Elevation Range Research Articles

Cuticular Hydrocarbon Profiles of Himalayan Bumble Bees (Hymenoptera: Bombus Latreille) are Species-Specific and Show Elevational Variation.

Bumble bees are important pollinators in natural environments and agricultural farmlands, and they are in particular adapted to harsh environments like high mountain habitats. In these environments, animals are exposed to low temperature and face the risk of desiccation. The Eastern Himalayas are one of the recognized biodiversity hotspots worldwide. The area covers subtropical rainforest with warm temperature and high precipitation as well as high mountain ranges with peaks reaching up to 7,000m, shaping a diverse floral and faunal community at the different elevational zones. To identify possible adaptation strategies, we investigated the cuticular hydrocarbon profiles of four bumble bee species occurring at different elevational ranges in Arunachal Pradesh, the northeastern most state in India. At 17 locations along an elevational gradient, we collected workers of two species from lower elevations (B. albopleuralis and B. breviceps; ~ 100m - 3,000m asl) and two species from higher elevations (B. prshewalskyi and B. mirus; ~ 2,800m - 4,500m asl). The CHC profiles of all four species showed a significant degree of variation in the composition of hydrocarbons, indicating species specificity. We also found clear correlation with elevation. The weighted mean chain length of the hydrocarbons significantly differed between the low and high elevation species, and the proportion of saturated hydrocarbons in CHC profiles significantly increased with the elevational range of the bumble bee species. Our results indicate that bumble bees living at high elevations reduce the risk of water loss by adapting their CHC composition on their cuticle, a phenomenon that has also been found in other insects like ants and fruit flies.

A neoclassical validation of balanced and unbalanced rotations on EAST H-mode discharges

Predicting residual stress (RS) contribution to intrinsic rotation is one of the major challenges in the study of momentum transport in tokamaks. One efficient experimental means of quantifying RS torque magnitude is to generate radially-flat and near-zero rotation profiles, termed ‘balanced rotations’ in this work, using counter-Ip Neutral Beam Injections (NBIs) to effectively cancel the torques from co-Ip NBIs. One remaining question, however, is on whether or not the attained velocity profile is well zeroed and flat enough so that the predicted RS torques based on perfect balance assumption can be used for further studies such as fitting of diffusive and convective coefficients to match with experiments. This article presents a neoclassical means of validating the attained balanced and unbalanced rotations at EAST to consequently validate the predicted RS torque profiles, using TRANSP/NUBEAM and a recently-developed neoclassical rotation/transport code TransROTA (Bae et al 2024 Comput. Phys. Commun. 296 108992). Both balanced and unbalanced EAST H-mode discharges are analyzed to find that the suggested neoclassical validation methodology successfully validates attained balanced rotations. It also finds that neoclassical gyroviscous (NGV) torque serves as the balance-breaking mechanism for axisymmetric plasmas and the balance-breakings start from the core and propagate towards the edge. This work also suggests the possibility of using the neoclassical methodology to find locally-balanced rotations at an elevated velocity range near ∼20 km s−1, which implies possible scaling of RS torques up to a certain elevated velocity range.

Responses of insectivorous bats to climate change in Nepal

AbstractThe order Chiroptera includes 55 species in Nepal, which have been recorded within a wide range of elevation between 64 and 4154 m above sea level. Assessing the potential distribution ranges in present climatic scenarios and forecasting changes in distribution ranges in future climate have been adopted to predict likely adverse impacts on biodiversity and natural ecosystems. However, very few studies have assessed the impact of climate change on bats globally and locally. We assessed the current potential distribution ranges of six representative species of bats occurring in Nepal using species distribution models (SDMs) and predicted their responses in future climatic scenarios. The occurrences of the representative species of bats were projected with six to eight environmental variables under the different climatic scenarios; present, and socioeconomic pathways 4.5 and 8.5 for the years of 2050 and 2070 deploying maximum entropy modeling. We used Arc GIS 10.7.1 to calculate the distribution range, area, and elevation for the bat species. Among 18 uncorrelated bioclimatic variables eight variables significantly contributed to the SDMs. Among the six species, two showed a wider range of current distribution. Under the future climatic scenarios, distribution ranges and latitudinal and elevation shifting were found to be species specific. Future distribution ranges for two species are predicted to be constricted, but no significant changes are predicted for the others. Major parts of the current and future distribution ranges of the bat species lie outside the current protected areas of the country. Landscape level and species‐specific conservation policies are necessary for bat conservation, and future surveys of bats should be targeted in western Nepal.

Interspecific competition impacts the occupancy and range limits of two ptarmigan species along the elevation gradient in Norway

Many mountain species are expected to respond to climate change through upslope shifts of their range limits, but competition may restrict or alter this response. Under traditional range‐limit theory, it is expected that lower‐elevation species are better competitors than closely related higher‐elevation species. However, recent work finds that this prediction is often unmet. We investigated evidence for the impact of competition during breeding season on the elevational range limits of a pair of closely related bird species, willow ptarmigan Lagopus lagopus and rock ptarmigan L. muta, in mainland Norway. The species share overlapping ranges that loosely divide slightly upslope from the treeline ecotone, with willow ptarmigan generally occupying lower sites and rock ptarmigan occupying higher sites. We used multi‐species occupancy models to test four competing hypotheses for how competition may affect the range limit between willow ptarmigan and rock ptarmigan: 1) asymmetric competition that restricts the lower range limit of rock ptarmigan; 2) asymmetric competition that restricts the upper range limit of willow ptarmigan; 3) condition‐specific competition that restricts both species' range limits; and 4) range limits unaffected by competition. We found evidence for a negative pairwise interaction between the two species. Changes in interaction strength along the elevation gradient suggested evidence for condition‐specific competition. However, a strong positive correlation between rock ptarmigan and higher‐elevation habitat resulted in a highly asymmetric outcome, where the upper range limit of willow ptarmigan was restricted but rock ptarmigan occupancy was fairly independent of willow ptarmigan. This outcome is opposite to the prediction of traditional range‐limit theory and may suggest a greater climate threat to willow ptarmigan than has been previously projected. Thus, our results demonstrate the importance of considering biotic interactions at both the higher and lower ends of species' range limits along elevation gradients.

Improved trade-off model of land use functions: Differentiated objective setting by territory spatial planning

Land use functions (LUFs) refer to the capacity of a land use system to supply human welfare; understanding the trade-offs among multiple LUFs to transform land systems for people and nature is pivotal. The traditional way to assess the degree of trade-off between functions based on the level of multiple functions ignores the differences in natural and social conditions for developing ecological, productive, and livelihood functions of land in different regions. That method makes it difficult to achieve effective land use optimization strategies. In this study, an improved framework for identified trade-offs of production-living-ecological function indicator was developed. Based on the national territory spatial planning, we constructed land use multifunctionality trade-offs degree (LUMTD) and analysed the relationship between the indicators. A generalized additive model was also used to explore the natural and human impacts on land use multifunctionality trade-offs. Land use conflicts were found to be more intense in high altitudes and in transition zones between high altitudes. The LUMTD in the plains dominated by classes I and II accounted for 50 % of the total; it was dominated by classes IV and V in the plateau and its transition areas and accounted for more than 50 % of the total. Our results suggest that the influence of natural and socioeconomic factors on LUMTD had a clear threshold, with the threshold effect of altitude on LUMTD beginning to occur within the 1,000 ∼ 2,000 m elevation range, of temperature at 10 °C, and of built-up land density at 1,200. An efficient differentiation strategy for avoiding land use conflict might be collaborative land management actions that focus on the coordinated development of land production, ecological, and living functions.

Kickstand Technique for Treatment of Valgus-Impacted Proximal Humerus Fractures

Purpose: Describe a new technique using a minimally invasive surgical intervention for the treatment of valgus-impacted proximal humerus fractures. The Kickstand technique is a novel approach that offers reliable fixation and union without the need for additional hardware. Materials and Methods: A retrospective case series of 3 patients with valgus-impacted proximal humerus fractures was treated with this Kickstand technique using an intramedullary fibular allograft. Postoperative x-rays and outcomes are presented. Results: The Kickstand technique was used to address valgus-impacted fractures in 3 patients. Postoperative range of motion and shoulder outcome scores were reported at 2 years for patients A and B, and at 1 year for patient C (Active range of motion external rotation: 28 degrees; Active range of motion elevation: 140 degrees; Simple Shoulder Test-12: 11; American Shoulder and Elbow Standardized Shoulder Assessment: 78). Postoperative Grashey and lateral x-rays for each patient show union of the valgus-impacted humerus. Conclusions: The Kickstand technique using intramedullary fibular allograft is an alternative fixation technique for displaced valgus proximal humerus fracture. It has the advantage of avoiding additional metallic hardware and allowing early motion but requires the use of intramedullary fibular allograft which can interfere with future use of stemmed humeral prosthesis.

Assessing the influence of elevation on satellite derived normalized difference vegetation index and land surface temperature in Rajasthan

Land surface temperature (LST) and its interaction with normalized difference vegetation index (NDVI) is crucial for better understanding of environmental changes in current scenario. However, very few or scanty research on the interrelationship between LST, NDVI and topographic elements has been done in India. Therefore, the purpose of conducting this study was to examine, how LST and NDVI change as a function of elevation in Rajasthan. In present study, MODIS derived NDVI and LST and digital elevation model (DEM) from shuttle radar topography mission (SRTM) have been used. Results revealed that the LST and NDVI both were significantly influenced by elevation. Elevation, NDVI and LST varied from -6 to 1698 m, -0.09 to 0.65 and 24 to 45°C throughout the study region. In contrast to LST, which has a decreasing gradient from western to eastern portions, the spatial variability of NDVI has decreasing gradients from southern and eastern to western regions. The highest mean LST value (39.76 ± 0.2.9 0C) was obtained at an elevation range of -6 to 168 m, whereas NDVI value (0.38 ± 0.06) at elevation ranges of 589 – 1698 m. The analysis of the correlations between LST, NDVI and elevation indicated that the elevation has strong positive correlation with NDVI (r2 = 0.26) and negative correlation with LST (r2 = 0.28). Findings from this kind of research can be utilized as a platform for environmental and land use planning for sustainable ecosystem management.

Patterns in the genetic structure of 49 lowland rain forest tree species co‐distributed on opposite sides of the northern Andes

AbstractThe Andes are a major dispersal barrier for lowland rain forest plants and animals, yet hundreds of lowland tree species are distributed on both sides of the northern Andes, raising questions about how the Andes influenced their biogeographic histories and population genetic structure. To explore these questions, we generated standardized datasets of thousands of SNPs from paired populations of 49 tree species co‐distributed in rain forest tree communities located in Panama and Amazonian Ecuador and calculated genetic diversity (π) and absolute genetic divergence (dXY) within and between populations, respectively. We predicted (1) higher genetic diversity in the ancestral source region (east or west of the Andes) for each taxon and (2) correlation of genetic statistics with species attributes, including elevational range and life‐history strategy. We found that genetic diversity was higher in putative ancestral source regions, possibly reflecting founder events during colonization. We found little support for a relationship between genetic divergence and species attributes except that species with higher elevational range limits exhibited higher dXY, implying older divergence times. One possible explanation for this pattern is that dispersal through mountain passes declined in importance relative to dispersal via alternative lowland routes as the Andes experienced uplift. We found no difference in mean genetic diversity between populations in Central America and the Amazon. Overall, our results suggest that dispersal across the Andes has left enduring signatures in the genetic structure of widespread rain forest trees. We outline additional hypotheses to be tested with species‐specific case studies.

Development genetic and stability classification of seasonal glacial lakes in a tectonically active area—A case study in Niangmuco, east margin of the Eastern Himalayan Syntaxis

The Niangmuco region on the east margin of the Eastern Himalayan Syntaxis features a large number of glacial lakes. The development process and stability classification of glacial lakes is of great significance to the study of seasonal glaciers in the eastern Himalayan margin, with implications for economic development and disaster prevention. Based on Landsat remote sensing image data from 2000 to 2021, this study analyzed the development and change characteristics of glacial lakes in the Niangmuco region during the past 21 years, and classified the stability of lakes with areas >0.02 km2 using the fuzzy consistent matrix method. In this area, 126 glacial lakes were identified within an elevation range of 3044–4156 m with a total area of 10.94 km2. These lakes primarily included glacial erosion lakes, valley lakes, tectonic lakes, and landslide dam lakes. Specifically, glacial erosion lakes accounted for 88.9% of the total number of lakes and 60.3% of the total lake area, followed by valley lakes with 6.3% and 23.7%, respectively. From 2000 to 2010, the total area of glacial lakes decreased from 10.53 km2 to 10.09 km2, which may be attributable to climate fluctuations. Subsequently, the area of lakes increased significantly to 10.94 km2 in 2021, an increase of 0.41 km2. Compared with 2000, among the lakes with a growth rate of 0.019 km2/a in 21 years, glacial erosion lakes exhibited the largest change. Among the classified glacial lakes in the study area, 95.7% were stable and relatively stable, mostly comprising glacial erosion lakes at high altitudes between 3468 and 4156 m. Only 4 unstable and extremely unstable glacial lakes were identified, and they were located near a fault zone. The findings show that the development and the change of glacial lakes in the area are primarily controlled by temperature and precipitation, and the topography and fault activity have important influences on the stability of glacial lakes.

Analgesic effect and safety of a half-dose transdermal buprenorphine patch after arthroscopic rotator cuff repair

ObjectiveTo retrospectively explore the effect of a half-dose buprenorphine transdermal patch for analgesia after arthroscopic rotator cuff repair (ARCR). MethodsThis analysis was performed with clinical data from patients who received unilateral ARCR in our hospital between October 2017 and December 2020. The patients were divided into three groups (30 cases each). In group A (control group), 100 mg flurbiprofen axetil (FA) was administered twice a day for 5 days after surgery. In group B (experimental group), 100 mg FA was administered twice a day for 5 days and half (2.5 mg) of a buprenorphine transdermal patch was applied after surgery; an additional half (2.5 mg) patch was applied 3 days later. In group C (condition control group), 100 mg FA was administered twice a day for 5 days and a 5-mg patch was applied directly after surgery. The visual analog scale (VAS) was administered repeatedly 1 day before surgery and 1, 2, 3, 5, and 14 days after surgery in each group. The simple shoulder test (SST) score, range of shoulder forward elevation (FE), and external rotation (ER) were recorded preoperatively and 12 weeks postoperatively. ResultsVAS scores on postoperative days 3 and 5 were significantly lower in groups B and C than in group A (p < 0.05). The VAS score on postoperative day 14 was significantly lower in group C than in group A (p < 0.05). The difference in VAS score between groups B and C was not significant (p > 0.05). All patients had significantly improved VAS scores, SST scores, FE, and ER at 12 weeks postoperatively. ConclusionThe half-dose buprenorphine transdermal patch had a good analgesic effect with minimal side effects after ARCR and did not delay the recovery of shoulder joint function.

Using photographs and deep neural networks to understand flowering phenology and diversity in mountain meadows

AbstractMountain meadows are an essential part of the alpine–subalpine ecosystem; they provide ecosystem services like pollination and are home to diverse plant communities. Changes in climate affect meadow ecology on multiple levels, for example, by altering growing season dynamics. Tracking the effects of climate change on meadow diversity through the impacts on individual species and overall growing season dynamics is critical to conservation efforts. Here, we explore how to combine crowd‐sourced camera images with machine learning to quantify flowering species richness across a range of elevations in alpine meadows located in Mt. Rainier National Park, Washington, USA. We employed three machine‐learning techniques (Mask R‐CNN, RetinaNet and YOLOv5) to detect wildflower species in images taken during two flowering seasons. We demonstrate that deep learning techniques can detect multiple species, providing information on flowering richness in photographed meadows. The results indicate higher richness just above the tree line for most of the species, which is comparable with patterns found using field studies. We found that the two‐stage detector Mask R‐CNN was more accurate than single‐stage detectors like RetinaNet and YOLO, with the Mask R‐CNN network performing best overall with mean average precision (mAP) of 0.67 followed by RetinaNet (0.5) and YOLO (0.4). We found that across the methods using anchor box variations in multiples of 16 led to enhanced accuracy. We also show that detection is possible even when pictures are interspersed with complex backgrounds and are not in focus. We found differential detection rates depending on species abundance, with additional challenges related to similarity in flower characteristics, labeling errors and occlusion issues. Despite these potential biases and limitations in capturing flowering abundance and location‐specific quantification, accuracy was notable considering the complexity of flower types and picture angles in this dataset. We, therefore, expect that this approach can be used to address many ecological questions that benefit from automated flower detection, including studies of flowering phenology and floral resources, and that this approach can, therefore, complement a wide range of ecological approaches (e.g., field observations, experiments, community science, etc.). In all, our study suggests that ecological metrics like floral richness can be efficiently monitored by combining machine learning with easily accessible publicly curated datasets (e.g., Flickr, iNaturalist).

Clonal alien plants in the mountains spread upward more extensively and faster than non-clonal

Alien species are colonizing mountain ecosystems and increasing their elevation ranges in response to ongoing climate change and anthropogenic disturbances, posing increasing threats to native species. However, how quickly alien species spread upward and what drives their invasion remains insufficiently understood. Here, using 26,952 occurrence records of 58 alien plant species collected over two centuries in the Czech Republic, we explored the elevation range and invasion speed of each alien species and the underlying factors driving these variables. We collected species traits relevant for invasion (e.g., clonality, flowering time, life span, invasion status, height, mycorrhizal type, native range, naturalized range, monoploid genome size, and Ellenberg-type indicator values for light, temperature, and nitrogen), human-associated factors (e.g., introduction pathways and the sum of economic use types), and minimum residence time. We explored the relationships between these factors and species’ elevation range and invasion speed using phylogenetic regressions. Our results showed that 58 alien species have been expanding upward along mountain elevations in the Czech Republic over the past two centuries. A stronger effect of species’ traits than human-associated factors has been revealed, e.g., clonality was a key trait supporting the invasion of alien species into the mountains, while human-associated factors showed no effect. Our findings highlight that the characteristics associated with rapid reproduction and spread are crucial for alien species’ invasion into montane regions. Identifying key drivers of this process is important for predicting the spatiotemporal dynamics of alien species in high-altitude ecosystems and thus employing apposite measures to reduce the threat to native plant species.

Impact of Climate Change on Agricultural Activities in Garhwal Himalayas: A Comprehensive Analysis on Shifts, Changes and Adaptation Strategies

Climate change is adversely affecting many facets of human lives, often varying with the magnitude and scale. The Himalayan environment is showing a perceived change in the climatic parameters and cryosphere response. The aim of the present study is to capture the community perceptions of climate change, and their approaches towards adaptation. A comprehensive field investigation was carried-out in the villages selected within the different elevation range, located in the Garhwal division of Uttarakhand. In the present study, 150 households were surveyed spreading over 25 villages. The analysis shows that most of the respondents (~95%) agreed, about the climate change through their responses, i.e. early and warm summer, short winter months and less snowfall. The variability of precipitation pattern, declining soil fertility and poor yields were the major challenges in agriculture sector, the main source of livelihood of the communities. Traditionally, people are adapting with climatic extremities with adjusting crops Calander, use of improved and high-yielding variety seeds, fertilizer and used of herbicides and pesticides. The findings of the study can be used to prepare policy framework in the climate change adaptations in the Himalayan region.

Species richness of Orthoptera declines with elevation while elevational range of individual species peaks at mid elevation.

Species richness has been shown to decrease, and elevational range increase (the Rapoport effect), with elevation as a consequence of biotic and abiotic factors, but patterns are inconsistent across taxonomic groups. Despite being an important indicator taxon and a component of local communities, Orthoptera distributions at higher elevations in Europe remain unclear. We investigated the relationship of Orthoptera species richness and elevational range with elevation in the Pyrenees mountains, Europe. We conducted sweepnetting surveys supplemented by hand-sampling, at 28 sites stratified by elevation, across three study areas. Using generalised linear models, we found that species richness declined with elevation. Elevation was an important predictor of species richness, but sampling effort and vegetation structure (height and cover) also contributed to estimates of species richness. Using a nonlinear regression to model the elevational range of species over the elevational gradient, we did not observe a Rapoport effect, with elevational range peaking at mid-elevation instead. Smaller elevational ranges of species found at high elevations may be due to a combination of sampling over a restricted elevational range and the presence of specialist high-elevation species. We argue that our findings are useful for understanding species distributions with elevation at the interface between local and regional scales. Clarifying the biotic and abiotic predictors of species distribution is important for informing conservation efforts and predicting consequences of climate change.

A Global Survey of Gravitationally Deformed Volcanoes on Venus

AbstractGravitational instabilities can develop at volcanoes of any size and in any geological setting and can lead to various types of volcano deformation, ranging from small‐scale landslides on the flanks of the edifice to large, deep‐seated sector collapses. As volcanoes grow, they impose an increasing load on the underlying basement, which can result in styles of gravitational deformation where the edifice sags or spreads outward under its own weight. In this study, we utilize our previously developed global catalog of volcanoes on Venus to analyze a subset of edifices that appears to have undergone gravitational deformation. We identify 162 volcanoes that display morphological evidence for gravitational deformation and classify them into four main categories based on associated deformational structures: landsliding, sector collapse, spreading, and sagging. Landsliding of volcano flanks or full sector collapse are the most common and geographically widespread deformational styles on Venus, and account for ∼64% of our data set. Edifices exhibiting structures linked to volcano spreading and sagging are relatively rare; nonetheless, we note for the first time on Venus the presence on a shield volcano of flank terraces, structures linked to sagging. We find that deformed volcanoes are distributed globally, are found at a range of elevations, are spatially proximal to a variety of tectonic structures, and are associated with various crustal thickness values, which together suggest that there are numerous drivers of volcano deformation on Venus.

Altitudinal range extension of nine-banded armadillo, Dasypus novemcinctus (Linnaeus, 1758) (Mammalia, Xenarthra), in Irazu Volcano National Park, Costa Rica

The nine-banded armadillo (Dasypus novemcinctus) is a widely distributed species throughout North and South America, however its distribution has been restricted by latitude and altitude due to cold temperatures. The maximum reported altitude for the nine-banded armadillo is between 2000–3000 m asl; hence, new records at high elevations might suggest range shifts. Here we report video evidence of a nine-banded armadillo at 3400 m asl near the summit of the Irazu volcano in Costa Rica, which extends upwards the previously known elevation range by 300 m. We speculate this altitudinal range extension is indicative of regime shifts of ecosystems due to climate variability in response to rising temperatures, such as previously reported for several species.

Identifying baseflow source areas using remotely sensed and ground‐based hydrologic data

AbstractUnderstanding how rainfall and snowmelt influence baseflow, the groundwater‐fed component of streamflow, is essential for sound water resources management. Current approaches to understand the spatial couplings between these processes and baseflow are limited. The most commonly used methods include geochemical tracers and hydrologic models. A key limitation of the first is cost, while the second is limited by the need for simplifying assumptions. This study developed a data‐driven approach which leverages satellite Earth observation data and ground‐based data to assess the degree to which baseflow is influenced by upstream rainfall and snowmelt in California's Sierra Nevada. The procedure involved: (1) separation of baseflow from streamflow time series using a low‐pass filtering technique, (2) quantification of aquifer drainage timescales through baseflow recession analysis, (3) application of time series and information theory methods to identify the areas which have the greatest impacts on baseflow through both rainfall and snowmelt, and (4) characterization of the elevation zones which have a prevailing influence on baseflow. Results suggest that areas which have the strongest impact on baseflow through rainfall and snowmelt are not necessarily the areas which experience the highest annual rates of snowmelt or rainfall; snowmelt occurring in the 3000–3700 m elevation range was found to be the most important driver of baseflow.

A Lightweight Spherical Generalized Luneburg Lens Antenna With Low Cross-Polarization Over a Wide Range in Azimuth and Elevation

A Lightweight Spherical Generalized Luneburg Lens Antenna With Low Cross-Polarization Over a Wide Range in Azimuth and Elevation

Plant canopies promote climatic disequilibrium in Mediterranean recruit communities.

Current rates of climate change are exceeding the capacity of many plant species to track climate, thus leading communities to be in disequilibrium with climatic conditions. Plant canopies can contribute to this disequilibrium by buffering macro-climatic conditions and sheltering poorly adapted species to the oncoming climate, particularly in their recruitment stages. Here we analyse differences in climatic disequilibrium between understorey and open ground woody plant recruits in 28 localities, covering more than 100,000 m2 , across an elevation range embedding temperature and aridity gradients in the southern Iberian Peninsula. This study demonstrates higher climatic disequilibrium under canopies compared with open ground, supporting that plant canopies would affect future community climatic lags by allowing the recruitment of less arid-adapted species in warm and dry conditions, but also it endorse that canopies could favour warm-adapted species in extremely cold environments as mountain tops, thus pre-adapting communities living in these habitats to climate change.

Classification of autism spectrum disorder using electroencephalography in Chinese children: a cross-sectional retrospective study

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by diverse clinical features. EEG biomarkers such as spectral power and functional connectivity have emerged as potential tools for enhancing early diagnosis and understanding of the neural processes underlying ASD. However, existing studies yield conflicting results, necessitating a comprehensive, data-driven analysis. We conducted a retrospective cross-sectional study involving 246 children with ASD and 42 control children. EEG was collected, and diverse EEG features, including spectral power and spectral coherence were extracted. Statistical inference methods, coupled with machine learning models, were employed to identify differences in EEG features between ASD and control groups and develop classification models for diagnostic purposes. Our analysis revealed statistically significant differences in spectral coherence, particularly in gamma and beta frequency bands, indicating elevated long range functional connectivity between frontal and parietal regions in the ASD group. Machine learning models achieved modest classification performance of ROC-AUC at 0.65. While machine learning approaches offer some discriminative power classifying individuals with ASD from controls, they also indicate the need for further refinement.