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The primary aim of this investigation was to examine the morphological diversity of leaves in naturally occurring populations of common hornbeam (Carpinus betulus L.) in Türkiye. Twelve common hornbeam populations, distributed over four distinct watersheds in the Eastern Black Sea Region, were sampled from three altitude levels, ranging from sea level to 1200 meters. Nine morphological characteristics of the leaves were analyzed biometrically. We found a high degree of phenotypic heterogeneity both within and among the investigated populations. The eco-geographic principle's classification of populations was disclosed. Altitude appeared to be the primary factor influencing variation in the majority of leaf attributes from the Camlıhemşin, Çaykara, and Espiye watersheds. Compared to trees at lower altitude, trees at higher altitudes were characterized by smaller leaves. The populations in the Trabzon-Maçka watershed, however, did not show this trend. Largest leaves were observed for trees from the Trabzon-Maçka watershed region at the second altitude level. Overall, our findings support the notion that the Eastern Black Sea area is a hotspot of biodiversity and that the intricate evolutionary process leading to leaf morphological variability may be a consequence of adaptation and plasticity. [ABSTRACT FROM AUTHOR]

Characterizing the uncertainties in retrieval, which include both systematic and random errors, of satellite‐derived precipitation products (SPPs) is crucial for the development of bias correction techniques aimed at enhancing the accuracy of precipitation retrieval algorithms. This study aimed to comprehensively and quantitatively analyse the retrieval uncertainties in various SPPs across different seasons, climate regions, precipitation rates, and elevations. Three satellite‐only SPPs from the Tropical Rainfall Measuring Mission (TRMM) and the Global Precipitation Measurement (GPM) mission, namely the TRMM Multi‐satellite Precipitation Analysis (TMPA‐rt) and the Integrated Multi‐satellite Retrievals for GPM (IMERG‐early and IMERG‐late), were tested at the daily scale from April 2014 to March 2018, benchmarked by ~2400 weather stations in China. In comparison to TMPA‐rt, both IMERG‐early and IMERG‐late exhibited reduced systematic errors across the majority of western China, particularly over the Tibetan Plateau during the summer. The percentages of systematic errors increased gradually with the rise in rainfall intensities and became predominant in all three SPPs beyond rain rates of 50 mm·day−1. Moreover, the systematic error ratios of IMERG products generally exhibited an upward trend with increasing elevation, whereas this feature is not significant in TMPA‐rt. In contrast to TMPA‐rt, the two IMERG‐based SPPs demonstrated much lower magnitudes of random errors in all climate regions over the Chinese mainland, although they did not exhibit a significant reduction in systematic errors. However, these two IMERG products still suffer from certain uncertainties in the mountainous regions of western China during winter, primarily stemming from deficiencies in the IMERG retrieval system in the snow/ice‐cover areas. In summary, it appears timely for this study to intercompare and quantify the systematic and random errors in mainstream SPPs from TRMM to GPM, providing insights for future algorithm upgrades and data generation. [ABSTRACT FROM AUTHOR]

The analysis of genetic variation underlying local adaptation in natural populations, together with the response to different external stimuli, is currently a hot topic in forest sciences, with the aim of identifying genetic markers controlling key phenotypic traits of interest for their inclusion in restoration and breeding programs.In Europe, one of the main tree species is Norway spruce (Picea abies (L.) H.Karst.). Using the MassARRAY® platform, 568 trees from North Rhine‐Westphalia (Germany) were genotyped with 94 single nucleotide polymorphisms (SNPs) related to circadian and growth rhythms, and to stress response. The association analysis of the selected markers with health status and elevation was performed using three different methods, and those identified by at least two of these were considered as high confidence associated SNPs.While just five markers showed a weak association with health condition, 32 SNPs were correlated with elevation, six of which were considered as high confidence associated SNPs, as indicated by at least two different association methods. Among these genes, thioredoxin and pseudo response regulator 1 (PRR1) are involved in redox homeostasis and ROS detoxification, APETALA2‐like 3 (AP2L3), a transcription factor, is involved in seasonal apical growth, and a RPS2‐like is a disease resistance gene.The function of some of these genes in controlling light‐dependent reactions and metabolic processes suggests signatures of adaptation to local photoperiod and the synchronization of the circadian rhythm. This work provides new insights into the genetic basis of local adaptation over a shallow elevation gradient in Norway spruce. [ABSTRACT FROM AUTHOR]

Experimental approaches to measure territory defence can be used to interpret the relative magnitude of intraspecific aggression in different ecological contexts. The aim of this study is to examine the response of Fijian forest bird species to conspecific intruders using playback of previously recorded songs along an elevational gradient. We address two questions: Do different foraging guilds in Fiji's forest birds show different patterns of territorial defence behaviour towards conspecific intruders? Secondly, do Fiji's forest birds show stronger territorial defence at higher elevations? We explore these questions across two foraging guilds (insectivore and omnivore) on Viti Levu Island, Fiji. All four focal species had a stronger response at the highest elevation, and the endemic insectivore had the strongest response. Perhaps high elevation insects are less abundant and hence increased aggressiveness is favoured to defend the territory, and/or perhaps in general more aggressive birds colonise higher elevation areas, both ideas that require further testing. This study provides first insights into response to conspecifics in Fiji's forest birds that can be explored in relation to avian behaviour also in the context of human activity, human disturbance and threats to the persistence of birds across elevational gradients. [ABSTRACT FROM AUTHOR]

Variations in functional traits serve as measures of plants' ability to adapt to environment. Exploring the patterns of functional traits of desert plants along elevational gradients is helpful to understand the responses and adaptation strategies of species to changing environments. However, it is unknown whether the relationship between functional traits and elevation is affected by differences in the species' elevational distributions (elevation preference and species' range). Importantly, most researches have concerned with differences in mean trait values and ignored intraspecific trait variation. Here, we measured functional traits of desert plants along a wide elevational gradient in the Tibetan Plateau and adjacent areas and explored functional trait patterns over elevation in species with different elevational distributions. We decomposed trait variation and further investigated characterizations of intraspecific variation. Ultimately, the main drivers of trait variation were identified using redundancy analysis. We found that species' elevational distributions significantly influenced the relationship of functional traits such as plant height, leaf dry matter content, leaf thickness, leaf nitrogen and carbon content with elevation. Species with a lower elevational preference showed greater trait variation than species with a higher elevational preference, suggesting that species that prefer high elevation are more conservative facing environmental changes. We provide evidence that interspecific trait variation in leaf thickness and leaf carbon content decreased with increasing species' range, indicating that increased variations in resistance traits within species make greater responsiveness to environmental changes, enabling species a wider range. Elevation, temperature and precipitation were the main drivers of trait variation in species with a low elevational preference, while the effect of precipitation on trait variation in species with a high elevational preference was not significant. This study sheds new insights on how plants with different elevational distributions regulate their ecological strategies to cope with changing environments. [ABSTRACT FROM AUTHOR]

In the urban canyon environment, the integer ambiguity is hard to be fixed completely mainly because of the multipath effects, hence partial ambiguity resolution (PAR) is developed. This paper systematically introduces a new model-driven PAR method considering elevation and C/N0. Firstly, the theory of partial ambiguity resolution, the elevation-C/N0 function, and the proposed elevation-C/N0 PAR method are deduced in detail. Secondly, the proposed elevation-C/N0 method is applied in the static and dynamic experiments. The performances of the proposed method are compared with the full ambiguity resolution method, traditional elevation-dependent method, and C/N0-dependent method. Comparisons indicate that the proposed elevation-C/N0 method outperforms other methods. The results show that no matter in the urban static experiment or the dynamic experiment, the ambiguity resolution and positioning solutions can be improved. [ABSTRACT FROM AUTHOR]

Under the current pattern of climate change, mountain bird populations are generally shifting their ranges to higher elevations, tracking their climatic optima. Nevertheless, space limitations at high altitudes constrain mountain species' resilience to climatic change, making them particularly vulnerable. In extreme cases, the climatic niche of some species can move beyond mountaintops, ultimately driving such species to extinction. This study presents the case of the northern wheatear Oenanthe oenanthe in mainland Spain and compares its breeding distribution from 2003 to 2022. Spain, where the species mostly occupies mountain areas, represents its southernmost distribution limit in Europe. We built environmental favourability models using information from the two most recent Spanish bird atlases and a set of climatic, topographic, human activity and lithological variables to determine the factors affecting the occurrence of the species. The influence of climate compared to all other factors was obtained using variation partitioning analysis. The northern wheatear has suffered a strong reduction (67%) in occupied areas and also in favourability throughout mainland Spain (especially in the south) where climate change may have far‐reaching consequences, including local extinctions. Climate explained more than 90% of the variation in the model obtained for 2022. Interestingly, the occupied areas were, on average, 100 m higher in 2022 than in 2003. If the effects of climate warming persist, the northern wheatear will likely disappear in its southernmost distribution limit, being the Sierra de las Nieves National Park population the most vulnerable in mainland Spain. For this reason, it is necessary to implement monitoring programmes for northern wheatear populations, with priority for mountain systems wherein they already occupy higher elevations, as well as further studies on other mountain species. [ABSTRACT FROM AUTHOR]

Simple Summary: Two ecogeographic rules predict morphological changes along latitudinal clines based on thermoregulatory causes. To maintain corporal heat in cold environments (higher latitudes), larger body sizes and shorter appendages and limbs are predicted by Bergmann's and Allen's rules, respectively. Both rules may also apply to elevational gradients, due to the decrease in external temperature as elevation increases. We evaluated whether these ecogeographic rules were true in two rodent species across an elevational gradient in central Chile. The species studied were Abrothrix olivacea and Phyllotis darwini, which coexist across this altitudinal range. Our results showed a low support for these rules, as well as an opposite body size trend between both species. Other than morphology, physiological and behavioral strategies could be more critical to thermoregulating in high, montane environments, and new hypotheses should be tested to explain the morphological changes that we observed in this study. Bergmann's and Allen's rules are two classic ecogeographic rules concerning the physiological mechanisms employed by endotherm vertebrates for heat conservation in cold environments, which correlate with adaptive morphological changes. Thus, larger body sizes (Bergmann's rule) and shorter appendages and limbs (Allen's rule) are expected in mammals inhabiting cold environments (higher latitudes). Both rules may also apply to elevational gradients, due to the decrease in external temperature as elevation increases. In this study, we evaluated whether these patterns were true in two coexisting sigmodontine rodents across an elevational gradient in central Chile. We analyzed whether the size of the skull, body, and appendages of Abrothrix olivacea (n = 70) and Phyllotis darwini (n = 58) correlated with elevation, as predicted by these rules in a range between 154 and 2560 m. Our data revealed weak support for the Bergmann and Allen predictions. Moreover, we observed opposite patterns when expectations of Bergmann's rules were evaluated, whereas Allen's rule just fitted for ear size in both rodent species. Our results suggest that morphological changes (cranial, body, and appendage sizes) may play a minor role in the thermoregulation of these two species at high elevations, although behavioral strategies could be more critical. Other ecological and environmental variables could explain the morphological trends observed in our study. These hypotheses should be assessed in future studies to consider the relative contribution of morphology, behavior, and physiological mechanisms to the thermal adaptation of these two rodent species at high elevations. [ABSTRACT FROM AUTHOR]

Premise: Mast flowering/seeding is often more extreme in lower‐resource environments, such as alpine compared to lowland habitats. We studied a masting herb that had less extreme masting at higher elevations, and tested if this difference could be explained by higher photosynthetic productivity and/or lower reproductive investment at the higher‐elevation sites. Methods: We examined the relationship between flowering intervals and carbon budget (i.e., the balance between reproductive investment and annual carbon fixation) in a masting herb, Veratrum album subsp. oxysepalum, across five lowland and six alpine populations in northern Japan. We evaluated the previous flowering histories of individual plants based on rhizome morphology and analyzed the masting patterns of individual populations. Total mass of the reproductive organs, as a proxy of reproductive investment, was compared between the lowland and alpine populations. Annual carbon fixation was estimated on the basis of photosynthetic capacity, total leaf area per plant, and seasonal transition of light availability. Results: Interval between high‐flowering years was shorter and total reproductive investment was smaller in the alpine than in the lowland populations. Owing to its high photosynthetic capacity and continuous bright conditions, annual carbon fixation per plant was 1.5 times greater in alpine habitat than in lowland habitat. These results suggest that V. album alpine populations have shorter flowering intervals than lowland populations due to faster recovery from energy loss after reproduction. Conclusions: Our study demonstrated that masting intervals in V. album populations can be explained by habitat‐specific carbon budget balances. [ABSTRACT FROM AUTHOR]

Forest biomass allocation is a direct manifestation of biological adaptation to environmental changes. Studying the distribution patterns of forest biomass along elevational gradients is ecologically significant for understanding the specific impacts of global change on plant resource allocation strategies. While aboveground biomass has been extensively studied, research on belowground biomass remains relatively limited. Furthermore, the patterns and driving factors of the belowground biomass proportion (BGBP) along elevational gradients are still unclear. In this study, we investigated the specific influences of climatic factors, soil nutrients, and key leaf traits on the elevational pattern of BGBP using data from 926 forests at 94 sites across China. In this study, BGBP data were calculated from the root biomass to the depth of 50 cm. Our findings indicate considerable variability in forest BGBP at a macro scale, showing a significant increasing trend along elevational gradients (p < 0.01). BGBP significantly decreases with increasing temperature and precipitation and increases with annual mean evapotranspiration (MAE) (p < 0.01). It decreases significantly with increasing soil phosphorus content and increases with soil pH (p < 0.01). Key leaf traits (leaf nitrogen (LN) and leaf phosphorus (LP)) are positively correlated with BGBP. Climatic factors (R2 = 0.46) have the strongest explanatory power for the variation in BGBP along elevations, while soil factors (R2 = 0.10) and key leaf traits (R2 = 0.08) also play significant roles. Elevation impacts BGBP directly and also indirectly through influencing such as climate conditions, soil nutrient availability, and key leaf traits, with direct effects being more pronounced than indirect effects. This study reveals the patterns and controlling factors of forests' BGBP along elevational gradients, providing vital ecological insights into the impact of global change on plant resource allocation strategies and offering scientific guidance for ecosystem management and conservation. [ABSTRACT FROM AUTHOR]

Land surface temperature (LST) and its interaction with normalized difference vegetation index (NDVI) are crucial for better understanding of environmental changes in current scenario. 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 in elevation range of -6 to 168 m, whereas NDVI value (0.38 ± 0.06) in elevation ranges of 589 - 1698 m. The elevation has strong positive correlation with NDVI (R² = 0.26) and negative correlation with LST (R² = 0.28). Findings from this research can be utilized as a platform for environmental and land use planning for sustainable ecosystem management. [ABSTRACT FROM AUTHOR]

The elevational patterns of soil microbial and nematodes diversity (SMND) and the determinants remain controversial. Moreover, how the SMND are modified simultaneously with an elevational gradient has not yet been established. In this study, we investigated the elevational patterns of the SMND and the relative importance among/within tree factors (i.e., tree diversity, identity, and quantity) and environmental factors (i.e., climate and soil) on the SMND. For this purpose, we analyzed datasets from 27 plots across nine elevation bands in the temperate forests of Mt. Gariwang, South Korea. We performed multimodel inference tests and subsequently conducted a variance partitioning to determine the most prominent factors controlling each SMND and compare the relative contribution of the trees and environmental effects. Our results revealed that bacterial and fungal diversity decreased along the elevation gradient. However, nematode diversity did not change significantly, indicating that site-specific environmental conditions may be more influential than the elevation per se. Moreover, this indicates that bacterial diversity was affected by the pH and functional dispersion of the leaf size, and that fungal diversity was governed only by the pH. However, nematode diversity was driven by aboveground biomass, ammonium-nitrogen, and tree size diversity. In summary, the soil microbial diversity was more strongly controlled by the environmental factors, whereas the tree factors were more important for nematodes. Our results show that the elevational patterns and determinants of SMND differed among the taxonomic groups in the common micro-food web. These findings provide new insights into the factors controlling the SMND in a temperate forest and expand the local knowledge of soil biodiversity which is necessary for promoting its mainstreaming. Thus, our results contribute to establishing a basis for more targeted and effective biodiversity conservation and management practices in forest ecosystems. [ABSTRACT FROM AUTHOR]

Climate change is one of the most prominent factors influencing the spatial distribution of plants in China, including gymnosperms. Climatic factors influence gymnosperm distribution along elevational gradients on the Qinghai–Xizang (Tibet) Plateau (QTP), and understanding how species adapt to these factors is important for identifying the impacts of global climate change. For the first time, we examined the county-level distribution of gymnosperm species on QTP using data from field surveys, published works, monographs, and internet sources. We used simulated distribution data of gymnosperms (N = 79) along the elevational gradients to investigate the overall impact of environmental variables in explaining the richness pattern of gymnosperms. Eighteen environmental variables were classified into three key variable sets (climatic seasonality, energy–water, and physical tolerance). We employed principal component analysis and generalized linear models to assess the impact of climatic variables on the gymnosperm's richness pattern. Gymnosperm species are unevenly distributed across the plateau and decline gradually from the southeast to the northwest. The altitudinal gradients have a unimodal relationship with the richness of gymnosperms, with the maximum species richness at an elevation of 3200 m. The joint effects of physical tolerance and energy–water predictors have explained the highest diversity of gymnosperms at mid-elevation. Because the richness peak correlates significantly with the wettest month's precipitation and moisture index, this confirms the significance of moisture on gymnosperm distributions due to increased precipitation during the wet season. Furthermore, our results provide evidence that climatic seasonality factors are involved in the decline of gymnosperm richness at high elevations. A total of 37% of gymnosperm species on QTP are listed as vulnerable, nearly threatened, or endangered, with elevations ranging from 600 m to 5300 m. As a result, we conclude that gymnosperms are at high risk of extinction because of the current climate fluctuations caused by global climate change. Our research offers fundamental data for the study and protection of gymnosperm species along the steepest elevation gradients. [ABSTRACT FROM AUTHOR]

Aim: Life in mountains is associated with multiple features that increase the risk of demographic collapses in populations – small geographic ranges, short breeding seasons, specialization to harsh climates – leading to the hypothesis that extinction risk is exacerbated in species inhabiting higher elevations. Here, we implement the first test of this hypothesis across the amphibian tree of life – the tetrapods with the largest proportion of montane species, and nature's most threatened animals. Location: Global. Time Period: Present. Major Taxa Studied: Class Amphibia. Methods: We collated a dataset spanning 8042 species from across all three amphibian orders (Anura, Caudata and Gymnophiona). We preformed phylogenetic logistic regressions to test the predictions that extinction risk increases with elevation, and whether this effect is caused by factors previously hypothesised to drive high‐elevation declines, including restrictions on species' geographic ranges, variation in their life histories and the presence of infectious disease. Results: Globally, extinction risk increases towards higher elevations. At order‐level, this relationship holds for frogs and salamanders. Even when controlling for geographic range size, life histories and infectious disease, extinction risk increases with elevation for amphibians combined and frogs globally, and in the Americas. In contrast, whereas extinction risk is greater among high‐elevation Eurasian amphibians, this relationship is explained by larger body sizes and lower fecundity. Main Conclusions: Our analyses indicate that after considering factors previously thought to explain the increase in extinction risk towards higher elevations (e.g., geographic range size, disease), elevation remains a significant predictor of amphibian extinction risk. Given that the only available tests of this hypothesis in other tetrapods (birds and reptiles) conflict with our findings, we suggest that physiological or life‐history features of amphibians may explain this observed phenomenon. [ABSTRACT FROM AUTHOR]

【Objective】 The ecological environment in the Dry-Hot Valley of the Jinsha River is harsh, resulting in poor vegetation growth and development. Exploring the soil carbon, nitrogen, and phosphorus stoichiometry and enzyme activity characteristics in this area is of great significance to the vegetation restoration and ecological management in the Dry-Hot Valley of the Jinsha River. 【Method】 The soil in the upper, middle, and lower reaches in the Dry-Hot Valley of the Jinsha River, spanning elevations from 800 m to 2000 m, were selected as the research subjects. Through field investigations, soil collection, and laboratory analysis, the basic physical and chemical properties, carbon, nitrogen and phosphorus contents, as well as soil enzyme activities were tested in this region. 【Result】 Under the influence of various environmental factors including climate, soil, and vegetation at different altitudes in the Dry-Hot Valley of the Jinsha River, the contents of soil organic carbon, total nitrogen, and total phosphorus in the upper, middle and lower reaches significantly increased with increasing altitude (P＜0.05); The harsh environmental factors in the Dry-Hot Valley of the Jinsha River had resulted in soil C/N, C/P, and N/P values being lower than the national average. Under the influence of climate, soil, vegetation and other environmental factors at different altitudes in the Dry-Hot Valley of the Jinsha River, the enzyme activities of soil urease, β-glucosidase, and acid phosphatase in the upper, middle, and lower reaches of the Jinsha River all increased significantly with increasing altitude (P＜0.05). Moreover, the content of soil carbon, nitrogen, and phosphorus at various altitudes was positively correlated with soil urease, β-glucosidase, and acid phosphatase activities (P＜0.01). The correlation among the elements provided more objective reflection of soil quality and changing characteristics in the Dry-Hot Valley of the Jinsha River. 【Conclusion】 The stoichiometric characteristics of soil carbon, nitrogen, and phosphorus, along with soil enzyme activity, exhibit high spatial heterogeneity at altitudes ranging from 800 m to 2000 m in the upper, middle and lower reaches of the Dry-Hot Balley of the Jinsha River. As altitude increases, there is corresponding increase in the content of soil carbon, nitrogen, and phosphorus as well as enzyme activity. [ABSTRACT FROM AUTHOR]

Objective Both high altitude and trisomy 21 (T21) status can negatively impact respiratory outcomes. The objective of this study was to examine the association between altitude and perinatal respiratory support in neonates with T21 compared with those without T21. Study Design This retrospective cohort study used the United States all-county natality files that included live, singleton, in-hospital births from 2015 to 2019. Descriptive statistics for neonates with and without the primary outcome of sustained assisted ventilation (>6 hours) were compared using t -tests and Chi-squared analyses. Multivariable logistic regression was used to determine the association between respiratory support and the presence of T21, and included an interaction term to determine whether the association between respiratory support and the presence of T21 was modified by elevation at delivery. Results A total of 17,939,006 neonates, 4,059 (0.02%) with T21 and 17,934,947 (99.98%) without, were included in the study. The odds of requiring sustained respiratory support following delivery were 5.95 (95% confidence interval [CI]: 5.31, 6.66), 4.06 (95% CI: 2.39, 6.89), 2.36 (95% CI: 1.64, 3.40), and 5.04 (95% CI: 1.54, 16.54) times as high for neonates with T21 than without T21 when born at low, medium, high, and very high elevations, respectively. The odds of requiring immediate ventilation support following delivery were 5.01 (95% CI: 4.59, 5.46), 5.90 (95% CI: 4.16, 8.36), 2.86 (95% CI: 2.15, 3.80), and 12.08 (95% CI: 6.78, 21.51) times as high for neonates with T21 than without T21 when born at low, medium, high, and very high elevation, respectively. Conclusion Neonates with T21 have increased odds of requiring respiratory support following delivery when compared with neonates without T21 at all categories of altitude. However, the odds ratios did not increase monotonically with altitude which indicates additional research is critical in understanding the effects of altitude on neonates with T21. Key Points Neonates with T21 have an increased need for perinatal respiratory support at all altitudes. The odds of needing perinatal respiratory support did not increase monotonically with elevation. Additional research is critical to understanding the effects of altitude on neonates with T21. [ABSTRACT FROM AUTHOR]

Local studies show upslope shifts in the distribution of tropical birds in response to warming temperatures. Unanswered is whether these upward shifts occur regionally across many species. We considered a nearly 2000‐km length of the Northern Andes, where deforestation, temperature, and extreme weather events have increased during the past decades. Range‐restricted bird species are particularly vulnerable to such events and occur in exceptionally high numbers in this region. Using abundant crowd‐sourced data from the Cornell Lab of Ornithology database, eBird, and the Global Biodiversity Information Facility, we documented distributions of nearly 200 such species. We examined whether species shifted their elevational ranges over time by comparing observed versus expected occurrences below a low elevational threshold and above a high elevational threshold for 2 periods: before and after 2005. We predicted fewer observations at lower elevations (those below the threshold) and more at upper elevations (those above the threshold) after 2005. We also tested for deforestation effects at lower elevations within each species' distribution ranges. We compared relative forest loss with the differences between observed and expected occurrences across the elevational range. Species' retreats from lower elevations were ubiquitous and involved a 23–40% decline in prevalence at the lowest elevations. Increases at higher elevations were not consistent. The retreats occurred across a broad spectrum of species, from predominantly lowland to predominantly highland. Because deforestation showed no relationship with species retreats, we contend that a warming climate is the most parsimonious explanation for such shifts. [ABSTRACT FROM AUTHOR]

The change grassland plant communities demonstrate with elevation has been one of the hot issues in ecological research, and there remain many unsolved problems. In order to further elucidate the rules of grassland plant community change with elevation, this study took the Burqin forest area as a research object, using field survey, redundancy analysis and grey correlation analysis to comprehensively assess the characteristics of change in grassland plant communities with elevation and the relationship of this evolution with environmental factors. The results showed that (1) the numbers of species, community biomass, community cover and community densities of grassland plant communities showed an "M" pattern with the increase in elevation. There were significant changes in the importance values and dominance of plants at different elevations; with increasing elevation, grassland plants became primarily dominated by cold-tolerant and well-adapted perennials. (2) The similarity coefficients of grassland plant communities at different elevations ranged from 0.06 to 0.62, i.e., from very dissimilar to moderately similar. (3) As the elevation increased, the Margalef species richness index, Shannon–Wiener diversity index, Simpson dominance index and Alatalo evenness index all showed an "M" pattern trend. (4) The degrees of correlation between temperature and precipitation and community biomass and species diversity were at a high level, and these were the most important environmental factors affecting the biomass and species diversity of grassland plant communities in the Burqin forest area. The results of this study can provide a theoretical basis for the rational utilization of grassland resources and for the sustainable development of grassland ecosystems in the Burqin forest area. [ABSTRACT FROM AUTHOR]

The ecology and diversity of flowering parasitic plants and their hosts are poorly investigated and usually ignored in Saudi Arabian plant communities. Therefore, this work aimed at assessing the ecology and diversity of parasitic plants and their hosts along an elevation gradient in the Al-Baha region (1300–2400 m.a.s.l.). Different quantitative vegetation parameters were applied to analyze the collected data. Eight parasitic plants from six genera and four families were identified along the gradient, with 67% of them being zoochorously dispersed species. They accounted for approximately 23.5% (8 out of 34) of those found throughout Saudi Arabia. Perennials, stem hemiparasites, and biregional taxa accounted for around 62.5% of the total parasites, whereas indigenous species accounted for 75%. The dominant family of parasitic species was Loranthaceae (50%), and Phragmanthera austroarabica A.G.Mill. & J.A.Nyberg was the most important species (IVI = 107.28). Orobanche cernua Loefl. and Loranthella deflersii (Tiegh.) S.Blanco & C.E.Wetzel were restricted to the dry zone (low elevation) only, while the other parasites were distributed across the surveyed region. Twenty-three host plants were identified throughout the study region. About 83% of them were phanerophytes and bioregional plants, with 91% being perennial species. The prevalent host plant family across all sites was Fabaceae, with Nicotina glauca Graham being the most important host species (IVI = 32.44%). P. austroarabica and Plicosepalus curviflorus Tiegh. preferred Vachellias as host plants, while Vachellia flava (Forssk.) Kyal. & Boatwr. was the heavily infected host by P. austroarabica. P. austroarabica had a broad spectrum of host range (13 host plants), while O. cernua had a very narrow host range (only Rumex nervosus Vahl). Individual parasite and host species were markedly more abundant in the wet zone than in the low-altitude dry zone. Further research is needed to fully understand such distinctive groups of plants and their negative and positive ecological consequences on plant biodiversity and natural ecosystems. [ABSTRACT FROM AUTHOR]

Changes in age structure, spatial distribution and intraspecific interactions across environmental gradients often reflect adaptations of plant populations to their environment. Our study explored the growth status of the Picea schrenkiana population on the north slope of the eastern Tianshan Mountains and tested the stress gradient hypothesis (SGH) against changes in the age structure and spatial pattern of P. schrenkiana populations along the environmental gradient. We sampled the forests at eight elevational locations, comprising a total of 24 plots of 30 × 30 m area from 1800 to 2500 m a.s.l. in the Jiangbulake region. By scanning the 3D structure of the forests and sampling tree rings in each plot, we precisely determined the spatial location and diameter of the breast height (DBH) of each P. schrenkiana individual. By fitting the DBH-age power model and g(r) function of the point pattern, we examined the age structure, spatial patterning and intraspecific interactions of local P. schrenkiana populations within each plot and their correlation with habitat parameters. The results indicate that (1) juveniles dominate the overall population density, age structure and spatial patterning of the P. schrenkiana population. Trees of low–middle elevations represent younger forests with faster growth and better regeneration, while trees at high elevations form older forests with slower growth and poorer regeneration. (2) The aggregated population patterns and positive intraspecific interactions occur mostly at medium elevations (2000 and 2100 m a.s.l.). (3) Population density, aggregation intensity and intraspecific interaction strength are strongly and positively correlated (p < 0.01). Our results did not fit the SGH but support a hump-shaped hypothesis that proposes that facilitation is stronger under medium stress along the elevational gradient. This study validates the spatial point pattern testing of the SGH of different types. We recommend the implementation of more intensive forest closure measures, together with a reduction in the harvesting intensity of trees to ensure the sustainable regeneration of P. schrenkiana forests in the eastern Tianshan Mountains. [ABSTRACT FROM AUTHOR]

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This study was carried out between 2013 and 2019 in five provinces located in Eastern and South Eastern Anatolian Region of Turkey. The dytiscid specimens were collected from a total of 226 sampling sites that altitudes varied between 500 and 2,700 meters. The 226 sampling sites were classified into one of six altitudinal levels defined by semi open intervals with amplitude of 300 m. A total of 45 species belonging to the family Dytiscidae were identified. A detailed ecological analysis related to altitude is made by means of the distribution of 45 identified species. The richness of species was analyzed at different altitudinal levels. The indicator species were determined by establishing their altitude profile in terms of reciprocal species-factor information. The species density is highest in altitudinal level 2 (800-1100m) and is gradually decrease by increasing of altitudinal level. Ten representative species are placed into three groups: species occurring at high altitude; species present at low altitude and species occurring along the entire altitudinal gradient. [ABSTRACT FROM AUTHOR]

Introduction. Bryophytes can reach levels of coverage sufficient to influence key ecological processes; for example, their water retention capacity can supply an appreciable amount of humidity to forest ecosystems. The variation in biomass and diversity of epiphytic liverwort species in a Mexican cloud forest (CF) in the state of Hidalgo was estimated along elevation and latitude gradients, as was the relationship between epiphytic liverwort structural attributes and environmental factors. Methods. Liverwort species were sampled in three municipalities with CF in Hidalgo State, at elevations of 1345-2019 m. In each municipality, two 0.1 ha plots were located at the two extremes of the gradient. For each of 10 trees per plot, three 10 × 10 cm areas of bark were selected as microplots, and from each microplot, samples of liverwort were obtained to determine structural data for the liverworts. Key results. Species diversity was highest at the upper elevation level (1985-2001 m), and lowest at the lower elevation level (1345-1375 m). The highest dry and saturated weight values (15.20 g and 83.30 g, respectively) were found at lower elevations, and the lowest (11.78 g and 60.04 g, respectively) at high elevations. Conclusion. Species diversity was positively related to elevation gradient, and species biomass decreased gradually with elevation. Beta diversity values were not associated with geographical distance between sites. Local factors, such as light input, available area, phorophyte species, humidity and temperature, may have more influence on the growth of epiphytic liverworts than elevation or geographical distance. [ABSTRACT FROM AUTHOR]

Premise: Little is known about the ability of individual species to grow successfully outside of their realized niche. Here, the vitality of two epiphytic bryophyte and two epiphytic lichen species were assessed in their fundamental and realized niches in the Pacific Northwest coniferous forest at low, mid, and high elevations. Methods: Two lowland epiphytic bryophyte species (Frullania nisquallensis, Neckera douglasii) and one lowland epiphytic lichen species (Usnea longissima) were transplanted to sites at mid and high elevations. One high‐elevation epiphytic lichen species (Hypogymnia rugosa) was transplanted to mid and low elevations. Results: The fundamental and realized niches of F. nisquallensis and U. longissima are similar, and they can both survive outside of their realized niches. For N. douglasii, dispersal limitations could shape its distribution along elevation and local microclimate conditions could be important for its vitality. Conclusions: Certain bryophyte and lichen species can survive outside of their realized niches, information that can contribute to knowledge about species niches along elevational gradients. Future studies should focus on cryptogam species interactions in a changing climate. [ABSTRACT FROM AUTHOR]

This research investigates the effect of blade density and elevation above sea level on the startup time (Ts) and power coefficient (Cp) of a 1-kW two-bladed wind turbine. The study uses three Iranian hardwoods as the blade material and four counties of Iran with low wind speeds and different elevations as the case studies. The BW-3 airfoil is considered as the blade profile. A multi-objective optimization process with the aid of the differential evolution (DE) algorithm is utilized to specify the chord length and twist angle. The findings demonstrate that, while the maximum Cp of the optimal blades designed with all three types of wood is high and equal to 0.48, the average Ts of the optimal blades designed with oak and hornbeam wood is 84% and 108% higher than that of alder wood, respectively. It is also observed that, while raising the elevation to 2250 m decreases the Cp by only 2.5%, the ideal blade designed to work at sea level could not manage to start rotating at a height of 1607 m and above. Finally, an improvement in the Ts and Cp was observed by performing optimization based on the local atmospheric conditions associated with the incrementing blade chord length at high elevations. [ABSTRACT FROM AUTHOR]

Dominant groups and rare groups often coexist in forests. Dominate plant families generally have more species diversity and occupy most of the biomass. However, their effects on community construction and species diversity maintenance remain to be studied. This study aims to investigate this question by using the two dominant plant families in a Chinese subtropical forest (Lauraceae and Fagaceae). In this study, 22 forest dynamic plots were established in the forest distribution area of Daming Mountain Nature Reserve at an elevation of 300–1400 m. We explored the elevational change in the community structure and its relationship with Lauraceae and Fagaceae using generalized additive models (GAM) and a regression analysis. Then we used a correlation analysis to describe the relationship between environmental factors and the community structure. Our results showed the species diversity index showed a hump-shape trend along the elevation, and the total basal area showed no significant change along the elevation. The richness of Lauraceae and Fagaceae showed a positive correlation with the species diversity, but only the richness of Fagaceae showed a positive correlated with the total basal area. Species diversity was positively correlated with soil total nitrogen and soil organic matter. Species diversity and the total basal area were negatively correlated with the soil pH. In summary, Lauraceae and Fagaceae are correlated for community structure, and this correlation is not affected by elevation. Fagaceae has played a more important role than Lauranceae. This study highlights the impact of dominant plant families on the forest community assembly along the elevational transect. [ABSTRACT FROM AUTHOR]

Protected areas are relatively free of human disturbance, are especially common in montane regions, and provide opportunities to study native fauna and flora. Stoneflies are model organisms to assess present and future environmental changes. While stoneflies inhabit cold lakes and a wide size range of lotic systems, diversity is greatest in streams draining mountain landscapes. This study addressed seasonal and elevation patterns of a stonefly fauna inhabiting a protected landscape draining the eastern flank of Mount Mitchell, the highest point of the Appalachian Mountains, USA. In total, 58 species were collected with estimated richness values ranging from 63 to 65. Species determinations were assisted with an integrative molecular approach using the mitochondrial barcode gene. Sampling during spring yielded the most species seasonally. Although certain species were only found at lower or higher sites, several were collected from across a broad range of elevations. Roughly 1/3 (21 = 36%) of the fauna present is known only from the southern Appalachian Highlands region, including one species described as new during this study. The assemblage reported here, however, did not closely align with other Appalachian fauna. Overall, well-structured faunal research continues to be important in light of continuing habitat modifications and climate change. [ABSTRACT FROM AUTHOR]

Flight is a crucial evolutionary novelty for insect diversification. Despite its importance, some insects lose this ability. Flight loss is related to the reduction in the veins and membrane of hind wings (brachypterism), often related to high elevations. Brachypterism evolved independently in some lineages of beetles, like in the family Passalidae. Due to the double function of the passalid hind wings (dispersion and acoustic communication), the wing reduction process is partial and apparently constrained by the stridulatory apparatus. The tribe Proculini is a good model to study brachypterism due to the number of flightless species and its distribution between low land and high montane ecosystems. We evaluated the relationship between wing reduction and elevation in the elytra and hind wings of 25 Proculini species distributed in Colombia, using linear measurements and geom-25etric morphometry. Specimens were categorized in three elevation ranges: low (0–999 m), middle (1000–1999 m), and high (<2000 m). In conclusion, this study demonstrates that elevation is most likely the factor that has driven size and shape modifications of the Passalidae hind wings and elytra. The present work is the first study that tests the relationship between brachypterism and elevation using Proculini species belonging to different genera. [ABSTRACT FROM AUTHOR]

Foliage leaves are the primary photosynthetic organ of the majority of vascular plants, and their area vs. biomass scaling relationships provide valuable insights into the capacity and investment in light interception, which is critical to plant growth and performance. The "diminishing returns" hypothesis (DRH), which is based primarily on data from gymnosperms and angiosperms, posits that leaf (lamina) area scales with leaf dry mass. on average with a scaling exponent less than 1.0. However, it remains uncertain whether DRH applies to ferns or whether ecological factors affect the scaling exponents governing fern leaf morphometrics. To address this issue, 182 individuals of 28 subtropical ferns species were studied at low, medium, and high elevations (i.e., 600 m, 900 m, and 1200 m, respectively) in Mount Wuyi National Park, Jiangxi Province, China. The scaling relationships between leaf area and leaf biomass for individual and total leaf of ferns at different elevations were examined by using standardized major axis regression protocols. Analyses of the 28 fern species (using Blomberg K-value protocols) indicated no phylogenetic biases among the species compositions of the three different elevations. In addition, at the individual plant level, individual leaf area (ILA) did not differ significantly among the three different elevations (P > 0.05). However, individual leaf mass (ILM) was significantly higher at 900m than at 1200m (P < 0.05), resulting in a significantly higher leaf mass per area (LMA) at the 900m elevation than at the 600m and 1200m elevations (P < 0.05). The ILA and ILM at the 900m elevation were significantly higher than at the 600m elevation (P < 0.05). At the species level, ILA and ILM did not differ significantly among the three elevations (P > 0.05). The total leaf area per individual (TLA) did not differ significantly across the different elevations (P > 0.05). However, total leaf mass per individual (TLM) did differ significantly (P < 0.05). At the individual plant level, the scaling exponents for ILA vs. ILM and TLA vs. TLM at the three different elevations were all significantly less than 1.0 (P < 0.05), which was consistent with the DRH. At the species level, the scaling exponents for the ILA vs. ILM were significantly less than 1.0 at the middle and high elevations, but not at the low elevation. The scaling exponents of the TLA and TLM were numerically highest in the middle elevation, and all were less than 1.0 for the three elevations. These results indicate that the scaling relationships of leaf area versus mass of subtropical ferns at different elevations support the DRH hypothesis. The study further informs our understanding of the resource allocation strategies of an ancient and diverse plant lineage. [ABSTRACT FROM AUTHOR]

This study was carried out in an area cultivated with durian in Gua Musang, Kelantan with a soil series of Rengam-Jerangau. The objective of this study was to determine the physicochemical properties of soil cultivated with durian at different elevations and samplings. The soil composite sampling was determined at three elevations (top, middle and bottom elevation) marked using GPS coordinate with two different depths (0-15 cm and 15-30 cm). The United States Department of Agriculture (USDA) of the soil texture is clay with bulk density ranging between 0.98 to 1.11 g/cm3. Significant parameters at alpha value of 95% include total carbon content (0.903% until 1.389%), total sulphur content (0.059% to 0.100%), exchangeable bases calcium, potassium and sodium at 3.520 cmolc/kg to 5.582 cmolc/kg, 0.380 to 0.581 cmolc/kg and 0.101 to 0.155 cmolc/kg respectively. From the significant parameters, only exchangeable potassium was affected by the by both elevation and depth of the sampling while the other parameters were only affected by the elevation. As some of the nutrients had been classified as low, extensive measures need to be done for healthy growth performance. [ABSTRACT FROM AUTHOR]

With an increase in human population over the past 30 years, regional land use in south Texas has shifted from grassland and shrubland to a peri-urban matrix. Despite this shift from natural areas to more anthropogenically modified habitats, native red harvester ants (Pogonomyrmex barbatus) have maintained nest sites within parts of these matrices. To determine which habitat characteristics in a peri-urban landscape may play a role in red harvester ant nest site selection, we mapped the location of nests in 2020 and 2021. We then evaluated nest presence and absence relative to elevation, percentage of surrounding impervious surfaces, distance to roadways, and tree canopy cover (using NDVI). For a sub-sample of the study site, we also measured soil moisture and estimated the potential foraging area per colony with Voronoi tessellation. We found that nests were clustered together near high human-use areas such as athletic fields, lawns, sidewalks, and railroad tracks. Nests were more likely to be found in areas with higher elevation and lower tree canopy cover, with no impact from surrounding impervious surfaces or soil moisture. In fact, many nests were observed immediately adjacent to roadways and in paved parking lots. Red harvester ants are highly adept at nesting in disturbed, urbanized matrices, but still appear to be constrained by certain environmental factors like shading, potential flood risk (elevation), and access to food resources (foraging area). [ABSTRACT FROM AUTHOR]

Seed dormancy contributes greatly to successful establishment and community stability and shows large variation over a continuous status scale in mountain ecosystems. Although empirical studies have shown that seed dormancy status (SDS) is shaped by elevation and phylogenetic history in mountain ecosystems, few studies have quantified their combined effects on SDS. Here, we collected mature seeds from 51 populations of 11 Impatiens species (Balsaminaceae) along an elevational gradient in the Gaoligong Mountains of southwest China and estimated SDS using mean dormancy percentage of fresh seeds germinated at three constant temperatures (15, 20, and 25°C). We downloaded 19 bioclimatic variables from WorldClim v.2.1 for each Impatiens population and used internal transcribed spacer (ITS), atpB‐rbcL, and trnL‐F molecular sequences from the GenBank nucleotide database to construct a phylogenetic tree of the 11 species of Impatiens. Logistic regression model analysis was performed to quantify the effects of phylogeny and environment on SDS. Results identified a significant phylogenetic SDS signal in the Impatiens species. Furthermore, elevation and phylogeny accounted for 63.629% of the total variation in SDS among the Impatiens populations. The best logistic model indicated that temperature was the main factor influencing variation in SDS among the Impatiens species, and model residuals were significantly correlated with phylogeny, but not with elevation. Our results indicated that seed dormancy is phylogenetically conserved, and climate drives elevational patterns of SDS variation in mountain ecosystems. This study provides new insights into the response of seed plant diversity to climate change. [ABSTRACT FROM AUTHOR]

The montane shrublands of southern Ecuador represent one of the least studied ecosystems, which in the last decade have been seriously threatened by increasing wildfires, deforestation, overgrazing, and conversion to forest plantations. Our main objective was to determine, at the local scale, the diversity of species composing the biological soil crust (BSC) at three elevations (2100, 2300, and 2500 m.a.s.l.) and their possible relationships with soil physical and chemical properties in montane shrublands. For this purpose, three monitoring plots of 100 m² were established at each elevation, and within each plot, 20 subplots were established (180 subplots sampled in total). In addition, composite soil samples were collected at a depth of 0 to 10 cm, and some physical and biochemical parameters (e.g., bulk density, texture, pH, organic matter, soil organic carbon, total nitrogen, available phosphorus, and potassium) of the soil were analyzed. The results show 35 species (23 lichens, 10 bryophytes and 2 cyanobacteria) at three elevations with a bell-shaped or hump-shaped distribution pattern. This allowed us to point out that the species richness was higher at the intermediate elevations and that the composition showed significant differences in the three elevations related to soil factors. Elevation and soil drivers may help to better chose the more suitable biological soil crust (lichen-dominated and bryophyte-dominated BSC) for the management and conservation of the montane scrub of Ecuador, which is strongly threatened by human activities. [ABSTRACT FROM AUTHOR]

Reproductive territoriality can be influenced by external and internal variables. Trade-offs between reproductive behaviors and other costly biological processes, such as immunity, exist across taxa, but the effects of novel diseases on these trade-offs remain poorly understood. Since the introduction of avian malaria to Hawaii in the early 1900s, low elevation Hawaii Amakihi (Chlorodrepanis virens) populations, which have undergone strong selection by the disease, have evolved increased malaria resilience. However, the effects of malaria selection on trade-offs between immunity and reproduction in Amakihi remain largely unknown. To begin exploring this relationship, we conducted simulated territorial intrusions on Amakihi at low elevation (where malaria selection has been stronger) and high elevation (where selection has been weaker) on Hawaii Island during the breeding season. We hypothesized that selection by avian malaria has favored greater investment in avian malaria resilience at the cost of reproductive behaviors. We predicted that low elevation Amakihi would be less territorial compared with high elevation Amakihi, while recognizing that variables other than disease pressures that may differ across elevation (e.g. competition, predation) could explain behavioral variation. Territoriality was reduced in low compared with high elevation Amakihi as measured by proximity and chases in response to the intrusion. Low elevation Amakihi generally flew less than high elevation individuals, although this relationship varied across the breeding season. Our correlational results demonstrate that territoriality is greater in high compared with low elevation Amakihi. Further investigations would help determine which factors differing across elevation underlie this variation in territoriality. [ABSTRACT FROM AUTHOR]

This article examines how consumers' exposure to the viewpoint of high versus low vertical position changes their risk-taking behavior. The author proposes that consumers' views of scenery from a high physical elevation induce an illusory sense of control, which in turn intensifies risk taking. Multiple studies show that exposure to the viewpoint of high vertical positions increases risk taking in both laboratory settings (Studies 1a, 1b, and 1c) and real settings (Study 4). In addition, the author demonstrates that an illusory sense of control mediates the effect of an elevated viewpoint on risk taking (Study 2) and that the effect of elevation on risk taking is attenuated when people use a low-level mental construal to process visual information (Study 3). [ABSTRACT FROM AUTHOR]

Soil microbial community composition and extracellular enzyme activity are two main drivers of biogeochemical cycling. Knowledge about their elevational patterns is of great importance for predicting ecosystem functioning in response to climate change. Nevertheless, there is no consensus on how soil microbial community composition and extracellular enzyme activity vary with elevation, and little is known about their elevational variations on the eastern Qinghai-Tibetan Plateau, a region sensitive to global change. We therefore investigated the soil microbial community composition using phospholipid fatty acids (PLFAs) analysis, and enzyme activities at 2,820 m (coniferous and broadleaved mixed forest), 3,160 m (dark coniferous forest), 3,420 m (alpine dwarf forest), and 4,280 m (alpine shrubland) above sea level. Our results showed that soil microbial community composition and extracellular enzyme activities changed significantly along the elevational gradient. Biomass of total microbes, bacteria, and arbuscular mycorrhizal fungi at the highest elevation were the significantly lowest among the four elevations. In contrast, extracellular enzyme activities involved in carbon (C)-, nitrogen (N)-, and phosphorus (P)- acquiring exhibited the maximum values at the highest elevation. Total nutrients and available nutrients, especially P availability jointly explained the elevational pattern of soil microbial community, while the elevational variation of extracellular enzyme activities was dependent on total nutrients. Microbial metabolism was mainly C- and P-limited with an increasing C limitation but a decreasing P limitation along the elevational gradient, which was related significantly to mean annual temperature and total P. These results indicated a vital role of soil P in driving the elevational patterns of soil microbial community and metabolism. Overall, the study highlighted the contrasting responses of soil microbial biomass and extracellular enzyme activities to elevation, possibly suggesting the differences in adaption strategy between population growth and resource acquisition responding to elevation. The results provide essential information for understanding and predicting the response of belowground community and function to climate change on the eastern Qinghai-Tibetan Plateau. [ABSTRACT FROM AUTHOR]

Obtaining terrain elevation data is essential for numerous engineering applications. However, regardless of the technique used to obtain the elevation data, there will be errors intrinsic to the instruments and to the measurement technique used, as well as depending on the model of Earth representation, which are plane, spherical or ellipsoidal. In this perspective, this work proposes a comparative approach between the elevation data obtained from the geodesic coordinates, provided by Global Navigation Satellite System (GNSS), and those obtained from Google Earth (GE) and Shuttle Radar Topography Mission (SRTM). The data collection was carried out in the urban section between km 125 to km 145,500 of Dom Pedro-I Highway (SP-065), State of São Paulo, Brazil. The quality of the results is evaluated based on the Mean Quadratic Error (RMSE). The main results showed that the elevation data obtained through the SRTM show greater agreement or adjustment to the GNSS data when compared to the higher quality and less variation than those obtained through the GE, since they have smaller RMSE and are closer to the average elevations calculated for the highway segment analyzed. However, it is worth noting that the use of GE can be a good alternative for low-cost preliminary studies. [ABSTRACT FROM AUTHOR]

Agroforestry systems have been recognized for their high carbon (C) capture but vary across agroforestry practices and elevation gradients. Four distinct traditional agroforestry practices namely, dispersed trees in perennial crops, homesteads, boundary plantations, and woodlots, under smallholdings along elevation gradients were assessed. Using stratified random sampling, 540 sample quadrats in three elevations were randomly selected for biomass carbon stocks accounting. In addition, 180 sample quadrats were randomly selected for litters, fine roots, and soil organic carbon assessment. Litters and fine roots carbon stocks were determined based on loss-on-ignition and soil organic carbon (0–30 cm and 30–60 cm) determined using Walkley–Black method. The mean (± sd) biomass carbon stock in the boundary plantation was significantly (p < 0.001) higher by 64, 80, and 91% than woodlots, dispersed trees in perennial crops, and homesteads, respectively. The mean (± sd) ecosystem carbon stock (in biomass, litters, fine roots, and soil) in boundary plantation was significantly (p < 0.001) higher by 71, 64, and 47% than homesteads, dispersed trees, and woodlots, respectively. Litters and fine roots biomass carbon stocks showed insignificant contributions to ecosystem carbon stocks, valued 0.4 and 1.9%, respectively. Ecosystem carbon stock was significantly (p < 0.001) higher at the upper and middle elevations than the lower elevation. Observation on the interactions between elevation gradients and agroforestry practices did not show significant effect. Future attempts in agroforestry designs for tree intensifications and enhanced ecosystem carbon stocks should take into account the various distinct agroforestry practices and elevation gradients. [ABSTRACT FROM AUTHOR]

Arthropods at high latitudes and elevations are likely to be vulnerable to effects from climate change such as increased temperatures and shifting vegetation boundaries. Though range shifts northwards and upslope have been reported for many arthropod taxa in temperate latitudes, baseline data needed to track such changes are scarce at northern latitudes. We investigated the influence of climate and vegetation cover on the abundance, diversity, and species composition of pollinators and epigeic arthropods along an elevation gradient in Denali National Park and Preserve, Alaska. We compared arthropods across three habitat types: low-elevation forest, mid-elevation shrubs, and high-elevation tundra along five replicate transects over three years. We collected 35,473 arthropods representing 510 species. Arthropod communities differed distinctly across the three habitat types, with tundra having the highest number of strong indicators and unique species. Elevation, air temperature, and vegetation structure were strong drivers for the ordination of sites. As treeline and shrubline shift upslope with climate change, we predict that distributions of some arthropods will shift to track these habitat boundaries and that tundra-associated arthropods will be most vulnerable as their habitat shrinks. Long-term monitoring of arthropods along elevation gradients at northern latitudes is needed to detect such declines. [ABSTRACT FROM AUTHOR]

Improving our understanding of the growth dynamics of trees along elevation gradients could help us predict their potential to store carbon and their vulnerability to changes in local and global environmental conditions, such as deforestation and climate change. This study is a review and analysis of the results obtained in recent dendrochronological studies of the effect of elevation and climate (temperature and precipitation) on the radial growth of trees in temperate zones, mainly in the Northern Hemisphere. Only 18 (32.1%) of the 56 studies analyzed found a correlation between radial growth of the trees (total chronologies) and elevation. The analysis of 56 chronologies of 46 tree species included in the 110 works reviewed, showed that only in 28.2% of them the correlation between radial growth versus temperature and precipitation was significant: positive in 3.6%, negative in 2.7%, and positive and negative in 21.8%, depending on the season of the year. The wide variation found in the radial growth response of the trees to elevation gradients may be related to multiple environmental factors at a local or regional scale, but also to the different sampling methods used in the studies. However, a moderate proportion of the studies analyzed (close to 30%) show that temperature and rainfall are related to trends in radial growth in different elevation ranges and regions of the world. [ABSTRACT FROM AUTHOR]

Leaf size varies conspicuously within and among species under different environments. However, it is unclear how leaf size would change with elevation, whether there is a general elevational pattern, and what determines the altitudinal variation of leaf size. We thus aimed to address these questions by focusing on the broad-leaved herbaceous species at high altitudes on the northeastern Qinghai-Tibetan Plateau. We measured the leaf size, leaf length, leaf width and leaf mass per area for 39 broad-leaved herbaceous species inhabited in the open areas along two mountain slopes from 3200 to 4400 m at the Lenglongling and the Daban Mountain, the northeastern Qinghai-Tibetan Plateau. We analyzed the altitudinal patterns in leaf size in relation to leaf inclination and leaf surface features, and applied a leaf energy balance model to discuss the underlying mechanisms. Leaf size decreased significantly at higher altitudes. The altitudinal reduction of leaf size was mainly attributed to the reduction of leaf length, and differed in different species, and in leaves with different inclination and leaf surface features. A leaf energy balance model with local environmental measurements demonstrates that leaf temperature tracks air temperature more closely in small than in large leaves, and that the leaf-size impact is stronger at higher latitudes. Based on the observational findings, we propose that the distribution upper-limit for broad-leaved herbaceous species would be at an elevation of about 5400 m on the northeastern Qinghai-Tibetan Plateau. [ABSTRACT FROM AUTHOR]

The triangular arrow from thin to thick indicates that the value of a variable gradually increases, the shape from thin to thick to thin indicates that the value of the variable increases and then decreases. [Display omitted] • Soil micro-food web attributes and soil multifunctionality (SMF) exhibited a similar single hump-shaped pattern with increasing elevation. • Multitrophic composition and multitrophic diversity indirectly driven SMF through soil micro-food web complexity. • The soil micro-food web complexity was of greater importance in regulating SMF. Variations in soil micro-food web characteristics under changing environments can exert profound consequences on soil multifunctionality. However, the intrinsic relationship between these changes and their dependence on long-term environmental factors remains largely unquantified. Here, we investigated the soil micro-food web attributes (i.e., multitrophic diversity, multitrophic composition and network complexity) and multiple types of soil functions (soil multifunctionality) along an elevation gradient on the Eastern Tibetan Plateau. The results showed that elevation significantly affected the multitrophic composition, and multitrophic diversity, soil micro-food web complexity and soil multifunctionality exhibited a similar single hump-shaped pattern with increasing elevation. Compared to multitrophic composition and multitrophic diversity, the soil micro-food web complexity was significantly and positively correlated with soil multifunctionality and was of greater importance in regulating soil multifunctionality. However, multitrophic composition and multitrophic diversity indirectly driven soil multifunctionality through soil micro-food web complexity. This empirical evidence demonstrates that soil micro-food web complexity is a better predictor of soil functions than the multitrophic composition and diversity metrics that have been commonly used in previous studies. In conclusion, our findings highlighted the perceived importance of soil micro-food web complexity in regulating soil multifunctionality in forests under changing environments. [ABSTRACT FROM AUTHOR]

Soil organic carbon (SOC) plays an important role in global carbon cycle which is influenced by multiple factors. Elevation, as one of these factors, has a close but complex relationship with SOC concentration. The traditional 'global' statistical models cannot capture the spatial variation thus are inefficient in revealing the relationships between SOC and elevation at the local scale. In this study, a 'local' model of geographically weighted regression (GWR) was used to explore the complex relationships between SOC and elevation in the topsoil of Ireland based on the dataset from National Soil Database of Ireland. The results indicated SOC and elevation exhibited the spatially continuously varying relationships across the study area. Positive relationships in the mountainous areas suggested SOC concentration increased with the increasing elevation. Negative relationships were observed in the midlands where SOC concentration decreased with the increasing elevation. Such varying relationships between SOC and elevation in Ireland were related to the two different main types of peat: blanket peat and raised peat. These two types of peat have different formation processes, thus are distributed at different elevations. In the mountainous areas, low temperature and high humidity create cool and anoxic environment that mitigates SOC mineralization, promoting the accumulation of blanket peat at a high elevation. In the midlands, the low-lying lakes and wetlands provide anoxic environment where raised peat is developed and located at a low elevation. The findings of the spatially varying relationships between SOC and elevation in Ireland have demonstrated the importance of modelling SOC at the 'local' level. Attention is required for soil mapping using a global algorithm and it is recommended that localized algorithms are considered in modelling SOC, taking the feature of continuous variation into consideration. [Display omitted] • Spatially varying relationships between SOC and elevation were revealed by GWR. • Positive relationships were observed in mountainous areas related to blanket peat. • Negative relationships were observed in the midlands related to raised peat. • GWR is effective in revealing the spatially continuously varying relationships. [ABSTRACT FROM AUTHOR]

Research that has been conducted documenting species richness patterns on tropical mountains has resulted in conflicting observations: monotonic declines with increasing elevation, monotonic increases with increasing elevation, and a mid‐elevation "bulge." Currently, it is unclear if these differences are due to environmental differences among study areas, the taxonomic groups or ecological groups (e.g., growth form) sampled, or the scale of study along elevation gradients. Because of the difficulty in sampling and identifying canopy‐dwelling plants, the number of inventories quantifying tropical epiphytes is relatively limited and recent. In this study, we provide a detailed qualitative and quantitative assessment of the vascular epiphyte flora and its spatial distribution on Volcán Maderas, Isla de Ometepe, Nicaragua, including weather and environmental measurements along the entire elevation gradient of the volcano. We sampled epiphytes in five distinct forest types associated with increasing elevation as follows: dry forest, humid forest, wet forest, cloud forest, and elfin forest. Five weather stations were placed along the elevation gradient for us to relate observed patterns to environmental conditions. A mid‐elevation peak in species richness was detected for all vascular epiphytes at approximately 1000 m in elevation (cloud forest), yet epiphyte abundance increased with increasing elevation. In total we identified 206 taxa of vascular epiphytes belonging to 26 families and 73 genera. The most species‐rich family was the Orchidaceae with 55 species for the entire elevation gradient, followed by Bromeliaceae (29 species), Araceae (23), Polypodiaceae (25), Dryopteridaceae (16), and Piperaceae (11), with all other families represented by fewer than 10 species each. We found that richness patterns differ phylogenetically across epiphyte groups, possibly due to different adaptive strategies, and species for the most part appear to be narrowly distributed within specific habitat zones along the elevation gradient. Variables associated with moisture, precipitation, humidity, mist, or cloud cover are key to understanding the observed patterns. [ABSTRACT FROM AUTHOR]

The research aims to analyze the correlation of altitude, soil chemical properties and shades on Arabica coffee yields in Humbang Hasundutan Regency Sumatera Utara Province. This research was conducted using survey method with purposive sampling approach. Sampling were conducted on altitude varied between 1200 – 1500 m asl. Soil samples in top soil and sub soil were taken in order to analyze pH, C, N, P2O5, K, and cation exchange capacity (CEC). Coffee plant growth variables observed including productive branches, number of bunches, number of fruit per bunches, diameter of canopy and total yield. Whereas the quality variable measured were physical quality and taste. Data on soil chemical properties, elevation, yield and coffee quality were analyzed using the correlation method. The results showed that under shaded condition, N, CEC, pH, K and P were positively correlated with height increase, while C-organic, productive branches, number of fruits per bunch and coffee production were negatively correlated. Whereas in the condition without shade, N, C, pH, K, productive branches, the number of fruit per bunch is negatively correlated with height increase, while CEC, P, number of bunches, diameter of canopy and coffee yield are positively correlated. Statistical data shows that under shaded condition, the strongest correlation showed by pH and P av (0.999), Whereas in an unshaded condition, yield and CEC showed the strongest correlation (0.994). [ABSTRACT FROM AUTHOR]

Pre- and post-fire airborne lidar data provide an opportunity to determine peat combustion/loss across broad spatial extents. However, lidar measurements of ground surface elevation are prone to uncertainties. Errors may be introduced in several ways, particularly associated with the timing of data collection and the classification of ground points. Ground elevation data must be accurate and precise when estimating relatively small elevation changes due to combustion and subsequent carbon losses. This study identifies the impact of post-fire vegetation regeneration on ground classification parameterizations for optimal accuracy using TerraScan and LAStools with airborne lidar data collected in three wavelengths: 532 nm, 1064 nm, and 1550 nm in low relief boreal peatland environments. While the focus of the study is on elevation accuracy and losses from fire, the research is also highly pertinent to hydrological modelling, forestry, geomorphological change, etc. The study area includes burned and unburned boreal peatlands south of Fort McMurray, Alberta. Lidar and field validation data were collected in July 2018, following the 2016 Horse River Wildfire. An iterative ground classification analysis was conducted whereby validation points were compared with lidar ground-classified data in five environments: road, unburned, burned with shorter vegetative regeneration (SR), burned with taller vegetative regeneration (TR), and cumulative burned (both SR and TR areas) in each of the three laser emission wavelengths individually, as well as combinations of 1550 nm and 1064 nm and 1550 nm, 1064 nm, and 532 nm. We find an optimal average elevational offset of ~0.00 m in SR areas with a range (RMSE) of ~0.09 m using 532 nm data. Average accuracy remains the same in cumulative burned and TR areas, but RMSE increased to ~0.13 m and ~0.16 m, respectively, using 1550 nm and 1064 nm combined data. Finally, data averages ~0.01 m above the field-measured ground surface in unburned boreal peatland and transition areas (RMSE of ~0.19 m) using all wavelengths combined. We conclude that the 'best' offset for depth of burn within boreal peatlands is expected to be ~0.01 m, with single point measurement uncertainties upwards of ~0.25 m (RMSE) in areas of tall, dense vegetation regeneration. The importance of classification parameterization identified in this study also highlights the need for more intelligent adaptative classification routines, which can be used in other environments. [ABSTRACT FROM AUTHOR]

Human activities have affected the urban environment resulting in a drastic change in the surface temperature. The impact of urban heat islands is noticeable in urban areas than in rural areas. The thermal band of Landsat 8 data is used to retrieve the spatial distribution of land surface temperature (LST) over Kohima Sadar for the years 2009, 2015 and 2020 with the Mono-window algorithm. Urban Thermal Field Variance Index (UTFVI) is used to assess the ecological condition in the area impacted by LST. Cartosat-1 Digital Elevation Model (Carto DEM) is used to understand the variations of LST and indices values with reference to the elevation profile located at different random points. The variations in the land cover are categorized as per the values of normalized difference vegetation index (NDVI) and built-up density index (BUI). This work estimates the influence of elevation over LST, vegetation, and the built-up area. Results implies a negative correlation between LST and NDVI whereas a positive correlation between LST and BUI. Likewise, NDVI and BUI show a strong negative correlation. It is observed that LST is independent of elevation profile but the variation of LST depends on the impact of change in topography urbanization, deforestation, and afforestation. There is no significant relationship of elevation with the variations in NDVI and BUI values. It is observed that the impact of emissivity influences the estimation of LST values. For the locations having the highest and lowest LST, NDVI, and BUI values, 50 random points are generated for the entire region, and validation is executed with the google earth historical image. [ABSTRACT FROM AUTHOR]

Gaultheria leucocarpa var. cumingiana (S.Vidal) T.Z.Hsu was long been treated as a variety but recent evidences on its matK analysis and pollen structure showed a distinct species. To verify this, we revisited its taxonomic treatment using field data on its morpho-anatomical and ecological characters. The taxon is distinct from G. leucocarpa and its varieties with its smaller leaves, larger calyx and corolla, red to purple or blackish fruit at maturity, distinct pollen structures and distinct in matK analysis; hence, we are proposing the alteration as Gaultheria cumingiana Vidal to be recognized as a distinct species and not just a variety of G. leucocarpa. Additionally, we presented its detailed anatomical features that shows a typical dicot shade leaf with well-defined air spaces and unusually high abaxial stomatal density, eustele stem and protostele root anatomy. The ecological characters of the plant are also presented in terms of edaphic factors, biodiversity indices and surrounding floral species. Elevation and shading emerged as the major factors contributing to the distribution of the taxon showing a narrow elevation range at high altitude and preference for shading particularly at lower elevation populations but higher elevated populations can tolerate full sunlight. These information are important baseline for conservation and better understanding of the unique but understudied flora of the Cordillera Central Range. [ABSTRACT FROM AUTHOR]

Tidal wetlands provide myriad ecosystem services across local to global scales. With their uncertain vulnerability or resilience to rising sea levels, there is a need for mapping flooding drivers and vulnerability proxies for these ecosystems at a national scale. However, tidal wetlands in the conterminous USA are diverse with differing elevation gradients, and tidal amplitudes, making broad geographic comparisons difficult. To address this, a national-scale map of relative tidal elevation (Z*MHW), a physical metric that normalizes elevation to tidal amplitude at mean high water (MHW), was constructed for the first time at 30 × 30-m resolution spanning the conterminous USA. Contrary to two study hypotheses, watershed-level median Z*MHW and its variability generally increased from north to south as a function of tidal amplitude and relative sea-level rise. These trends were also observed in a reanalysis of ground elevation data from the Pacific Coast by Janousek et al. (Estuaries and Coasts 42 (1): 85–98, 2019). Supporting a third hypothesis, propagated uncertainty in Z*MHW increased from north to south as light detection and ranging (LiDAR) errors had an outsized effect under narrowing tidal amplitudes. The drivers of Z*MHW and its variability are difficult to determine because several potential causal variables are correlated with latitude, but future studies could investigate highest astronomical tide and diurnal high tide inequality as drivers of median Z*MHW and Z*MHW variability, respectively. Watersheds of the Gulf Coast often had propagated Z*MHW uncertainty greater than the tidal amplitude itself emphasizing the diminished practicality of applying Z*MHW as a flooding proxy to microtidal wetlands. Future studies could focus on validating and improving these physical map products and using them for synoptic modeling of tidal wetland carbon dynamics and sea-level rise vulnerability analyses. [ABSTRACT FROM AUTHOR]

(1) Background: Understanding the diversity of communities of arbuscular mycorrhizal fungi (AMF) is the basis for understanding the ecological functions of AMF. (2) Methods: The community diversity and distribution of AMF at different elevations in tropical montane rainforests of Mt. Jianfenfling and Mt. Diaoluo were explored using high-throughput sequencing technology. (3) Results: A total of 283 AMF operational taxonomic units (OTUs) were identified from roots and the number of unique OTUs was 173, accounting for 61.13% of the total number discovered in these tropical montane rainforests. At different altitudes, high turnovers of AMF were observed, with the maximum proportion of unique OTUs between two altitudes being 45.16%, recorded between a.s.l. 250 m and 900 m on Mt. Diaoluo. The highest Sobs, Shannon and Pielou diversity indices appeared at 650 m on Mt. Diaoluo. For the two mountains, the soil properties of C, N and C/N have significant impacts on the genera Scutellospora, Paraglomus and unclassified in Archaeosporaceae, while the genera Glomus, Diversispora and Acaulospora are significantly affected by soil P and pH. It can be considered that altitude probably determines the presence of AMF communities by affecting edaphic properties. (4) Conclusions: There are abundant AMF associated with roots in the tropical montane rainforests of China. Furthermore, a high turnover of OTUs was found to exist between the mountains and at different altitudes, revealing diverse AMF community structures in tropical montane rainforests. [ABSTRACT FROM AUTHOR]