Qinling Mountains Research Articles

Higher water ecological service values have better network connectivity in the middle Yellow River basin

There are numerous ecological challenges that are of considerable concern caused by urbanization and natural calamities. The spatial pattern of the landscape is of great significance in maintaining species diversity and regulating material cycles and individual ecophysiological processes as a medium for ecosystem service functions. Resolving the conflicting relationships between people and land necessitates the precise identification of essential ecological sources. Therefore, there is an urgent need to investigate the relationship between ecological sources and ecosystem service values (ESVs) and to optimize the matter and energy.connectivity network. The study optimizes ecological network simulation using a penetration threshold, population density inverse distance formula, and geodetector weight analysis, constructs ecological spatial networks and evaluates their structure using the minimum cumulative resistance (MCR) model and complex network analysis, and discusses the relationship between network topological characteristics (NTCs) and the spatial pattern of the various ESVs. The results show that the major sources and corridors are primarily along the banks of the Wei River and the Fen River. The clustering coefficient has a significant negative correlation with both water supply and water regulation service values. It is found that the sources with higher ecological service values related to water resources have better network connectivity. This result plays a major reference role for the identification of several crucial ecological components, such as sources, nodes and stepping stones, in the middle Yellow River basin (MYRB). Ultimately, we propose strengthening the ecological protection of the eastern part of the Qinling Mountains and increasing the ecological communication capacity of the forestland on both sides of the river valley to create an optimized ecological pattern.

Vertical measurements of atmospheric CO2 and 14CO2 at the northern foot of the Qinling Mountains in China

The CO2 and 14CO2 levels in air samples from the northern foot of the Qinling Mountains (Xi'an, China) were determined. In 2021, a hexacopter unmanned aerial vehicle sampled air at different heights, from near-ground to 2000 m. The objectives of this study were to determine vertical characteristics of CO2 and 14CO2, the sources of different-height CO2, and the influence of air mass transport. The CO2 concentrations mainly exhibited a slight decreasing trend with increasing height during summer observations, which was in contrast to the increasing trend that was followed by a subsequent gradual decreasing trend during early winter observations, with peak CO2 levels (443.4 ± 0.4–475.7 ± 0.5 ppm) at 100–500 m. The variation in vertical concentrations from 20 to 1000 m in early winter observations (21.6 ± 19.3 ppm) was greater than that in summer observations (14.6 ± 14.3 ppm), and the maximum vertical variation from 20 to ∼2000 m reached 61.1 ppm. Combining Δ14C and δ13C vertical measurements, the results showed that fossil fuel CO2 (CO2ff, 56.1 ± 15.2 %), which mainly come from coal combustion (81.2 ± 3.4 %), was the main contributor to CO2 levels in excess of the background level (CO2ex) during early winter observations. In contrast, biological CO2 (CO2bio) dominated CO2ex in summer observations. The vertical distributions of CO2ff in early winter observations and CO2bio in summer observations were consistent with those of CO2 during early winter and summer observations, respectively. The strong correlation between winter CO2bio and ΔCO (r = 0.81, p < 0.01) indicated that biomass burning was the main contributor to CO2bio during early winter observations. Approximately half of the air masses originated from the Guanzhong Basin during observations. The results provide insights into the vertical distribution of different-sources of atmospheric CO2 in scientific support of formulating carbon emission-reduction strategies.

High-resolution climate change during the Marine Isotope Stage 3 revealed by Zhouqu loess in the eastern margin of the Tibetan Plateau

A consensus has not yet been reached on effects of climate change and driving mechanisms between the Tibetan Plateau (TP) and adjacent monsoonal areas during the Marine Isotope Stage 3 (MIS 3). Loess–paleosol sequences from the TP provide valuable information about the MIS 3 environmental history. Detailed color index and a diffuse reflectance spectral (DRS) analysis of Zhouqu (ZQ) loess from the Western Qinling Mountains were conducted to investigate climate change on the eastern margin of the TP during the MIS 3. Our results show that the variations in color index and iron oxide content in ZQ loess are mainly caused by the pedogenesis and climate conditions. The lightness (L*) value and hematite (Hm) content were used to reconstruct the precipitation history and temperature changes, respectively. The reconstructed records revealed that climate change during the MIS 3 was characterized by high frequency and large amplitude, with millennial-scale changes superimposed on orbital-scale changes. Warm–humid climate occurred in the late MIS 3, while the early climate of MIS 3 was relatively cold–dry. The Indian summer monsoon (ISM) and temperature variations during the MIS 3 mainly occurred due to obliquity and precession. The North Atlantic cooling led to the southward movement of the Intertropical Convergence Zone, and the downstream cooling of the atmosphere by the westerly jet could result in events on a millennial-scale in the eastern margin of the TP. The interhemispheric forcing may play an important role in driving the strong summer monsoon in the late MIS 3.

Soil carbon and nitrogen accumulation during long-term natural vegetation restoration following agricultural abandonment in Qingling Mountains

Agricultural land abandonment has been proposed as a strategy for reducing greenhouse gas emissions, increasing soil carbon (C) sequestration, and enhancing soil nitrogen (N) levels in degraded ecosystems. However, the dynamic patterns of soil C and N pools and fractions following long-term agricultural abandonment are not well understood. In this study, we investigated the dynamics of soil organic C (SOC), recalcitrant organic C (RC), total N (TN), and recalcitrant organic N (RN) in 0–40 cm soils along a natural vegetation restoration gradient (i.e., croplands→grasslands→shrublands→forests) following agricultural abandonment in China's Qinling Mountains. Our results showed that the concentrations of SOC, RC, TN, and RN increased significantly along with vegetation restoration, but the SOC and TN stocks only increased in the 0–10 and 0–20 cm layers, respectively. The highest growth rates of new SOC (28.96 g m−2 yr−1) and new RC (9.87 g m−2 yr−1) were observed in shrublands, followed by the grasslands (new SOC, 14.80 g m−2 yr−1; new RC, 5.02 g m−2 yr−1) and forests (new SOC, 9.06 g m−2 yr−1; new RC, 3.74 g m−2 yr−1). The δ15N values of litter, fine root, and soil decreased significantly with stand age, indicating that the N cycling in abandoned ecosystems gradually became less open than that of croplands during vegetation restoration processes. The ratios of RN/TN decreased significantly with stand age across all soil layers, while the ratios of RC/SOC at 0–40 cm soils did not change with stand age and the differences among croplands, grasslands, shrublands, and forests were not significant. Our study reveals that soil C and N stocks only accumulate in topsoils during ∼110 years of natural vegetation restoration and the recalcitrancy indices of soil C and N displayed different dynamic patterns, and also indicates that agricultural abandonment is an effective approach to increasing soil C and N stocks and mitigating the negative effects of agriculture on soil C and N pools.

Coupling Coordination Relationship and Driving Force Analysis between Gross Ecosystem Product and Regional Economic System in the Qinling Mountains, China

As a new concept for systematically evaluating ecosystem services, Gross Ecosystem Product (GEP) provides an effective means to comprehensively reveal the overall status of the ecosystem, the impact of economic activities on the ecological environment, and the effectiveness of ecological protection efforts. GEP accounting has been conducted in various regions; however, GEP’s application in natural reserves still requires further exploration. Taking the Qinling Mountains as the research area, this paper aims to assess the relationship between GEP and economic development on the basis of the GEP accounting system. The results indicated that: (1) From 2010 to 2020, GEP tended to increase continuously and exhibited a distribution pattern with high value regions in the east and west, and low value regions in the north and south. (2) Over the years, the coupling coordination degree between GEP and GDP was in a consistent upward trend. In 2020, a good coupling coordination state between GEP and GDP was achieved in most districts and counties. (3) With the relative development between GEP and GDP, the social economy of most districts and counties lagged behind GEP in 2010. The number of districts and counties lagging in GEP in 2020 increased, while the number of regions with a balanced development of GEP and GDP was still relatively discouraging. (4) In general, elevation, contagion, temperature, population density, and precipitation were the main drivers of coupling coordination degree between GEP and GDP. If the relationship between economic development and ecological environmental protection can be reasonably balanced, it will further promote the sustainable development of nature reserves, and provide a scientific basis for sustainable policy-making in other similar areas.

Plant Diversity Changes and Its Driving Factors of Abandoned Land at Different Restoration Stages in the Middle of the Qinling Mountains

The process of vegetation restoration is often accompanied by significant changes in aboveground plant diversity. To explore the driving mechanism of litter nutrient-soil nutrient-enzyme activity stoichiometry on aboveground vegetation change is of great importance for maintaining regional biodiversity conservation and ecological stability. Taking typical abandoned farmland of different restoration years （1， 8， 16， 31， and 50 a） in the Qinling Mountains as the research object， the variation characteristics of plant community diversity during vegetation restoration were analyzed through field investigation. Litter nutrients， soil nutrients， and the activities of five extracellular enzymes， including β-1，4-glucosidase （BG）， cellobiohydrolase （CBH）， β-1，4-N-acetylglucosaminidase （NAG）， leucine aminopeptidase （LAP）， and acid phosphatase （AP）， were determined. The characteristics of litter nutrients， soil nutrients， and enzyme stoichiometric ratios during vegetation restoration and the driving mechanism of plant diversity changes were discussed. The results showed that the plant community diversity index firstly decreased and then increased with the increase in vegetation restoration years， and the minimum was reached at 16 years after restoration. The results of principal component analysis showed that there were significant differences between total plant community diversity index and litter-soil-enzyme stoichiometric characteristics in different years of vegetation restoration. The plant community diversity index had a strong positive correlation with litter C∶P ratio and litter N∶P ratio but had a negative correlation with soil enzyme C∶P ratio （EEA C∶P）. The results of redundancy analysis showed that soil EEA C∶P had the highest explanation rate of plant diversity changes during vegetation restoration （25.93%）， followed by soil TP （5.94%）， which was the key factor regulating plant diversity changes. In conclusion， plant species and quantity increased significantly in abandoned farmland in the middle part of the Qinling Mountains at the late stage of vegetation restoration. Changes in the soil environment affected microbial metabolic activities and thus changed enzyme activities. Litter-soil-soil extracellular enzymes affected the community environment and plant diversity through feedback and regulation. EEA C∶P and TP were the main driving factors of aboveground plant diversity change during vegetation restoration.

Atmospheric CO2 and 14CO2 observations at the northern foot of the Qinling Mountains in China: Temporal characteristics and source quantification

A two-year (March 2021 to February 2023) continuous atmospheric CO2 and a one-year regular atmospheric 14CO2 measurement records were measured at the northern foot of the Qinling Mountains in Xi'an, China, aiming to study the temporal characteristics of atmospheric CO2 and the contributions from the sources of fossil fuel CO2 (CO2ff) and biological CO2 (CO2bio) fluxes. The two-year mean CO2 mole fraction was 442.2 ± 16.3 ppm, with a yearly increase of 4.7 ppm (i.e., 1.1 %) during the two-year observations. Seasonal CO2 mole fractions were the highest in winter (452.1 ± 17.7 ppm) and the lowest in summer (433.5 ± 13.3 ppm), with the monthly CO2 levels peaking in January and troughing in June. Diurnal CO2 levels peaked at dawn (05:00–07:00) in spring, summer and autumn, and at 10:00 in winter. 14C analysis revealed that the excess CO2 (CO2ex, atmospheric CO2 minus background CO2) at this site was mainly from CO2ff emissions (67.0 ± 26.8 %), and CO2ff mole fractions were the highest in winter (20.6 ± 17.7 ppm). Local CO enhancement above the background mole fraction (ΔCO) was significantly (r = 0.74, p < 0.05) positively correlated with CO2ff in a one-year measurement, and ΔCO:CO2ff showed a ratio of 23 ± 6 ppb/ppm during summer and winter sampling days, much lower than previous measurements and suggesting an improvement in combustion efficiency over the last decade. CO2bio mole fractions also peaked in winter (14.2 ± 9.6 ppm), apparently due to biomass combustion and the lower and more stable wintertime atmospheric boundary layer. The negative CO2bio values in summer indicated that terrestrial vegetation of the Qinling Mountains had the potential to uptake atmospheric CO2 during the corresponding sampling days. This site is most sensitive to local emissions from Xi'an and to short distance transportation from the southern Qinling Mountains through the valleys.

Distribution of the Asiatic golden cat (Catopuma temminckii) and variations in its coat morphology in China.

Of the 12 wild felid species found in China, Asiatic golden cat (Catopuma temminckii) is one of the least studied species. This medium-sized cat with a prominently polymorphic coat was once distributed across much of southern China, but is believed to have experienced severe decline and range contraction during the past decades, primarily due to anthropogenic pressures. A lack of knowledge of its current distribution, ecology, and natural history has greatly hindered the implementation of conservation and management actions for this species. In this study, for the first time, we compiled the state-wide occurrence records (N = 409), mainly from the camera-trapping surveys, of Asiatic golden cats from 2008 to 2019, and predicted its distribution across the country through species distribution modeling using random forest algorithm. The results showed that the predicted habitats were mainly located in southwest China and suggested a rather low probability of possible current distribution across its vast historic range in central, eastern, and southern China. We divided its current range into four geographic regions (i.e., Qinling Mountains, Hengduan Mountains, East Himalayas, and southern Yunnan region) and considered the cats in each region as a regional population within the country. From the 287 camera-trapping detections with photographs and/or videos collected across all populations, we identified six coat morphs and determined their occurrence percentages: common golden (47.4%), spotted (20.9%), red (13.6%), dark cinnamon (10.1%), melanistic (7.0%), and gray (1.0%). The complexity of coat morph composition within regional populations showed an increasing gradient from northeast to southwest. Among the four regional populations, the East Himalayas hosted the highest abundance and coat variation with all six morphs recorded. Our study results update the current distribution and coat morphology variations of this elusive cat in China and provide important knowledge to guide future research and conservation planning for this threatened species.

Forest fragmentation causes an isolated population of the golden takin (Budorcas taxicolor bedfordi Thomas, 1911) (Artiodactyla: Bovidae) in the Qinling Mountains (China)

Budorcas taxicolor bedfordi is a rare animal uniquely distributed in the Qinling Mountains (China). Human disturbance and habitat fragmentation have directly affected the survival of B. t. bedfordi. It is urgent to clarify the genetic diversity and genetic structure of the B. t. bedfordi population and implement effective conservation measures. In this study, 20 new polymorphic microsatellite loci were isolated by Illumina sequencing. The genetic diversity and population structure of 124 B. t. bedfordi individuals from three populations (Niubeliang population, Zhouzhi population, and Foping population) were analysed according to these 20 microsatellite loci. Our results indicated that B. t. bedfordi had a low level of genetic variability and that there was inbreeding in the three populations. The population genetic structure analyses showed that the Niubeliang population had a trend of differentiation from other populations. National roads can affect population dispersal, while ecological corridors can promote population gene exchange. None of the three B. t. bedfordi populations experienced bottleneck effects. For conservation management plans, the Zhouzhi population and Foping population should be considered one management unit, and the Niubeliang population should be considered another management unit. We suggest building an ecological corridor to keep the habitat connected and formulating tourism management measures to reduce the influence of human disturbance on B. t. bedfordi.

Assessment framework of water conservation based on analytical modeling of ecohydrological processes

The water conservation (WC) function is an important indicator for ecosystem health. However, the commonly-used technical term like water retention (WR) and its computation methods could not well reflect the concept of WC because WR focused on the amount of water retained in vegetation canopy and soil, whereas WC includes WR and water supply as well. This study is to propose a new index for assessing the WC function (WCI) by integrating ecological and hydrological factors including WR, water yield, and vegetation production. We further developed a new framework for calculating spatiotemporal dynamics of WCI using ecohydrological modeling of Soil and Water Assessment Tool (SWAT) and remote sensing data. We then used the framework to assess the spatiotemporal dynamics of WC function in the Weihe River Basin (WHRB), the largest tributary of the Yellow River. Compared to the traditional method, our newly-developed approach is more reasonable because it could reflect water retention amount, temporal stability of water yield, and vegetation quality. Further, the case study can tell it is our new index (with forest being the highest, followed by grassland and cropland), instead of WR (with grassland being the highest and forest being the least), that could reflect the definition of WC and meet our cognition. Spatially, the high WCI (0.4 ∼ 0.6) areas are mainly located in the southern and central-eastern parts of the WHRB, characterized by relatively higher forest coverage (e.g., the Qinling Mountains in the southern part of the study area in southern part and representative ‘Grain-For-Green’ in central-eastern part). In brief, this study enhances understanding of the WC function and also provides a method for assessing the dynamics of WC that can be applicable to other regions.

Study on the environmental status of Shichigou Village, Rim yu, Qinling Mountains

Abstract The article illustrates and analyzes the environmental features of Rim Valley and Shifangou Village in the northern Qinling Mountains. Firstly, the ecological characteristics of Rim Valley in terms of elevation, slope, slope direction, river network, and land use classification were summarized through Arcgis mapping so as to overview the environment of Shifangou village as a sub-body of the Rim Valley; secondly, the environmental data of Shifangou village were obtained through field research, and the village landscape evaluation was conducted according to the local conditions, and the methods used were hierarchical analysis and villagers’ rating method, which were based on four dimensions of village environment: ecological elements, production elements, life elements, and feelings elements. The technique used is hierarchical analysis and villagers’ rating method, which mainly evaluates the rural environment in four dimensions, namely, rural ecological elements, rural production elements, rural life elements, and rural feeling elements, and expands on the basis of the “Three Lives” research method, focusing on people’s feelings towards the countryside, so as to arrive at the basic situation of the environment in Shifangou Village.

The Crested Ibises expanding to plain areas exhibit a higher tolerance of human proximity

Animals must strike a balance between anti-predation behavior and other essential behaviors, such as foraging. Within the same species, strategies may vary on individuals' risk-taking preferences, and in this process the environment is a determinant, in addition to predator regime. The Crested Ibis (Nipponia nippon) exhibits such tendency. This is an endangered species, once inhabiting exclusively in China's Qinling Mountain. This used to be the sole remaining wild population. However, over recent decades, this population has expanded. A portion has relocated to breed in the lower plain area, which is characterized by elevated level of human activities and landscape complexity. We used flight initiation distance (FID) as an indicator of the ibises' risk-taking preference, particularly their response to human proximity. Additionally, we examined the environmental factors influencing their foraging site selection, including altitude, terrain openness, human activity intensity and human construction. Our findings revealed a significantly shorter FID among individuals relocating to plain habitats, indicating a higher tolerance of human proximity. The results showed that FID decreased with distance to the nearest human settlement. Another finding is that FID was independent of instant human activity intensity and environmental factors (altitude and terrain openness). These different may arise from various combinations of human activity, predation risk, and food abundance within the two habitats. These results provide insights into the insitu conservation of the threatened species within the context of global urbanization.

The Characteristics of Traditional Folk Houses in the Laoxiancheng village Town of Houzhenzi in the Northern Foothills of Qinling Mountains

The Characteristics of Traditional Folk Houses in the Laoxiancheng village Town of Houzhenzi in the Northern Foothills of Qinling Mountains

Fault Geometry and Late Quaternary Kinematics Along the Tieluzi Fault: Implications for Tectonic Deformation and Eastward Expansion of the Tibetan Plateau, China

AbstractThe Tieluzi Fault is the largest structure in the East Qinling Mountains, and is considered to be the easternmost continuation of the Altyn Tagh‐Haiyuan‐Qinling Fault System (AHQFS) that allows the eastward extrusion of the Tibetan Plateau and South China Block. We studied the fault geometry and kinematics of the Tieluzi Fault using field investigations, detailed interpretations of high‐resolution satellite imagery and digital elevation models, and late Quaternary dating methods. Paleoseismic investigations indicate that the most recent earthquake along the Tieluzi Fault occurred before 1,500–1,300 cal. BP. Geological and geomorphological observations show that segments west of Lushi County are more active than those to the east. The spatial variations in tectonic activity along the Tieluzi Fault are interpreted to be related to four possible mechanisms: strike change, discontinuity, intersection, and branch. The late Quaternary left‐lateral slip rate is determined to be 0.9 ± 0.1 mm/yr on the Tieluzi Fault. The prominent left‐lateral faulting along the Tieluzi Fault suggests that most of the left‐lateral displacement along the eastern AHQFS has been accommodated by the Tieluzi Fault, which forms the most frontier of the eastward expansion of the Tibetan Plateau. Furthermore, we suggest that the left‐lateral faulting in the East Qinling Mountains is a response to relative eastward motion of the South China block pushed by the Tibetan Plateau with respect to the North China Plain Block. Also, our results indicate that the Tibetan Plateau has undergone a stepwise eastward expansion.

Population genomic data reveal low genetic diversity, divergence and local adaptation among threatened Reeves's Pheasant (Syrmaticus reevesii)

Population genomic data could provide valuable information for conservation efforts; however, limited studies have been conducted to investigate the genetic status of threatened pheasants. Reeves's Pheasant (Syrmaticus reevesii) is facing population decline, attributed to increases in habitat loss. There is a knowledge gap in understanding the genomic status and genetic basis underlying the local adaptation of this threatened bird. Here, we used population genomic data to assess population structure, genetic diversity, inbreeding patterns, and genetic divergence. Furthermore, we identified candidate genes linked with adaptation across the current distribution of Reeves's Pheasant. The present study assembled the first de novo genome sequence of Reeves's Pheasant and annotated 19,458 genes. We also sequenced 30 individuals from three populations (Dabie Mountain, Shennongjia, Qinling Mountain) and found that there was clear population structure among those populations. By comparing with other threatened species, we found that Reeves's Pheasants have low genetic diversity. Runs of homozygosity suggest that the Shennongjia population has experienced serious inbreeding. The demographic history results indicated that three populations experienced several declines during the glacial period. Local adaptative analysis among the populations identified 241 candidate genes under directional selection. They are involved in a large variety of processes, including the immune response and pigmentation. Our results suggest that the three populations should be considered as three different conservation units. The current study provides genetic evidence for conserving the threatened Reeves's Pheasant and provides genomic resources for global biodiversity management.

How Do Driving Factors Affect Vegetation Coverage Change in the Shaanxi Region of the Qinling Mountains?

Understanding the effects of natural and human disturbance factors on fractional vegetation coverage (FVC) is significant in the promotion of ecological and environmental protection. However, most of the relevant studies neglect to consider differences in the effect of driving factors on areas with different vegetation change characteristics. In this paper, we have combined Theil-Sen median trend analysis and Mann-Kendall testing to identify degraded and restored areas. Differences in the impact of various factors on FVC in terms of degradation, restoration, and the whole region were distinguished quantitatively using the geodetector model. Additionally, the constraint line approach was used to detect the influence thresholds of factors on FVC. The results are shown as below: (1) FVC showed an overall improving trend, and vegetation restoration and degradation areas accounted for 69.2% and 22.0%, respectively. (2) The two dominant factors affecting FVC were Digital Elevation Model (DEM) and temperature for both degraded and restored regions. However, the explanatory power of precipitation was noticeably different between regions. (3) Most natural factors had a “convex” constraint effect on FVC, which gradually weakened with an increase in the variable below the threshold and vice versa. Human disturbance factors negatively constrained FVC, and the constraint effect increased with increased human activity. This study can help decision-makers optimize specific implementation policies relating to ecological restoration and sustainable development.

Early–middle Jurassic source to sink evolution and its tectonic significance in the northeastern Sichuan Basin

This paper discusses the sedimentary environment and source supply in the sedimentary area and their coupling relationship through a detailed description of the deposits from the Ziliujing Formation to Shaximiao Formation of the Lower–Middle Jurassic on the Tieshan section in the Dazhou City, northeastern Sichuan Province, through sedimentary characterization, determination of the paleocurrent direction, analysis of heavy minerals, and detrital zircon U–Pb dating. The results show that the Zhenzhuchong Member is sufficiently supplied with detrital sediments and is dominantly composed of fluvial-delta deposits. The Dongyuemiao Member—the first member of the Lianggaoshan Formation—is dominated by lacustrine deposits, with the detrital supply increased initially in the early Lianggaoshan. The second member of the Lianggaoshan Formation suggests a significant increase in detrital supply, with shrunken lake basin and changed paleocurrent direction. The Shaximiao Formation reveals a complete disappearance of the lake basin in the northern Sichuan Basin. The comprehensive analysis on source supply indicates that the change in source property is apparently coupled with the change in the sedimentary environment, both controlled by orogenesis around the basin. It is inferred from the zircon age distribution that the changes in the sedimentary environment and source supply during the late Ziliujing period and the middle and late Lianggaoshan period resulted from the uplifting of the Micangshan Mountain, Dabashan Mountain, and Qinling Mountain, respectively.

Changes of Surface Water Resources in China's Mountains in the Past 50 Years

Mountains, provide crucial water resources for the development of human society, are the water towers of the world. However, mountain water resources have undergone marked changes in recent decades, posing a threat to sustainable human development. Based on long-term hydrological, meteorological, and related environmental data, this study analyzes the evolving patterns of water resources in China's mountains over the past 50 years using trend analysis methods. The results indicate that surface water resources in China's major mountains have undergone noticeable changes over the past 50 years, with varying trends among different mountains. The Qinghai-Tibet Plateau and Tianshan regions show an overall increasing trend in surface water resources, while the Hengduan Mountains, Taihang Mountains, Qinling Mountains, Changbai Mountains, and Yunnan-Guizhou Plateau have witnessed decreasing trends to varying degrees. Furthermore, there are differences in the primary processes influencing surface water resource changes across various mountains. For example, climate change plays a predominant role in driving surface water resource changes in the high-altitude Qinghai-Tibet Plateau and Tianshan region, while human-related activities exert a stronger impact on surface water resource changes in other mountains. To address the challenges brought about by changes in China's mountain surface water resources, it is crucial to take into full consideration the unique natural environments and social systems of each mountain.

Asian Monsoon and Local Valley Wind Caused Transport of Volatile Organic Compounds Episode Across Qinling Mountain in China

AbstractTransport of volatile organic compounds (VOCs) and their oxidation products enhances ozone (O3) levels in the downwind areas. Qinling Mountain, with high altitude, affects the climate and air quality in China, but its impacts on VOCs transport and regional O3 pollution are poorly understood. The present study measured ambient VOCs at a high‐altitude site in Qinling Mountain in China in summer and winter in 2020, and investigated how the mountain influenced the regional transport of VOCs and O3. Transport of VOCs (formaldehyde up to 5 ppbv) across Qinling Mountain was observed, which caused rapid increase of O3 at night (80–152 ppbv) at the mountain top. In August, southeasterly air masses from surrounding areas were the main sources of oxygenated VOCs, while nonmethane hydrocarbons originated mainly from the Guanzhong Basin (GZB) north of the mountain. High loading of tropospheric formaldehyde was distributed on the pathway of the southeasterly air mass, which verified the transport of VOCs across Qinling Mountain. In December, westerly air masses passing through GZB contributed most to the ambient VOCs. Asian monsoon and local valley wind together drove the accumulation of O3 and VOCs on the mountain top, which exacerbated the O3 pollution in the adjacent areas. This study revealed the transport of O3 and VOCs across Qinling Mountain and highlighted the need for regional collaborative control of air quality in Northwest China.

Characteristics of Soil Arsenic Contamination and the Potential of Pioneer Plants for Arsenic Remediation in Gold Mine Tailings.

Arsenic (As) contamination of gold mine tailings poses major threats to the natural environment and human health, necessitating adequate management measures. To investigate the soil As contamination level and the potential of pioneer plants for As remediation, the soil and plants of an abandoned gold mine tailings in the Qinling Mountains were analyzed. The level of As contamination was assessed using the single-factor pollution index and potential ecological risk index, and its bioeffectiveness was analyzed. The enrichment capability of plants was investigated using the bioaccumulation factor and translocation factor. Redundancy analysis and partial least squares regression were employed to investigate factors affecting the distribution of As in soil and plants. The results show that As in soil mainly existed in the difficult-available state, with serious contamination and extremely high ecological risk. Lythrum salicaria L. and Equisetum ramosissimum Desf. are the preferred plants for remediation of As contamination through screening pioneer plants. Soil total nitrogen (STN) and available phosphorus (SAP) are the main factors influencing the characteristics of As distribution in the soil. Soil available potassium (SAK), water content (SWC), and SAP promote the accumulation of As by plants. This study provides plant materials and new ideas for mine ecological remediation.