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The Yanchang Formation is extensively developed in the Ordos Basin and its surrounding regions. As one of the best terrestrial Triassic sequences in China and the major oil-gas bearing formations in the Ordos Basin, its age determination and stratigraphic assignment are important in geological survey and oil-gas exploration. It had been attributed to the Late Triassic and regarded as the typical representative of the Upper Triassic in northern China for a long time, although some scholars had already proposed that the lower part of this formation should be of the Middle Triassic age in the mid-late 20th century. In this paper, we suggest that the lower and middle parts of the Yanchang Formation should be of the Ladinian and the bottom possibly belongs to the late Anisian of the Middle Triassic, mainly based on new fossils found in it and high resolution radiometric dating results. The main source rocks, namely the oil shales and mudstones of the Chang-7, are of the Ladinian Age. The upper part of the Yanchang Formation, namely the Chang-6 and the above parts, belongs to the Late Triassic. The uppermost of the Triassic is missed in most parts of the Ordos Basin. The Middle-Upper Triassic Series boundary lies in the Yanchang Formation, equivalent to the boundary between Chang-7 and Chang-6. The Ladinian is an important palaeoenvironmental turning point in the Ordos Basin. Palaeoenvironmental changes in the basin are coincidence with that of the Sichuan Basin and the main tectonic movement of the Qinling Mountains. It indicates that tectonic activities of the Qinling Mountains are related to the big palaeoenvironmental changes in both the Ordos and Sichuan Basins, which are caused by the same structural dynamic system during the Ladinian. [ABSTRACT FROM AUTHOR]

The Qinling mountain chain is the highest mountain from the west to the east. The Qinling orogenic belt is a typical compound continental orogenic belt in the world. The Qinling mountain chain is not only a natural demarcation line dividing China into the southern and the northern part with different geography, climate, organisms and river systems, but also a culture boundary between cultures named Huanghe River in the north and the Changjiang River in the south. The Xi'an Qinling Zhongnanshan World Geopark is situated in the major portion of the collision juncture between the south and the north plates of China, which is also typical section of the Qingling orogenic belt. It has been paid a great attention for its long history of geological evolution, intensive tectonics, varieties of rocks, intact stratigraphy, frequent magmatic movements, varieties of metamorphic rocks and abundant geological heritage sites. This paper clarifies the Qinling Zhongnanshan World Geopark of the regional geological background from three aspects which are regional geological setting, evolution of regional geology and regional stratigraphy. With an integrated analysis and classification, the paper details main features of geological relics and geological remains of scientific significance in the geopark, on a base of conducting an investigation and system research for the geological relic resources of the world geopark. It is concluded that it has outstanding universal values in scientific research, Pedagogical potential, tourism and aesthetics. As stated above, the resources in Qinling Zhongnanshan are diverse and important to scientific research, tourism development and popular science. [ABSTRACT FROM AUTHOR]

The analysis of the tree radial growth response to climate is crucial for dendroclimatological research. However, the response relationships between tree-ring indices and climatic factors at different timescales are not yet clear. In this study, the tree-ring width of Huashan pine (Pinus armandii) from Huashan in the Qinling Mountains, north-central China, was used to explore the response differences of tree growth to climatic factors at daily, pentad (5 days), dekad (10 days) and monthly timescales. Correlation function and linear regression analysis were applied in this paper. The tree-ring width showed a more sensitive response to daily and pentad climatic factors. With the timescale decreasing, the absolute value of the maximum correlation coefficient between the tree-ring data and precipitation increases as well as temperature (mean, minimum and maximum temperature). Compared to the other three timescales, pentad was more suitable for analysing the response of tree growth to climate. Relative to the monthly climate data, the association between the tree-ring data and the pentad climate data was more remarkable and accurate, and the reconstruction function based on the pentad climate was also more reliable and stable. We found that the major climatic factor limiting Huashan pine growth was the precipitation of pentads 20–35 (from April 6 to June 24) rather than the well-known April–June precipitation. The pentad was also proved to be a better timescale for analysing the climate and tree growth in the western and eastern Qinling Mountains. The formation of the earlywood density of Chinese pine (Pinus tabulaeformis) from Shimenshan in western Qinling was mainly affected by the maximum temperature of pentads 28–32 (from May 16 to June 9). The maximum temperature of pentads 28–33 (from May 16 to June 14) was the major factor affecting the ring width of Chinese pine from Shirenshan in eastern Qinling. [ABSTRACT FROM AUTHOR]

The Lengshuibeigou Pb-Zn-Ag deposit is located in the Qinling superlarge metallogenic belt, China. The Pb-Zn-Ag orebodies are hosted in the Proterozoic Luanchuan Group. The ore types are hydrothermal veins and skarns type. The ore-forming process can be divided into three stages: (1) quartz-pyrite; (2) quartz-sulphide; and (3) quartz-carbonate. This paper used stable and radiogenic isotopes to study the characteristics of the Lengshuibeigou Pb-Zn-Ag deposit. The temperature and salinity of fluids tend to decrease from the early skarn and quartz- pyrite stages to the late quartz-carbonate stage. The ranges of δO (SMOW) and δD (SMOW) values of the ore-forming fluids range from −0.03 to +4.97‰ and from −83.00 to −72.00‰, respectively. The δS values of pyrite, sphalerite and galena from the skarntype and hydrothermal-type vein ores range from +0.34 to +5.88‰, which is similar to those of porphyry-type Mo-W deposits in the area, but is different from those in the strata. The sulphur in both types of ores may have been derived from magmatic sources. The ranges of Pb/Pb, Pb/Pb and Pb/Pb ratios in the sulphide ores are 17.457-17.765, 15.423-15.606 and 37.712-39.012, respectively, which are comparable with those of feldspars in porphyry granites in the Nannihu ore field and less radiogenic than those in the host strata. These new data support the likelihood that the fluids and metals associated with Lengshuibeigou Pb-Zn-Ag deposit were carried by the porphyry magmatic system. The Ar/Ar plateau age of 137.9 ± 0.4 Ma age obtained from the Lengshuibeigou Pb-Zn-Ag deposit is likely its mineralization age. This paper is useful not only for interpretation of the genesis of the magmatic-hydrothermal deposits but also significant for mineral exploration in the area especially for finding large deposits in large magmatic districts where various types of base metal deposits might occur. [ABSTRACT FROM AUTHOR]

China is a mainland country rich in natural morel recourses, having records of half of the worldwide 61 morel phylospecies. In this study, 31 collections of ascocarps from the north Qinling Mountains, 4 collections of commercial cultivars from the south Qinling Mountains, and 3 Morchella mycelium clones from commercial cultivars were investigated using the genealogical concordance phylogenetic species recognition (GCPSR) method. Maximum-likelihood was employed for the construction of phylogenetic trees. A total of five phylogenetic species were found among the 38 collections, namely Morchella sp. Mes-8, Mes-9, Mes-13, and Mes-25, and Morchella chensiensis (IF556780), in addition to the false morel (Verpa bohemica). The identification of cultivated Morchella sp. Mel-2, Mel-6, Mel-10, and Mel-12 coincided with that of the commercial farms. A total of 80% (4/5) of yellow morels were new records for the Qinling region, except Mes-19; moreover, a novel monophyletic lineage, Morchella chensiensis, was found to be distinct from the previously reported phylospecies by single gene and combined genes analysis, thus being herein proposed as a new phylospecies. All collections from this study showed continental endemism, and all Qinling Mountains collections were grouped together in rDNA phylogenetic trees. The study provided insights on biodiversities in this key region of China. [ABSTRACT FROM AUTHOR]

The Dashui porphyry granitoids in the western Qinling Orogen are spatially associated with the Dashui gold deposit, but their ages and tectonic setting have not been well defined yet in previous studies. This paper reports the results and understandings obtained from our original study in geochronology and isotope and element geochemistry. SHRIMP zircon U-Pb dating yielded ages of 213.7 ± 2.7 Ma for granitic stock and 215.1 ± 2.5 and 210.2 ± 1.6 Ma for granitic dikes. The granitoids are characterized by high LREE but low HREE and HFSE. They have (87Sr/86Sr) i ratios of 0.706 to 0.709 and εNd(t) values of −5.3 to −7.6. The majority of zircons in the Dashui granitoids have εHf(t) values ranging from −6.2 to 6.7 and TDM2(Hf) ages from 743 to 1464 Ma. The isotope signatures, together with La/Y and Mg# values, show that the magmas are mainly sourced from partial melting of a subducted slab, and possibly assimilated immature sediments during upward migration. Thus, the Dashui granitoids most likely formed in a volcanic arc where supra-subduction zone melts assimilated lower crustal material no later than 215 Ma. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Regional culture of the Qinling Mountains shows distinct features since it was born in the local outstanding ecological environment, study on local architecture is significant for the dominant expression of regional culture, protection of local environment, and echoing with the theme of ecological civilization construction. This paper, on the basis of the mutual influence and evolution of regional culture and style of local residential buildings, explored the reasons for the weakening of local architectural style, and specified the significance of promoting local style of the living environment. By studying the influence of local natural environment and humanistic environment on architectural style along the northern foot of the Qinling Mountains, the paper explored the expression of regional culture in residential buildings, with Xian Garden (Xi'an Yuanzi) as an example, and aimed at giving useful help to the dominant expression of regional culture in modern residential buildings. [ABSTRACT FROM AUTHOR]

Forty-nine wild oil plants which are abundant in the Tsinling and Zhongtiao Mountains were investigated and screened as raw material for biodiesel production. The oil content was tested and found to be greatly variable, ranging from 10 to 62.8 %. Fatty acid profiles of their vegetable oils were analyzed, and their acid value, saponification number, and iodine value were found to range from 1.6 to 61.3 mg KOH/g, 128.6 to 225.9 mg KOH/g, and 54.3 to 120.9 g I/100 g, respectively. Cetane number, kinematic viscosity, specific gravity, high heating values, and cold filter plugging point of the 49 vegetable-oil methyl esters (MEs) were empirically calculated and were found to vary from 38.8 to 66.6, 2.9 to 4.2 mm/s, 841.4 to 883.8 kg/m, 39.0 to 47.5 kJ/g, and −14.3 to 13.2 °C, respectively. Almost half (25 species) of all the sampled resources were found to be suitable for biodiesel production since the profiles of their vegetable-oil MEs met the major specifications of Chinese and European Union biodiesel standards, GB/T20828 and EN-14214, respectively. Grey relational analysis was used during the optimum-species screening process. The difference between the individual species and the artificial designed ideal species (the best biodiesel plant type in this paper) was calculated and evaluated with the help of grey relational grade, which varied from 0.467 to 0.686. Finally, the selected plants, Prunus salicina Linn. and Amygdalus davidiana (C.) C. de Vos, were considered as the optimal feedstock for biodiesel production. [ABSTRACT FROM AUTHOR]

In this paper, we present zircon U-Pb age and Hf isotope data to document the significance of magma mixing in the formation of Late Jurassic granitoid intrusions in the eastern Qinling Orogen, China. The Muhuguan granitoid pluton from this orogen consists of monzogranite and lesser biotite granite and granodiorite, all containing abundant hornblende-rich cumulates, dioritic xenoliths, and mafic magmatic enclaves (MMEs). The monzogranite and granodiorite are intruded by a number of lamprophyre dykes. Both a cumulate and a dioritic xenolith samples have concordant zircon U-Pb ages of ca. 161 ± 1 Ma, but possess contrasting Hf isotopic compositions. The cumulate has more radiogenic zircon Hf isotopes with negative ε( t) values (−7.9 to −2.5) and T ages of 0.9-1.1 Ga, indicating its derivation likely from basaltic rocks of the Neoproterozoic to early Paleozoic Kuanping Group in the area. The dioritic xenolith has much lower zircon ε( t) values of −19.5 to −8.8 and T ages of 2.4-1.7 Ga, consistent with a juvenile Paleoproterozoic crust source presumably represented by the metabasic rocks of the Qinling Group in the area. Individual samples of the monzogranite, MME, and a lamprophyre dyke have U-Pb ages of 150 ± 1, 152 ± 1, and 152 ± 1 Ma, respectively, demonstrating coeval mafic and felsic magmatism in the Late Jurassic. The lamprophyre dyke has homogeneous, highly negative zircon ε( t) values (−29.8 to −24.8) and Archean T ages (3.0-2.7 Ga), and its genesis is interpreted as partial melting of an ancient enriched subcontinental mantle source. Zircons from the fine-grained MME show a large range of ε( t) between −29.1 and −9.8, overlapping values of the monzogranite and lamprophyre dyke samples. Zircon U-Pb age and Hf isotopes of the MMEs are consistent with their formation by mixing of crustal- and enriched mantle-derived magmas. The main group of zircons from the monzogranite has ε( t) values (−17.9 to −9.3) and T ages (2.3-1.8 Ga) that are compatible with the dioritic xenoliths, indicating that the former was produced by partial melting of Paleoproterozoic crustal source with involvement of mantle-derived magmas. Mafic magmatism revealed from the Muhuguan pluton indicates that the eastern Qinling Orogen was dominated by lithospheric extension during the Late Jurassic. Compilation of existing geological and geochronological data suggests that this extensional event started in Late Jurassic (ca. 160 Ma) and persisted into the Early Cretaceous until ca. 110 Ma. The Jura-Cretaceous extension may have resulted from the late Mesozoic westward subduction of the Pacific plate beneath the East Asian continental margin. [ABSTRACT FROM AUTHOR]

The relationship between temperature and drought was investigated using the temperature-sensitive growth of Larix chinensis Beissn in the Qinling Mountains, central China. Extremely high tree-ring width index values (TRWI) agreed well with dry conditions defined by the dryness-wetness index (DWI) obtained from data in Chinese historical documents and climate-related papers between 1814 and 1956 (before the short of instrumental measurements); the reverse applied to extremely low TRWI values. The main severe drought epochs occurred from the late 1850s to the 1870s, the 1920s to 1930s and in the 2000s, whereas wet spells occurred from 1817-1827 and 1881-1886. The droughts in the 2000s exhibited a similar pattern as the ones from the 1920s to 1930s, with obviously an increasing temperature. The variation of tree growth agreed well with other reconstructed temperature series from nearby and remote regions, suggesting that Larix chinensis could respond to broad-scale climate variability. The longest cold interval, 1817-1827, could be associated with the influence of the Tambora eruption in 1815. [ABSTRACT FROM AUTHOR]

Appraisal of tourism development planning is a core link tot its authoritativeness and legalization. Currently, China's appraisal work is mainly confined to qualitative analysis and presents "pro forma" irrational phenomena. The paper constructs 25-index appraisal system from the 4 levels of standardization, scientification, feasibility and innovation and takes tourism development planning in Qinling Mountains, Shananxi Province as an empirical study. The results show that 1. the appraisal system is composed of compiling system, planning object system and management system and the appraisal stakeholders are divided into core stakeholders and fringe stakeholders; 2. feasible index weighs the most, at the core position, followed by scientific index, as the key target of examination and appraisal; innovative index places the third, attention is paid to the planning contents and technical innovation and standardized index weighs the least, which is closely related to planning forms and content system; 3. demonstration link of the results of tourism development should be increased to carry on the evaluation ways combining qualitative, quantitative and grading contents and develop the management system. [ABSTRACT FROM AUTHOR]

Two new species of the genus Amphinemura, A. albicauda sp. n. and A. dingoidea sp. n. from the southern Qinling Mountains, Foping County of Shaanxi Province, western China, are described based on both sexes and the larval stage. The new species are compared with related taxa, and the A. sinensis species group is defined for an Oriental lineage of the genus. Amphinemura sinensis (Wu, 1926) and A. unihamata (Wu, 1973) are reported from Shaanxi for the first time, and the hitherto unknown female of A. unihamata is described. A distribution map of the Amphinemurinae known from Qinling Mountains is given. [ABSTRACT FROM AUTHOR]

A checklist of 63 species of tardigrades from the Tsinling Mountains is given in this paper. Thirty-seven species of tardigrades that had never been found in the Tsinling Mountains were reported here. Twenty of them are new records for the mountains, 15 of them are new records for China, two of them are new to science. Pseudechiniscus pilatoi sp. n. is similar to Pseudechiniscus quadrilobatus Iharos, 1969. It differs from P. quadrilobatus in different cuticular sculpture, in the joints of paired-plates, near the dorsal median line, uplifting but not protruding backward, and in lacking notches on terminal plate. Echiniscus marleyi sp. n. differs from E. canadensis Murray in having filaments D; it differs from E. mediantus Marcus in lacking filaments C but in having filaments D; it differs from E. spinulosus (Doyère) in lacking teeth B, C, E, and in having filaments D instead of teeth D. [ABSTRACT FROM AUTHOR]

The tectonic evolution of South Qinling, which is a main part of the Qinling orogenic belt, is still in dispute and deformation history of South Qinling is poorly studied. In this paper, detailed structural, microstructural, quartz c-axis fabric analysis, and geochronology results for the Madao gneiss in South Qinling are presented to characterize the deformation history. Results show that rocks in the northern part (Tiefodian-Laozhanggou) experience general shearing and deform at relative low temperature. The shear sense generally is south to north. In contrast, rocks in the southern part (Laozhanggou-Panjiahe) are weakly sheared with pure shear features and evidence of high-temperature deformation. Based on the analyses, we conclude that there exist two distinct deformation geometries in the Madao gneiss and accordingly we can divide the deformation into two stages. The early stage is represented by regional shortening, while the late stage features northward thrust shearing and evidence shows that it was a progressive process between them. LA-ICP MS U-Pb dating of zircons from pre-deformational migmatite veins yields age of 198.5 ± 2.0 Ma. This result, in combination with the age of post-deformational granite, indicates that the northward thrust shearing of the Madao gneiss occurred in the Late Triassic. In view of these results and other reported data in South Qinling, we propose that deformation in Madao gneiss may result from the initial collision and subsequent northward accretion in Late Triassic. [ABSTRACT FROM AUTHOR]

The large Huachanggou gold deposit, on the southern margin of the Mian-Lue Suture in western Qinling Orogen (central China), is hosted in the Devonian Sanhekou Group composed of spilite, limestone and phyllite. The mineralization is considered to have occurred in three stages: (1) Early quartz-pyrite veins, (2) Middle quartz-sulphides veins, and (3) Late carbonate-quartz veinlets, with gold being introduced mainly in the second stage. Quartz formed in the two earlier stages contains four types of fluid inclusions, namely (1) Pure CO2, (2) CO2-H2O, (3) Solid-bearing and (4) NaCl-H2O, whereas the late-stage minerals contain only the NaCl-H2O inclusions. The inclusions in quartz formed in the early-, middle- and late stages have yielded total homogenization temperatures of 272−385 °C, 232−395 °C and 118−228 °C, respectively, with salinities no higher than 12 wt.% NaCl equiv. For the middle-stage, trapping pressures estimated from the CO2-H2O inclusions for the altered spilite-type (123−326 MPa) and quartz vein-type (132−342 MPa) orebodies correspond to mineralization depths of 12 km and 13 km, respectively. We suggest that fluid boiling and mixing may have caused rapid precipitation of metallic sulphides and native gold. Through boiling and influx of meteoric water, the ore-forming fluid system has evolved from CO2-rich to CO2-poor and from metamorphic to meteoric, as indicated by the decreasing δ18Owater values from the early- to late stages. Integrating the evidence obtained from regional geology, ore deposit geology, fluid inclusion and C-H-O isotope geochemistry, we conclude that the Huachanggou gold deposit is best ascribed to be an orogenic-type system formed in the tectonic setting of the north-vergent oceanic plate subduction along the Mian-Lue Suture during the Late Triassic. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The Early Cretaceous Houyaoyu granite porphyries are located in the south margin of the North China Craton. Field observations, petrography, geochronology, major and trace elemental and Sr-Nd isotopic compositions are reported to elucidate the genesis of the Houyaoyu granite porphyries. SIMS zircon U-Pb analyses for the Houyaoyu granite porphyries yield two concordant ages of 133.2±2.3 (2σ) and 131±1.1 (2σ) Ma, respectively. Major and trace elemental compositions indicate that these porphyries are high-K I-type granites with high contents of SiO2, K2O, Rb, U, Pb, low Nb, Ta, Ti, and P. Initial 87Sr/86Sr ratios range from 0.708 3 to 0.709 7, and εNd(t) values range from -9.13 to -12.3, with corresponding two-stage depleted-mantle Nd model ages (T2DM) varying from 1.57 to 1.91 Ga. This suggests that the Houyaoyu granite porphyries were predominantly derived from ancient lower continental crust, with minor involvement of mantle-derived components. On the basis of the tectonic evolution of the Qinling Orogen and geochemical characteristics of the Houyaoyu granite porphyries, it is proposed that they were formed in an extensional tectonic setting related to lithospheric destruction of the North China Craton, and produced Mo and Pb-Zn mineralization in East Qinling Orogen. [ABSTRACT FROM AUTHOR]

This study is the first attempt to understand the synergistic impact of anthropogenic and biogenic emissions on summertime ozone (O3) formation in the Guanzhong (GZ) Basin where Xi'an, the oldest and the most populous city (with a population of 9 million) in northwestern China, is located. Month-long (August 2011) WRF-Chem simulations with different sensitivity experiments were conducted and compared with near-surface measurements. Biogenic volatile organic compounds (VOCs) concentrations was characterized from six surface sites among the Qinling Mountains, and urban air composition was measured in Xi'an city at a tower 100ma.s. The WRF-Chem control experiment reasonably reproduced the magnitudes and variations of observed O3, VOCs, NOx, PM2.5, and meteorological parameters, with normalized mean biases for each parameter within -21 %. Subsequent analysis employed the factor separation approach (FSA) to quantitatively disentangle the pure and synergistic impacts of anthropogenic and/or biogenic sources on summertime O3 formation. The impact of anthropogenic sources alone was found to be dominant for O3 formation. Although anthropogenic particles reduced NO2 photolysis by up to 60 %, the anthropogenic sources contributed 19.1 ppb O3 formation on average for urban Xi'an. The abundant biogenic VOCs from the nearby forests promoted O3 formation in urban areas by interacting with the anthropogenic NOx . The calculated synergistic contribution (from both biogenic and anthropogenic sources) was up to 14.4 ppb in urban Xi'an, peaking in the afternoon. Our study reveals that the synergistic impact of individual source contributions to O3 formation should be considered in the formation of air pollution control strategies, especially for big cities in the vicinity of forests. [ABSTRACT FROM AUTHOR]

Entomopathogenic fungi are considered to be a safe microbiological pesticide alternative to chemical control. Efforts are underway to understand precisely their taxonomy and natural distribution through mycological and biodiversity studies based on molecular markers. Here, we present descriptions of the diversity of the entomopathogenic fungi in the genera Metarhizium and Beauveria found along the elevational gradients of the Qinling subtropical and temperate forests of Shaanxi province in China, using morphological aspects and molecular markers. Molecular characterization using the Mz_IGS3 intergenic region revealed that Metarhizium isolates phylogenetically clustered in the PARB clade with four different distinguishable species, but the 5′- TEF gene allowed only ambiguous delimitation of Metarhizium species. Beauveria isolates were characterized by sequence analyses of the translation elongation factor 1-α and the Bloc region. The richness of Metarhizium species decreased with increasing elevation, with Metarhizium robertsii s.l. being the most abundant species along the elevational gradient. Our bioassay suggests that certain species of Metarhizium are significantly pathogenic to the insect model Tenebrio molitor at both the adult and larvae stages and could potentially serve as a control of insect pests of forests. [ABSTRACT FROM AUTHOR]

The carbon balance of forests is controlled by many component processes of carbon acquisition and carbon loss and depends on the age of vegetation, soils, species composition, and the local climate. Thus, examining the carbon balance of different forests around the world is necessary to understand the global carbon balance. Nevertheless, the available information on the carbon balance of Larix principis-rupprechtii forests in the Qinling Mountains remains considerably limited. We provide the first set of results (2010-2013) from a long-term project measuring forest-atmosphere exchanges of CO2 at the Qinling National Forest Ecosystem Research Station (QNFERS), and compare the net ecosystem exchange (NEE) based on biometric measurements with those observed via the eddy covariance method. We also compare the total ecosystem respiration via scaled-up chamber and eddy covariance measurements. The net primary productivity (NPP) was 817.16 ± 81.48 g.C.m-2.y-1, of which DBliving and Dtotal accounted for 77.7%, and 22.3%, respectively. Total ecosystem respiration was 814.47 ± 64.22 g.C.m-2.y-1, and cumulative annual soil respiration, coarse woody debris respiration, stem respiration, and leaf respiration were 715.47 ± 28.48, 15.41 ± 1.72, 35.28 ± 4.78, and 48.31 ± 5.24 g.C.m-2.y-1, respectively, accounting for 87.85%, 1.89%, 4.33%, and 5.93% of the total ecosystem respiration. A comparison between ecosystem respiration from chamber measurements and that from eddy covariance measurements showed a strong linear correlation between the two methods (R2 = 0.93). The NEE of CO2 between forests and the atmosphere measured by eddy covariance was -288.33 ± 25.26 g.C.m-2.y-1, which revealed a carbon sink in the L. principis-rupprechtii forest. This number was 14% higher than the result from the biometric measurements (-336.71 ± 25.15 g.C.m-2.y-1). The study findings provided a cross-validation of the CO2 exchange measured via biometric and eddy covariance, which are beneficial for obtaining the true ecosystem fluxes, and more accurately evaluating carbon budgets. [ABSTRACT FROM AUTHOR]

The Western Qinling has been acknowledged to witness superimposed orogeny including north subduction of Paleotethys ocean and collision between North China and South China blocks; however, the precise timing constraints on transition of tectonic regime are remaining enigmatic. The Wenquan composite batholith comprising five phases and mafic enclaves is an ideal example to unlock this puzzle. The host granitoids are felsic, metaluminous to peraluminous, and high-K calc-alkaline to shoshonitic suite with I-type affinity. The mafic enclaves, however, are intermediate, and high-K calc-alkaline to shoshonitic. Zircon ages of multiple phases indicate an episodic growth lasting nearly 30 million years ranging from 238, 228, 218 to 208 Ma, consistent to Triassic igneous activity recording a transition regime from a subduction setting to a syn-collision setting and a post-collision setting in Western Qinling. Lead isotopes of whole-rock and K-feldspar at Wenquan and Lu-Hf isotopes of zircons separated from biotite monzogranite porphyry, porphyritic monzogranite, monzogranite porphyry, and hosted mafic enclaves suggest that the heat and the hot mafic melt initiated by the break-off of the northward subducting South China block lithosphere triggered partial melting of the Mesoproterozoic subcontinental lithospheric mantle to produce mafic magmas, and the underplated mafic magmas caused partial melting of the shallow subducted Mesoproterozoic lower crust generating granitic magmas at Wenquan. Combined our field observations and petrology study with a holistic review on previous geochronological and geochemical data of Triassic granitoids throughout the Western Qinling, we in this contribution proposed that the Triassic igneous activity in the Western Qinling corresponding to superimposed orogeny evolved from the northward subduction of Palaeotethys ocean (250–235 Ma) through syn-collision (228–215 Ma) to post-collision (215–185 Ma) between the North China and South China blocks. [ABSTRACT FROM AUTHOR]

Soil degradation has been reported worldwide. To better understand this degradation, we selected Pinus armandii and Quercus aliena var. acuteserrata forests, and a mixed forest of Q. aliena var. acuteserrata and P. armandii in the Qinling Mountains in China for our permanent plots and conducted three investigations over a 20-year period. We determined the amounts of available nitrogen (N) and phosphorus (P) in the soil to track the trajectory of soil quality and compared these with stand characteristics, topographic and climatic attributes to analyze the strength of each factor in influencing the available N and P in the soil. We found that the soil experienced a severe drop in quality, and that degradation is continuing. Temperature is the most critical factor controlling the soil available N, and species composition is the main factor regulating the soil available P. Given the huge gap in content and the increasing rate of nutrients loss, this reduction in soil quality will likely negatively affect ecosystem sustainability. [ABSTRACT FROM AUTHOR]

The correspondence between five precipitation products, including CMORPH, GPCP-2, TRMM 3B43, GPCC, and ITPCAS, and ground-based measurements of precipitation were evaluated on annual, seasonal, and monthly scales during 2000–2014 in the Qinling-Daba Mountains over China, which is a significant area with vital value of climate and hydrology. Performances of the precipitation products in the relatively arid/humid years were also analyzed. In general, ITPCAS data displayed the highest accuracy, GPCP-2 and CMORPH data showed relatively poor performance, and GPCC and TRMM 3B43 data were average at different temporal scales among the five precipitation products. The Pearson correlation coefficient of each station had minor fluctuations for the five precipitation products. A larger deviation was found at Wudu station, most likely due to the undulating terrain. The performances of the precipitation products from highest to least accuracy are as follows: ITPCAS > TRMM 3B43 > GPCC > GPCP-2 > CMORPH. Except for CMORPH (-20.76%), the percentage precipitation differences (PPDs) of the other four precipitation products fluctuated in the range of 10% during the relatively arid (2001) and humid (2011) years. In addition, all precipitation products and ground gauge observed precipitation did not show an obvious gradient with altitude, which is different from that in other mountainous areas and is perhaps due to complex terrain, lack of observation in high altitudes, and precipitation undercatch. In consideration of the significance of Qinling-Daba Mountains as the geographic and ecological dividing lines, the present study may provide a new perspective for hydrological, climatic, and ecological researches and practices in local and other mountainous areas. [ABSTRACT FROM AUTHOR]

The concentrations and stoichiometry of certain elements (carbon, nitrogen and phosphorus) are critical to the maintenance of plant functional and environmental adaptation during plant growth. We explore how the concentrations of C, N and P and the ratios of C:N, C:P, and N:P in the leaves of differently aged Larix principis-rupprechtii Mayr. plantations changed with growing season and stand age from 2012 to 2015 in the Qinling Mountains, China. The results showed that the element concentration and stoichiometric ratios in leaves were significantly affected by sampling month, stand age and sampling year; and multiple correlations with stand age were observed in different growing seasons. Compared to global element concentrations and stoichiometry in plants, the leaves of larch stands in the study region had higher C and P concentrations and C:N and C:P ratios but lower N concentrations and N:P ratios than global levels. The leaf N:P ratios of all of the larch stands were generally less than 14, suggesting that the growth of larch stands was limited by N in the study region. Our study facilitates the management and restoration of forest plantation and provides a valuable contribution to the global pool of leaf nutrition and stoichiometry data. [ABSTRACT FROM AUTHOR]

Large-scale Quercus variabilis natural secondary forests are protected under the Natural Forest Protection (NFP) program in China to improve the ecological environment. However, information about nutrient characteristics and carbon (C) storage is still lacking. Plant biomass and C, nitrogen (N) and phosphorus (P) stoichiometry of tree tissues, shrubs, herbs, litter, and soil were determined in young, middle-aged, near-mature and mature Quercus variabilis secondary forests in the Qinling Mountains, China. Tree leaf N and P concentrations indicated that the N-restricted situation worsened with forest age. The per hectare biomass of trees in decreasing order was near-mature, mature, middle-aged, then young stands. The majority of the biomass was in the stems (44.88-48.15%), followed by roots (24.54-28.68%), and branches (10.15-14.16%), and leaves made up the lowest proportion (2.86-3.55%) of trees. C storage at plant layer increased significantly with age, reaching maximum values in near-mature stand (100.4 Mg·ha-1) and then decreasing in mature stands. Soil C storage at a depth of 0 to 100 cm was 82.8, 96.8, 85.8, 104.2 Mg·ha-1, and C storage of forest ecosystem was 122.8, 163.0, 184.9, 178.3 Mg·ha-1 in young, middle-aged, near-mature, mature stands, respectively. There were significant correlations between biomass and C, N, P stoichiometry in different layers, especially in young stands. [ABSTRACT FROM AUTHOR]

Environmental heterogeneity contributes to various habitats and may influence the diversity and activity patterns of wildlife among habitats. We used camera traps to assess wildlife habitat use in Guanyinshan Nature Reserve from 2009 to 2012. We focused on four types of habitat including open areas with gentle slope (<15°) (Type1), low elevation areas (about 1500-1700 m) with high bamboo coverage (Type2), high elevation areas (about 2100-2300 m) with high canopy coverage (Type3), and wildlife migration passages (Type4). We analyzed the differences in species richness, relative abundance index (RAI), species diversity, and animals' activity pattern among habitats. Total six species were analyzed on activity pattern, which are Takin ( Budorcas taxicolor), tufted deer ( Elaphodus cephalophus), Himalayan goral ( Naemorhedus goral), wild boar ( Sus scrofa), golden pheasant ( Chrysolophus pictus), and porcupine ( Hystrix hodgsoni). The results are (1) that there were significant differences in richness and RAI among habitats; (2) Type4 habitat had the highest richness and RAI while Type2 had the highest species diversity; giant pandas were found in these two habitats; (3) there were significant differences in species' activity during daytime and nighttime; and (4) differences appeared in habitat preference of the most abundant species. Takin and tufted deer preferred Type1, Himalayan goral preferred Type2, and golden pheasant preferred Type3. Type4 habitat was used by most animals. All these revealed that habitat heterogeneity plays an important role in species diversity and the importance for conservation. [ABSTRACT FROM AUTHOR]

Porphyry Cu and Mo deposits are two economically important types of metal deposits worldwide, but factors controlling their difference remain enigmatic. Compared with the well-studied large porphyry Mo province in the south margin of the North China Block (S-NCB), the origin of newly discovered porphyry Cu deposits in the South Qinling (SQB) is poorly constrained. Integrated zircon LA-ICPMS U-Pb and molybdenite Re-Os ages and geological evidence indicate three stages of magmatism at Lengshuigou: (1) late Neoproterozoic (718 to 704 Ma) quartz diorite + albitite + granite association during the pre-ore stage, (2) 146 to 145 Ma granodiorite porphyry during the syn-ore stage, and (3) 145 Ma granite porphyry during the post-ore stage. Elemental and Sr-Nd isotopic evidence provide important constraints on their magma source. Pre-ore Neoproterozoic quartz diorite + albitite + granite was derived by re-melting of a mixture of crustal and juvenile mantle materials, and stronger fractional crystallization was involved in these ore-hosting intrusions than in contemporary granitoids hosted in the Douling Group. Syn-ore granodiorite porphyry was derived from mantle-derived magma with contributions from different proportions of crustal components. Post-ore granite porphyry was derived mainly from a crustal source. Nearly contemporaneous porphyry Cu and Mo systems were identified in Qinling Province, including the 147-139 Ma porphyry Mo systems in the S-NCB and 150-146 Ma porphyry Cu systems in the SQB. Granitic stocks related to porphyry Cu systems in the SQB are characterized by moderate SiO contents (58.01-69.07 %) and less radiogenic Nd-Hf isotopes (εNd = −3.8 to −6.3, εHf = −4.5 to +1.6), whereas the granitic stocks related to porphyry Mo deposits in the S-NCB have high SiO concentrations (64.00-76.00 %) and more radiogenic Nd-Hf isotopes (εNd = −18.0 to −11.6, εHf = −26.3 to −13.5). In addition, molybdenite from the Chigou and Lengshuigou porphyry Cu deposits in the S-NCB show higher Re contents (77.50-394.3 ppm) than those from nearly contemporaneous porphyry Mo deposits (9.34-49.7 ppm) in the S-NCB. These lines of evidence indicate that a higher proportion of mantle component was involved in the formation of porphyry Cu deposits in the SQB than nearly contemporaneous porphyry Mo deposits in the S-NCB. It is most likely that the nature of the magma source plays an essential role in the differences between porphyry Cu and Mo deposits. [ABSTRACT FROM AUTHOR]

Surface soils from the tourist areas of the northwest Qinling Mountains were analyzed to determine the concentrations, probable sources and potential risks of hydrocarbons. Concentrations of aliphatic and aromatic hydrocarbons ranged from 4.18 to 3240 ng g−1and 0.0462 to 101 ng g−1dry weight, respectively. The extent of soil contamination by hydrocarbons was generally typified by unpolluted to slightly polluted levels. The incremental lifetime cancer risks (ILCRs) for exposure to soil-borne PAHs indicated complete safety for tourists. Early diagenesis of natural products, bacteria activities and petroleum were the three main sources of aliphatic hydrocarbons, while the transport of air pollutants from pyrolytic processes was the main origin of PAHs. Because the photochemical reaction of PAHs in the atmosphere would produce lower ratios for Ant/(Ant + Phe), BaA/(BaA + Chr) and IcdP/(IcdP + BghiP), but a higher ratio for Fla/(Fla + Pyr), the source classification highly depended on the diagnostic ratios chosen. The plot of ΣCOM/Σ13PAH vs. ΣLMW/ΣHMWPAHprovide additional information to distinguish the origins of PAHs, and it showed a cluster of pyrogenic sources except for sample JFS-8. Four sources were resolved by principal component analysis: (1) a low temperature pyrogenic process related to the use of fossil fuel and biomass, such as charcoal, straw and wood, which contributes 63.1% of the measured PAHs; (2) the potential contribution of diagenetic processes, contributing 18.4%; (3) traffic emissions, contributing 9.27%; and (4) bioconversion/bacterial action, contributing 5.82%. Additionally, there was a good exponential relationship (r2= 0.969) between the naturaln-alkanes ratio (NAR) and carbon preference index for C23–C35(CPI23–35) for all samples, which is of great use for the determination of the origins of aliphatic hydrocarbon. [ABSTRACT FROM PUBLISHER]

The giant panda ( Ailuropoda melanoleuca) is one of the most endangered animals in the world, and it is recognized worldwide as a symbol for conservation. A previous study showed that wild and captive pandas, especially those of the Qinling subspecies, were exposed to toxicants in their diet of bamboo; the ultimate origin of these toxicants is unknown. Here we show that atmospheric deposition is the most likely origin of heavy metals and persistent organic pollutants ( POPs) in the diets of captive and wild Qinling pandas. Average atmospheric deposition was 199, 115, and 49 g·m−2·yr−1 in the center of Xi'an City, at China's Shaanxi Wild Animal Research Center ( SWARC), and at Foping National Nature Reserve ( FNNR), respectively. Atmospheric deposition of heavy metals (As, Cd, Cr, Pb, Hg, Co, Cu, Zn, Mn, and Ni) and POPs was highest at Xi'an City, intermediate at SWARC, and lowest at FNNR. Soil concentrations of the aforementioned heavy metals other than As and Zn also were significantly higher at SWARC than at FNNR. Efforts to conserve Qinling pandas may be compromised by air pollution attendant to China's economic development. Improvement of air quality and reductions of toxic emissions are urgently required to protect China's iconic species. [ABSTRACT FROM AUTHOR]

The Qinling panda subspecies ( Ailuropoda melanoleuca qinlingensis) is highly endangered with fewer than 350 individuals inhabiting the Qinling Mountains. Previous studies have indicated that giant pandas are exposed to heavy metals, and a possible source is vehicle emission. The concentrations of Cu, Zn, Mn, Pb, Cr, Ni, Cd, Hg, and As in soil samples collected from sites along a major highway bisecting the panda's habitat were analyzed to investigate whether the highway was an important source of metal contamination. There were 11 sites along a 30-km stretch of the 108th National Highway, and at each site, soil samples were taken at four distances from the highway (0, 50, 100, and 300 m) and at three soil depths (0, 5, 10 cm). Concentrations of all metals except As exceeded background levels, and concentrations of Cu, Zn, Mn, Pb, and Cd decreased significantly with increasing distance from the highway. Geo-accumulation index indicated that topsoil next to the highway was moderately contaminated with Pb and Zn, whereas topsoil up to 300 m away from the highway was extremely contaminated with Cd. The potential ecological risk index demonstrated that this area was in a high degree of ecological hazards, which were also due to serious Cd contamination. And, the hazard quotient indicated that Cd, Pb, and Mn especially Cd could pose the health risk to giant pandas. Multivariate analyses demonstrated that the highway was the main source of Cd, Pb, and Zn and also put some influence on Mn. The study has confirmed that traffic does contaminate roadside soils and poses a potential threat to the health of pandas. This should not be ignored when the conservation and management of pandas is considered. [ABSTRACT FROM AUTHOR]

The article discusses geochronology and tectonic impacts of diabase intruded into Xiangshan Group in the Southeastern Alxa Block, North West China.Topics discussed include tectonic junction between the North China Block and the western Qinling–North Qilian Orogenic Belt, use of sensitive high-resolution ion microprobe II to measure zircon ages of the diabase, and high potassium content in the region.

From a global perspective, karst geological disaster has great influence on the tunnel construction. Once it is not handled properly, the karst problems in the tunnel area will cause great disaster, such as water inrush, mud gushing and collapse, etc. These karst disasters seriously affect the construction progress of the tunnel, resulting in equipment damage, casualties, and so on. The construction of Yichang-Wanzhou (YW) railway tunnel has created a miracle in the field of Chinese tunneling. The geology of tunnel area is quite complex, the karst disaster is remarkable, and the engineering construction is extremely difficult. In this paper, the karst characteristics, unfavorable geological disasters, and treatment methods of YW railway tunnel were analyzed systematically. The YW railway tunnel and Zhengzhou-Wanzhou (ZW) railway tunnel are both located in the Qinling-Daba (QB) mountainous area, and the regional geological conditions of them are very similar. Therefore, the research in this paper can be extended to the QB mountainous area, thus providing a reference for the construction of ZW railway tunnel. The investigation can also provide reference for the similar engineering. [ABSTRACT FROM AUTHOR]

At present, there is limited research on the effect of climate change on the growth of trees in the Qinling Mountains, and the effect of altitude has rarely been considered. In order to accurately grasp the impact of climatic factors on the natural forest in this region, the effect of water and temperature conditions on the radial growth of Pinus armandii was studied according to dendroclimatology principles. Response function and multivariate regression methods were applied to study the response of the tree-rings, including earlywood width and latewood width, of P. armandii at three elevations (1600-1800, 1800-2000, 2000-2200 m) to climate change in this region. The results showed that the radial growth of P. armandii at the three elevations contained rich climatic information. The tree-ring widths at the three elevations were significantly negatively correlated with September temperature of the previous year and May temperature of the current year (P < 0.05) and were also negatively correlated with August precipitation of the previous year and May precipitation of the current year. The late-wood width of P. armandii at 1600-1800 m and 1800-2000 m was less sensitive to temperature and precipitation than that of the earlywood. The latewood width of P. armandii at 2000-2200 m was significantly negatively correlated with December temperature of the previous year and May temperature of the current year (P < 0.01), and was significantly and positively correlated with August precipitation of the previous year (P < 0.05). Characteristic analysis of the special years showed that large quantities of precipitation in September and October of the previous year were more likely to result in the formation of a very wide tree-ring. High spring and summer temperatures and less precipitation from April to June more likely resulted in the formation of extremely narrow tree-rings. Therefore, high precipitation in autumn of the previous year was conducive to the growth of P. armandii, whereas high temperature and drought in spring and summer inhibited the growth of P. armandii. [ABSTRACT FROM AUTHOR]

It is generally accepted that leaf litter covers seeds, which may be beneficial for their survival, but it is unclear whether leaf litter contributes in different ways to the survival of plant seeds with contrasting sizes. In this study, we examined the effect of different levels of leaf litter coverage on seed predation and foraging/caching for small-seededPinus tabulaeformisand large-seededPinus armandiiin the Qinling Mountains, China. Our results showed that leaf litter failed to protectP. armandiiseeds from being removed by small rodents, whereas it improved seed survival forP. tabulaeformis.P. tabulaeformiswere eatenin situ, whereas moreP. armandiiseeds were eaten in the high leaf litter coverage plots. Therefore, we propose that leaf litter affects the survival and predation rates for large and smallPinusseeds in the Qinling Mountains, China. [ABSTRACT FROM PUBLISHER]

Brachymystax lenok tsinlingensis is an endangered freshwater fish and distributed in mountains steams of Qinling Mountains, China. In this study, a comparative study of the mtDNA control region (D-loop) was performed to analyze its natural population structure and the genetic diversity of 53 individuals from four locations (TB, YX, LX and ZZ populations). Sequence analysis revealed three different domains and two feature sequences of the control region. The estimated haplotype and nucleotide diversity were 9 and 0.0023, respectively. Genetic structure analysis showed a high-level genetic diversity of B. lenok tisnlingensis ( h = 0.6060 ± 0.1499). The AMOVA analysis indicated that 26.02% of total variation came from individual populations, and 73.98% from variation within the four geographic populations, which showed low genetic differentiation between the four geographic groups. Test of neutral evolution and mismatch distribution indicated that no historical expansion occurred in these populations. The high genetic diversity and low genetic differentiation would provide new information for conservation and exploitation of this species. [ABSTRACT FROM AUTHOR]

The internal genetic clock of semelparous mast-flowering bamboo species creates gregarious regions of flowering and death, thus leading to fuel-load accumulation that potentially promotes fire (Fire-Cycle Hypothesis). Higher abundance of bamboo could be expected to provide greater fuel loads after flowering. Here, we investigated the possible link between bamboo dominance and fire occurrence. As the main food source for the giant panda in the Qinling Mountains of China, Bashania fargesii (Farges Canebrake) and Fargesia qinlingensis (Arrow Bamboo) dominate lower (1000-1900 m) and higher elevations (1800-2700 m), respectively. Four soil profiles (elevation ranging from 1240 to 2170 m) in areas of known recent bamboo flowering events (∼1980) and adjacent non-flowering sites were assessed for phytoliths and charcoal. Characteristic phytoliths were chosen to describe bamboo dynamics, and charcoal particles were extracted from the soil to reconstruct fire history. Carbon 14 dating of soil charcoal samples was conducted using an accelerator mass spectrometry technique. In addition, we chose two depths (28-52 and 90-100 cm) in one Bashania profile ( B. fargesii forest) and one Fargesia profile ( F. qinlingensis forest) for phytolith dating. Our findings indicate that bamboo has been a dominant component of these ecosystems almost for the entire profile; some 6400 yrs for Bashania and ca. 10000 yrs for the Fargesia. It is also clear from the charcoal and phytolith data that bamboo abundance and recent mast flowering were significantly related to fire occurrence for lower elevation Bashania while the higher elevation Fargesia was not. One of the four profiles had chronological charcoal records throughout and the oldest charcoal aged was ∼1410 yr BP, suggesting an anthropogenic origin. The mixing of phytolith and charcoal made it unrealistic to describe temporal dynamics of bamboo and fire events, and thus our interpretation is cognizant of the dating discrepancies and conservative (less-speculative). Due to the long history of bamboo and much shorter history of fire within the profile, our data lend little evidence to the Fire-Cycle Hypothesis. [ABSTRACT FROM AUTHOR]

In order to study the dynamic compression mechanical properties of engineering rock under high strain rate （100~102 S−1）loads, dynamic compression tests of three common engineering rocks (marble, sandstone and granite) taken from the Qinling Mountain are studied subjected to five different kinds of shock air pressure using Φ 100 mm split Hopkinson pressure bar test system improved with purple copper waveform shaper. The dynamic compression stress-strain curves, dynamic compressive strength, peak strain, energy absorption rate and elastic modulus of three rocks variation with strain rate are researched. The dynamic compression failure modes under different strain rates are analyzed. Then the three-dimensional numerical simulations of waveform shaper shaping effects and stress wave propagation in the SHPB tests are carried out to reproduce the test results. The research results show that the dynamic compression stress-strain curves show certain discreteness, and there is an obvious rebound phenomenon after the peak. With the increase in strain rate, the dynamic compressive strength, peak strain and energy absorption rate are all in a certain degree of increase, but the elastic modulus have no obvious change trend. Under the same strain rate, the dynamic compressive strength of granite is greatest while of sandstone is least. With the increase in strain rate, the margin of increase in peak strain and energy absorption rate of granite is greatest while of sandstone is least. The failure modes of the sample experience a developing process from outside to inside with the increase of strain rate. [ABSTRACT FROM AUTHOR]

An integrated study involving whole-rock and Sr-Nd-Hf isotope geochemistry and zircon geochronology and trace element combined with detailed field investigation was carried out for the composite Meiwu batholith in the West Qinling orogenic belt of central China to probe the origins of its compositional diversity and its emplacement history. The batholith is composed of quartz diorite, granodiorite and biotite granite, with abundant mafic magmatic enclaves and minor tonalitic enclaves in the granodiorite. The crystallization age of the batholith is ~240-245Ma. Geochemical and Sr-Nd-Hf isotopic data indicate that the magmas that formed the quartz diorite and the mafic enclaves were derived by partial melting of enriched lithosphere mantle, followed by variable degrees of hybridization with crustal magmas in deep crustal hot zones. These initially heterogeneous, hybrid magmas successively intruded into the upper crust and coalesced into a large magma chamber. Zircon trace element and Hf isotopic compositions suggest that the outer fine-grained part of the quartz diorite pluton crystallized from a less differentiated magma as a result of rapid cooling and thus preserved its initial heterogeneities, whereas the inner medium- grained part of the quartz diorite pluton crystallized from a convecting, isotopically homogeneous magma that had undergone advanced magmatic differentiation. The Sr-Nd-Hf isotope compositions of the mafic magmatic enclaves are strikingly similar to those of the host granodiorite, implying their isotopic equilibration. The tonalitic enclaves have high Sr/Y ratios and most probably represent magmas derived from partial melting of thickened mafic lower crust. The Sr- Nd-Hf isotope data suggest that the granodiorite and biotite granite were dominantly derived from isotopically heterogeneous crustal sources. However, the granodiorite also has relatively high Mg#, Cr, and Ni, indicating a minor contribution from a mantle source. The granodiorite was constructed incrementally from a number of discrete melt batches that were generated by partial melting of mafic lower crust under variable water fugacity. These melt batches did not assemble into a large magma chamber and thus preserved their source chemical features. The granodiorite magma was also replenished by mafic and high Sr/Y magmas, resulting in abundant and compositionally diverse magmatic enclaves. The biotite granite formed by the successive accumulation of discrete magma pulses generated by dehydration melting of mafic lower crust under water-absent conditions. These magma pulses coalesced into a small single magma chamber where they underwent fractional crystallization. The various rock types exhibit distinct geochemical variations, indicating that the Meiwu batholith was constructed from multiple injections of magma over a protracted period. Fractional crystallization, assimilation, magma mixing and/or mingling occurred during magma ascent and at the emplacement level. Distinct magma sources played a primary role in controlling the chemical diversity of the igneous bodies at pluton and batholith scale. [ABSTRACT FROM AUTHOR]

Chinese cork oak (Quercus variabilis) forests are protected on a large-scale under the Natural Forest Protection (NFP) program in China to improve the ecological environment. However, information about carbon (C) storage to increase C sequestration and sustainable management is lacking. Biomass, C, nitrogen (N) and phosphorus (P) storage of trees, shrubs, herb, litter and soil (0-100 cm) were determined from destructive tree sampling and plot level investigation in approximately 30-year old Chinese cork oak forests on the south slope of the Qinling Mountains. There was no significant difference in tree components' biomass estimation, with the exception of roots, among the available allometric equations developed from this study site and other previous study sites. Leaves had the highest C, N and P concentrations among tree components and stems were the major compartments for tree biomass, C, N and P storage. In contrast to finding no difference in N concentrations along the whole soil profile, higher C and P concentrations were observed in the upper 0-10 cm of soil than in the deeper soil layers. The ecosystem C, N, and P storage was 163.76, 18.54 and 2.50 t ha-1, respectively. Soil (0-100 cm) contained the largest amount of C, N and P storage, accounting for 61.76%, 92.78% and 99.72% of the total ecosystem, followed by 36.14%, 6.03% and 0.23% for trees, and 2.10%, 1.19% and 0.03% for shrubs, herbs and litter, respectively. The equations accurately estimate ecosystem biomass, and the knowledge of the distribution of C, N and P storage will contribute to increased C sequestration and sustainable management of Chinese cork oak forests under the NFP program. [ABSTRACT FROM AUTHOR]

Quantitative trait differences are often assumed to be correlated with molecular variation, but the relationship is not certain, and empirical evidence is still scarce. To address this issue, we sampled six populations of the cereal aphid Sitobion avenae from areas north and south of the Qinling Mountains, and characterized their molecular variation at seven microsatellite loci and quantitative variation at nine life-history traits. Our results demonstrated that southern populations had slightly longer developmental times of nymphs but much higher lifetime fecundity, compared to northern populations. Of the nine tested quantitative characters, eight differed significantly among populations within regions, as well as between northern and southern regions. Genetic differentiation in neutral markers was likely to have been caused by founder events and drift. Increased subdivision for quantitative characters was found in northern populations, but reduced in southern populations. This phenomenon was not found for molecular characters, suggesting the decoupling between molecular and quantitative variation. The pattern of relationships between FST and QST indicated divergent selection and suggested that local adaptation play a role in the differentiation of life-history traits in tested S. avenae populations, particularly in those traits closely related to reproduction. The main role of natural selection over genetic drift was also supported by strong structural differences in G-matrices among S. avenae populations. However, cluster analyses did not result in two groups corresponding to northern and southern regions. Genetic differentiation between northern and southern populations in neutral markers was low, indicating considerable gene flow between them. The relationship between molecular and quantitative variation, as well as its implications for differentiation and evolution of S. avenae populations, was discussed. [ABSTRACT FROM AUTHOR]

We have developed a 202-year tree-ring width chronology of Shensi fir ( Abies chensiensis) growing in an open canopy forest at the treeline of the eastern Qinling Mountains. Climate response analyses revealed that the ring width of Shensi fir trees is primarily controlled by the range of temperature from February-June. The regression model that we used for statistical temperature reconstruction passed the leave-one-out cross-validation used in dendroclimatology, resulting in a quality-controlled February-June reconstruction for the eastern Qinling Mountains. The model accounts for 36.7% of the instrumental temperature variance during the period of 1960-2012. Warm springs and early summers occurred during AD 1870-1873, 1909-1914, 1927-1958 and 1997-2012, while the periods of AD 1874-1908, 1915-1926 and 1959-1996 were relatively cold. Spatial climate correlation analyses with gridded land surface data revealed that our temperature reconstruction contains a strong regional temperature signal for central China. The linkages of our temperature reconstruction with sea surface temperature in the Atlantic and Pacific oceans suggest the connection of regional temperature variations to large-scale ocean-atmosphere-land circulation. Preliminary analysis of links between large-scale climatic variation and the temperature reconstruction also shows that there is a relationship between extremes in spring and early summer temperature and anomalous atmospheric circulation in the Qinling Mountains. Overall, our study provides reliable information for the research of past temperature variability in the Qinling Mountains, China. [ABSTRACT FROM AUTHOR]

The spatial separation of the Qinling Mountains from the western mountains has caused morphological and genetic distinctions of giant pandas. Could this separation also cause the pandas' behavior change? In this research, we focused on the pandas' movement pattern and selected two wild panda groups in Foping and Wolong Nature Reserves (NR) to represent the populations in the Qinling and Qionglai Mountains, respectively. We hypothesized that the Qinling pandas have developed a different seasonal movement pattern compared with the pandas in the western mountains. We analyzed the radio tracking data from two NRs by using GIS. Our results showed the following significant differences: (1) The Foping pandas live most of the year in the low elevation areas and move higher during June and remain through August while the Wolong pandas live most of the year in the high elevation areas and move lower in April and stay through June; (2) Comparing their low and high elevational areas shows the distinct spatial patterns between reserves, forming two obviously separated clusters in Foping but a single-compact cluster in Wolong; (3) Foping pandas move an average of 425 m ± 147 s.d. daily, while Wolong pandas move an average of 550 m ± 343 s.d. daily; and (4) Three habitat factors (i.e., terrain, temperature, and bamboo nutrient) were taken as the driving forces and analyzed, and they showed a strong support explanation to these different movement behaviors of pandas in two NRs. Our findings have important implications for management, for instance, it needs to be careful considering the behavior difference of the pandas when reintroducing them to the wild. [ABSTRACT FROM AUTHOR]

The nutritious acorns produced by oak trees ( Quercus spp.) are attacked frequently by insects that feed on seed reserves. However, previous studies have partly considered the effects of insect infestations on animal seed dispersal and subsequent plant regeneration. In this study, we tested whether the effects of insect infestations on seed dispersal were frequency dependent (i.e., ratio of noninfested to infested acorns). We tracked the seed dispersal of plastic-tagged noninfested and insect-infested Q. aliena var. acuteserrata acorns with different frequencies in the Qinling Mountains in central China. Our results demonstrated that noninfested acorns were removed more rapidly, regardless of the infestation rates. Insect-infested acorns were also more likely to be eaten in situ, whereas noninfested acorns were more likely to be scatter-hoarded independent of infestation rates. Moreover, noninfested acorns were dispersed further and had higher survival rates than insect-infested acorns. Our findings suggest that the seed dispersal advantages of noninfested acorns compared with infested acorns was not frequency dependent, thereby indicating a consistently higher dispersal likelihood of noninfested acorns. [ABSTRACT FROM AUTHOR]

Traditionally, a limited number of species and genera dominate the tree stock in streets and urban sites, and recent surveys in European and North American cities show that few species/genera continue to dominate. Yet, over the past decades, a growing proportion of those commonly used species have shown increasing difficulties to cope with urban sites. This has led to considerable and persistent arguments for using a more varied range of trees, including stress-tolerant species, at urban paved sites. This study examined forest systems occurring between 1300-2200 m asl. in the Qinling Mountains, China, in order to evaluate the oriental white oaks (Quercus aliena var. acuteserrata Maximowicz ex Wenzig) growth and development in warm and dry forest habitats and hence evaluate its potential for urban paved sites in northern parts of central Europe and in adjoining milder parts of northern Europe. In total, 102 oriental white oak where found in the studied plots and here showed very promising development in habitats experiencing drier conditions than those in park environments in Copenhagen, and is therefore interesting for urban paved sites were the demands of a greater catalogue of tolerant trees are highly needed. [ABSTRACT FROM AUTHOR]

Sinopodophyllum hexandrum is an important medicinal plant whose genetic diversity must be conserved because it is endangered. The Qinling Mts. are a S. hexandrum distribution area that has unique environmental features that highly affect the evolution of the species. To provide the reference data for evolutionary and conservation studies, the genetic diversity and population structure of S. hexandrum in its overall natural distribution areas in the Qinling Mts. were investigated through inter-simple sequence repeats analysis of 32 natural populations. The 11 selected primers generated a total of 135 polymorphic bands. S. hexandrum genetic diversity was low within populations (average He = 0.0621), but higher at the species level (He = 0.1434). Clear structure and high genetic differentiation among populations were detected by using the unweighted pair group method for arithmetic averages, principle coordinate analysis and Bayesian clustering. The clustering approaches supported a division of the 32 populations into three major groups, for which analysis of molecular variance confirmed significant variation (63.27%) among populations. The genetic differentiation may have been attributed to the limited gene flow (Nm = 0.3587) in the species. Isolation by distance among populations was determined by comparing genetic distance versus geographic distance by using the Mantel test. Result was insignificant (r = 0.212, P = 0.287) at 0.05, showing that their spatial pattern and geographic locations are not correlated. Given the low within-population genetic diversity, high differentiation among populations and the increasing anthropogenic pressure on the species, in situ conservation measures were recommended to preserve S. hexandrum in Qinling Mts., and other populations must be sampled to retain as much genetic diversity of the species to achieve ex situ preservation as a supplement to in situ conservation. [ABSTRACT FROM AUTHOR]

Upper Triassic to Upper Jurassic strata in the western and northern Sichuan Basin were deposited in a synorogenic foreland basin. Ion-microprobe U-Pb analysis of 364 detrital zircon grains from five Late Triassic to Late Jurassic sandstone samples in the northern Sichuan Basin and several published Middle Triassic to Middle Jurassic samples in the eastern Songpan-Ganzi Complex and western and inner Sichuan Basin provide an initial framework for understanding the Late Triassic to Late Jurassic provenance of western and northern Sichuan Basin. For further understanding, the paleogeographic setting of these areas and neighboring hinterlands was constructed. Combined with analysis of depocenter migration, thermochronology and detrital zircon provenance, the western and northern Sichuan Basin is displayed as a transferred foreland basin from Late Triassic to Late Jurassic. The Upper Triassic Xujiahe depocenter was located at the front of the Longmen Shan belt, and sediments in the western Sichuan Basin shared the same provenances with the Middle-Upper Triassic in the Songpan-Ganzi Complex, whereas the South Qinling fed the northern Sichuan Basin. The synorogenic depocenter transferred to the front of Micang Shan during the early Middle Jurassic and at the front of the Daba Shan during the middle-late Middle Jurassic. Zircons of the Middle Jurassic were sourced from the North Qinling, South Qinling and northern Yangtze Craton. The depocenter returned to the front of the Micang Shan again during the Late Jurassic, and the South Qinling and northern Yangtze Craton was the main provenance. The detrital zircon U-Pb ages imply that the South and North China collision was probably not finished at the Late Jurassic. [ABSTRACT FROM AUTHOR]

The North Dabashan thrust belt, which is located in South Qinling, is bounded by the Ankang fault on the north and the Chengkou–Fangxian fault on the south. The North Dabashan thrust belt experienced multiple stages of structural deformation that were controlled by three palaeostress fields. The first structural event (Middle Triassic) involved NNW–SSE shortening and resulted in the formation of numerous dextral strike-slip structures along the entire Chengkou–Fangxian fault zone and within the North Dabashan thrust belt, which suggests that the South China Block moved to the NW and was obliquely subducted under the North China Block. The second structural event (Late Triassic–Early Jurassic) involved NE–SW shortening that formed NW–SE-trending structures in the North Dabashan thrust belt. The third structural event (Late Jurassic–Early Cretaceous) involved ENE–WSW or nearly E–W shortening and resulted in additional thrusting of the North Dabashan thrust belt to the WSW and formation of the WSW-convex Chengkou–Fangxian fault zone, which has an oroclinal shape. Owing to the pinning of the Hannan massif and Shennongjia massif culminations, numerous sinistral strike-slip structures developed along the eastern Chengkou–Fangxian fault zone and were superimposed over the early dextral strike-slip structures. [ABSTRACT FROM AUTHOR]

This study identifies 'centers of endemism' for typhlocybine leafhoppers in China, revealing diversity patterns and congruence of patterns between total species richness and endemism. Distribution patterns of 774 Typhlocybinae (607 described and 167 undescribed species) were mapped on a 1.5° × 1.5° latitude/longitude grid. Total species richness, endemic species richness and weighted endemism richness were calculated for each grid cell. Grid cells within the top 5% highest values of weighted endemism richness were considered as 'centers of endemism'. Diversity patterns by latitude and altitude were obtained through calculating the gradient richness. A congruence of diversity patterns between total species richness and endemism was confirmed using correlation analysis. To investigate the bioclimatic factors (19 variables) contributing to the congruence between total species richness and endemism, we compared the factor's difference between non-endemic and endemic species using the Kruskal-Wallis test. Eleven centers of endemism, roughly delineated by mountain ranges, were identified in central and southern China, including the south Yunnan, Hengduan Mountains, Qinling Mountains, Hainan Island, Taiwan Island and six mountain areas located in western Sichuan, northwest Fujian, southeast Guizhou, southeast Hunan, central and western Guangdong, and north Zhejiang. Total species richness and endemic species richness decreased with increased latitude and had a consistent unimodal response to altitude. The proportions of endemism decreased with increased latitude and increased with rising altitude. Diversity patterns between total species richness and endemism were highly consistent, and 'Precipitation of Coldest Period' and 'Temperature of Coldest Period' may contribute to the congruence of pattern. Migration ability may play a role in the relationship of endemism and species richness; climate, environment factors and important geologic isolation events can also play crucial effects on relationships under special conditions. [ABSTRACT FROM AUTHOR]

The Yangshan gold deposit, Gansu Province, is the largest gold deposit in China and the best representative of the western Qinling gold province. Granite dykes can be observed in the orefield, of which some are spatially associated with the gold orebodies. Gold mineralization was debated between magmatic hydrothermal and metamorphic hydrothermal models in previous studies due to a shortage of precise isotopic ages of the granite dykes in the orefield. In this contribution, we report in-situ zircon LA-ICP-MS U-Pb ages combined with Hf isotope and REE data. The age of granite dykes is constrained to be 220.2 ± 3.1 Ma, coeval with the regional development of Triassic granitoids, which resulted from the northward subduction of the Mian-Lue oceanic plate. The εHf(t) values of inherited and new zircon grains from the granite dykes show that the granite dykes have a complex source dominated by sediments which were sourced from the North China Craton, Yangtze Craton and Qinling Orogen, and accumulated in a fore-arc setting. The granite dykes were derived from partial melting of the fore-arc sediment prism induced by the fluids sourced from metamorphic devolatilizaiton of the underthrust Mian-Lue oceanic plate. The Yangshan gold deposit was formed at about 190 Ma, some 30 Myr later than the intrusion of the granite dykes, ruling out the possibility that gold mineralization was caused by Triassic granitic magmatism. The Yangshan gold deposit is a transitional system between Carlin- and orogenic-types that resulted from continental collision orogeny, metallogeny and fluid flow. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The East Qinling region in central China, hosting several tens of Mesozoic magmatic-hydrothermal Mo deposits, is one of the largest molybdenum belts in the world. The Zhifang Mo deposit is hosted in volcanic rocks of the Xiong'er Group in the Waifangshan area, Qinling Orogen. Previous studies variously correlated the mineralization in this deposit with Yanshanian magmatism or Palaeo-Mesoproterozoic volcanic-hydrothermal events. The orebodies are associated with quartz veins and controlled by subsidiary faults of the Machaoying Fault. The ore-forming process can be divided into the early, middle and late stages and is characterized by quartz-pyrite, quartz-polymetallic sulphide and quartz-carbonate veins, respectively. The early-stage quartz is structurally deformed, suggesting a compressional tectonic regime; the middle-stage sulphides fill the fractures of the early-stage assemblages and show no deformation, suggesting a tensional setting; the late-stage veins mostly infill the open-space fissures. Three types of fluid inclusions (FIs) are identified at the Zhifang deposit: H2O-NaCl (W-type), CO2-rich (C-type) and daughter mineral-bearing inclusions (S-type). Fluid inclusions of early-stage quartz homogenize between 380 and 470 °C, with salinities ranging from 0.4 to 9.6 wt.% NaCl equiv., whereas the late-stage calcite contains only the W-type FIs with homogenization temperatures of lower than 240 °C, and salinities of 0.4-8.7 wt.% NaCl equiv. This indicates that the ore fluid system evolved from CO2-rich, probably metamorphic hydrothermal to CO2-poor, meteoric fluid. All three types of FIs can be observed in the middle-stage quartz, and even in the microscopic domain of a crystal, suggesting that this heterogeneous association was trapped from a boiling fluid system. These FIs homogenized at temperatures ranging from 250 to 360 °C and display two salinity clusters of <18.5 and 29.1-29.9 wt.% NaCl equiv. These results suggest that metal precipitation resulted from fluid boiling. The estimated trapping pressures of FIs range from 101 to 285 MPa, suggesting an alternating lithostatic-hydrostatic fluid system, which was controlled by a fault-valve at the depth of 10 km. The δ34S values of ore minerals from the Zhifang Mo deposit show a range between −11.8‰ and 6.0‰, with a bimodal distribution. The early-stage pyrite has a positive δ34S value of 6.0‰ that is similar to the host rocks of the Xiong'er Group and the Taihua Supergroup, suggesting that the wall rocks contributed much of the sulphur to the early-stage pyrite during fluid-rock interaction. However, the δ34S values of the middle-stage sulphides have negative mean and restricted range from −11.8‰ to −4.5‰. The widespread rutile grains coexisting with molybdenite in the middle-stage correlate the negative δ34S values with relatively oxidized fluids. We consider phase separation as an efficient mechanism for ore-fluid oxidation and molybdenum deposition based on fluid inclusions and sulphur isotope data. Geological, fluid inclusion and sulphur isotope data of the Zhifang Mo deposit suggest that the Mo mineralization is unrelated to the Yanshanian magmatism or the Palaeo-Mesoproterozoic volcanic-hydrothermal event. Here we propose that the Zhifang Mo deposit may be considered as an orogenic mineral system, with its formation in an active continental margin related to the northward subduction of the Mian-Lue oceanic plate during the Triassic. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]