballi DNA. The characterized samples showed 99-100% similarity with other isolates of B. caballi based on the RAP-1 gene, available in GenBank. In the final logistic regression model, the variables associated with B. caballi infection in horses were as follows: age below two years (OR=3.33; IC=1.7-6.5), farms located in low altitudes (OR=3.52; IC=1.7-7.3) and Dermacentor nitens infestation (OR=1.91; IC=1.1-3.4). Furthermore, a high level of D. nitens infestation in horses was also a factor associated with positivity for B. caballi (OR=2.11; IC=1.25-3.54). In summary, young horses bred in low altitude regions characterized with high temperatures, and infested by D. nitens, mainly with a higher level of infestation, are more likely to be infected by B. caballi. This epidemiological study provides statical evidence that the D. nitens tick play a role as the biological vector of B. caballi in the studied region.

The siphonic energy transfer between hot solar wind and cold martian ionosphere through open magnetic flux rope

A mechanism for energy transfer from the solar wind to the Martian ionosphere through open magnetic flux rope is proposed based on the observations by Mars Atmosphere and Volatile EvolutioN (MAVEN). The satellite was located in the dayside magnetosheath at an altitude of about 700 km above the northern hemisphere. Collisions between the hot solar wind protons and the cold heavy ions/neutrals in the subsolar region can cool the protons and heat the heavy ions. As a result, the magnetosheath protons are siphoned into the ionosphere due to the thermal pressure gradient of protons and the heated heavy ions escape along the open magnetic field lines. Although direct collisions in the lower-altitude region were not detected, this physical process is demonstrated by MAVEN measurements of enhanced proton density, decreased proton temperature and oppositely directed motions of hot and cool protons within the flux rope, which are very different from the observational features of the flux transfer events near the Earth’s magnetopause. This mechanism could universally exist in many contexts where a collisionless plasma region is connected to a collisional plasma region. By reconstructing the magnetic geometry and the cross-section of the flux rope using the Grad-Shafranov technique, the ion loss rates are quantitatively estimated to be on the order of 1023 s−1, which is much higher than previously estimated.

Comparison of Fourteen Reference Evapotranspiration Models With Lysimeter Measurements at a Site in the Humid Alpine Meadow, Northeastern Qinghai-Tibetan Plateau.

Evapotranspiration is a key component in the terrestrial water cycle, and accurate evapotranspiration estimates are critical for water irrigation management. Although many applicable evapotranspiration models have been developed, they are largely focused on low-altitude regions, with less attention given to alpine ecosystems. In this study, we evaluated the performance of fourteen reference evapotranspiration (ET0) models by comparison with large weight lysimeter measurements. Specifically, we used the Bowen ratio energy balance method (BREB), three combination models, seven radiation-based models, and three temperature-based models based on data from June 2017 to December 2018 in a humid alpine meadow in the northeastern Qinghai–Tibetan Plateau. The daily actual evapotranspiration (ETa) data were obtained using large weighing lysimeters located in an alpine Kobresia meadow. We found that the performance of the fourteen ET0 models, ranked on the basis of their root mean square error (RMSE), decreased in the following order: BREB > Priestley-Taylor (PT) > DeBruin-Keijman (DK) > 1963 Penman > FAO-24 Penman > FAO-56 Penman–Monteith > IRMAK1 > Makkink (1957) > Makkink (1967) > Makkink > IRMAK2 > Hargreaves (HAR) > Hargreaves1 (HAR1) > Hargreaves2 (HAR2). For the combination models, the FAO-24 Penman model yielded the highest correlation (0.77), followed by 1963 Penman (0.75) and FAO-56 PM (0.76). For radiation-based models, PT and DK obtained the highest correlation (0.80), followed by Makkink (1967) (0.69), Makkink (1957) (0.69), IRMAK1 (0.66), and IRMAK2 (0.62). For temperature-based models, the HAR model yielded the highest correlation (0.62), HAR1, and HAR2 obtained the same correlation (0.59). Overall, the BREB performed best, with RMSEs of 0.98, followed by combination models (ranging from 1.19 to 1.27 mm day−1 and averaging 1.22 mm day−1), radiation-based models (ranging from 1.02 to 1.42 mm day−1 and averaging 1.27 mm day−1), and temperature-based models (ranging from 1.47 to 1.48 mm day−1 and averaging 1.47 mm day−1). Furthermore, all models tended to underestimate the measured ETa during periods of high evaporative demand (i.e., growing season) and overestimated measured ETa during low evaporative demand (i.e., nongrowing season). Our results provide new insights into the accurate assessment of evapotranspiration in humid alpine meadows in the northeastern Qinghai–Tibetan Plateau.

High altitude Relieves transmission risks of COVID-19 through meteorological and environmental factors: Evidence from China

Existing studies reported higher altitudes reduce the COVID-19 infection rate in the United States, Colombia, and Peru. However, the underlying reasons for this phenomenon remain unclear. In this study, regression analysis and mediating effect model were used in a combination to explore the altitudes relation with the pattern of transmission under their correlation factors. The preliminary linear regression analysis indicated a negative correlation between altitudes and COVID-19 infection in China. In contrast to environmental factors from low-altitude regions (<1500 m), high-altitude regions (>1500 m) exhibited lower PM2.5, average temperature (AT), and mobility, accompanied by high SO2 and absolute humidity (AH). Non-linear regression analysis further revealed that COVID-19 confirmed cases had a positive correlation with mobility, AH, and AT, whereas negatively correlated with SO2, CO, and DTR. Subsequent mediating effect model with altitude-correlated factors, such as mobility, AT, AH, DTR and SO2, suffice to discriminate the COVID-19 infection rate between low- and high-altitude regions. The mentioned evidence advance our understanding of the altitude-mediated COVID-19 transmission mechanism.

The relationship between rising temperatures and malaria incidence in Hainan, China, from 1984 to 2010: a longitudinal cohort study

The influence of rising global temperatures on malaria dynamics and distribution remains controversial, especially in central highland regions. We aimed to address this subject by studying the spatiotemporal heterogeneity of malaria and the effect of climate change on malaria transmission over 27 years in Hainan, an island province in China. For this longitudinal cohort study, we used a decades-long dataset of malaria incidence reports from Hainan, China, to investigate the pattern of malaria transmission in Hainan relative to temperature and the incidence at increasing altitudes. Climatic data were obtained from the local meteorological stations in Hainan during 1984-2010 and the WorldClim dataset. A temperature-dependent R0 model and negative binomial generalised linear model were used to decipher the relationship between climate factors and malaria incidence in the tropical region. Over the past few decades, the annual peak incidence has appeared earlier in the central highland regions but later in low-altitude regions in Hainan, China. Results from the temperature-dependent model showed that these long-term changes of incidence peak timing are linked to rising temperatures (of about 1·5°C). Further, a 1°C increase corresponds to a change in cases of malaria from -5·6% (95% CI -4·5 to -6·6) to -9·2% (95% CI -7·6 to -10·9) from the northern plain regions to the central highland regions during the rainy season. In the dry season, the change in cases would be 4·6% (95% CI 3·7 to 5·5) to 11·9% (95% CI 9·8 to 14·2) from low-altitude areas to high-altitude areas. Our study empirically supports the idea that increasing temperatures can generate opposing effects on malaria dynamics for lowland and highland regions. This should be further investigated and incorporated into future modelling, disease burden calculations, and malaria control, with attention for central highland regions under climate change. Scientific and Technological Innovation 2030: Major Project of New Generation Artificial Intelligence, National Natural Science Foundation of China, Beijing Natural Science Foundation, National Key Research and Development Program of China, Young Elite Scientist Sponsorship Program by CAST, Research on Key Technologies of Plague Prevention and Control in Inner Mongolia Autonomous Region, and Beijing Advanced Innovation Program for Land Surface Science.

Differential Expression of Metabolism-Related Genes in Plateau Pika (Ochotona curzoniae) at Different Altitudes on the Qinghai-Tibet Plateau.

According to life history theory, animals living in extreme environments have evolved specific behavioral and physiological strategies for survival. However, the genetic mechanisms underpinning these strategies are unclear. As the highest geographical unit on Earth, the Qinghai–Tibet Plateau is characterized by an extreme environment and climate. During long-term evolutionary processes, animals that inhabit the plateau have evolved specialized morphological and physiological traits. The plateau pika (Ochotona curzoniae), one of the native small mammals that evolved on the Qinghai–Tibet Plateau, has adapted well to this cold and hypoxic environment. To explore the genetic mechanisms underlying the physiological adaptations of plateau pika to extremely cold ambient temperatures, we measured the differences in resting metabolic rate (RMR) and metabolism-related gene expression in individuals inhabiting three distinct altitudes (i.e., 3,321, 3,663, and 4,194 m). Results showed that the body mass and RMR of plateau pika at high- and medium-altitudes were significantly higher than those at the low-altitude. The expression levels of peroxisome proliferator-activated receptor α (pparα), peroxisome proliferator-activated receptor-γ coactivator-1α (pgc-1α), and the PR domain-containing 16 (PRDM16) in white (WAT) and brown (BAT) adipose tissues of plateau pika from high- and medium-altitudes were significantly higher than in pika from the low-altitude region. The enhanced expression levels of pgc-1α and pparα genes in the WAT of pika at high-altitude showed that WAT underwent “browning” and increased thermogenic properties. An increase in the expression of uncoupling protein 1 (UCP1) in the BAT of pika at high altitude indicated that BAT increased their thermogenic properties. The gene expression levels of pparα and pgc-1α in skeletal muscles were significantly higher in high-altitude pika. Simultaneously, the expression of the sarcolipin (SLN) gene in skeletal muscles significantly increased in high-altitude pika. Our results suggest that plateau pika adapted to an extremely cold environment via browning WAT, thereby activating BAT and enhancing SLN expression to increase non-shivering thermogenesis. This study demonstrates that plateau pika can increase thermogenic gene expression and energy metabolism to adapt to the extreme environments on the plateau.

Patterns in pottery use reveal different adaptive strategies between lower and higher altitude regions on the Tibetan Plateau: Chemical evidence from pottery residues

It has long been recognised that the frigid and hypoxic environment on the high-altitude Tibetan Plateau influences the choices of cooking methods and food compositions. Although commonly used for cooking in the plain areas during the Neolithic Age, the functions of pottery in the high-altitude regions have rarely been examined from archaeological studies. In the present study, lipid residues of pottery fragments from Klu lding (ca. 2900 m a.s.l.) and Khog Gzung (ca. 3900 m a.s.l.) were analysed to present the insight of pottery use and subsistence strategies at different elevations around 3600-3000 BP in the southern Tibetan Plateau. The lipid molecular and isotopic data indicate that vessels were mainly used, though less intensively compared with the plain areas, for the processing of animal fats. At Klu lding, pig adipose fats contribute large proportions of the lipid residues, and leafy plants were used as regular complements to the diets. At Khog Gzung, the broad range of carbon isotopic values points to the wide vertical migrations of the ruminants, implying the hunting of wild ungulates or seasonal transhumance. The first lipid residue analysis performed on high-altitude pottery offers supplementary information about human subsistence strategies for altitudinal adaptations. In the low-altitude regions, the use of local food resources including leafy plants and porcine fats was consistent with the more sedentary lifestyle, providing complements to the early agricultural system. In the high-altitude regions, higher mobility was associated with long-distance hunting or early pastoralism.

Ground validation and error decomposition for six state-of-the-art satellite precipitation products over mainland China

Evaluating the quality of satellite precipitation products (SPPs) is crucially important for SPPs' applications and improvements. This study aims to comprehensively evaluate the accuracy of six widely used SPPs (GSMaP, IMERG, TMPA, CMORPH, PERSIANN, and CHIRPS) from 2000 to 2017 over mainland China using 2372 rain gauges. The performance of SPPs at different spatio-temporal scales and altitudes are explored. The probability density function (PDF) at different precipitation intensities is also considered. In addition, special attention has been paid to analyze the error components of SPPs from different sources. Results demonstrate that: (1) GSMaP outperforms other SPPs with good statistical metrics, followed by IMERG. PERSIANN and CHIRPS have more space for improvement. All SPPs perform well in summer while worse in winter. Meanwhile, the accuracy of all SPPs varies region by region, which is better in southeast coastal basins than in northwest inland basins. (2) The overall performance in low-altitude regions is superior to high-altitude regions. The KGE (or RMSE) shows a significant negative (or positive) correlation with altitude, whereas POD, FAR, and CSI exhibit a slight dependence on altitude. (3) TMPA can well reproduce the PDF of different precipitation intensities. All SPPs' PDF is more consistent with gauges for moderate (5–10 mm/d) and heavy precipitation (10–50 mm/d), while deviates from gauges for tiny/light (0.1–5 mm/d) and violate precipitation (>50 mm/d). (4) The error components of each SPP could be larger than total errors, and the false bias is the major error source. GSMaP achieves a better performance with low hit and missed bias, whereas CHIRPS behaves poorly with large hit, missed and false bias. On the whole, the study demonstrates the error characteristics and accuracy performance of six mainstream SPPs over mainland China, which is expected to provide valuable information for hydrometeorology applications.

Diversity and Phosphate Solubilization Efficiency of Phosphate Solubilizing Bacteria Isolated from Semi-Arid Agroecosystems of Eastern Kenya.

Phosphorus (P) is a major nutrient required for plant growth but it forms complexes with other elements in soil upon application. A cost-effective way of availing P to plants is by use of Phosphate Solubilizing Bacteria (PSB). There is a wide range of PSB suited for diverse agro-ecologies. A large part of Eastern Kenya especially the lower altitude regions are semi-arid with nutrient depleted soils and predominated by low-income smallholders farmers who do not afford costly inorganic fertilizers. To alleviate poor soil nutrition in this agroecosystem, we sought to study the diversity of phosphate solubilizing bacteria and their phosphate solubilization efficiency. The bacteria were selectively isolated in Pikovskaya’s agar media. Bacterial colonies were enumerated as Colony Forming Units and morphological characterization determined by analyzing morphological characteristics. Genetic characterization was determined based on sequencing of 16S rRNA. A total of 71 PSB were isolated and they were placed into 23 morphological groups. Correlation analysis showed a negative correlation between phosphate solubilizing bacteria and the levels of phosphorus, iron, calcium, magnesium and soil pH. Analysis of 16S rRNA sequences revealed that the genetic sequences of the isolates matched the strains from the genera Burkholderia, Pseudomonas, Bacillus, Enterobacter, Pantoea, Paraburkholderia, Cronobacter, Ralstonia, Curtobacterium, and Massilia deposited in NCBI Database. Analysis of Molecular Variance showed that variation within populations was higher than that of among populations. Phosphate solubilization index values ranged between 1.143 and 5.883. Findings on biodiversity of phosphate solubilizing bacteria led to identification of 10 candidate isolates for plant growth improvement and subsequently, bio-fertilizer development.

土地利用转变与海拔高度协同作用黄土高原植被固碳变化特征

PDF HTML阅读 XML下载 导出引用 引用提醒 土地利用转变与海拔高度协同作用黄土高原植被固碳变化特征 DOI: 10.5846/stxb202106211643 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 陕西省自然科学基础研究计划项目（2017JZ008） Vegetation carbon sequestration in the Loess Plateau under the synergistic effects of land cover change and elevations 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:全球固碳释碳问题一直是近年来关乎民生的热点话题，区域碳源/碳汇对生态环境的重要性不言而喻。基于CASA模型估算黄土高原1990-2015年植被净初级生产力的年际变化，并分析土地利用变化、海拔高度及两者协同作用对其综合影响，结果表明：（1）黄土高原1990-2015年植被NPP与植被固碳总体呈增加趋势，年均NPP增速2.74 gC m-2 a-1，年均固碳增速1.13 TgC/a，研究区林地年均NPP （619.5 gC m-2 a-1）远超其他用地类型，固碳效果理想；（2）黄土高原年均NPP随高程的增加先降低后升高，年总NPP和固碳量随高程增加变化趋势相反；（3）研究区土地利用转变类型中退耕还林的植被固碳效果最好；而林地变为耕地或草地均不能达到固碳目的，此外，更推荐在研究区海拔低于1500 m变草为耕，海拔高于1500 m退耕还草，海拔高于3000 m变耕、草为林。以期为区域尺度的生态环境建设提供一定的参考和科学依据。 Abstract:Global carbon sequestration and release has been a hotspot issue concerning people's livelihood in recent years. The importance of regional carbon sequestration and release to the ecological environment was self-evident. It is of great theoretical and practical significance to use remote sensing data and appropriate estimation model to quantitatively estimate NPP (Net Primary Productivity) and analyze spatio-temporal pattern of vegetation carbon sequestration and carbon release in the Loess Plateau. Based on the CASA (Carnegie Ames Stanford Approach) model, this paper estimated the annual change of the NPP on the loess plateau from 1990 to 2015, and analyzed the comprehensive effects in the process of Land Use/Land Cover Change (LUCC), elevations and their synergistic effects. It found that:(1) vegetation NPP and carbon sequestration showed an increasing trend in the Loess Plateau from 1990 to 2015. The annual average growth rate of NPP was 2.74 gC m-2 a-1 and the annual average growth rate of carbon sequestration was 1.13 TgC/a. The average annual NPP (619.5 gC m-2 a-1) of forest land in the study area was much higher than that of other land types, which was an ideal means of carbon sequestration. (2) The annual mean NPP of the Loess Plateau increased year by year, but the annual mean annual NPP decreased first and then increased with the increase of elevation, while the annual total NPP and carbon sequestration showed opposite trends with the increase of elevation. (3) In the study area, conversion of cropland to forest contributed the most to vegetation carbon sequestration among all land use changes types, meanwhile, the conversion of forest into cropland or grassland could not achieve carbon sequestration. In addition, it is recommended to convert grassland to cropland when the elevation is lower than 1500 m, return cropland to grassland when the elevation is higher than 1500 m, and convert cropland and grassland to forest when the elevation is higher than 3000 m in the study area. The study focuses on the effect of carbon sequestration under the synergistic effect of land use change and elevations. It is concluded that the development and utilization of land in the study area leads to the increase of carbon sequestration, while the ecological return of land leads to the increase of carbon sequestration; Moreover, it is more suitable to convert cropland to forest at low and high altitude regions than at middle altitude in the study area, in order to provide reference and guidance for the ecological environment in the regional scale. 参考文献 相似文献 引证文献

Functional Traits and Ecological Strategies of Bryophytes in Response to Environmental Gradients of the Western Ghats of Sahyadri Mountain Range, Maharashtra (India)

The Western Ghats, recognized as a global biodiversity hotspot, houses a diverse array of flora and fauna, including bryophytes. These non-vascular plants play critical roles in ecosystem functioning, but their functional traits and ecological strategies in response to environmental gradients remain poorly understood in this region. This study aims to investigate the functional traits and ecological adaptations of bryophytes along temperature, humidity, and altitude gradients in the Sahyadri Mountain Range of Maharashtra, Western Ghats, India.In this research, field surveys are conducted across distinct forest types to sample bryophyte communities. Specific leaf area, shoot density, growth forms, and reproductive strategies ire quantified as key functional traits. Relationships between functional traits and environmental gradients ire analysed using regression models and multivariate techniques. Additionally, dominant ecological strategies among bryophytes ire identified based on trait composition.Our findings reveal a rich diversity of bryophytes in the Western Ghats, with 120 species identified across the sampled sites. Species composition varied significantly along the environmental gradients, with higher species richness observed in areas with higher humidity and lair altitude. Specific leaf area exhibited a negative correlation with temperature, indicating water conservation strategies in response to warmer conditions. Shoot density sloid positive associations with humidity, suggesting competitive adaptations under higher moisture availability.Furthermore, bryophytes in higher altitudes and cooler climates exhibited distinct growth forms, such as cushions and mats, likely to withstand harsh environmental conditions. Ecological strategies predominantly varied among forest types, with stress-tolerant strategies prevailing in the drier, low-altitude regions, and competitive strategies dominant in the cooler, high-altitude regions.These findings shed light on the adaptive capabilities of bryophytes in the Western Ghats and their ecological responses to changing environments. Understanding bryophyte functional traits and ecological strategies is vital for assessing their roles in ecosystem resilience and functioning. The insights from this study hold implications for biodiversity conservation, ecosystem management, and climate change assessments in the Western Ghats and other mountainous regions worldwide

Altitudinal Gradient Characteristics of Spatial and Temporal Variations of Snowpack in the Changbai Mountain and Their Response to Climate Change

The variations in the snowpack in water towers of the world due to climate change have threatened the amount and timing of freshwater supplied downstream. However, it remains to be further investigated whether snowpack variation in water towers exhibits elevational heterogeneity at different altitude gradients and which climatic factors mainly influence these differences. Therefore, Changbai Mountain, a high-latitude water tower, was selected to analyze the changes in the snowpack by the methods of modified Mann–Kendall based on the daily meteorological data from the China Meteorological Data Service Centre. Meanwhile, the responses of snowpack change to climatic factors over recent decades were assessed and generalized using additive models. The results showed that the snow depth was greater in the higher altitude areas than in the lower elevation areas at different times. Areas with a snow depth of over 70 mm increased significantly in the 2010s. Increasing trends were shown at different altitudes from December to March of the next year during 1960~2018. However, a significant decreasing trend was shown in April, except for altitudes of 600–2378 m. The snow cover time at different altitudes showed a trend of first increasing and then decreasing during 1960~2018. The date of maximum snow depth appears to be more lagged as the altitude increases. In addition, the spring snowpack melted significantly faster in the 2010s than that in the 1960s. The snowpack variation in low-altitude regions is mainly influenced by ET and relative humidity. However, the mean temperature gradually became an important factor, affecting the snow depth variation with the increase in altitude. Therefore, the results of this study will be beneficial to the ecological protection and sustainable development of water towers.

Alteration of Behavioral Inhibitory Control in High-Altitude Immigrants.

Behavioral inhibitory control (BIC) acts as a key cognitive ability, which is essential for humans to withhold inappropriate behaviors. Meanwhile, many studies reported that long-term exposure to high altitude (HA) may affect cognitive ability. However, it is not clear whether long-term exposure to HAs may affect the BIC of an individual. To clarify the role of altitude in the behavioral control of adults and the underlying neural mechanism, we explored the BIC neural activity profiles of healthy immigrants from low-altitude (LA) regions to HA regions. Combining a two-choice oddball paradigm and electrophysiological techniques, this study monitored the N2 and P3 event-related components and neural oscillations across LA and HA groups. Results showed longer reaction times (RTs) for the HA group than the LA group. Relative to the LA group, lower N2 and P3 amplitudes were observed for the HA group. Significant positive correlations were also found between P3 amplitude and theta/delta band power across both groups. Importantly, lower theta/delta band powers were only observed for the HA group under the deviant condition. Collectively, these findings suggest that long-term exposure to HAs may attenuate BIC during the response inhibition stage and provide valuable insights into the neurocognitive implications of environmental altitude on BIC.