Aims: The evergreen broad-leaved forest is a zonal vegetation type in the subtropical region of China. Evergreen broad-leaved forests are widely distributed in China, so a variety of vegetation subtypes are available. This study aims to discuss the differences between evergreen broad-leaved forest communities from the eastern coast to the western interior.

Methods: We selected Tiantong, Gutian Mountains (GTS), Badagongshan Mountains (BDGS), Zhujiangyuan (ZJY), Diaoling Mountains (DLS) and Jizu Mountains (JZS) forest dynamics plots as the research objects. Based on nationally available data on woody plants in the six plots, we first unified the species’ names and counted the number of families, genera, and species of each plot. Then we investigated the distribution type and growth-form of all species. Based on these results, we compared the species composition and structure differences of six plots by Jaccard similarity analysis, the redundancy analysis, and the species-area curve analysis.

Results: The results showed: (1) The richness of woody plants in the BDGS plot was the highest, followed by TT plot, GTS plot, JZS plot, DLS plot and ZJY plot. The species composition of evergreen broad-leaved forests in the eastern region of mid-subtropical China is significantly different from that in the western region, with species belonging to the same vegetation subtype being more similar. (2) On the composition of growth form spectrum, the woody plants in the plots of the eastern region mainly belong to tropical families and tropical genera, with most families and genera distributed in the Pantropic zone. In other plots, the woody plants mainly belonged to tropical families but most belonged to temperate genera within the tropical families, with the most genera distributed in the Northern Temperate zone. (3) Plots in the eastern and central regions hold more trees than shrubs, while in the western region, plots hold more shrubs than trees. Only the BDGS plot holds more deciduous woody plants (59.2%) than evergreen woody plants (40.8%), while in other plots, the opposite is true. (4) The BDGS plot differs the most in the richness of evergreens (97) and deciduous woody plants (141), while the DLS plot differs the most in the proportion of evergreens (69.8%) and deciduous woody plants (30.2%).

Conclusion: Our results reflect the differences in community species composition, species diversity, and community structure among typical evergreen broad-leaved forests, mixed evergreen and deciduous broad-leaved forests, and semi-humid evergreen broad-leaved forests in mid-subtropical China. The study supplements the comparative analysis among multiple vegetation subtypes in evergreen broad-leaved forests and provides a scientific basis for revealing the species turnover characteristics and change patterns among evergreen broad-leaved forests from the eastern to the western region in mid-subtropical China.

Aims: The forest dynamics plots have been used as an effective platform to study the mechanism of biodiversity maintenance and community assembly. The semi-humid evergreen broad-leaved forest (SHEBF) is the zonal vegetation in the Central Yunnan Plateau. Because of the long-term influence of human activities and natural disturbance such as wildfires, the original SHEBF communities have been mostly destroyed, and replaced by secondary vegetation types. The extreme shrinkage of this zonal vegetation has raised increasing concern of conservation. Based on three forest dynamics plots we established in the Central Yunnan Plateau, we aim to explore the general characteristics of SHBEF in its floristic composition, community structure and diversity

Methods: According to the Center for Tropical Forest Science (CTFS) standards at the Smithson Institute for Tropical Research, we established three forest dynamics plots (10 ha (500 m × 200 m), 8.24 ha (one subplot with 260 m × 240 m and two subplots with 100 m × 100 m), and 20.16 ha (720 m × 280 m)) as the data collection source of SHEBF from the following three areas: Zhujiangyuan (ZJY) in Qujing City, Diaoling Mountains (DLS) in Chuxiong City, and Jizu Mountains (JZS) in Dali City, respectively. The community data of the three forest dynamics plots were obtained using a portable backpack LiDAR and a laser rangefinder. We implemented floristic analysis, community classification, and community structure analysis for the communities in the plots.

Results (1) A total of 619 species of vascular plants belonging to 120 families and 355 genera were found in the three plots, including 70 families, 120 genera, 157 species in the ZJY plot, 92 families, 224 genera, 319 species in DLS plot, 100 families, 255 genera, 353 species in JZS plot. (2) A total of 103,951 woody individuals with DBH ≥ 1 cm were found in the three plots, including 24,932 individuals in the ZJY plot, 25,222 individuals in the DLS plot, 53,797 individuals in the JZS plot, with densities of 2,493, 3,061, and 2,690 ind./ha, respectively. (3) The proportion of temperate floras at the genus and species levels of all vascular plants in three plots was 51.3% and 24.7%, and the proportion of endemic species in plots was 33.0%. (4) The plant communities in plots were divided into eight alliances, Castanopsis orthacantha alliance, C. delavayi alliance, Lithocarpus craibianus alliance, L. dealbatus alliance, Pinus yunnanensis alliance, Cyclobalanopsis delavayi alliance, L. mairei alliance and Quercus senescens alliance; the DLS plot had the highest alliances diversity and ZJY plot the least. (5) The DBH class structure of tree species in the JZS plot and DLS plot were inverted “J” type, and unimodal in ZJY plot. The community data indicated that an intensive fire disturbance covered a part of the JZS plot 80-100 years ago, and a light-to-moderate disturbance swept across the DLS plot 50-80 years ago, and a stand replacing fire occurred the ZJY plot 36 years ago.

Conclusion: This study laid a foundation for long-term systematic monitoring of the SHEBF community based on the forest dynamics plots while providing a theoretical basis for the diversity protection of this vegetation type and the sustainable forest management.

Aims: Spatial patterns of biodiversity can reflect the community assembly processes and the mechanisms of species coexistence within ecosystems. The semi-humid evergreen broad-leaved forest is a type of vegetation zone located in the semi-humid climate of the western subtropical region of China. To date, there have been many studies investigating the species diversity of this type of vegetation, but studies into the patterns of spatial heterogeneity of species diversity and its determinants are still relatively lacking, and research utilizing large dynamics plot has not yet been reported. To better understand the maintenance mechanism of species diversity, we explored the characteristics of spatial heterogeneity and species diversity and their main environmental determinants in a 20.16 ha forest dynamics plot located in the Jizu Mountains.

Methods: Based on data collected from woody plants and TWINSPAN classification results from 504 quadrats 20 m × 20 m in the 20.16 ha forest dynamics plot in the Jizu Mountains, this article utilized regression analysis and the Mantel test to analyze the distribution patterns of α and β diversity, and their correlation with respective environmental factors.

Results (1) In the plot, we found that the species richness of the Pinus yunnanensis community and its trees and shrubs were all higher than that of the Castanopsis delavayi community and C. orthacantha community; the C. delavayi community and its shrubs species richness were both higher than that of the C. orthacantha community, while its tree species richness was higher than C. orthacantha community. On the contrary, the Shannon-Wiener value of the C. orthacantha community was found to be the highest among all species, followed by the C. delavayi community, while the value of the P. yunnanensis community was the lowest. Based on the net interspecific relationship index (NRI), the phylogenetic structures of the C. orthacantha community, C. delavayi community, and P. yunnanensis community were clustering, random, and overdispersion, respectively. (2) The factors that demonstrated a universal impact on species richness included the total nitrogen and pH, the relative altitude, and the sum of basal area of woody plants. The main factors affecting the richness of tree diversity included total nitrogen level and pH and the sum of basal area. The dominant factor influencing shrub species richness was the relative altitude, followed by total nitrogen, slope, and the topographic wetness index. (3) The species β diversity pattern showed that differences in species composition and turnover rate increased with increasing spatial and environmental distances, indicating that the more similar the environment, the more similar the community.

Conclusion: This study reflects the significant differences in species diversity and composition between the pioneer P. yunnanensis community and the stable C. orthacantha community and C. delavayi community in the Jizu Mountains forest dynamics plot, which describes the characteristics of species coexistence and species diversity maintenance corresponding to the heterogeneous patches of semi-humid evergreen broad-leaved forests, and provides a basis for further mechanistic investigations.

Background & AimsThe vertical structure of a forest is the vertical arrangement of aboveground vegetation elements. This feature of the forest affects plant and animal diversity and ecosystem function, and thus has been the focus of many plant ecologists. The development of portable backpack LiDAR technology allows for scanning of 3D forest structure over a large area with high precision. The purpose of this study is to explore the vertical structural characteristics of the semi-humid evergreen broad-leaved forest in Jizu Mountains on the scale of plot and individual tree.

Methods: The most important parameters of the vertical forest structure are: the canopy height (CH), the leaf area index (LAI), and the characteristics of individual tree. The CH directly reflects the biomass and the LAI represents photosynthetic capacity of plants. Based on a portable backpack LiDAR, the CH and LAI of a 20.16 ha semi-humid evergreen broad-leaved forest dynamics plot in the Central Yunnan Plateau were carefully scanned and quantitatively analyzed. On the basis of topographic correction and community classification, the vertical change and horizontal pattern of the LAI of the forest community were extracted and analyzed, and the parameters of single tree morphology and vertical structure of common tree species were surveyed quantitatively.

Results: The results showed that: (1) the distribution of CH and LAI in a 20 m × 20 m square was close to a normal distribution; (2) according to the vertical distribution of LAI, the canopy of the large plot can be divided into four layers: the upper canopy, the middle canopy, the lower canopy, and the shrub layer; (3) the vertical variation of LAI of the Castanopsis orthacantha community and the C. delavayi community showed a single-peak pattern with peak heights of 15 m and 13 m, respectively, and that of the Pinus yunnanensis community showed a double-peak pattern with peak heights of 5 m and 10 m; (4) the parameters of different tree species showed great variation, but the value of crown area/diameter was relatively uniform.

Conclusion This is the first study in China to quantitatively analyze a 3D pattern of LAI for a semi-humid evergreen broad-leaved forest with a complex structure based on LiDAR technology. This work may provide a useful database for future studies of forest biodiversity of this type and for comparative studies between different forest types.

Aims: Forest gaps are a common form of forest disturbance and play an important role in forest regeneration and species coexistence. The forest gaps serve as the basis for the forest landscape’s shifting mosaic structure. We aim to provide the scientific basis for better conservation and management of the semi-humid evergreen broad-leaved forests in the Jizu Mountains.

Methods: This study analyzed the species composition and DBH class structure of all woody plants (including all standing living trees and coarse woody debris (CWD) based on a survey of the forest dynamics plot in a semi-humid evergreen broad-leaved forest in the Jizu Mountains starting in 2022. The spatial patterns of the basal area of all woody plants and the number of forest gap makers (FGM) in the plot were mapped using ArcGIS. An environmental interpretation using a generalized linear model combined with variance partitioning analysis was performed.

Results (1) The number and the basal area of CWD were about 13.6% and 15.8% for all standing living trees, respectively. A total of 57 woody species contributed to CWD formation, with a total of 12,317 individual trees; among which 12 species acted as FGMs, with a total of 2,280 individual trees. (2) The DBH class structure of standing living trees and CWD was like an inverted “J” type: with more individual trees having smaller DBH classes and fewer larger classes, indicating the main source of tree mortality was the self-thinning process during the early stage of community succession. (3) The number and average density of the FGM decreased as follows: trunk snapping (TS), dead fallen tree (DFT), standing dead tree (SDT), and leaning live tree (LLT); The sum of basal area for the standing living trees, CWD, and FGM differed significantly within the plot, with the hillsides on both sides of the gully being higher and at the gully bottom being lower; the number of all four types of FGM were abundant on the hillsides on both sides of the shallow gully, while it was lowest in the bottom of the shallow gully, all three types of FGM were distributed in the bottom and the hillsides on both sides of the deep gully except for LLT. (4) The variance of environmental factors increased as follows: 16.7% for SDT, 25.6% for DFT, 37.2% for TS, and 76.0% for LLT. Biological competition and a self-thinning process caused the formation of SDT and DFT. Soil nutrient contributed the most to the number of LLT, while topographic factors and biological factors drive the formation of TS.

Conclusion: The semi-humid evergreen broad-leaved forest in the Jizu Mountains has small-scale disturbances, the number of SDT and DFT is closely associated with the tree density within the forest community. For LLT, soil nutrient influences the rate of tree survival more than topographic factors. Areas in the forest where TS occurres are driven by topographic factors and biological factors.

Aim: Subtropical semi-humid evergreen broad-leaved forest is a unique forest type in Southwest China. We expect to enhance our understanding of the characteristics and drivers of community dynamics in this ecosystem by studying the spatial and temporal patterns and regeneration strategies of the dominant tree species.

Methods: Using the first community survey data of the forest dynamics plot in a semi-humid evergreen broad-leaved forest in the Jizhu Mountains, Yunnan Province, we explored the patterns of seedlings, saplings, and adults of five dominant tree species and compared their population structure in DBH classes. The multi-scale spatial patterns of regeneration and adult populations were modeled using a probability density function g(r). A comparison of ordinary least squared and multi-scale geographical weighting regression models were used to assess the factors influencing the seedling and sapling density of the dominant tree species.

Result: (1) Castanopsis orthacantha, C. delavayi, Schima argentea, and Lithocarpus craibianus exhibited a growing population DBH class structure. The Pinus yunnanensis had a declining population structure. (2) The patterns of regeneration and adult populations of all five species were clustered at small scales (0-50 m), but the intensity of clustering decreased with increasing scales, shifting to random or uniform distributions. The distributions of juvenile and adult populations of Pinus yunnanensis showed a significant negative correlation at small scales, while the distribution of juvenile and adult populations of the other four broad-leaved species showed a significant positive correlation. (3) The multi-scale geographical weighting regression model explained 58.7% and 26.9% more than the ordinary least squares model for the change of population regeneration densities of seedlings and saplings, respectively, showing a significant effect of spatial autocorrelation in population patterns. The model results indicated that the seedling density pattern was constrained more by stochasticity in seed dispersal than by habitat factors, while the sapling density pattern was dominated by that of habitat factors.

Conclusions: Except for Pinus yunnanensis, the other four dominant tree species in the sample plot of the semi-humid evergreen broad-leaved forest in the Jizhu Mountains regenerate well. The spatial patterns of regeneration of all five species are constrained by both stochastic dispersal limitation and deterministic environmental filtration, but the dominant constraint shifts from the former to the later as regeneration progressesfrom the seedling phase to the sapling phase.

Aims: Semi-humid evergreen broad-leaved forest (SEBF) represents a distinct sub-type of evergreen broad-leaved forests within the subtropical region of western China. Despite their ecological significance, the functional diversity of SEBFs remains in adequately understood. This study aims to conduct a comprehensive analysis of plant traits and functional diversity within SEBFs and elucidate the environmental factors influencing their variations.

Methods: This research was conducted across the expanse of the Central Yunnan Plateau, the primary natural habitat for SEBFs. We conducted surveys within five well-protected SEBF sites, namely Jinguangsi (JGS), Jizu Mountains (JZS), Diaoling Mountains (DLS), Qiongzhusi (QZS), and Zhujiangyuan (ZJY). A total of 29 plots measuring 20 m × 20 m were sampled. Key plant traits including the maximum height (H_max), specific leaf area (SLA), and wood density, were recorded for collected samples. Functional diversity indices such as functional richness (FRic), functional divergence (FDiv), functional evenness (FEve), and functional redundancy (Rstar) were calculated based on these traits. Additionally, life-form spectrums and community-weighted mean trait values (CWM) were assessed for different sample sites and community types. Environmental factor analysis, using variance partitioning, was employed to gauge the impact of various ecological factors on the variations in functional diversity within SEBFs.

Results: Within the semi-humid evergreen broad-leaved forests (SEBFs) of the Central Yunnan Plateau, the CWM of key traits, namely H_max, SLA and wood density, exhibited no significant differences among various sample sites and community types. The shrub layer demonstrated higher CWM_SLA values compared to the tree layer, while their CWM_wood_density remained consistent at 0.5 g/cm³. In terms of diversity, both species diversity and functional diversity varied between the tree layer and shrub layer. Notably, JZS and DLS exhibited the highest values for FRic, FEve, and Rstar, indicating greater resilience and stability in these two sample sites. However, different community types of SEBFs, based on various dominant species, displayed similar FDiv, FEve, and Rstar values, differing only in FRic. FRic and Rstar were both significantly positively correlated with species richness (P < 0.05), while their relationships with other functional diversity indices were not significant. Factor analysis revealed that climate and soil nutrient contributed more than 60% of variances in CWM and functional diversity within SBEFs. Additionally, human activities emerged as influential factors in shaping the functional diversity of these forest communities.

Conclusion: Our results shed light on the characteristics of CWM values and functional diversity within the SEBFs, particularly in the context of tree layer and shrub layer. We have observed distinct spatial variations across different sample sites. Interestingly, despite the existence of different community types based on various dominant species, these communities occupy different functional niches yet exhibit a remarkable degree of functional convergence in terms of directional divergence, evenness, and redundancy. These findings provide valuable insights into the functional diversity of SEBFs, which, in turn, can inform and enhance efforts related to forest conservation and biodiversity restoration.

Aims: This study focuses on the semi-humid evergreen broad-leaved forests (SEBFs) in Central Yunnan Plateau, a zonal vegetation characterized by varying patches sizes and shapes distributed around rural villages. Through remote sensing based vegetation mapping and field vegetation investigation, we aimed to explore the spatial patterns of fragmented SEBF patches, the changes in plant species diversity of SEBFs in relation with its patch size and distance class from villages, and assess the effects of environmental and anthropogenic factors on the species composition of SEBFs communities.

Methods: This study investigated the fragmentation features of SEBFs and their impact on species diversity. We conducted spatial analysis and species diversity assessments using the patch and community data from SEBFs. SEBFs’ patches were derived from Landsat 8 OLI imageries in combination of supervised classification and visual interpretation. α diversity and β diversity were compared among the plot community types. And the species composition was compared using non-metric multidimensional scaling to indicate the importance of environmental drives.

Results (1) In Central Yunnan Plateau, the existing SEBFs only accounted for 1.5% of their potential, climate-determined distribution range. This area comprised 92 forest patches covering a space greater than 100 ha, whereas forest patches covering an area of < 10 ha accounted for 54.6% of the total patch number but only 7.8% of the total area. This highlighted the significant shrinking and fragmenting of this vegetation type’s area. (2) Remarkably, 99% of forest patches were within 3 km from rural villages. A trend emerged where patches farther away from villages had larger area, but the species α diversity did not show significant changes except for species evenness. For sample plots in patches with different area classes, α diversity only showed significant changes in species richness; larger patches exceeding 100 ha exhibited higher species richness. In contrast, the closer a patch was to a village, the more simplified and more homogeneous its species composition tended to be. (3) β diversity among plot communities was primarily driven by species replacement. Forest islanding was a key factor influencing changes in species composition of SEBFs communities. Moreover, the impact of human interference on species composition was significantly greater than that of local habitat heterogeneity (water conditions) and regional climate gradients (low temperature limitations).

Conclusion: The SEBFs in the Central Yunnan Plateau are abundant near villages with fragmented small patches, and these areas are experiencing notable degradation due to human interference. This situation is urgent and demands attention and the implementation of necessary protective measures.

Aims: As one of the richest areas of mammal diversity in China, the Hengduan Mountain region is a major source and endemic zone for natural epidemics. However, few studies have investigated the effects of habitat variation and human intervention on the community structure of small mammals via persistent monitoring in this region. Therefore, the aim of this study is to assess the disparities in habitat selection and determine the influence of human disturbance on small mammals’ community structure by monitoring these communities within four characteristic habitats in Diannan Town, Jianchuan County. This will provide information for subsequent local plague control and biodiversity conservation efforts.

Methods: Surveys were conducted in Diannan Town by deploying rat cages randomly in the four predominant habitats (vegetable garden, cropland, shrub and neighborhood region) from January 2005 to December 2017. The time, location, species, and other characteristics of the captured animals were recorded. The Shannon-Wiener diversity index, Pielou evenness index and Simpson dominance index of the four habitats were calculated, and the chi-square test was used to analyze the differences in the number of small mammals captured in four different habitats in Diannan Town.

Results: The species accumulation curves of the four habitats increased at a diminishing rate over time, and the ratio of actual number of species to estimated number of species was greater than 80%, indicating sufficient sampling. This survey captured a total of 16,060 small mammals. The dominant species in Diannan Town are Eothenomys miletus and Apodemus chevrieri, and the number of small mammals captured in each habitat varied highly. The vegetable garden exhibited the highest Shannon-Wiener diversity index (1.26), and the neighborhood region had the lowest (1.08). The vegetable garden and cropland had the highest community similarity index (0.94).

Conclusion: This study finds that species composition, diversity index, and evenness index of small mammals vary among different habitat types in Diannan Town. Regions with high levels of human disturbance and low plant resources have low diversity indices while habitats with good resource conditions and moderate human disturbance have higher diversity indices. Further, habitats with fewer food resources and less human disturbance, such as the shrub habitat, have slightly lower diversity indices. Therefore, rodent borne disease control and prevention, such as that for the plague in Diannan Town, should be focused in cropland and vegetable garden regions.

Aims: Ailao Mountain is located at the intersection of three major geographical regions, Qinghai-Tibet Plateau, Hengduan Mountains and Yunnan-Guizhou Plateau. This study aims to explore the diversity of ant communities that reside within this distinctive region and to understand how variations in ant community structure and diversity are influenced by climate difference arising from altitude.

Methods: To address these aims, we surveyed ant species diversity along the elevational gradients on the east slope of Ailao Mountain National Nature Reserve by using transect and plot sampling and diversity index methods.

Results: In total, 150 species from 47 genera and 7 subfamilies of Formicidae were identified. Lasius himalayanus emerged as the dominant species in the ant community, accompanied by two common species, 20 relatively common species, 55 relatively rare species and 72 rare species. The rare species constituted 48% of the total species surveyed. The sequence of Shannon-Wiener diversity index of ant communities across the four vertical zones on the east slope are as follows: middle-south zone > north zone > middle-north zone > south zone.

Conclusion Ant species numbers, diversity indexes, and individual densities are significantly negatively correlated with altitude, implying these indexes are mainly controlled by altitude and air temperature. Concurrently, the main indexes were found to frequently express multi-domain effect phenomenon and occasionally exhibit mid-domain effect phenomenon, indicating that ant species assemblies have adapted to the various climate types from different altitudes on the slope. Moreover, human activity and the dry-hot valley climate have disrupted the ant communities, and the ant species richness on the east slope of Ailao Mountain National Nature Reserve was lower than the west slope due to humidity. According to similarity coefficients, ant communities residing in different habitats of the nature reserve were significantly differentiated and possess various ecological functions and protection value.

Aims: Porcine diarrhea disease is still an intractable problem with complicated infection mode. The aim of this study was to identify the viral community composition in porcine diarrhea stools systematically, and excavating the potential risk agents.

Methods: Viral metagenomics technology was used to analyze the viral community composition of the diarrhea stools in piglets via high-throughput sequencing. Then the complete viral sequences were spliced and their genetic characteristics were further analyzed by constructing the phylogenetic trees.

Results: A total of 1,676,726 RNA contigs and 95,111 DNA contigs were obtained, with RNA and DNA virus sequences accounting for 38.58% and 3.10%, respectively. Astroviridae, Caliciviridae and Picornaviridae were the top three in the total community. Although DNA viruses occupied a relatively low proportion, there was a wide variety of CRESS-DNA viruses, including 18 kinds of CRESS-DNA viruses. Forty-six whole genome sequences were obtained by depth sequence splicing, including 2 porcine astrovirus (PAstV) isolates, 3 bastrovirus (BAstV) isolates, 2 sapporo isolates, 16 picobirnaviridae (PBV) isolates and 23 CRESS-DNA isolates. One of the Sapporo isolates belonged to GII/3 subtype, which was closely related to human Sapporo virus. Four of the 16 PBVs were classified as GGI subtype, and the other 12 isolates were classified as GGII subtype. Besides, one of the 23 CRESS-DNA viruses was the member of Genomoviridae, 12 were Smacoviridae members, and the others were unclassified CRESS-DNA viruses.

Conclusion: RNA viruses play dominate role in pig diarrhea feces with high host diversity, suggesting that there may be interspecific gene recombination. However, the potential pathogenicity needs to be further explored and verified. These data would provide database for the prevention and control of clinical porcine diarrhea disease.

Aims: In recent years, with nearing the completion of channelization project of the Jialing River, the fragmentation of aquatic habitats, the decline of fish resources and other issues caused by the dams are becoming increasingly acute. Under the circumstances, it has been a worrying problem that whether the fish genetic diversity has been affected. The aim of this study is to analyze the genetic diversity and genetic structure of Saurogobio dabryi population under the background of cascade water conservancy project in the Jialing River by using mitochondrial control region sequence and microsatellite loci as molecular markers.

Methods: From July to December in 2018, 113 tails of S. dabryi were collected from Jialing River where the sampled sites were Chaotian District (CT), Cangxi County (CX), Peng’an County (PA) and Hechuan District (HC), respectively. The genetic diversity and genetic structure of S. dabryi population under the background of cascade water conservancy project were studied by using the mtDNA control region sequences and 10 microsatellite loci.

Results: The results showed that in genetic diversity analysis, whether mitochondria data or microsatellite marker, the genetic diversity parameters of HC population (PIC = 0.543, π = 0.0264, Hd = 0.940) were significantly higher than upstream and midstream (CT, CX and PA) populations. It was speculated that this phenomenon may be associated with HC population was located in the Yangtze river mainstream intersection. On the contrary, the genetic diversity and haploid number of CT population was higher, which may be associated with the population expansion in CT population, recently. In the analysis of population structure, CT, CX and PA populations were in the same branch and HC population in an independent branch. Haplotype network diagram and phylogenetic analysis showed the same result, which might be related to the geographical isolation caused by water conservancy projects and the formation of downward gene flow caused by water release.

Conclusion: The research results not only reveal the genetic diversity characteristics, population structure and population dynamics of S. dabryi population in each section of Jialing River under the background of cascade water conservancy project development, but also provide basic data for the genetic research of small and medium-sized fish in Jialing River in the future. By comparing the results of this study with the morphological differences, it was verified that there were also significant genetic differences in the population of S. dabryi in each section of Jialing River under the condition of significant differences in external morphology, so the phenomenon indicates that the natural geographical differences and genetic differences shaped the genetic pattern of species together.

Aims: The input of aboveground plant resources into the belowground components is considered a key factor in regulating soil biota communities, as plants serve as the primary energy source for nearly all soil organisms. However, our understanding of how plant litter identity and diversity influence the diversity and communities of soil microorganisms and microfauna remains limited. Therefore, the objective of this study is to investigate the impact of different plant litter identity and diversity on soil bacterial and nematode diversity and communities.

Methods: In this study, soil bacteria and nematodes were selected as the subjects of investigation. Through pot experiments, we first introduced litter from various dominant tropical forest plant species individually, aiming to explore the influence of distinct plant litter identity on the diversity and communities of soil bacteria and nematodes. Subsequently, we established five gradients of litter diversity, including a control (with no added litter), one-species litter (from Sloanea tomentosa), two-species mixed litter (Sloanea tomentosa + Strychnos cathayensis), four-species mixed litter (Sloanea tomentosa + Strychnos cathayensis + Orophea laui + Pometia pinnata), and seven-species mixed litter (Sloanea tomentosa + Strychnos cathayensis + Orophea laui + Pometia pinnata + Ficus virens + Ficus sagittata + Castanopsis indica). The aim was to investigate the impact of varying plant litter diversity on the diversity and communities of soil bacteria and nematodes.

Results: Our results revealed the following: (1) Litter addition significantly increased soil carbon, nitrogen, available phosphorus, available potassium content, and notably raised soil pH. (2) Compared to the control treatment (no litter addition), adding litter from a single plant species led to a decrease in bacterial and nematode diversity. (3) Similarly, adding litter from different individual plant species had significant impacts on both bacterial and nematode communities compared to the control treatment. However, among the various litter addition treatments, only the litter from the Parashorea chinensis significantly differed in bacterial community composition from the other treatments, while differences in bacterial and nematode communities between other treatments were not significant. (4) Litter diversity significantly influenced bacterial and nematode diversity and community composition. Specifically, bacterial and nematode diversity increased with higher litter diversity gradients. Under high diversity conditions (four and seven species), bacterial and nematode communities showed less similarity compared to treatments with lower litter diversity (CK, one, and two species).

Conclusion: These findings suggest that aboveground litter diversity not only directly affects the soil microbial communities, but also influences soil faunal communities at higher trophic levels through cascading effects. The results provide important theoretical references for understanding the relationship between plant and bacterial and nematode diversity and communities, the aggregation effect of soil nutrient patches in tropical forests, the mechanism of biodiversity maintenance, and the potential impacts of the loss of plant diversity on soil ecosystems in the context of global change.

Background & Aim: Birds, located at the upstream of the ecological food chain, serve as crucial reference indicators for environmental quality and pollution. However, monitoring the status and trends of bird diversity in ecosystems poses a significant challenge. Establishing an all-weather bird diversity detection in system requires an extensively applicable machine learning-based birdsong recognition algorithm. To facilitate a precise comprehension of the research status pertaining to machine learning-based birdsong recognition algorithms and their developmental trends, we introduce the fundamental concepts of birdsong recognition and provides an overview of machine learning-based bird sound recognition algorithms from the perspective of model structure design.

Summary: Given the interdisciplinary nature of machine learning-based birdsong recognition technology, the algorithms can be classified into the following categories based on research directions: probabilistic model, template matching, time series analysis, transfer learning, data fusion, ensemble learning, metric learning-based, and unsupervised clustering birdsong recognition algorithms. We review the technical context of these categories in the context of performing birdsong recognition tasks. Furthermore, we present an analysis of the characteristics and limitations of these algorithms, along with a comparison of their birdsong recognition effectiveness in birdsong recognition. It also discusses commonly used standardized birdsong open-source datasets for birdsong and evaluation metrics applied. Finally, we outline the challenges confronted by existing methods and identifies potential future research directions in this field.

Perspectives: We endeavor to furnish scholars and developers involved in birdsong recognition research with a comprehensive reference framework, enabling them to better comprehend the existing technologies and potential developmental trends. Currently, there is a need to enhance the accuracy and robustness of machine learning-based birdsong recognition methods, especially for large-scale data samples. Additionally, the promotion and application of these methods still encounter several challenges that require resolution. The future investigations should focus on the following aspects: (1) optimization and improvement models; (2) integrating of multimodal data; (3) application of transfer learning; (4) expansion of application scenarios; and (5) establishing and standardization of databases.

Background & AimThe floral spur stands out as a key innovative trait that has evolved in response to the interaction between plants and pollinators. This trait is widely distributed in angiosperms, showcasing a highly variable morphology among different species. Previous research has focused on exploring the complex relationship between floral spur and their corresponding pollinators.

ProgressFirstly, this review introduces the concept and function of the spur, elucidating the diversity in spur morphology, length, color, and contents of across various species; secondly, it describes the factors contributing to intraspecific and interspecific variations in floral spur morphology; then, it summarizes a series information on cellular and key molecular mechanisms governing the formation and development of floral spur. The distribution of the spur in angiosperms, coupled with the diversity in spur formation sites and the molecular mechanisms of development, suggests that the multiple origins of the spur with convergent evolutionary features, but the pattern of floral spur formation and development appears non-conserved in the evolutionary progression.

Prospects This review offers the following perspectives for future research on floral spur: (1) Constructing a comprehensive database documenting the phenotypes of angiosperm floral spurs to provide fundamental data for the systematic investigations; (2) Constructing a mutant library of floral spur through genetic engineering and other tools to further verify the contribution of floral spur variants to species diversity; (3) Investigating the molecular mechanisms of the formation and development of floral spur using a multi-omics approach.

Background: The digestive tracts of animals host intricate microbial communities that play a crucial role in the physiological and metabolic processes of the animals. Current research suggests that the evolution and diversity of these digestive tract microbiota are influenced by factors such as the animals’ living environment, dietary habits, and lifestyle. Furthermore, the composition and function of the microbial communities in the digestive tract can also impact the animals’ evolution. The interaction between parasitic and host species is acknowledged as a significant driving force for microbial diversity during the evolutionary processes of both.

Progress This paper focuses on the interaction between animals and digestive tract microorganisms, summarizes the evolutionary relationship between animals and digestive tract microorganisms and the composition of digestive tract microflora in different animals, and discusses the relationship between animals and digestive tract microflora in adaptive evolution and the dominant microorganisms in digestive tract of different animals. Despite the diversity of gut microbial composition in animals, it was found that 70% to 90% of gut microbial communities in most animals still come from the phyla Firmicutes and Bacteroidetes, which may be due to their significant role in the degradation of complex carbohydrates.

Conclusion: Current research should take into account the definition of the evolutionary trend of animals and digestive tract microorganisms, the speed of evolution, and the influence of competition and cooperation between animals and digestive tract microorganisms on the evolutionary relationship between the two, so as to verify its accuracy.

Background: Entomopathogenic fungi are a group of fungi that parasitize insects and cause insect death, with high insecticidal efficacy and low impact on the environment. Entomopathogenic fungi have important application and are often used as biopesticides to control pests.

ProgressThis paper provides an overview of the categorization information for insect pathogenic fungi and elaborates on the processes involved in fungal infection of the host, changes in host behavior, and the mechanism of spore transport during infection. Following that, the strategies used by insects to fight infection are sorted, focusing mostly on body wall defense, autoimmune system protection, and behavioral avoidance of fungal pathogens. On the basis of this, the coevolutionary relationship between the defense mechanisms of insects and the harmful mechanism of fungi on insects is examined.

ProspectsWe look forward to future research directions, emphasizing that the effects of insect population density and spore concentration in the environment on infectious disease outbreaks should be investigated based on basic models of infectious disease transmission dynamics, and that fungal transmission patterns should be studied to guide field applications.