Unimodal Pattern Research Articles

Zoogeography and diversity patterns of the family Cicadellidae (Hemiptera) in Toshka Region, Egypt

ABSTRACT Leafhoppers (family: Cicadellidae) are among the most common plant sap-sucking pests, causing damage to wild and agronomic plants worldwide. The current paper aims to assess the zoogeography, diversity and population dynamics of the leafhopper species in an agricultural land converted ecosystem. Twenty species (two identified only to the genus level) belonging to 17 genera, 10 tribes, and three subfamilies were collected from Toshka Region, Aswan Governorate, Egypt, in 2020. The most common cicadellid species was Orosius albicinctus, representing 46.7% of the total catch. Low values of species richness and diversity were measured for leafhopper species as compared with those reported in our recent study carried out in Alexandria and Qena governorates. In sum, conversion of any natural ecosystem to agricultural land uses may cause declines in insect diversity. However, desert conversion may increase the diversity pattern of some insect pests. Analysis of the zoogeographic affinities of the leafhopper species from Toshka Region indicated a closer affiliation to the Palaearctic Region (35%) than any other region. Most leafhopper populations exhibited a unimodal seasonal pattern and were abundant in hot and dry months (May–September). The abundance of some leafhopper species correlated positively with temperature (seven species) and negatively with relative humidity (nine species). Six of these species correlated with both variables. This study is the first to investigate leafhopper communities in a converted ecosystem of Toshka Depression, Western Desert.

Structural and functional characteristics of soil microbial community in a Pinus massoniana forest at different elevations.

Shifts in forest soil microbial communities over altitudinal gradients have long been attracting scientific interest. The distribution patterns of different soil microbial communities along altitudinal gradients in subtropical mountain forest ecosystems remain unclear. To better understand the changes in soil microbial communities along an altitude gradient, we used Illumina MiSeq metagenome sequencing technology to survey the soil microbial communities in a Pinus massoniana forest at four elevations (Mp1000, Mp1200, Mp1400, Mp1600) and in a tea garden in Guizhou Leigong Mountain in Southwestern China. We observed that the richness of bacteria, fungi, and viruses in the soil microbial community changed in a unimodal pattern with increasing elevation while that of Archaea first increased significantly, then decreased, and finally increased again. Euryarchaeota and Thaumarchaeota were the predominant Archaea, Proteobacteria and Acidobacteria were the predominant bacterial groups, Ascomycota and Basidiomycota were the predominant fungal groups, and Myoviridae, Podoviridae, and Siphoviridae were the predominant virus groups. Amino acid transport and metabolism, energy production and conversion, signal transduction mechanisms, and DNA replication, restructuring and repair were the predominant categories as per NOG function gene-annotation. Carbohydrate metabolism, global and overview map, amino acid metabolism, and energy metabolism were predominant categories in the KEGG pathways. Glycosyl transferase and glycoside hydrolase were predominant categories among carbohydrate enzyme-functional genes. Cluster, redundancy, and co-occurring network analyses showed obvious differences in the composition, structure, and function of different soil microbial communities along the altitudinal gradient studied. Our findings indicate that the different soil microbial communities along the altitudinal gradient have different distribution patterns, which may provide a better understanding of the mechanisms that determine microbial life in a mid-subtropical mountain forest ecosystem.

Linkage between microbial functional genes and net N mineralisation in forest soils along an elevational gradient

AbstractSoil net nitrogen (N) mineralisation, the difference between organic nitrogen mineralisation and mineral nitrogen immobilisation, changes with elevation, thereby determining plant productivity and soil N cycling along elevation gradients. However, it has yet to be established how different microbial functional genes influence the rate of soil net N mineralisation along such gradients. To address this deficiency in our current knowledge, we performed metagenomic sequencing to identify soil microbial functional genes encoding enzymes involved in N cycling at five forest sites along an elevational gradient spanning a range from 1503 to 3182 m above sea level. Our results indicate that the rate of net N mineralisation follows a unimodal pattern with increasing elevation, with a peak (0.18 mg kg−1 d−1) being detected at the mid‐high elevation site. Further, we detected a significant correlation between the abundance of genes encoding enzymes involved in denitrification and ammonia assimilation pathways and net N mineralisation rate (p < 0.05). Moreover, we established that microbial species in the phyla Cyanobacteria, Acidobacteria and Planctomycetes, harbouring keystone functional genes, play a predominant role in determining the rate of net N mineralisation. Our findings also revealed soil substrate content (ammonium nitrogen and nitrite nitrogen, soil organic carbon, and C:N ratio) and soil environment (soil temperature and soil moisture) to be the major drivers of net N mineralisation in soil via their regulatory effects on the composition of microbial communities and functional genes. Our characterisation of the microbial metagenomic basis of net N mineralisation in forest soils accordingly highlights the importance of the combined contributions of soil microbial functional genes, soil substrate, and environmental factors in determining the cycling of N in forest soils at different elevations.Highlights Net N mineralisation rate followed a unimodal pattern along an elevational gradient. Denitrification and ammonia assimilation genes were correlated with net N mineralisation rate. Cyanobacteria play a dominant role in determining net N mineralisation rate. Soil substrate and environment determine microbial functional gene distribution.

ME-PLAN: A deep prototypical learning with local attention network for dynamic micro-expression recognition

As one of the important psychological stress reactions, Micro-expressions (MEs) are spontaneous and subtle facial movements, which usually occur in a high-stake situation and can reveal genuine human feelings and cognition. ME, Recognition (MER) has essential applications in many fields such as lie detection, criminal investigation, and psychological healing. However, due to the challenges of learning discriminative ME features via fleeting facial subtle reactions as well as the shortage of available MEs data, this research topic is still far from well-studied. To this end, in this paper, we propose a deep prototypical learning framework, namely ME-PLAN, with a local attention mechanism for the MER problem. Specifically, ME-PLAN consists of two components, i.e., a 3D residual prototypical network and a local-wise attention module, where the former aims to learn the precise ME feature prototypes through expression-related knowledge transfer and episodic training, and the latter could facilitate the attention to the local facial movements. Furthermore, to alleviate the dilemma that most MER methods need to depend on manually annotated apex frames, we propose an apex frame spotting method with Unimodal Pattern Constrained (UPC) and further extract ME key-frames sequences based on the detected apex frames to train our proposed ME-PLAN in an end-to-end manner. Finally, through extensive experiments and interpretable analysis regarding the apex frame spotting and MER on composite-database, we demonstrate the superiority and effectiveness of the proposed methods.

Genetic Diversity Analysis of the Chinese Daur Ethnic Group in Heilongjiang Province by Complete Mitochondrial Genome Sequencing.

Mitochondrial DNA (mtDNA) has the characteristics of maternal inheritance, high mutation rate, high copy number, and no recombination. As the most powerful tool for studying the origin and evolution of modern humans, mtDNA has great significance in the research of population genetics and evolutionary genetics. Here, we provide new insights into the maternal genetic history of the Daur ethnic group by generating complete mitochondrial genomes from a total of 146 Daur individuals in China. We also collected the published complete mitochondrial genome sequences of 5,094 individuals from 56 worldwide populations as reference data to further explore the matrilineal genetic landscape of the Daur ethnic group. First, the haplotype diversity was 0.9943 ± 0.0019 and nucleotide diversity was 0.0428 ± 0.0210. The neutrality tests of the Daur group showed significant negative values and the mismatch distribution curve was obviously distributed in a unimodal pattern. The results showed that the Daur ethnic group has high genetic diversity and may have experienced recent population expansion. In addition, the main haplogroups of the Daur population were haplogroup D (31.51%), M* (20.55%), C (10.28%), F (7.53%), and B (6.85%), all of which were prevalent in northern China. It probably implies the northern Chinese origin of the Daur population. The PCA, F ST, and phylogenetic analysis results indicated that the Daur group formed a cluster with East Asian populations, and had few genetic differences with the populations in northern China. More importantly, we found that disease-related mutation sites of the mitochondrial genome may be related to ethnic groups, which may have important implications for the prevention and occurrence of specific diseases. Overall, this study revealed the complexity and diversity of the matrilineal genetic background of the Daur ethnic group. Meanwhile, it provided meaningful data for the research on the diversity of the human genome.

Avian species richness and tropical urbanization gradients: Effects of woodland retention and human disturbance.

Urbanization is a major driver of tropical biodiversity loss. In temperate regions avian species richness–urbanization intensity relationships typically exhibit unimodal patterns, with peak richness at intermediate urbanization levels. In tropical regions, the form of such relationships and the extent to which they are moderated by patches of seminatural habitat are unclear. We address these questions in Bangkok, Thailand (one of the largest and most rapidly expanding tropical mega‐cities) and generate conservation recommendations for tropical biodiversity in urban locations. We use repeated point count surveys at a random location, and the largest available woodland patch, in 150 1 km × 1 km grid cells selected along the urbanization gradient. Woodland patches support higher species richness compared with randomized locations (except for non‐natives), and avian species richness declines linearly with increasing urbanization. The contrast with unimodal patterns in temperate regions is probably driven by divergent patterns of habitat heterogeneity along tropical and temperate urbanization gradients. Moreover, we provide novel evidence that retaining patches of urban woodland moderates adverse impacts of urbanization on avian species richness. For most species groups, the benefits of woodland increase as urbanization intensifies, despite such woodland patches being very small (mean of 0.38 ha). Avian species richness in woodland patches is maximized, and community composition less similar to that in randomized locations, when woodland patches are larger and visited by fewer people. Assemblages of forest‐dependent species (which provide additional ecological functions) have higher richness, and are less similar to those in randomized locations, in patches of woodland with higher tree species richness and biomass. Finally, species richness in randomized sites is greatest when they are closer to woodland patches, and such assemblages more closely resemble those of woodland sites. Our work highlights four strategies for tropical urban bird conservation: (1) conserving woodland patches across the urbanization gradient regardless of patch size, (2) improving the quality of existing woodland by increasing tree biomass and diversity, (3) creating additional woodland that is well distributed throughout the urban area to minimize effects of habitat isolation and (4) reducing human disturbance, especially in areas of the highest habitat quality, while ensuring that the benefits of connecting people to nature are realized in other locations.

Robinia pseudoacacia decline and fine root dynamics in a plantation chronosequence in the Yellow River Delta, China

Abstract Fine roots (<2 mm in diameter) play a significant role in tree growth and stand productivity. However, knowledge of fine root dynamics in saline alkali soil remains limited. Using sequential soil core and ingrowth core methods, we assessed the dynamics of aboveground biomass (AGB) and production (AGP), fine root biomass (FRB), production (FRP) and turnover (FRT), and soil properties (water content [SWC], salt content [SSC], pH and nutrients) in 2-, 18-, 32- and 42-year-old black locust (Robinia pseudoacacia L.) stands in the Yellow River Delta, China. Corresponding to the unimodal growth pattern in AGP, the AGB of black locust rapidly increased until age 32 and then slowed down. In contrast, across all depths, FRB and FRP took a unimodal pattern with a decrease in growth around age 32, and FRT continually decreased with stand age. SWC and soil nutrients increased with stand age, whereas SSC and pH decreased with stand age until age 32 and then increased. Based on the correlation analysis, we may presume that in addition to the age effect, the decline of black locust in AGP is most likely caused by SWC, SSC, and pH stresses through the dysfunction in nutrient absorption by fine roots.

Effects of Elevation Gradient on Soil Carbon and Nitrogen in a Typical Karst Region of Chongqing, Southwest China

AbstractElevation changes create gradients in abiotic factors, which in turn affect soil erosion and carbon cycling. However, how elevation changes control soil ecological processes through temperature and the mechanism that affects the carbon cycle remain unclear. Therefore, we have studied the distribution of temperature, bulk density (BD), soil pH, mean weight diameter (MWD), clay, and diversity of soil fungal community diversity, and discussed the critical factors affecting soil organic carbon (SOC) and nitrogen (N) in a typical karst mountainous area. The results showed that the dominant phyla were Ascomycota (42.28%), Mortierellomycota (20.6%), Basidiomycota (17.83%), and Rozellomycota (11.82%). The elevation distributions of MWD, fungal diversity, the rate of SOC and N stocks change per temperature index, and SOC and N stocks all exhibited unimodal patterns. Additionally, temperature, fungal diversity, MWD, BD, and clay were the dominant factors explaining the variability of SOC and N, and SOC and N had a positive relationship with pH, BD, MWD, clay‐silt content, warmth index, and Sobs and Shannon diversity. Analyses showed that the warmth index regulated soil aggregates through fungal diversity and combined with BD to affect carbon sequestration, which was controlled by clay, the C:N ratio, and pH during the process. These conclusions have important implications for improving the SOC sequestration capacity in karst mountainous areas.

Cashew leaf and nut blight disease outbreaks under unimodal rainfall pattern in Tanzania

Cashew (Anacardium occidentale L.) which is an important cash crop in Tanzania, is susceptible to various abiotic and biotic stresses. Cashew leaf and nut blight disease caused by Cryptosporiopsis spp. is a devastating disease of cashew crop resulting in a significant reduction of nut production. We conducted a study to assess the association between weather variables, particularly rainfall and temperature, on cashew leaf and nut blight disease (CLNBD) outbreaks and establish a minimum wetness duration period for initiation and development of the disease. Poisson regression analysis indicated a significant association between rainfall and temperature with CLNBD incidence (df = 3, Chi Pr < 0.001). Rainfall was positively associated with CLNBD and a unit increase of 1 mm in rainfall caused a 2 percent increase in the percentage of disease incidence (e = + 0.01995, p < 0.011). However, temperature was negatively associated with disease incidence and a unit increase of 1 °C in temperature caused a 21.56% decline in disease incidence (e = –0.2428, p < 0 .001). Blight incidence was significantly higher (p < 0.001) during the rainy season (range: 11.7 to 36.6%) compared to the dry season (1.4 to 11.5%). Cashew trees in Mtwara District recorded higher blight disease incidence as compared to the rest of the studied areas. This study also established that symptoms for blight disease on cashew leaves appear 8 h post exposure to continuous wet periods. Thus, it appears that for the blight pathogen to initiate and complete its infection processes, a continuous wet period of at least 8 h is required. Findings from this study, particularly the association of rainfall and temperature on disease epidemics, can be used as tools for forewarning incidences of CLNBD. This would help timely initiation of appropriate management strategies.

The latitudinal gradient in plant community assembly processes: Ameta-analysis.

Beta(β)-diversity, or site-to-site variation in species composition, generally decreases with increasing latitude, and the underlying processes driving this pattern have been challenging to elucidate because the signals of community assembly processes are scale-dependent. In this meta-analysis, by synthesising the results of 103studies that were distributed globally and conducted at various spatial scales, we revealed a latitudinal gradient in the detectable assembly processes of vascular plant communities. Variations in plant community composition at low and high latitudes were mainly explained by geographic variables, suggesting that distance decay and dispersal limitations causing spatial aggregation are influential in these regions. In contrast, variation in species composition correlated most strongly with environmental variables at mid-latitudes (20-30°), reflecting the importance of environmental filtering, although this unimodal pattern was not statistically significant. Importantly, our analysis revealed the effects of different spatial scales, such that the correlation with spatial variables was stronger at smaller sampling extents, and environmental variables were more influential at larger sampling extents. We concluded that plant communities are driven by different community assembly processes in distinct biogeographical regions, suggesting that the latitudinal gradient of biodiversity is created by a combination of multiple processes that vary with environmental and species size differences.

Safety analytics at a granular level using a Gaussian process modulated renewal model: A case study of the COVID-19 pandemic

With the advance of intelligent transportation system technologies, contributing factors to crashes can be obtained in real time. Analyzing these factors can be critical in improving traffic safety. Despite many crash models having been successfully developed for safety analytics, most models associate crash observations and contributing factors at the aggregate level, resulting in potential information loss. This study proposes an efficient Gaussian process modulated renewal process model for safety analytics that does not suffer from information loss due to data aggregations. The proposed model can infer crash intensities in the continuous-time dimension so that they can be better associated with contributing factors that change over time. Moreover, the model can infer non-homogeneous intensities by relaxing the independent and identically distributed (i.i.d.) exponential assumption of the crash intervals. To demonstrate the validity and advantages of this proposed model, an empirical study examining the impacts of the COVID-19 pandemic on traffic safety at six interstate highway sections is performed. The accuracy of our proposed renewal model is verified by comparing the areas under the curve (AUC) of the inferred crash intensity function with the actual crash counts. Residual box plot shows that our proposed models have lower biases and variances compared with Poisson and Negative binomial models. Counterfactual crash intensities are then predicted conditioned on exogenous variables at the crash time. Time-varying safety impacts such as bimodal, unimodal, and parabolic patterns are observed at the selected highways. The case study shows the proposed model enables safety analytics at a granular level and provides a more detailed insight into the time-varying safety risk in a changing environment.

Occupancy-frequency distribution of birds in land-sharing and -sparing urban landscapes in Europe

Species richness is a widely used proxy for patterns of biodiversity variation in metacommunities. However, deeper analyses require additional metrics, such as the occupancy-frequency distributions (SOFD) of different local communities. The SOFD patterns indicate the number of shared species between study sites; therefore, they can provide new insights into the current debate on how to create more biodiversity-friendly cities. Breeding birds were counted from 593 point-count stations located in five 500 m × 500 m squares in land-sharing (LSH; low-density built areas interspersed with green spaces) and five similar nearby squares in land-sparing (LSP; densely built-up with set-aside, large-sized, continuous green spaces) landscapes in nine cities across Europe. High beta-diversity (with over 42% of the 103 species detected being restricted to a single city and only 7% found in all studied cities) showed the uniqueness of cities at the continental scale. Urban bird metacommunities followed the unimodal-satellite SOFD pattern at the European continental scale but a bimodal symmetric or asymmetric distribution at the city-level scale, suggesting that many common species occur in cities on a smaller scale. The LSP urban areas followed a unimodal satellite SOFD pattern with numerous rare species. In contrast, the LSH areas fit several types of bimodal SOFD patterns equally well, where communities share several common species. The findings also highlight the need to use multi-scale approaches to analyze the effects of LSH-LSP urban designs on urban bird diversity.

Estimation of temperature and flooding depth thresholds for Phragmites australis rhizome bud sprouting

AbstractCurrent climate models predict more intense rainstorms and temperature extreme events under future global climate change. Estimation of environmental factors thresholds might provide important information for the common patterns of species distributions and management of wetland ecosystems. The laboratory experiment and the greenhouse experiment examined separately the effects of temperature (10 constant temperature regimes of 8, 10, 12, 14, 16, 19, 22, 26, 30 and 35°C) and flooding depth (10 flooding depth treatments of −15, −10, −5, 0, +5, +10, +15, +20, +25 and +30 cm relative to the substrate surface) on rhizome bud sprouting and establishment of Phragmites australis. Our results revealed that the final sprouting percentage, relative growth rate and ramet height showed hump‐shaped relationships with temperature. Higher temperature led to shorter mean time to sprout, faster sprouting rate and greater ramet survival. The estimated base temperature for rhizome bud sprouting was 5.0 ± 1.27°C. The optimum temperature for rhizome bud sprouting and early growth might be the range of 23–30°C. The final sprouting percentage, relative growth rate and ramet height showed unimodal patterns with flooding depth. The mean time to sprout was increased with deeper flooding depth, while sprouting rate and ramet survival were decreased. The optimum flooding depth for rhizome bud sprouting and early growth might be the range of −7 to 0 cm. Our results will contribute to a better understanding of the influence of climate change on early plant recruitment processes and distribution of P. australis.

Seasonal and interannual variations of ecosystem photosynthetic characteristics in a semi-arid grassland of Northern China

Abstract The ecosystem apparent quantum yield (α), maximum rate of gross CO2 assimilation (Pmax) and daytime ecosystem respiration rate (Rd), reflecting the physiological functioning of ecosystem, are vital photosynthetic parameters for the estimation of ecosystem carbon budget. Climatic drivers may affect photosynthetic parameters both directly and indirectly by altering the response of vegetation. However, the relative contribution and regulation pathway of environmental and physiological controls remain unclear, especially in semi-arid grasslands. We analyzed seasonal and interannual variations of photosynthetic parameters derived from eddy-covariance observation in a typical semi-arid grassland in Inner Mongolia, Northern China, over 12 years from 2006 to 2017. Regression analyses and a structural equation model (SEM) were adopted to separate the contributions of environmental and physiological effects. The photosynthetic parameters showed unimodal seasonal patterns and significantly interannual variations. Variations of air temperature (Ta) and soil water content (SWC) drove the seasonal patterns of photosynthetic parameters, while SWC predominated their interannual variations. Moreover, contrasting with the predominant roles of Ta on α and Rd, SWC explained more variance of Pmax than Ta. Results of SEM revealed that environmental factors impacted photosynthetic parameters both directly and indirectly through regulating physiological responses reflected by stomatal conductance at the canopy level. Moreover, leaf area index (LAI) directly affected α, Pmax and Rd and dominated the variation of Pmax. On the other hand, SWC influenced photosynthetic parameters indirectly through LAI and canopy surface conductance (gc). Our findings highlight the importance of physiological regulation on the photosynthetic parameters and carbon assimilation capacity, especially in water-limited grassland ecosystems.

Tectonic Juxtaposition of Two Independent Paleoproterozoic Arcs by Cenozoic Duplexing in the Arun Tectonic Window of the Eastern Nepalese Himalaya

The tectonic evolution of the Himalayan orogenic belt before Cenozoic convergence is important to understand its modern structural framework. There is still controversy regarding the tectonic history of the lower Lesser Himalaya Sequence (LHS) in the frame of the Paleoproterozoic geological record. In this study, integrated analysis of field geology, zircon U-Pb age, Hf isotope, and whole-rock geochemistry was conducted across the LHS and the Main Central Thrust zone in the Arun Valley, eastern Nepal, to address their Precambrian tectonic evolution and the later convergence. Two groups of metasedimentary rocks with different age spectrums of detrital zircons and Hf isotope in the Paleoproterozoic can be distinguished in an imbricated duplexing system in the study area. One group with a maximum depositional age around ca. 1800 Ma has a unimodal detrital zircon pattern and negative zircon ƐHf (t) values ranging from −8.9 to 0.9. These data can be interpreted to reflect the deposition of zircons close to a Japanese-type arc that was isolated from the northern Indian Craton. The other group of calc-silicate rocks and quartzite with multiple peaks of detrital zircons in the Paleoproterozoic show a younger maximum depositional age around ca. 1,600 Ma and variable zircon ƐHf (t) values ranging from −6.7 to 8.8, indicating their deposition in a back-arc basin of an Andean-type arc established on the northern Indian Craton. The geochemistry of an orthogneiss sample dated at 1783 ± 11 Ma indicates high potassium, peraluminous granodiorite protolith emplaced in a volcanic arc or syn-collisional tectonic setting, supporting the existence of the Paleoproterozoic Andean-type arc. We hypothesize that possibly two arc systems developed, respectively, onto and in the proximity of northern Indian Craton in the Paleoproterozoic at the final stages of the Columbia supercontinent formation. These two arcs were juxtaposed either in the Paleoproterozoic or Cenozoic time, and were finally imbricated during the Cenozoic duplexing.

Explanation of beta diversity in European alpine grasslands changes with scale

AbstractThe importance of environmental difference among sites and dispersal limitations of species to the explanation of diversity differs among biological systems and geographical regions. We hypothesized that climate and then dispersal limitation will predominantly explain the similarity of alpine vegetation at increasing distances between pairs of regions at subcontinental extent. We computed the similarity of all pairs of 23 European mountain regions below 50° N after dividing the species lists of each region by calcareous or siliceous substrates. Distance decay in similarity was better fitted by a cubic polynomial than a negative exponential function, and the fit was better on calcareous than on siliceous substrate. Commonality analysis revealed that the proportion of explanation of beta diversity by climatic difference had unimodal patterns on a gradient of increasing distance between regions, while explanation by dispersal limitation had consistently rising patterns on both substrates. On siliceous substrate, dispersal limitation explained more of the variation in beta diversity only at longer distances, but it was predominant at all distances on calcareous substrate. The steeper response to distance at &lt;1600 km and &gt;2600 km may indicate dispersal limitation at different temporal scales, and the uptick in the response to distance at the longest distances may reflect how isolated some regions have been before and since the last glacial maximum.

Responses of Macroinvertebrate Assemblages to Flow in the Qinghai‐Tibet Plateau: Establishment and Application of a Multi‐Metric Habitat Suitability Model

AbstractAnthropogenic impacts and climate change modify instream flow, altering ecosystem services and impacting on aquatic ecosystems. Alpine rivers and streams on the Qinghai‐Tibet Plateau (QTP) are especially vulnerable to disturbance owing to limited taxonomic complexity. The effects of flow have been studied using specific taxa, yet the flow‐biota relationships of assemblages are poorly understood. A multi‐metric habitat suitability model (MM‐HSM) was developed using integrated measures of entire macroinvertebrate assemblages to substitute for habitat suitability indices derived from individual taxa. The MM‐HSM was trained using macroinvertebrates data from three alpine rivers on the QTP, including the Yarlung Tsangpo, the Nujiang, and the Bai rivers, and then validated using data from a forth alpine river (the Lanmucuo). The model produced predictions using the training data set (R2 = 0.587) and the validation data set (R2 = 0.489). By coupling the MM‐HSM with hydrodynamic simulations, the relationship between weighted usable area and flow (0.11–1.99 m3 s−1) for macroinvertebrate assemblages was established, whereby a unimodal response pattern was observed for the Lanmucuo River. This contrast with monotonically positive or negative relationships observed for individual indicator taxa further supported our hypothesis that the response pattern of entire macroinvertebrate assemblages to flow would differ from responses of individual indicator taxa. The MM‐HSM provides a novel framework to quantify flow‐biota relationships, which is a useful approach for integrated river management.

Climate change perception and local adaptation of natural resource management in a farming community of Cameroon: A case study

Climate change is perceived by communities at different levels and their adaptation measures are often corresponding to local understanding and realities. A socio-economic survey and field observations were conducted among 95 Bàkì farmers in the Ntui district of Central Cameroon, to examine the community's perception of the changes observed and the adaptation measures undertaken locally. Apart from the relative homogeneity of its community, the area was chosen for its climatic conditions. This area is characterized by a bimodal rainfall pattern on the one hand and by a transitional rainfall pattern between the bimodal patterns of the far south and the unimodal pattern of northern Cameroon. The study found that the Bàkì community has developed a classification of the climatic seasons through the changes observed over time, namely the increase in temperature, the decrease in rainfall, and the resurgence of extreme events such as the recurrence of violent winds and drought. The classification confirms the locally important changes in climate that affect the agricultural calendar and thereby the planning of the community's socio-economic activities. In response to the effects observed, the farmers have developed an adaptation strategy that includes reverting to more appropriate farming practices and more resistant varieties. Notably, the farmers use a reading grid of climatic and environmental variations as a reference to decide on adaptive actions and adaptation measures. The study results reconfirm that perception of climate change is strongly influenced by age and education.

Vegetation Classification and Distribution Patterns in the South Slope of Yarlung Zangbo Grand Canyon National Nature Reserve, Eastern Himalayas

Yarlung Zangbo Grand Canyon National Nature Reserve has the most complete vertical vegetation belts in China. However, identification and distribution of vertical vegetation belts is still uncertain and in debate. To explore the above issues, 190 plots were surveyed within the reserve from 2019 to 2021. Based on the vegetation plot data, cluster analysis, ordination analysis, and biodiversity statistics were performed to reveal the structure of vertical vegetation belts–the driving factors of vegetation distribution–to describe the main biodiversity patterns. Five vertical vegetation belts were identified by clustering. NMDS ordination showed that the main factor of vegetation distribution is elevation. Based on the results of the analysis and previous literature, a new scheme of vertical vegetation belts in the south slope of the reserve was proposed. There was a lower montane seasonal rainforest belt (600–1100 m), a lower montane evergreen broadleaf forest belt (1100–1800 m), a middle montane semi-evergreen broadleaf forest belt (1800–2400 m), a subalpine evergreen needleleaf forest belt (2400–3800 m), a alpine shrubland and meadow belt (3800–4400 m), an alpine sparse vegetation belt (4400–4800 m), and a nival belt (4800–7782 m). Among them, the seasonal rainforest belts are the northernmost distribution of this type, and the semi-evergreen broadleaf forest belts exist only in the Eastern Himalayas. The study showed a unimodal pattern in plant species diversity, the peak of which is about 1900 m. The middle montane semi-evergreen broadleaf forest belt had the highest species diversity in the reserve. This study settled the issues regarding the vertical vegetation belts, the main drivers of vegetation and assessment of plant species diversity in the south slope of the Yarlung Zangbo Grand Canyon National Nature Reserve. It provides essential support for the management and conservation of these ecosystems in the reserve.

Changes in the soil nematode community among climate zones do not keep pace with changes in plant communities

Revealing the distribution patterns of soil nematode communities among climate zones helps uncover the spatial distribution patterns of belowground biodiversity. The aims of this study were to reveal the spatial distribution patterns of the taxonomic composition, diversity and trophic structure of soil nematode communities among continuous climate zones. Investigations were conducted for five altitudinal vegetation types, i.e., subtropical evergreen broad-leaved forest (SEB), subtropical evergreen and deciduous broad-leaved mixed forest (SEDB), warm temperate deciduous broad-leaved forest (WTDB), mid-temperate coniferous and broad-leaved mixed forest (MTC) and cold temperate coniferous forest (CTC), on the eastern slope of Gongga Mountain from 2014 to 2017. The taxonomic compositions of the soil nematode communities in the SEDB, WTDB, MTC and CTC were similar but differed markedly from that in the SED, with patterns varying among sampling years. Abundances and diversity showed unimodal distribution patterns, with maximum values occurring in the WTDB. The abundances of the four trophic groups varied significantly among the vegetation types. Relative abundances stabilized for bacterivores and plant parasites but declined for fungivores and increased for omnivores-predators from the SEB to the CTC. The ratio of fungivores to bacterivores in the SEB was significantly higher than those in the other vegetation types, implying that the trophic structure and material cycling channels differed among forest types. The spatial distribution of the soil nematode communities was mainly influenced by pH, total K, total P and soil temperature. These findings suggested that the taxonomic composition, abundance, diversity and trophic structure of soil nematode communities vary among climate zones, but the changes in the soil nematode communities among climate zones did not keep pace with those in aboveground plant communities.