Mountains Of China Research Articles

Seasonal variations of canopy spectra and their indications to carbon fluxes in a temperate forest in northeast China

The seasonal variations of forest canopy spectral characteristics are critical to improving the utilization of remote sensing methodology to quantify forest physiology, especially forest carbon sink. However, the seasonal variations of forest canopy spectra are poorly understood. Combined field survey and EO-1 Hyperion imageries, we extracted the spectral curves of seven forest types of Changbai Mountain in China in seven periods. We also calculated various remote sensing indexes and analyzed their seasonal change of spectral characteristics among different forest types. Optimal indexes were selected to indicate the seasonal variation of forest carbon fluxes. Our results showed that there were differences in spectral curves among forest types. The reflectance of coniferous forests was lower than that of broad-leaved forests in growing season. Changbai Scotch pine forest owned the lowest spectral reflectance, whereas the reflectance of Mongolian oak forest was the highest, especially in the near-infrared region. The red edge slope (RES) of broad-leaved forest was higher than coniferous forest in spring and summer. The RES of broad-leaved and coniferous forests was similar in autumn. The red edge position of various forest types showed slight shift in different seasons. Four typical forest types showed different spectral characteristics with seasonal changes. The seasonal variation of coniferous forest spectral curves was not obvious. The seasonal variation of broad-leaved forest spectra was the largest. Most of the spectral indexes can indicate the seasonal variation characteristics of each forest type. Enhanced vegetation index (EVI) is better than normalized difference vegetation index (NDVI) to indicate the forest phenology. Seasonal curves of spectral indexes were different in all forest types. Spectral indexes of coniferous forests were most stable throughout the year. The curves of each index in broad-leaved forests showed significant difference in autumn, which may be influenced by the understory vegetation after their defoliation. For broad-leaved Korean (BK) pine forest, the scaled value of photochemical reflectance index (SPRI)*EVI owned the highest correlation with gross primary productivity (R = 0.99 and P < 0.01) and net ecosystem exchange (R = − 0.77 and P < 0.05), respectively. SPRI*NDVI showed the highest correlation with ecosystem respiration (R = 0.96 and P < 0.01). The seasonal variation of carbon fluxes of different forest types retrieved from the optimal remote sensing index were consistent, but their peaks occurred at different times.

Fractionation and risk assessment of potentially toxic elements in surface soil from northeast China mountains

Fractionation and risk assessment of potentially toxic elements in surface soil from northeast China mountains

Phylogenomics reveals the evolution, biogeography, and diversification history of voles in the Hengduan Mountains

The Hengduan Mountains (HDM) of China are a biodiversity hotspot whose temperate flora and fauna are among the world’s richest. However, the origin and evolution of biodiversity in the HDM remain poorly understood, especially in mammals. Given that the HDM shows the highest richness of vole species in the world, we used whole-exome capture sequencing data from the currently most comprehensive sampling of HDM voles to investigate their evolutionary history and diversification patterns. We reconstructed a robust phylogeny and re-estimated divergence times of the HDM voles. We found that all HDM voles could be divided into a western lineage (Volemys, Proedromys, and Neodon) and an eastern lineage (Caryomys and Eothenomys), and the two lineages originated from two migration events from North Eurasia to the HDM approximately 9 Mya. Both vole lineages underwent a significant acceleration of net diversification from 8–5 Mya, which was temporally congruent with the orogeny of the HDM region. We also identified strong intertribal gene flow among the HDM voles and hypothesized that frequent gene flow might have facilitated the speciation burst of the HDM voles. Our study highlights the importance of both environmental and biotic factors in shaping the biodiversity of mammals in mountain ecosystems.

An integrative analysis of lncRNAs and mRNAs highlights the potential roles of lncRNAs in the process of follicle selection in Taihang chickens

Taihang chickens are a domestic breed distributed throughout Hebei province in the Taihang Mountains of China and are characterized by their high meat and egg quality. However, the relatively limited egg production by this breed constrains their more widespread commercial utilization. The follicle selection process is closely linked to oocyte development and ovulation, making it a key determinant of laying performance and fecundity in hens. To understand the biological basis for such follicle selection and to identify the associated regulatory pathways, we conducted a genome-wide analysis of long noncoding RNAs (lncRNAs) and mRNAs from the pre-hierarchical follicles and hierarchical follicles of Taihang laying hens. We identified 81 lncRNAs and 528 mRNAs that were differentially expressed during follicle selection, and integrated network analyses suggested that these RNAs were associated with the cell cycle, focal adhesion, oocyte meiosis, peroxisome proliferator-activated receptor signaling, and steroid hormone biosynthesis pathways. The identified lncRNAs were also predicted to influence a series of target genes in cis and trans, suggesting that they may be important regulators of ovarian follicular development. Overall, the present analysis of lncRNA and mRNA expression patterns associated with ovarian follicle development offers a new foundation for future studies of reproductive physiology in Taihang chickens, highlighting new opportunities to improve the laying performance of this important domestic breed.

Regional metal pollution risk assessment based on a long short-term memory model: A case study of the South Altai Mountain mining area, China

The discharge of wastewater and waste rock in mining production activities is a significant hidden cause of soil heavy metal pollution. The accumulation of heavy metals in soil occurs through a variety of processes, and exposure to these metals can permanently damage the human body. Due to multiple factors, such as the formation causes, sources, and distribution trends of heavy metals in mineral resources, reasonably applying different machine learning methods to monitor and evaluate heavy metal pollution remains challenging. In this paper, we choose the copper mining area in the southern Altai Mountains of China as the study area, and 19 different types of spatial data are uniformly managed in a distributed database to improve monitoring efficiency. Furthermore, we propose a heavy metal pollution evaluation framework based on a stacked long short-term memory (LSTM) model, which considers spatial data correlations and extracts spatial clustering features. Information is screened through state updating in the framework, the short-term memory features of long sequences are extracted, and an effective prediction model is established. The results show that 26 of the 31 mining occurrences in the study area are in moderate- and high-pollution-risk grids, suggesting that the spatial distribution of copper mines is consistent with the predicted spatial distribution of pollution risk. Overall, these results show that using the optimized stacked LSTM model to integrate multisource geological features and mine the internal rules of feature information has a positive effect on improving the risk assessment of heavy metal pollution.

Macro- and microphysical characteristics of snowfall and non-snowfall clouds in the West Tianshan Mountains of China based on cloud radar

The macro- and microphysical characteristics of wintertime precipitating clouds and non-precipitating clouds over the West Tianshan Mountains, China, were analyzed with the use of Ka-band radar and weighing rain gauge observations. The data were collected from January to February 2019, December 2019, and from December 2020 to February 2021. Snowfall clouds mainly ranged from 0.15 ~ 2.50 km and had a reflectivity (Z) of mostly 10 ~ 33 dBZ. Non-snowfall clouds were primarily distributed within the height range of 2 ~ 8 km, and the Z values were within the range of − 22 ~ 15 dBZ. Compared with non-snowfall clouds, snowfall clouds have a higher particle water content (M) but a similar radial velocity (V). Light and moderate snowfall clouds were mainly located at heights of 0.15 ~ 3.50 km and had Z values concentrated from 5 ~ 24 dBZ. Heavy snowfall clouds were characterized by a Z of 5 ~ 30 dBZ below 3.5 km. The proportion of clouds with an M value > 0.1 g·m−3 below 2 km was noticeably higher for heavy snow events than for light and moderate snow events. The differences in the distributions and values of snowfall cloud V values were small among the different snow types, and descending motions occurred below 6 km, with V ranging − 1.4 ~ − 0.3 m·s−1. The heights of the non-snowfall cloud top and base during the day were lower than those at night. The snowfall cloud top did not show noticeable diurnal variations. The cloud top and base heights of the non-snowfall clouds both showed a single-peak distribution. The cloud top values of snowfall clouds exhibited bimodal distributions.

Light thinning can improve soil water availability and water holding capacity of plantations in alpine mountains.

The establishment of large-scale forest plantations in the arid and semi-arid area of the Qilian Mountains in China has effectively protected water and soil resources and enhanced carbon sequestration capacity of forest ecosystems. However, the effects of different management practices in these plantations on soil water holding capacity (SWHC) and soil water availability (SWA) are uncertain in this fragile ecosystem. Here, we investigated the effects of no thinning (NT), light thinning (LT, 20% thinning intensity), and heavy thinning (HT, 40% thinning intensity) on SWHC and SWA in different soil depths of a forest plantation, and compared them to those in a natural Picea crassifolia forest (NF). Our results revealed that at low soil water suction stage, SWHC in the plantations (LT, HT, and NT) was greater in the topsoil layer (0-40 cm) than that in the NF site, while SWHC in the subsoil layer (40-80 cm) in NF was significantly greater than that in the thinning stands. At medium and high-water suction stage, SWHC in LT and NF stands was greater than that in HT and NT. Soil water characteristic curves fitted by VG model showed that the relative change in soil water content in LT topsoil layer was the smallest and SWHC was greatest. Changes in soil physicochemical properties included higher bulk density and lower total porosity, which reduced the number of macropores in the soil and affected SWHC. The bulk density, total porosity, silt content, and field capacity were the main factors jointly affecting SWA. High planting density was the main reason for the low SWA and SWHC in NT, but this can be alleviated by stand thinning. Overall, 20% thinning intensity (light intensity thinning) may be an effective forest management practice to optimize SWHC and SWA in P. crassifolia plantations to alleviate soil water deficits.

Simulation of Forest Distribution in the Qilian Mountains of China with a Terrain-based Logistic Regression Model

Abstract Predicting vegetation distribution strengthens ecosystem management, protection, and restoration in arid and degraded areas. However, data quality and incomplete data coverage limit prediction accuracy for Picea crassifolia Kom. (Qinghai spruce) forest in the Qilian Mountains of China. Here, we used a logistic regression model combined with high-resolution vegetation distribution data for different sampling scales and digital elevation models (DEMs) to determine the potential distribution of P. crassifolia forest in the Dayekou catchment in the Qilian Mountains. We found that the model with the best simulation accuracy was based on data with a DEM scale of 30 m and a sampling accuracy of 90 m (Nagelkerke’s R2 = 0.48 and total prediction accuracy = 83.89%). The main factors affecting the distribution of P. crassifolia forest were elevation and potential solar radiation. We conclude that it is feasible to calculate the distribution of arid mountain forests based on terrain and that terrain data at 30 m spatial resolution can fully support the simulation of P. crassifolia forest distribution.

The geography of religions: Comparing Buddhist and Taoist sacred mountains in China

AbstractIncreasing attention has been given to geographical contributions to cultural heritage in religion. However, comparative quantitative research remains scarce. As a first attempt, this study presents findings from comparative spatial and statistical analyses of the geographical distribution and features of mountains in China sacred in Taoism and Buddhism. Because both have strong orientations to natural environments, we find more similarities than differences between them, even though the two religions have different origins, philosophies, and doctrines. The results empirically support the influences of Taoism on Buddhism in China, findings that supplement current understandings of Buddhism in China in terms of the geographical dynamics of integration and sinicisation of Chinese culture. The findings also enrich current debates, including in this journal, emphasising the importance of environmental symbols in studies on geography and religion. Connecting humanity with physical geography in light of the changes, including grief, being wrought in the Anthropocene, we hope to inspire more geographically grounded and methodologically eclectic studies on religions.

Dual adaptation for biodiversity and people: Nexus in ecological protection using a case study of the Qilian Mountains in China

Ecosystem-based management (EBM) has attracted wide attention in climate change adaptation strategy. However, EBM requires the realization of co-benefits of biodiversity and human wellbeing improvement. Furthermore, overall and internal knowledge of the ecoregion of interest is essential. With this knowledge, EBM can be integrated better into the spatial planning process. The present study proposes a dual service strategy for ecosystem-based adaptation (EbA): the ecosystem-based adaptation for human index (EbA-HI) and the ecosystem-based adaptation for biodiversity index (EbA-BI), which are examined at finer spatial scales. The Qilian Mountain protected area was used as an example to investigate the spatiotemporal characteristics of the two indices. Panel quantile regression was used to identify factors influencing the spatial distribution variations. Both EbA-HI and EbA-BI increased by 1.87% and 0.84%, respectively, from 2003 to 2019 in the Qilian Mountain Protected Area. Nevertheless, variations in the values of these indices, as well as their factors, were evident in different areas. Higher air temperatures significantly facilitated the increase in both EbA-HI and EbA-BI. A higher degree of land use positively affected EbA-HI but negatively impacted EbA-BI. Our findings illustrate the complexity associated with EbA and elucidate the need for in-depth theoretical thinking and practical adaptation measures for efficient ecosystem management, which will help to sustain and improve both biodiversity and human well-being.

Diversity of Dictyostelid Cellular Slime Molds, Including Two Species New to Science, in Forest Soils of Changbai Mountain, China.

Dictyostelid cellular slime molds (dictyostelids) are protists that are common inhabitants of most soils, where they feed upon bacteria. Changbai Mountain is the highest mountain in northeast China. Soil samples collected on Changbai Mountain yielded 11 isolates representing six species of dictyostelid samples. Two of these species (Dictyostelium robusticaule and Heterostelium recretum) were found to be new to science, based on morphology, SSU rDNA sequences, and an ATPase subunit 1 gene (atp1) phylogeny. The present study also demonstrated that the increased accuracy and lower costs associated with the use of atp1 sequences make them a complement of SSU rDNA sequences for identifying dictyostelids. Changbai Mountain is characterized by a higher diversity of dictyostelids than indicated by the few previous reports. Moreover, the data for Changbai Mountain, compared with comparable data for Taiwan, suggest that differences in diversity at the family level are possibly related to latitude. Mixed broadleaf-conifer forests produced more isolates and species than broadleaf forests at the same elevation and also had the highest species richness, which indicates an effect of vegetation on dictyostelids. However, the pattern of slightly decreasing diversity with increasing elevation in dictyostelids was also apparent. IMPORTANCE Dictyostelium robusticaule and Heterostelium recretum are two new species of dictyostelids reported in this study. The potential use of atp1 sequences is a complement of SSU rDNA sequences for the identifying dictyostelids. A pattern of slightly decreasing diversity with increasing elevation in dictyostelids was observed, with the conditions that exist at lower elevations apparently more suitable for dictyostelids, whereas differences of diversity observed at the family level are possibly related to latitude.

The complete chloroplast genome of Rhododendron shanii W.P. Fang (Ericaceae), a endemic plant from the Southern Dabie Mountains of China

Rhododendron shanii W.P. Fang 1983 (Ericaceae) is woody plant naturally distributed in the southwest of Anhui, China. The complete chloroplast genome sequence of R. shanii was generated by whole-genome next-generation sequencing data and assembled based on three Rhododendron species chloroplast genome. The complete chloroplast genome sequence of R. shanii was 204,170 bp and divided into four distinct regions: small single-copy region (2615 bp), large single-copy region (107,189 bp), and a pair of inverted repeat regions (47,183 bp). The genome annotation displayed 150 genes, including 95 protein-coding genes, 47 tRNA genes, and eight rRNA genes. Phylogenetic analysis with the Ericaceae reported chloroplast genomes revealed that R. shanii is sister to the clade comprising R. delavayi, R. griersonianum and R. platypodum.

Variation model of north-south plant species diversity in the Qinling-Daba Mountains in China

Understanding the variation patterns of mountain plant species diversity is becoming increasingly important in forest ecosystem management and protection. However, the research on plant species diversity has mainly focused on changes in whole plant species. Therefore, an in-depth study of the change mode of plant species via different classification methods and its impact on the overall change in plant diversity is very important for forestland restoration and biodiversity protection. In this study, the Qinling-Daba Mountains, a major feature of China's north–south transitional zone, were selected as the study area. Based on the floristic data of 58 nature reserves in the Qinling-Daba Mountains and its adjacent areas, the north–south change patterns of plant orders, families, genera and species diversity were first analyzed. Second, plant species were divided into different groups according to taxonomic group (orders, families and genera), life form (trees, shrubs and herbs) and endemism (species endemic and nonendemic to China). The change patterns of each group in the north–south direction were analyzed. Finally, the effects of different groups on the north–south change patterns of whole species are discussed. The species diversity of orders, genera and species exhibited a typical latitudinal gradient pattern, specifically, it gradually decreases from south to north, but the species diversity is relatively scattered. According to the north–south variation in species diversity in each order, families and genus, 5% of the orders, 2% of the families and 6% of the genera were positively correlated with latitude, and the rest were negatively correlated or uncorrelated. According to the north–south variation patterns of different life forms, the diversity of trees and shrubs showed a bimodal Gaussian distribution with latitude. According to the north–south variation patterns of plant endemism, the diversity of endemic species showed a Gaussian distribution with latitude, but the diversity of nonendemic species was negatively correlated with latitude. The dispersion of whole species diversity is caused by species in a few orders, families and genera, trees and shrubs, and endemic species. They may be more strongly affected by the vertical zonality of the mountains, which is inconsistent with the typical latitude gradient model. Our research will provide a basis for forestland management, nature reserve establishment and biodiversity conservation. • We examined a latitudinal gradient model of plant diversity in the Qinling-Daba Mountains. • The latitudinal gradient patterns of a few taxa are inconsistent with the typical patterns. • The relationships between tree and shrub diversity and latitude have Gaussian distributions. • Qinling-Daba Mountains is one of distribution areas of species endemic to China.

Modelling the response of larch growth to age, density, and elevation and the implications for multifunctional management in northwest China

Plantations of Rupprecht’s larch (Larix principis-rupprechtii) have been widely established in the drylands of northwest and north China under traditional fast-growing plantation management strategies. These strategies and the long-term logging ban have led to over-populated stands with lower structural and functional stability, less economic benefit and higher water consumption. To guide the sustainable management of larch plantations, field surveys and historical data compilation were undertaken in the Liupan Mountains of northwest China. The main influencing factors (stand structure and site condition) and their effects on mean tree height, mean DBH and timber volumes were determined based on up-boundary line analysis. Tree growth models coupling the effects of tree age, stand density, and elevation were established. Both height and DBH markedly increased initially and then slowly with tree age, decreased with stand density, and showed unimodal change with elevation. The coupled growth models accounted for 72–78% of the variations in tree height, DBH and timber growth. Recommendations for future plantation management are: (1) prolong the rotation to at least 60 years to produce large-diameter, high-quality timber and maintain greater carbon stocks; (2) zone the target functions of stands by elevation; and, (3) reduce stand density for balanced supply of multiple ecosystem services. The growth models developed can predict growth response of larch plantations to density alteration under given ages and elevations, and assist the transformation from traditional management for maximum timber production to site-specific and multifunctional management with longer rotations and moderate tree density.

Assessment of Sustainable Development of Rural Settlements in Mountainous Areas: A Case Study of the Miaoling Mountains in Southwestern China

As a model based on the harmonious development of society, economy, population, and resources, sustainable development is an essential driving force for a country’s social and economic development. The countryside is an important part of the country, and its sustainable development has been given attention, but existing research lacks a focus on the sustainable development of rural settlements in mountainous areas. In this paper, the rural settlements in the Miaoling Mountains of China are taken as the research object, a geographic detector is used to determine the weight of rural settlement sustainable development factors, a rural settlement sustainable development model is constructed, and a local spatial autocorrelation method is used to quantitatively analyse the level of sustainable development of the rural settlements and the influencing factors related to both the natural environment and socio-economic levels. The results show that (1) 78% of rural settlements in the Miaoling Mountains have a medium to low level of sustainable development and are weak in overall sustainability. (2) The spatial differentiation of the sustainable development levels of rural settlements in the Miaoling Mountains are apparent, and the high sustainable development level settlements are mainly distributed around the urban areas. In contrast, the low sustainable development level settlements are scattered. (3) The level of sustainable development is positively correlated spatially with gross domestic product (GDP), arable land, elevation, normalised difference vegetation index (NDVI), water systems, and roads, and negatively correlated spatially with slope. Of these, GDP, arable land, and elevation have a more substantial influence on the level of sustainability of rural settlements. According to the local autocorrelation analysis, the positively correlated settlement types are mainly clustered in distribution, while the negatively correlated settlement types are sporadic.

Satellite-Observed Spatio-Temporal Variation in Spring Leaf Phenology of Subtropical Forests across the Nanling Mountains in Southern China over 1999–2019

Knowledge of spatio-temporal variation in vegetation phenology is essential for understanding environmental change in mountainous regions. In recent decades, satellite remote sensing has contributed to the understanding of vegetation phenology across the globe. However, vegetation phenology in subtropical mountains remains poorly understood, despite their important ecosystem functions and services. Here, we aim to characterize the spatio-temporal pattern of the start of the growing season (SOS), a typical spring leaf phenological metric, in subtropical forests across the Nanling Mountains (108–116° E, 24–27° N) in southern China. SOS was estimated from time series of GEOV2 leaf area index (LAI) data at 1 km spatial resolution during the period 1999–2019. We observed a slightly earlier regional mean SOS in the southern of the region (24–25° N) than those in the central and northern regions. We also observed spatially varying elevation gradients of the SOS. The SOS showed a change slope of −0.2 days/year (p = 0.21) at the regional scale over 1999–2019. In addition, approximately 22% of the analyzed forested pixels experienced a significantly earlier SOS (p &lt; 0.1). Partial correlation analysis revealed that preseason air temperature was the most responsible climate factor controlling interannual variation in SOS for this region. Furthermore, impacts of air temperature on the SOS vary with forest types, with mixed forests showing a stronger correlation between the SOS and air temperature in spring and weaker in winter than those of evergreen broadleaf forests and open forests. This suggests the complication of the role of air temperature in regulating spring leaf phenology in subtropical forests.

Elevation affects the ecological stoichiometry of Qinghai spruce in the Qilian Mountains of northwest China.

Environmental heterogeneity in temperature, moisture, and soil fertility caused by elevation gradients can affect the trade-offs in the survival strategies of tree species. There is uncertainty about the allocation of resources to different tissues of trees in response to the elevation gradient with respect to carbon (C), nitrogen (N), and phosphorus (P). Here, the C, N, and P content of leaves, branches, trunks, and thick and fine roots of Picea crassifolia (Qinghai spruce) and their stoichiometric changes across three different elevations were investigated in the Qilian Mountains. We found that N:P of Qinghai spruce was <14 in all tissues at most elevations, indicating that Qinghai spruce was more susceptible to N limitation. Meanwhile, the N content and N:P of Qinghai spruce each were significantly negatively correlated with temperature (p < 0.05), and its P content was lower at high elevation. The contribution of soil–climate interactions on the elevation gradient to each tissue type was 34.02% (leaves), 16.84% (branches), 67.78% (trunks), 34.74% (thick roots), and 49.84% (fine roots), indicating that interacting climate and soil factors on the elevation gradient predominately drove the C, N, and P content and stoichiometry variation in each tissue type of Qinghai spruce trees. The results of this study clarify that the elevation gradient regulates the elemental content and resource allocation in Qinghai spruce, providing basic data and an important timely reference for future forest management in the regions where coniferous trees grows. These findings also help improve our understanding of elevational patterns of forest ecosystem stoichiometry in arid and semiarid regions.

Taxonomic status of intraspecific germplasm resources of Vaccinium uliginosum based on chloroplast matK gene and SRAP molecular markers

BACKGROUND: Abundant germplasm resources of Vaccinium uliginosum are present in Changbai Mountain in China, which have considerable research and development value. They include the naturally distributed alpine V. uliginosum, the white-fruited V. uliginosum variety, and various fruit shapes dominated by ellipses. However, the relevant research is limited, and the taxonomic status of various specific germplasm resources has not been addressed. OBJECTIVE: The genetic relationship and taxonomic status of four species of V. uliginosum germplasm resources in Changbai Mountain were investigated. METHODS: The chloroplast matK gene and SRAP molecular markers of 94 V. uliginosum samples were analyzed. RESULTS: According to the analysis of chloroplast matK gene, all four types were divided into three branches. The results showed low variation among natural samples of V. uliginosum in China and a relationship between haplotype distribution and geographical distribution. The results of the SRAP molecular marker analysis divided the V. uliginosum population into five branches. The multiple individuals of the same trait were clustered together, and different partial samples were clustered together. CONCLUSIONS: Diploid alpine V. uliginosum and tetraploid V. uliginosum were identified as two subspecies of V. uliginosum. The elliptical fruit shapewas the variant of tetraploid round blue fruit V. uliginosum, and the white-fruited V. uliginosum variety is a variant.

Bird Beta Diversity in Sharp Contrasting Altai Landscapes: Locality Connectivity Is the Influential Factor on Community Composition.

Simple SummaryUnderstanding the ecological processes involved in establishing a metacommunity, a collection of small communities linked by species dispersal, could help with biodiversity conservation. In this work, we examine how local community connectivity affects the distributional patterns of various bird species across metacommunities in the strikingly different Altai landscapes. We discovered that connectivity was most important for determining community composition in metacommunities. High beta diversity and a high turnover component in the research region showed that regional-scale conservation efforts should consider overall biodiversity. Although they are not part of the Altai-Sayan biodiversity ecoregion, the riparian and desert landscapes are essential to the birds that reside in the mountain ranges and should be regarded as integral parts of the ecoregion, and high connectivity stepping-stone habitats in these landscapes should be protected.Located on the southwest slope and plain areas of the Altai Mountains in China, this study aims to explore bird composition variation (beta diversity) in mountain landscape (metacommunity M), riparian landscape (metacommunity R), desert landscape (metacommunity D) and across the three landscapes (metacommunity A), and to assess how patch connectivity with environmental and spatial factors influence species distributional patterns across multiple metacommunities. In 78 transect lines over the study area, 9724 detections of 139 bird species were detected. We calculated the beta diversity, its turnover and nestedness components in four metacommunities. We used the variation partitioning method to investigate the relative importance between the environment, spatial variation and locality connectivity in driving bird community composition variation. We found high beta diversities with a small contribution of nestedness components in all four metacommunities. When only a single set of predictors is contained in the model, the predictor that best explains the variation of bird community composition is connectivity in metacommunity M, R and D and spatial predictor in metacommunity A. In all three sets of predictors, 73.8~85.4% of variations of community composition can be explained in the four metacommunities, and connectivity always contributed the most. High beta diversity and a high turnover component imply that regional-scale conservation efforts should be thought of as preserving overall biodiversity. A conservation strategy is to keep stepping-stone habitats with good connectivity in the middle of the riparian landscape. Along with the Altai-Sayan biodiversity ecoregion, the desert and riparian environments are essential for birds residing in the mountainous terrain. Furthermore, they should be regarded as integral parts of the ecoregion.

Metabarcoding of fecal DNA reveals the broad and flexible diet of a globally endangered bird.

Knowing the diet of endangered wild animals is a prerequisite for species-specific conservation and habitat management. The Sichuan partridge Arborophila rufipectus is a globally endangered Galliformes species endemic to the mountains of southwest China. Existing information on the diet of this species is biased and fragmented owing to traditional observation methods. Little is known about their dietary composition or how they respond to temporal variations in food resources throughout the year. In this study, a dietary analysis was performed on 60 fecal samples using DNA Metabarcoding of invertebrates and plants to determine the primary animal and plant components of the diet across 3 critical periods of adult life history (breeding, postbreeding wandering, and overwintering). Preys from the dipteran order, followed by the lepidopteran and araneaen spp., were the predominant, animal-derived foods. Symplocos, Rubus, Celastrus, Holboellia, and Actinidia spp. supply a large abundance of fruits and seeds for this omnivorous bird. Substantial temporal dietary changes among the 3 periods and a general shift toward lower dietary diversity during the breeding season were observed, suggesting that the Sichuan partridge can adjust their diet according to the availability of food resources and their own needs. Characterizing the composition and seasonal changes in Sichuan partridge diets informs the habitat management of native flora (the plant taxa that can generate berries and seeds, such as Symplocos, Rubus, Celastrus, and Holboellia, which are likely of conservation interest) to achieve full life-cycle conservation.