Elevational Diversity Patterns Research Articles

Soil bacteria and fungi on tropical mountainsides: Joint effects of weathering, climate, and chemical factors

Contemporary environmental factors such as temperature and pH are generally identified as primary influences on microbial diversity, while the role of geological processes remain understudied. Here, we investigated the diversity and community composition of bacteria and fungi along an elevational gradient from703 to 4514 m on Mt. Kilimanjaro, East Africa. We further examined the effects of contemporary environment and geological processes such as weathering on microbial communities and diversities. For community composition, bacteria and fungi showed clear differentiation along elevations and their community dissimilarities increased with elevational distance indicating elevational distance-decay relationships. Multiple variables such as weathering, climate and chemical factors were significantly associated with microbial communities and showed greater effects on bacterial than fungal communities. Specifically, soil pH mainly shaped bacterial communities, while mean annual temperature for fungi, followed by other variables such as weathering processes. For Shannon diversity, bacteria and fungi showed significant hump-shaped elevational patterns with the peak values at 1857 and 1436 m, respectively. Shannon diversity was mainly affected by soil weathering accounting for 8.9% of the total variance for bacteria, while jointly by weathering and climate accounted for 14.3% of fungi. For the community uniqueness, represented by local contribution to beta diversity (LCBD), there were U-shaped patterns for both taxonomic groups. LCBD was mainly explained by the joint effects of chemical and climate variables which accounted for 51.1% and 33.4% for bacteria and fungi, respectively. Our results highlight the effects of soil weathering processes on diversity and community composition for bacteria and fungi. Thus, the integration of weathering with contemporary environments could provide new insights into microbial elevational diversity patterns.

Functional and phylogenetic structure of mammals along elevational gradients in the Central and East Himalayas

BackgroundMountain ecosystems are critical hotspots of global biodiversity, yet the dynamics of community assembly along their elevational gradients are not well understood. This gap is primarily due to the complexity of environmental and biotic interactions that influence species distribution and community structure. Although extensive research has been conducted on certain taxa, such as small mammals and bats, comprehensive studies encompassing entire mammal assemblages are lacking. Our research aims to bridge this gap by examining the taxonomic, phylogenetic, and functional diversity, as well as the assemblage structures of mammal communities across elevational gradients in the Central and East Himalayas, exploring how diverse ecological and evolutionary processes impact community assembly.MethodsWe analyzed mammal elevational diversity patterns using species richness, functional diversity (FD), and phylogenetic diversity (PD). We compared the observed values of community structure, such as mean pairwise phylogenetic distance (MPD) and mean pairwise functional distance (MFD), with null-model corrected effect sizes to identify patterns and processes of community assembly. Using structural equation modeling and hierarchical partitioning, we investigated the relationships between climate, productivity, and various facets of diversity, describing the organization of each component across different elevations.ResultsTaxonomic, functional, and phylogenetic diversity generally decreased with elevation but showed varied patterns such as mid-elevation peaks, low-elevation plateaus, or monotonic declines across different regions. Richness-controlled functional diversity increased towards mid-low elevations and decreased at higher elevations in both regions, whereas richness-controlled phylogenetic diversity lacked consistent patterns. Phylogenetic structures tended to cluster from mid to high elevations, indicating closer relationships than those observed in random communities, likely due to significant environmental turnover near tree lines. Functional structure showed greater clustering at high elevations and increased over-dispersion at lower elevations, suggesting that species are more functionally similar than expected at higher elevations and more diverse at lower elevations. Our results revealed that environmental factors, evolutionary histories, and trait-driven ecological processes collectively shape species richness along these gradients.ConclusionsOur results showed incongruent community structures across phylogenetic and functional diversity. Generally, functional traits are closely linked to environmental conditions, reducing the chance of observing traits that are misaligned with their surroundings. Species with similar ecological roles or distinct evolutionary lineages often show convergent adaptations to highland environments. Additionally, our findings emphasize that community assembly varies with the biogeography and diversification history of individual mountain ranges, complicating the development of a generalized theory. Using multiple measures is important for accurate community structure assessments and effective conservation planning, as variable elevational patterns exist across different diversity dimensions.

Ant impacts on global patterns of bird elevational diversity.

Using data on bird species elevational distributions from the world's mountain ranges, bird diets, and the distribution of the ant genus Oecophylla, we report that global patterns in bird elevational diversity show signals of competition with ants. Oecophylla is an abundant and effective predator of invertebrates, preying on the same species that invertivorous birds feed on. In mountain ranges with Oecophylla present in the foothills, the maximum species richness of invertivorous birds (but not other trophic guilds) occurs, on average, at 960 m, ca. 450 m higher than in mountain ranges without Oecophylla, resulting in a mid-elevation peak in bird species richness. Where Oecophylla is absent, bird species richness for all guilds generally show monotonic declines with increasing elevation. We argue that Oecophylla reduces prey density for invertivorous birds and that low prey abundance reduces invertivorous bird density, which in turn is correlated with lower bird species richness. These findngs suggest that competition between distantly related taxa can set range limits, leading to emergent diversity patterns over large scales.

Dispersal limitations and ecological adaptions shape phylogenetic diversity patterns of angiosperm woody plant communities along latitudinal and elevational gradients in East Asian islands

For centuries, ecologists have been captivated by the assembly of local communities from regional species pools, which gives rise to spatial diversity patterns. This study focused on hierarchical filtering process, which involves dispersal limitation and climatic constraint across regional to local scale, that underpins plant biodiversity patterns in East Asian islands, as one of the biodiversity hotspots with high endemicity. We used vegetation and species pool datasets of angiosperm woody plant communities collected from seven mountains across Japan to Taiwan to explore the relative contributions of local factors of individual plots, islands, latitude, elevation, and climatic variables related to the pattern of phylogenetic community assembly. Using linear regression and variation partitioning, we found that the island factor had the strongest filtering effect followed by latitude. Elevation and local factors (slope, aspect) accounted for a very small proportion of the variance in phylogenetic dispersion and community clade age between member species. Geographical factors involving islands, distance, and elevation had overriding filtering effects over climatic factors (minimum temperature of the coldest month, precipitation of the driest month) in shaping woody plant assembly patterns at the regional scale across East Asia islands. Tropical niche conservatism contributed to shaping woody plant communities in temperate region and high elevational regions on subtropical mountains as young and closely related species coexisted in those regions due to their adaptation to cold climates. This also explained the minor climate effects on species sorting in temperate mountains characterized by temperate-specific species pool which had already been filtered by cold climates. Inconsistent elevational phylogenetic diversity patterns in East Asia islands suggest a mountain-specific process that governs community assembly along elevational gradients, likely attributed to the location and climate of the mountain. These results suggest that historical factors (geohistorical isolation) related to islands and mountains contribute to in situ diversification that shaped plant diversity gradient from subtropical to temperate forests.

Ant Species Distribution Models Reveal Mixed Elevational Diversity Patterns in Complete Elevation Gradients: Past and Present Climatic Effects?

Ant Species Distribution Models Reveal Mixed Elevational Diversity Patterns in Complete Elevation Gradients: Past and Present Climatic Effects?

The Role of Vegetation in Elevational Diversity Patterns of Tenebrionid Beetles in Central Italy

Vegetation tends to vary in a systematic fashion along elevational gradients, leading to the possibility of recognizing distinct vegetational belts, which are frequently used to describe and interpret elevational variations in biodiversity. However, anthropogenic changes can create landscapes dominated by secondary grasslands in areas formerly occupied by forests, thus altering the natural sequence of vegetation types. The present research illustrates how the distribution of tenebrionid beetles in central Italy is influenced by secondary vegetation. Classical schemes of vegetational belts were modified into a scheme of main vegetation types that include secondary vegetations. Tenebrionid species presence/absence in each vegetation type was then assessed. Species richness tended to decrease with elevation in both natural and secondary vegetations. Geophilous (ground-dwelling) species (which include many endemics) prevailed in natural and secondary grasslands, while xylophilous species (associated with trees) prevailed in the natural forests. Similarities in tenebrionid composition indicated the presence of two main groups: one associated with forests and the other with natural and secondary grasslands. Geophilous species prevailed among tenebrionids with Mediterranean distributions, whereas xylophilous species prevailed among species distributed mainly in Europe and the Palearctic. High values of richness, biogeographical complexity and proportion of endemics make secondary vegetations of high conservation concern.

Deterministic processes drive turnover-dominated beta diversity of breeding birds along the central Himalayan elevation gradient

Beta diversity, the variation of community composition among sites, bridges alpha and gamma diversity and can reveal the mechanisms of community assembly through applying distance-decay models and/or partitioning beta diversity into turnover and nestedness components from functional and phylogenetic perspectives. Mountains as the most natural experiment system provide good opportunities for exploring beta diversity patterns and the underlying ecological processes. Here, we simultaneously consider distance-decay models and multiple dimensions of beta diversity to examine spatial variations of bird communities, and to evaluate the relative importance of niche-based and neutral community assembly mechanisms along a 3600-m elevational gradient in the central Himalayas, China. Our results showed that species turnover dominates taxonomic, functional, and phylogenetic beta diversity. We observed strongest evidence of spatial distance decays in taxonomic similarities of birds, followed by its phylogenetic and functional analogues. Turnover component was highest in taxonomic beta diversity, while nestedness component was highest in functional beta diversity. Further, all correlations of assemblage similarity with climatic distance were higher than that with spatial distances. Standardized values of overall taxonomic, functional, and phylogenetic beta diversity and their turnover components increase with increasing elevational distance, while the standardized values of taxonomic and phylogenetic nestedness decreased with increasing elevational distance. Our results highlighted the niche-based deterministic processes in shaping elevational bird diversity patterns that were determined by the relative roles of decreasing trend of environmental filtering and increasing trend of limiting similarity along elevation distances.

Species elevational richness gradient and species-area relationship in mountain vegetation of Javakheti highland (Georgia)

Elevational gradients in species richness and species-area relationships are among the most interesting patterns in ecology and biogeography. Both patterns can be characteristic of the same system; however, current knowledge of how these patterns co-exist and how we can disentangle their contributions to biodiversity structure is insufficient. In this article, we tested the effect of elevation and area on the formation of plant species diversity patterns in the forest-free Javakheti Highlands (Georgia). Samples (170 plots) were collected within elevations of 1400-3100 m, and the diversity distribution was examined in relation to altitude, available band area, and sampling. In total, 564 species from 67 families were recorded. Plant species richness was highest at mid-elevations (1900–2200 m), irrespective of area and sampling effort. This was in line with other studies from the Caucasus indicating the generality of plant elevational diversity patterns in the region. Area was not an important predictor of species richness; however, this may be considered a result of insufficient sampling. Our study shows that more research is needed to understand the effect of area on patterns of elevational biodiversity distribution.

Soil Phosphorus Availability Controls Deterministic and Stochastic Processes of Soil Microbial Community along an Elevational Gradient in Subtropical Forests

Revealing the assembly mechanisms of the soil microbial community, which is crucial to comprehend microbial biodiversity, is a central focus in ecology. The distribution patterns of microbial elevational diversity have been extensively studied, but their assembly processes and drivers remain unclear. Therefore, it is essential to unravel the relationship between the deterministic and stochastic processes of the microbial community assembly and elevational gradients. Here, our study built upon previous physicochemical analyses of soil samples collected along an elevational gradient (900–1500 m) in Daiyun mountain, a subtropical forest located in southeastern China. Using the phylogenetic-bin-based null model analysis (icamp) and multiple regression on matrices approach, we explored the major drivers that influence the assembly processes of soil bacterial and fungal community across elevations. The results showed that: (1) bacterial rare taxa exhibited a broad habitat niche breadth along the elevational gradient; (2) homogeneous selection and homogenizing dispersal proved to be the most important assembly processes for the bacterial and fungal community; (3) soil phosphorus availability mediated the relative importance of deterministic and stochastic processes in the soil microbial community. Notably, the relative abundance of dominant microbial taxa controlled by homogeneous selection and homogenizing dispersal increased with increasing soil phosphorus availability. Collectively, the assembly processes of microbial elevational communities of the subtropical mountains in China can be explained to some extent by variations in the soil phosphorus availability. This conclusion provides valuable insights into the prediction of soil microbial diversity and phosphorus nutrient cycling in subtropical montane forests.

Soil Micro-eukaryotic Diversity Patterns Along Elevation Gradient Are Best Estimated by Increasing the Number of Elevation Steps Rather than Within Elevation Band Replication.

The development of high-throughput sequencing (HTS) of environmental DNA (eDNA) has stimulated the study of soil microbial diversity patterns and drivers at all scales. However, given the heterogeneity of soils, a challenge is to define effective and efficient sampling protocols that allow sound comparison with other records, especially vegetation. In studies of elevational diversity pattern, a trade-off is choosing between replication within elevation bands vs. sampling more elevation bands. We addressed this question for soil protists along an elevation gradient on Mt. Asahi, Hokkaido, Japan. We compared two sampling approaches: (1) the replicate strategy (five replicates at six elevational bands, total = 30) and (2) the transect strategy (one sample in each of 16 different elevational bands). Despite a nearly twofold lower sampling effort, the transect strategy yielded congruent results compared to the replicate strategy for the estimation of elevational alpha diversity pattern: the regression coefficients between diversity indices and elevation did not differ between the two options. Furthermore, for a given total number of samples, gamma diversity estimated across the entire transect was higher when sampling more elevational bands as compared to replication from fewer elevational bands. Beta diversity (community composition turnover) was lower within a given elevational band than between adjacent bands and increased with elevation distance. In redundancy analyses, soil organic matter-related variable (the first principal component of soil organic matter, water content, total organic carbon, and nitrogen by whom were highly correlated) and elevation best explained elevational beta diversity pattern for both sampling approaches. Taken together, our results suggest that sampling a single plot per elevation band will be sufficient to obtain a good estimate of soil micro-eukaryotic diversity patterns along elevation gradients. This study demonstrated the effectiveness of the transect strategy in estimating diversity patterns along elevation gradients which is instructive for future environmental or even experimental studies. While not advocating for completely replacing replication-based sampling practices, it is important to note that both replicate and transect strategies have their merits and can be employed based on specific research goals and resource limitations.

Temperature drives elevational diversity patterns of different types of organisms in Qinghai-Tibetan Plateau wetlands

The spatial pattern and driving mechanism of biodiversity along elevational gradients are key topics in ecology. However, it is still unclear whether the multidimensional diversity of different types of organisms shows a similar response to elevation changes. Here, we measured the species and phylogenetic diversity of plants, bacteria, fungi, and microbial functional groups (nitrifiers, denitrifiers, methanogens, and methanotrophs) in 36 wetland sites on the Qinghai-Tibetan Plateau. The results showed that both species and phylogenetic diversity of plants, bacteria, and fungi exhibited a significant elevational gradient, in direct contrast to no significant diversity changes observed for denitrifiers, methanogens, and methanotrophs along the same altitude gradient. Our findings suggest that elevation and temperature were more likely to associate with the diversity of plants, bacteria, and fungi than the diversity of microbial functional groups, with important implications for assessing the effect of ongoing climate warming on biodiversity in Qinghai-Tibetan alpine wetlands.

The spatial patterns of diversity and their relationships with environments in rhizosphere microorganisms and host plants differ along elevational gradients.

Identifying spatial patterns of biodiversity along elevational gradients provides a unified framework for understanding these patterns and predicting ecological responses to climate change. Moreover, microorganisms and plants are closely interconnected (e.g., via the rhizosphere) and thus may share spatial patterns of diversity and show similar relationships with environments. This study compared diversity patterns and relationships with environments in host plants and rhizosphere microorganisms (including various functional groups) along elevational gradients across three climatic zones. We found that above-and belowground diversity decreased monotonically or showed a hump-shaped or U-shaped pattern along elevation gradients. However, the diversity patterns of plants, bacteria, and fungi varied depending on the taxon and climatic zone. Temperature and humidity strongly contribute to above-and belowground diversity patterns and community composition along elevational gradients. Nonetheless, soil factors might be important regulators of diversity patterns and the community composition of plants and microorganisms along these gradients. Structural equation modeling revealed that environmental factors had a stronger direct effect on rhizosphere microbial diversity than host plant diversity. In sum, spatial patterns of diversity and their relationships with environments in rhizosphere microorganisms and their host plants differed at the regional scale. Different functional groups (e.g., pathogen, mycorrhiza and nitrifier) of soil microorganisms may have divergent elevational patterns and environmental responses. These data improve our understanding of elevational diversity patterns, and provide new insights into the conservation of biodiversity and ecosystem management, especially under climate change.

Butterfly Diversity at the Different Elevations along Crocker Range Park, in Malaysian Borneo

The butterfly diversity and assemblages at five substations located at the different elevations along the Crocker Range Park, ranging from 396m to 1,891m a.s.l were documented in this study. The butterfly samplings were conducted from April to December 2019, involving 10 sampling sessions. The butterflies were sampled by using 20 baited traps and an aerial net at 20 sampling stations. A total of 727 individuals were sampled comprising 187 species. Nymphalidae was the dominant family at the five substations, which accounted for approximately 53% of the total species and 71% of the total individuals recorded, while Ypthima pandocus was the dominant species. The highest number of species was recorded at Keningau substation (965-1,062 m a.s.l) but the highest number of individuals was recorded at Mahua substation (1060-1,249 m a.s.l). Mount Alab substation recorded the least number of butterfly species and individuals. The overall pattern indicated that the butterfly species and abundance were relatively high at an elevation range of about 960-1,250 m a.s.l. Keningau substation was the most diverse area as shown by Shannon-Wiener Index (H’=2.885), followed by Inobong, Mahua and Ulu Kimanis substations. Ten endemic species were sampled in this study with most of these found at an elevation above 965 m a.s.l. The information obtained from this study would contribute to a better understanding of the elevational diversity pattern of tropical biota and also could serve as baseline data for conservation management at Crocker Range Park in facing threats on biodiversity, including global warming.

Elevational diversity patterns of rodents differ between wet and arid mountains

AbstractAimPatterns of species richness along elevation gradients vary with geographic and environmental factors but evidence for similar variation in functional and phylogenetic diversity remains scarce. Here, we provide the most comprehensive evaluation to date of elevational gradients in taxonomic, functional, and phylogenetic diversity of rodents – one of the most ecologically diverse groups of mammals – and test the effects of latitude and aridity on their variation for the first time.LocationForty‐nine mountains on five continents.Time periodContemporary.Major taxa studiedRodents (Rodentia).MethodsWe compiled elevational distributions of 374 rodent species across 49 elevational gradients. For each gradient, we quantified – in 100‐m elevational bins – rodent species richness and functional and phylogenetic richness, evenness, and dispersion, and their species richness‐corrected equivalents. To assess how rodent diversity varies with elevation, we fitted a series of models that included elevation, average latitude, and aridity of each mountain system while accounting for variation in study design and sampling effort.ResultsA common mid‐elevational peak in species richness among mountains contrasts with functional and phylogenetic diversity pattern variation (model shape and slope) explained by the aridity at a mountain's base. Specifically, we find that functional and phylogenetic richness and dispersion decline with elevation in wet mountain systems but increase with elevation in arid mountains.Main conclusionsIn this first comparative analysis of mammal functional and phylogenetic elevational gradients, we find that the decoupling of each from species richness is particularly pronounced in arid regions. Wet‐mountain lowlands and arid‐mountain highlands harbour the most functionally and phylogenetically diverse rodent communities, indicating that water availability is a strong environmental filter in structuring diversity of small mammals on mountain gradients. High regularity of species distances within assemblages supports a constant role for competition across all elevations and niche expansion in elevations with greater species richness.

Lichen holobionts show compositional structure along elevation.

Holobionts are dynamic ecosystems that may respond to abiotic drivers with compositional changes. Uncovering elevational diversity patterns within these microecosystems can further our understanding of community-environment interactions. Here, we assess how the major components of lichen holobionts-fungal hosts, green algal symbionts, and the bacterial community-collectively respond to an elevational gradient. We analyse populations of two lichen symbioses, Umbilicaria pustulata and U. hispanica, along an elevational gradient spanning 2100 altitudinal metres and covering three major biomes. Our study shows (i) discontinuous genomic variation in fungal hosts with one abrupt genomic differentiation within each of the two host species, (ii) altitudinally structured bacterial communities with pronounced turnover within and between hosts, and (iii) altitude-specific presence of algal symbionts. Alpha diversity of bacterial communities decreased with increasing elevation. A marked turnover in holobiont diversity occurred across two altitudinal belts: at 11°C-13°C average annual temperature (here: 800-1200m a.s.l.), and at 7°C-9°C average annual temperature (here: 1500-1800m a.s.l.). The two observed zones mark a clustering of distribution limits and community shifts. The three ensuing altitudinal classes, that is, the most frequent combinations of species in holobionts, approximately correspond to the Mediterranean, cool-temperate, and alpine climate zones. We conclude that multitrophic microecosystems, such as lichen holobionts, respond with concerted compositional changes to climatic factors that also structure communities of macroorganisms, for example, vascular plants.

Co‐ordinated elevational diversity patterns for soil bacteria, fungi, and plants in alkaline soils of arid northwestern China

AbstractPlants often show remarkable elevational distribution patterns in arid‐montane ecosystems. However, it is not clear if soil microbes follow elevational diversity patterns, even though they represent the majority of biodiversity and drive varieties of ecological processes. Here, we conducted a survey of fungal and bacterial communities across an elevational gradient from 2350 to 3850 m in a typical mountainous grassland of arid northwestern China. Our results revealed co‐ordinated alpha and beta diversity patterns for soil microbes and plants along the elevational gradient, and the richness and Shannon diversity of bacteria, fungi, and plants exhibited a unimodal elevational pattern. The unimodal diversity pattern for soil microbes was further confirmed by the shifts in the relative abundance of dominant bacterial phyla (Actinobacteria, Firmicutes and Nitrospirae) and fungal phyla (Zygomycota) along the elevational gradient. Soil variables (soil pH, organic carbon, total nitrogen, available phosphorus, and nitrate nitrogen) explained the largest proportion of the variability in both bacterial and fungal communities, followed by plant (richness and Shannon diversity) and climatic (mean annual temperature and precipitation) variables. These environmental factors together explained a larger proportion of variability in bacterial communities (54.88%) than in fungal communities (24.15%). Our results strongly supported the existence of co‐ordinated elevational diversity patterns for soil microbes and plants in arid‐montane ecosystems, and highlighted that the importance of soil pH in microbial elevational patterns was also apparently in alkaline soils.Highlights Soil bacteria and fungi follow elevational diversity patterns of plants. Species richness and Shannon diversity index exhibited unimodal elevational patterns. Soil, plant, and climatic factors are co‐responsible for microbial diversity. These factors explained more variation in bacteria than that in fungi. Microbial diversity is more vulnerable to precipitation than temperature.

Elevational diversity pattern and allochronic divergence of scorpionflies in the Qinling Mountains

Scorpionflies (Mecoptera, Panorpidae) as a relict group of holometabolous insects normally inhabit dense vegetations of mountain regions in the northern hemisphere. They are vulnerable to temperature changes and deforestation and thus play a significant role in insect conservation as ecological indicators. However, their elevational distribution and seasonal emergence patterns remain largely unknown. We documented the elevational richness gradient of scorpionflies in the Qinling Mountains, central China. The result revealed a distinct pattern of mid-elevational peak (hump-shaped) in species richness. The linear relationship between elevational locations of the whole community and emergence dates showed a gradual movement from lower to higher elevations over time. Niche divergence is an important ecological mechanism for closely related species to co-exist in the same region. Our investigation showed that allochronic divergences of adult emergence occurred mainly in intermediate elevations to reduce interspecific competition for resources. Spatio-temporal niche divergence was also detected in closely related species, especially in Cerapanorpa scorpionflies. Our results showed a clearer pattern of elevational diversity of scorpionflies and indicated that niche conservatism and divergence could explain the richness pattern at the same time. The area of intermediate elevations with the greatest species richness should receive a priority consideration for insect conservation for such a cool-adapted group of insects.

Elevational Diversity Patterns of Green Lacewings (Neuroptera: Chrysopidae) Uncovered With DNA Barcoding in a Biodiversity Hotspot of Southwest China

Elevational diversity patterns can reflect the responses of biodiversity to climate change spatially. We investigate the species diversity patterns of green lacewings (an important predatory group of insects) along the gradient of elevation from the Shaluli Mountains (Mts. Shaluli), which belong to the Hengduan Mountains in southwestern China, one of the important hotspots of global biodiversity. We combined multiple approaches, including Automatic Barcode Gap Discovery (ABGD), Assemble Species by Automatic Partitioning analysis (ASAP), General Mixed Yule Coalescent (GMYC), Poisson tree processes (bPTP), multi-rate Poisson tree processes (mPTP), to delimit the green lacewings species based on the standard barcoding region of cytochrome c oxidase subunit I (COI). The α-diversity and β-diversity patterns of green lacewings from the Mts. Shaluli along the gradient of elevation were analyzed, with further exploration on how the temperature effect elevational-diversity pattern on broad-scale (county scale) elevational gradients. The DNA barcoding reference library consisted of 40 green lacewing species from the Mts. Shaluli. The α-diversity of green lacewings decreased with the increasing elevation. The temperature was found to have a significant effect on the abundance and Shannon-Wiener diversity index but not on the species richness. Nestedness replaced turnover as the main component of Sørensen’s dissimilarity with the increasing elevation, and greater nestedness occurred at low temperature areas. The combination of a reliable DNA barcoding database could improve the accuracy and efficiency to investigate the species diversity patterns of green lacewings. Temperature, resource, and resultant interspecific competitions may have important roles in explaining the species diversity patterns of green lacewings from the Mts. Shaluli. Priority of conservation should be given to the species at low elevation, middle elevation, and relatively high temperature regions under the background of global climate warming.

Vascular Epiphyte Assemblages on Isolated Trees along an Elevational Gradient in Southwest Panama

Ongoing destruction of tropical forests makes isolated pasture trees potentially important for the persistence of original forest dwellers such as many vascular epiphytes. We studied epiphyte assemblages on 100 isolated trees at ten pasture sites in southwest Panama along an elevational gradient ranging from 140 to 1240 m a.s.l. We analysed epiphyte species composition (richness, similarity) and registered climate and host trait variables of potential influence on their occurrence. We found a total of 5876 epiphyte individuals belonging to 148 species. Epiphyte abundance, species richness and diversity all varied about 4-fold among the 10 sites, with a high similarity of epiphyte assemblages among sites. Two sites at 870 and 1050 m a.s.l. did not fit into the overall elevational trend of increased abundance, species richness and diversity. However, all three measures were significantly correlated with humidity as the independent variable. This highlights that a gradient in humidity, and not elevation as such, is responsible for the typical elevational changes in epiphyte assemblages, so that special local conditions may lead to deviations from expected patterns. Our documentation of current elevational diversity patterns also provides a baseline for the study of long-term changes in epiphyte assemblages in anthropogenically modified landscapes.

Contrasting patterns and drivers of soil bacterial and fungal diversity across a mountain gradient.

Microbial elevational diversity patterns have been extensively studied, but their shaping mechanisms remain to be explored. Here, we examined soil bacterial and fungal diversity and community compositions across a 3.4 km elevational gradient (consists of five elevations) on Mt. Kilimanjaro located in East Africa. Bacteria and fungi had different diversity patterns across this extensive mountain gradient-bacterial diversity had a U shaped pattern while fungal diversity monotonically decreased. Random forest analysis revealed that pH (12.61% importance) was the most important factor affecting bacterial diversity, whereas mean annual temperature (9.84% importance) had the largest impact on fungal diversity, which was consistent with results obtained from mixed-effects model. Meanwhile, the diversity patterns and drivers of those diversity patterns differ among taxonomic groups (phyla/classes) within bacterial or fungal communities. Taken together, our study demonstrated that bacterial and fungal diversity and community composition responded differently to climate and edaphic properties along an extensive mountain gradient, and suggests that the elevational diversity patterns across microbial groups are determined by distinct environmental variables. These findings enhanced our understanding of the formation and maintenance of microbial diversity along elevation, as well as microbial responses to climate change in montane ecosystems.