Altitude Gradient Research Articles

Modern pollen distribution across Mizoram, northeastern India, impacted by regional climate and anthropogenic activities

Modern pollen-rain analysis was carried out for the first time across central, western and eastern regions of Mizoram, encompassing different regional climatic zones. The vegetation experiences massive ecological pressure as a consequence of environmental factors, including the monsoon winds from the Bay of Bengal, high temperature, precipitation conditions, and varied topography. Additionally, intense human activities in the state of Mizoram impact the forest landscape in the remote northeastern part of India. These include agricultural activities such as shifting cultivation ( Jhum), commercial crop plantations such as banana, rubber, oil palm, tea, etc., pastoral activities and others. We collected moss cushion samples across transects in the central, western and eastern regions of Mizoram, to comprehend the impact of natural and anthropogenic factors on the modern vegetation and resultant pollen taxa on the surface deposits. The modern pollen data were analyzed statistically, including constrained redundancy analysis (RDA). The RDA analysis revealed the impact of bioclimatic variables on the pollen record, such as isothermality, precipitation in the warmest quarter and annual precipitation. The most significant variable was isothermality (bio_3) which indicated the dominance of anthropogenically impacted sites on the species distribution. Here, we identified that an interplay of climate- and anthropogenic-driven forcing were primarily controlling the modern vegetation and pollen-rain across Mizoram. The anthropogenic indicator pollen, such Poaceae (>50 µm), Caryophylaceae, Asteroideae, Cannabaceae, and Palmae at various sites reveal the impact of anthropogenic activities on the modern vegetation. The results reveal the impact of climatic zones, altitude gradients, anthropogenic activities and vegetation distribution on the pollen yield from the surface deposits.

Effects of Soil Properties and Altitude on Phylogenetic and Species Diversity of Forest Plant Communities in Southern Subtropical China

The altitudinal distribution pattern of biodiversity is a hot topic in ecological research. This study specifically aims to investigate how altitude influences the spatial distribution of species and phylogenetic and functional diversity within plant communities. By examining three range-gradient communities of Daqing Mountain-Community I (0–300 m), Community II (300–600 m), and Community III (600–900 m), we explore the interrelationship between species diversity, phylogenetic indices, and environmental drivers (altitude, soil physical properties, and chemical properties). We found (1) a correlation between species diversity and phylogenetic structure in Daqing Mountain. Species diversity decreased and then increased with increasing altitude; phylogenetic diversity decreased with increasing altitude, and the phylogenetic structure changed from dispersed to aggregated; (2) Altitude and soil physical and chemical properties are important drivers of species richness, phylogenetic diversity, and phylogenetic structure along the altitude gradient; (3) The structural equations showed that soil physical properties and altitude rise were the key factors contributing to the decrease in biodiversity in Daqing Mountain, with total soil porosity directly influencing soil physical properties and soil water content indirectly. This study not only reveals the pattern of plant diversity along the altitude of Daqing Mountain but also provides a basis for plant conservation planning, habitat maintenance, and management coordination.

АДАПТИВНАЯ ИЗМЕНЧИВОСТЬ ПРИРОДНЫХ ЦЕНОПОПУЛЯЦИЙ PRUNUS ARMENIACA L. ПО МОРФОЛОГИЧЕСКИМ ПРИЗНАКАМ ЛИСТА ВДОЛЬ ВЫСОТНОГО ГРАДИЕНТА (ДАГЕСТАН)

The article presents the results of a study of the adaptive variability of morphological traits of leaves of natu- ral cenopopulations of Prunus armeniaca L. (common apricot) along the altitudinal gradient using the example of Intramountain Dagestan. Three model cenopopulations of Intramountain Dagestan along the Avarskoye Koysu River basin, which differ most strongly along the altitudinal gradient (600–1420 m above sea level), were selected as reference points. Analysis of the adaptability of P. armeniaca cenopopulations in the conditions of Dagestan showed a significant role of the altitude above sea level on the variability of leaf morphological traits. It was found that the greatest dependence on the altitude gradient have the traits “width of the leaf blade” and “length to the wide part of the leaf,” as well as index indicators calculated on their basis. Analysis of the variability of quan- titative leaf traits by the variation coefficient (CV, %) showed that the variability of traits decreases along the alti- tude gradient, which may indicate a decrease in the population optimum of the species with altitude above sea level. The results of the comparative analysis were confirmed by the results of ANOVA and regression analyses. The variance components for the ovoidness indices were 62.8%, and roundness – 37.1%, leaf width – 22.5%, length to the wide part of the leaf – 17.4% and SLA – 15.6%. Based on the results of regression analysis, it was revealed that the altitudinal level negatively effects on the leaf size of natural coenopopulations of P. armeniaca by narrowing of the leaf width and shortening of the length to the wide part of the leaf, which ultimately results in the formation of oval-ovate leaves. The determination coefficients (r2 ) showed a noticeable linear relationship be- tween the selected traits and the altitudinal gradient, with the exception of leaf width. The index of vitality of cenopopulations (IVC) showed a deterioration in growing conditions in the direction from low-mountain cenopopulations to mid-mountain ones (from 1.04 to 0.96), while the low value of dimensional plasticity (ISP=1.08) indicates the relative stability of leaf traits along the altitudinal gradient.

Effect of Warming on Soil Fungal Community Along Altitude Gradients in a Subalpine Meadow.

The subalpine grassland ecosystem is sensitive to climatic changes. Previous studies investigated the effects of warming on grassland ecosystems at a single altitude, with little information about the response of subalpine meadows to warming along altitude gradients. This study aimed to evaluate the effects of warming on aboveground grass, belowground soil properties, and fungal community along altitude gradients in the subalpine meadow of Mount Wutai using the high-throughput sequencing method. Warming reduced the restriction of low temperatures on the growth of subalpine grass, resulting in increasing grass biomass, community height, and coverage. More grass biomass led to higher soil organic carbon resources, which primarily affected fungal community composition following warming. Warming might induce more stochastic processes of fungal community assembly, increasing fungal diversity at low altitudes. In contrast, warming triggered more deterministic processes to decrease fungal diversity at medium and high altitudes. Warming might improve the efficiency of soil nutrient cycling and organic matter turnover by increasing the relative abundance of soil saprotrophs and improving fungal network connectivity. The relative abundance of certain grass pathogens significantly increased following warming, thereby posing potential risks to the sustainability and stability of subalpine meadow ecosystems. Overall, this study comprehensively evaluated the response of the subalpine meadow ecosystems to warming along altitude gradients, clarifying that warming changes soil fungal community composition at different altitudes. The long-term monitoring of pathogen-related shifts should be conducted in subalpine meadow ecosystem following warming. This study provided significant scientific insights into the impact of future climatic changes on subalpine ecosystems.

Elevation Determines Fungal Diversity, and Land Use Governs Community Composition: A Dual Perspective from Gaoligong Mountains.

Soil fungi are closely tied to their surrounding environment. While numerous studies have reported the effects of land-use practices or elevations on soil fungi, our understanding of how their community structure and diversity vary with elevation across different land-use practices remains limited. In the present study, by collecting soil samples from four different land uses in the Gaoligong Mountain area, namely shrublands (SLs), coffee plantations (CPs), cornfields (CFs), and citrus orchards (COs), and combining them with the changes in altitude gradients (low: 900 m, medium: 1200 m, high: 1500 m), high-throughput sequencing technology was used to analyze the composition and diversity of soil fungal communities based on the collected soil samples. The results showed that the interaction between land-use types and elevation significantly influenced the structure and diversity of fungal communities, although their relative importance in shaping fungal diversity or community structure varied. Specifically, elevation posed a stronger effect on fungal community alpha-diversity and functional guilds, whereas land-use types had a greater influence over fungal community composition. Our study reveals the individual and combined effects of land-use practices and elevation on the structure and diversity of soil fungal communities in the Gaoligong Mountain region, enhancing our understanding of the distribution patterns and driving mechanisms of soil fungal communities in this biodiversity-rich region.

Anatomical-Foliar Diversity of Agave salmiana subsp. salmiana (Asparagaceae) in Three Populations of the Teotihuacán Region (Mexico).

Agave salmiana Otto ex Salm-Dyck is an endemic Mexican plant distributed from 1230 to 2460 m above sea level, native to the arid zones of central and southern Mexico. It is a traditionally used species, with morphotypes ranging from wild to cultivated, with an ample cultural and management history. The species is important because it generates employment, and its products are used for self-consumption and are marketed as raw materials; however, little is known about its leaf anatomical description or studies that report the variation in its characters in terms of its level of management and its altitudinal gradient. To address this, we collected leaf samples from three localities of the Teotihuacan region in the State of Mexico (Mexico) and obtained anatomical leaf sections; with these, we also obtained thirty-eight parameters to quantitatively describe leaf anatomy. Thus, in this study, the general anatomical description of the leaf of Agave salmiana subsp. salmiana is presented. Unique leaf characters and others shared with the species of the genus were identified for the leaf of A. salmiana subsp. salmiana. In addition, significant variation was observed when comparing the three sampled localities (78.95%). From the analysis of anatomical characters, abaxial outer periclinal wall length, length of adaxial palisade parenchyma cells, fiber length, surface area of abaxial epidermal cells, width of abaxial palisade parenchyma cells, and total length of parenchyma in adaxial palisade were found to distinguish individuals from the three localities analyzed and the differences are related to management and altitude gradients.

Analysis of Key Environmental Variables Affecting Fish Communities and Species Distribution in Asian Lotic Ecosystems

In 2011, Korea installed artificial structures on four rivers to secure water resources and reduce flood damage; however, these structures have altered ecosystems and aquatic communities. This study analyzed fish communities and environmental variables at 72 sites in the Geumgang River. Fish communities and environmental variables before weir installation were examined using site data from 2008 to 2009. The results showed that Cyprinidae dominated the 70 observed species. A self-organizing map categorized the 72 sites into four groups based on fish communities. Sensitive and insectivorous species decreased, whereas tolerant and omnivorous species increased from Groups I to IV. Twenty-one indicator species were identified, with fewer and less distinct distribution patterns in Groups II and III than in Groups I and IV. The fish assessment index (FAI) showed a decline in grades A and B and an increase in grades C and D from Groups I to IV. Correlation analysis between the FAI and environmental variables indicated that fish communities in the Geumgang River were mainly influenced by water quality, reflecting altitude gradients and pollution levels. This study’s findings are anticipated to significantly inform water management strategies for the Geumgang, Yeongsangang, Nakdonggang, and Hangang Rivers.

A Retrospective Report on the Infestation and Distribution of Chiggers on an Endemic Rodent Species (Apodemus latronum) in Southwest China.

Chiggers are the exclusive vector of Orientia tsutsugamushi, which is the causative agent of scrub typhus. Based on the field surveys in southwest China between 2001 and 2022, this paper retrospectively reported the chigger infestation and distribution on the large-eared field mouse (Apodemus latronum), an endemic rodent species in the region, for the first time. A total of 933 chiggers were collected from 501 mice, and these chiggers were identified as 2 families, 8 genera, and 61 species. The overall infestation prevalence (PM) and mean abundance (MA) of A. latronum with chiggers reached 19.76% and 1.86 mites/per mouse, respectively. The chigger infestation indices on adult A. latronum (PM = 38.28%, MA = 5.11) were higher than those on juvenile mice (PM = 12.63%, MA = 0.97) with p < 0.01, showing an age bias of infestation. The relative fatness (K) was used to reflect the nutrition status of the mouse host. The mouse hosts with good nutrition (K = 3.4 ± 0.89 g/cm3) harbored fewer chiggers than the hosts with poor nutrition (K = 2.2 ± 0.90 g/cm3) (p < 0.01). The infestation indices of chiggers on A. latronum obviously fluctuated along different altitude gradients (p < 0.01). With the increase in altitudes, the β diversity of the chigger community showed a gradually increasing tendency. The spillover chord diagram, which was based on indices of PAC (potential for apparent competition), revealed high spillover potentials of dominant chigger species dispersing from high altitude gradients to the lowest one. The chigger abundance was positively correlated with the mean monthly temperature (tmp), mean monthly humidity (hum), the mean monthly precipitation (pre), and the human footprint (hfp), and it was negatively correlated with the altitude (ele) (p < 0.05). The temperature and humidity are the most important factors which influence the chigger infestation.

Effect of Grasses on Native Tree Seedling Establishment Along a Water Stress Gradient: Results of Forest and Greenhouse Experiments

ABSTRACTAnthropogenic activities such as cattle grazing and forest clearing have led to the establishment of early successional grass layers in some native forests, which may inhibit or entirely prevent native tree regeneration. We hypothesize that increased grass coverage reduces or eliminates the establishment of native tree seedlings by limiting water availability to seeds and seedlings. This study aims to evaluate the impact of grass cover on tree seedling survival under varying levels of soil water stress. We conducted a field experiment using 36 experimental exclosures in two northwest Patagonian valleys, representing a regional gradient in altitude, rainfall, and tree canopy openness. Additionally, a greenhouse experiment was performed with 36 pots, manipulating four levels of grass cover and three levels of water stress. Results from both experiments showed similarities: in the field, the likelihood of finding a live tree seedling was approximately 2.78 times higher in areas without grass compared with grass‐covered sites. In the greenhouse, the presence of grass reduced the final number of established seedlings by an average of 43% across all irrigation levels, indicating significant water competition. These findings suggest that management practices promoting grass invasion could severely hinder tree regeneration in forests not adapted to large herbivore intensive grazing. Such situation may be exacerbated in regions suffering water limitation in the growing season or where the climate change would intensify water stress.

Altitude Distribution Patterns and Driving Factors of Rhizosphere Soil Microbial Diversity in the Mountainous and Hilly Region of Southwest, China

The distribution characteristics of the microbial community in rhizosphere soils of different altitudinal gradients were explored to uncover ecological factors affecting microbial community composition. In this study, the community variations of bacteria and fungi in the rhizosphere soil of Chrysanthemum indicum L. were analyzed. Samples were distributed along an altitudinal gradient of 300–1500 m above sea level in the Fuling watershed of the Three Gorges Reservoir area, China. The analysis was conducted using Illumina MiSeq high-throughput sequencing and bioinformatics analyses. Through correlation analysis with ecological factors, the altitude distribution pattern and driving factors of soil microbial diversity in the mountainous and hilly region of Chongqing were explored. According to the results, the richness and diversity of rhizosphere soil bacteria increased with altitude, while fungi were the richest and most diverse at an altitude of 900 m. The composition of the microbial community differed among different altitudes. Actinobacteria, Proteobacteria, Acidobacteriota, Chloroflexi, Bacteroidota, Ascomycota, unclassified_k_Fungi, Basidiomycota, and Mortierellomycota dominated the microbial community in rhizosphere soil. Correlation analysis showed that the distribution of rhizosphere soil microbial communities correlated with soil ecological factors at different altitudes. Moisture, pH, total nitrogen, total potassium, available potassium, urease, and catalase were significantly positively correlated with rhizosphere soil bacterial α-diversity, while their correlations with fungi were not significant. Variation partition analysis showed that the combined effects of soil physical and chemical factors, enzyme activity, and microbial quantity regulated bacterial community structure and composition. Their combined contributions (19.21%) were lower than the individual effects of soil physical and chemical factors (48.49%), enzyme activity (53.24%), and microbial quantity (60.38%). The effects of ecological factors on fungal communities differed: While the soil physical and chemical factors (44.43%) alone had a clear effect on fungal community structures, their combined contributions had no apparent effect. The results of this study not only contribute to a deeper understanding of the impact mechanism of altitude gradient on the diversity of rhizosphere soil microbial communities, but also provide a scientific basis for the protection and management of mountainous and hilly ecosystems. It lays a foundation for the future exploration of the relationship between microbial communities and plant–soil interactions.

Quantitative classification and biodiversity characteristics of plant communities in Luoshan Mountain steppe, Ningxia, China

To understand the distribution pattern and influencing factors of plant community and diversity along the altitude gradient, we examined plant community types, plant diversity and phylogenetic diversity of mountain steppe in Luoshan, Ningxia, and analyzed the relationship between the plant community and its diversity and environmental driving factors. The results showed that the main community types in the mountain steppe were Asterothamnus centraliasiaticus community, Caragana tibetica community, Convolvulus tragacanthoides community, Stipa bungeana community, Stipa breviflora＋Ajania achilloides community, Artemisia frigida community, Roegneria alashanica＋S. breviflora＋Hedysarum polybotrys community, S. breviflora＋Stipa grandis community, S. grandis＋S. bungeana community, Cyperus glomeratus community, S. grandis community and Carex aridula community. The distribution of mountain steppe community was mainly affected by altitude, soil alkali-hydrolyzed nitrogen, water content, available potassium, silt and organic matter contents, with altitude and soil water content having the greatest effects (P<0.01). The Patrick index and phylogenetic diversity index (PD) of plant community showed an increasing trend with the altitude increase, the Shannon index and Pielou index showed a unimodal trend, and the phylogene-tic structure gradually changed from aggregation to dispersion. There was a significant positive correlation between species diversity index and PD index. Shannon index was negatively correlated with net relatedness index (NRI). Plant species diversity and phylogenetic diversity of mountain steppe were mainly affected by soil water content, available potassium, total nitrogen, silt and sand contents. NTI was significantly affected by altitude, while the NRI index was significantly affected by soil silt content.

Respiration Activity of Microbial Biomass in the Main Types of Mountainous Soils along the Altitude Gradient of the Central Caucasus

Respiration Activity of Microbial Biomass in the Main Types of Mountainous Soils along the Altitude Gradient of the Central Caucasus

Diversity of Orchid in Abies nephrolepis Nature Reserve in Shanxi, China.

Abies nephrolepis Nature Reserve has complex habitats and rich species diversity but lacks systematic ecological surveys. We focused on Orchid in Abies nephrolepis Nature Reserve, investigated and analyzed Orchid diversity and changes in community structure according to the characteristics of the alpine valleys in the study area, in terms of altitude gradient and habitat type, using the sample line method and the quadrat method. The results showed that 11 genera and 13 species of Orchidaceae were found in the survey, among which the species richness of Malaxis monophyllos was the highest, Neottia puberula was the second highest, and the species richness of Tulotis ussuriensis was the lowest, and the species with relative plurality ≥ 10% were Malaxis monophyllos (51.69%), Neottia puberula (14.77%), and Cypripedium guttatum (11.15%). The results of diversity analysis showed that Orchidaceae species were rich and the diversity index were the highest in the middle altitude area of 1950-2250 m; the distribution of Orchidaceae in the low altitude area was obviously clustered, and the similarity with the high altitude area was low. With the increase in altitude, the number of species showed an increase and then a decrease, showing a single-peak state, which was in line with the theory of "Intermediate altitude expansion hypothesis". The species and number of Orchidaceae in different habitats of Abies nephrolepis Nature Reserve also varied considerably, with Shannon-Wiener diversity index being the highest in EV4 (Abies nephrolepis + Picea meyeri + Picea wilsonii + Larix gmelinii var. principis-rupprechtii-Lonicera hispida-Carex lanceolata community) and EV5, and the smallest in EV1 habitats, Pielow evenness index being the highest in EV5 habitats and the lowest in EV1 habitats, and Simpson's index being the highest in EV5 habitats and the lowest in EV1 habitats. This study provides a scientific basis for strengthening regional monitoring of species diversity and protecting biodiversity.

Environmental Factors Drive the Biogeographic Pattern of Hippophae rhamnoides Root Endophytic Fungal Diversity in the Arid Regions of Northwest China.

Hippophae rhamnoides subsp. sinensis Rousi (Abbrev. H. rhamnoides) stands as a vital botanical asset in ameliorating the ecological landscape of the arid regions in Northwest China, where its rhizospheric microorganisms serve as linchpins in its growth and developmental dynamics. This study aimed to explore the community structure characteristics and origin differences of root endophytic fungi in H. rhamnoides. Samples were collected from 25 areas where H. rhamnoides is naturally distributed along an altitude gradient in the northwest region. Then, endophytic fungi from different regions were analyzed by using high-throughput sequencing technology to compare the structural characteristics of endophytic fungi and examine their association with environmental factors. FUNGuild was employed to analyze the community structure and functions of endophytic fungi, and the results showed that each region had its own dominant endophytic fungal flora, demonstrating the differences in origin of endophytic fungi, and the specific endophytic flora acquired from the original soil in the growing season of H. rhamnoides will help us construct the microecological community structure. Furthermore, the study identified and assessed the diversity of fungi, elucidating the species structure and highlighting dominant species. The RDA analysis revealed that available phosphorus (AP), available potassium (AK), and total nitrogen (TN) exhibit significant correlations with the composition and diversity of root-associated fungi. In conclusion, the fungal community structure is similar within the same region, while significant differences exist in the taxonomic structure and biodiversity among different regions. These findings shed light on the intricate interplay and mechanisms governing the ecological restoration of H. rhamnoides, offering a valuable framework for advancing green ecology initiatives and harnessing the potential of root-associated microorganisms in this species.

Influence of columnar versus vertical distribution of aerosol properties on the modulation of shortwave radiative effects

Quantifying the interaction of atmospheric aerosols with incoming solar radiation remains a challenge owing to the limitations associated with measuring aerosol optical properties. This study investigates how the distribution of aerosol properties, whether columnar or vertical, affects the aerosol radiative forcing (ARF) and heating rates (HRs) across different atmospheric layers under cloud-free conditions in the shortwave region. We also assess the atmospheric parameters, namely, pressure, temperature, water vapour density, and ozone density, from in-situ measurements, reanalysis data, and a standard tropical atmosphere to understand their impact on ARF and HR estimates across seasons. Our findings show that aerosol absorption is highest during monsoon, while it is lowest in the winter. Significant atmospheric warming due to aerosols resulted from the substantial cooling at the surface. Columnar properties of aerosols measured at limited or multiple wavelengths yield similar ARF and HR estimates, provided spectral dependency is considered using the Angstrom exponent across seasons. However, the vertical profiles of aerosol extinction, together with a constant single scattering albedo (SSA) along the atmospheric column versus an actual SSA profile, led to notable differences in ARF and HRs, specifically in pre-monsoon and monsoon periods. Free tropospheric aerosol absorption is underestimated when using columnar properties compared to vertical distribution, while boundary layer absorption is overestimated (> 10 Wm-2). The heterogeneity in aerosol types across atmospheric layers significantly influenced aerosol absorption, highlighting the importance of accurate vertical distribution information. HR profiles obtained with vertical distribution reflect the structure of aerosol extinction, whereas those estimated with columnar properties result in smoother profiles that fail to capture altitude gradients. Aerosol-induced HRs are higher within the boundary layer and free troposphere in the monsoon season for all scenarios of defined aerosol properties. These findings underscore the need for actual vertical profile measurements of aerosol properties to quantify aerosol radiation interaction.

Altitudinal Effects on Soil Microbial Diversity and Composition in Moso Bamboo Forests of Wuyi Mountain.

Moso bamboo (Phyllostachys edulis) forest is a key ecosystem and its soil microbial community plays a crucial role in maintaining the ecosystem's functions, but it is very vulnerable to climate change. An altitude gradient can positively simulate environmental conditions caused by climate change, and hence, it provides an efficient means of investigating the response of soil microorganisms to such climatic changes. However, while previous research has largely concentrated on plant-soil-microorganism interactions across broad altitudinal ranges encompassing multiple vegetation types, studies examining these interactions within a single ecosystem across small altitudinal gradients remain scarce. This study took Moso bamboo forests at different altitudes in Wuyi Mountain, China, as the research object and used high-throughput sequencing technology to analyze the soil microbial community structure, aiming to elucidate the changes in soil microbial communities along the altitude gradient under the same vegetation type and its main environmental driving factors. This study found that the structure of bacterial community was notably different in Moso bamboo forests' soil at varying altitudes, unlike the fungal community structure, which showed relatively less variance. Bacteria from Alphaproteobacteria phylum were the most dominant (14.71-22.91%), while Agaricomycetes was the most dominating fungus across all altitudinal gradients (18.29-30.80%). Fungal diversity was higher at 530 m and 850 m, while bacterial diversity was mainly concentrated at 850 m and 1100 m. Redundancy analysis showed that soil texture (sand and clay content) and available potassium content were the main environmental factors affecting fungal community structure, while clay content, pH, and available potassium content were the main drivers of bacterial community structure. This study demonstrates that the altitude gradient significantly affects the soil microbial community structure of Moso bamboo forest, and there are differences in the responses of different microbial groups to the altitude gradient. Soil properties are important environmental factors that shape microbial communities. The results of this study contribute to a deeper understanding of the impact of altitude gradient on the soil microbial community structure of Moso bamboo forests, thus providing support for sustainable management of Moso bamboo forests under climate change scenarios.

Effects of Environmental Factors on the Diversity of Grasshopper Communities along Altitude Gradients in Xizang, China.

To determine the grasshopper species composition, altitudinal distribution patterns, and their main drivers, we conducted a study in Xizang using 33 sample plots ranging from 600 to 4100 m. Grasshoppers were collected from August to October during 2020-2022 using sweep nets. A total of 1159 grasshoppers from six families, 28 genera, and 44 species were identified, with Omocestus cuonaensis and Aserratus eminifrontus as the dominant species, comprising 30.03% and 10.26% of total grasshoppers, respectively. The results showed that species richness and the Margalef richness index of grasshopper communities decreased significantly (p < 0.05) with increasing altitude, peaking at 1100-1600 m and lowest values at 2600-3100 m. Similarly, the Shannon-Wiener index and Simpson dominance index also decreased significantly (p < 0.05) with an increase in altitude, showing the highest and lowest values at 600-1100 m and 3100-3600 m, respectively. The Jaccard similarity coefficients among grasshopper communities varied from 0 to 0.40 across altitudinal gradients, indicating different degrees of dissimilarity. The results of Pearson correlation analyses showed that the Shannon-Wiener index, species richness, Margalef richness index, and Simpson dominance index of grasshopper communities were significantly negatively correlated with the temperature factors and soil pH, but they were significantly positively correlated with the moisture factors. Hierarchical partitioning identified annual mean temperature-daily difference, precipitation in the coldest season, and driest month precipitation as the primary factors explaining variance in grasshopper community diversity in Xizang. These findings provided greater insights into the mechanisms underlying insect community structure, distribution patterns, and diversity in Xizang ecosystems, including implications for the effects of global warming on insect communities.

Difference in microbial community structure along a gradient of crater altitude: insights from the Nushan volcano.

The variation in the soil microbial community along the altitude gradient has been widely documented. However, the structure and function of the microbial communities distributed along the altitude gradient in the crater still need to be determined. We gathered soil specimens from different elevations within the Nushan volcano crater to bridge this knowledge gap. We investigated the microbial communities of bacteria and fungi in the soil. It is noteworthy that the microbial alpha diversity peaks in the middle of the crater. However, network analysis shows that bacterial (nodes 760 vs 613 vs 601) and fungal (nodes 328 vs 224 vs 400) communities are most stable at the bottom and top of the crater, respectively. Furthermore, the soil microbial network exhibited a decline, followed by an increase across varying altitudes. The core microorganisms displayed the highest correlation with pH and alkaline phosphatase (AP, as determined through redundancy analysis (RDA) and Mantel tests for correlation analysis. The fungal community has a higher number of core microorganisms, while the bacterial core microorganisms demonstrate greater susceptibility to environmental factors. In conclusion, we utilized Illumina sequencing techniques to assess the disparities in the structure and function of bacteria and fungi in the soil.IMPORTANCEThese findings serve as a foundation for future investigations on microbial communities present in volcanic soil.

Distributions and controlling factors of soil total nitrogen and nitrogen fractions along an altitude gradient in Qinghai-Tibet Plateau

Distributions and controlling factors of soil total nitrogen and nitrogen fractions along an altitude gradient in Qinghai-Tibet Plateau

Variations in iron-bound organic carbon in soils along an altitude gradient and influencing factors in a subtropical mountain ecosystem of southern China

Variations in iron-bound organic carbon in soils along an altitude gradient and influencing factors in a subtropical mountain ecosystem of southern China