Shangri-La Region Research Articles

Titan’s surface spectra at the Huygens landing site and Shangri-La

Titan is an icy satellite of Saturn with a dense atmosphere and covered by a global photochemical organic haze. Ground based observations and the Huygens descent probe allowed to retrieve the main spectral signature of the water ice (Griffith, C.A. et al. [2003]. Science 300(5619), 628–630; Coustenis, A. et al. [2005]. Icarus 177, 89–105) at the surface, possibly covered by a layer of sedimented organic material (Tomasko, M.G. et al. [2005]. Nature 438(7069), 765–778). However, the spectrum of the surface is not yet understood. In this study, we find that the surface reflectivity at the Huygens Landing Site (HLS) is well modeled by a layer of water ice grains overlaid by a moist layer of weakly compacted photochemical aggregated aerosols. Moist soils have spectra shifted toward short wavelengths relatively to spectra of dry soils. Cassini observations of Shangri-La region from orbit also show a very dark surface with a reflectivity peak shifted toward short wavelengths in respect to the reflectivity peak of bright surfaces, revealing a dichotomy between terrains based to their spectra in visible.

Biogeography of Shangri-la flora in southwestern China

Shangri-la region of southwestern China is within the Hengduan Mountains biodiversity hotspot and is exceptional in floral diversity. Based on intensive field investigations and herbarium specimens, 6807 species of native seed plants from 1297 genera and 166 families were recognized. The flora is dominated by families and genera with cosmopolitan and north temperate distributions, including Apiaceae, Asteraceae, Ericaceae, Fabaceae, Gentianaceae, Lamiaceae, and the genera Pedicularis, Rhododendron, and Salix, which contribute up to 73.15 % of the total number of species, but only make up a small portion of the total number of families and genera. Families and genera with fewer species more commonly have tropical distributions, while East Asian and Chinese endemic families and genera are mostly monotypic and oligotypic, and contribute little to the floristic diversity of the region. It is revealed that the flora of Shangri-la might have evolved through rapid speciation mainly from families and genera of cosmopolitan and north temperate distributions with the uplift of the Himalayas and climatic oscillations after the late Tertiary. The macroevolution of the flora in the Shangri-la region interpreted by floristic patterns is well supported by phylogeographic studies on plant taxa in Hengduan-Qinghai-Tibet Plateau regions.

Snow cover dynamics in and around the Shangri-La County, southeast margin of the Tibetan Plateau, 1974–2012: the influence of climate change and local tourism activities

The Shangri-La County and its surrounding areas lie within the Hengduan Mountains system at the southwestern margin of the Tibetan Plateau, and belong to the core zone of Three Parallel Rivers of Yunnan Protected Areas. There are numerous snow mountains of special ecological and cultural significance. The investigation of snow cover dynamics is important for understanding how snow cover responds in the context of climate change. In this study, the spatial and temporal dynamics of snow cover in the entire area were analysed using 28-scene Landsat images from 1974–2012. Snow cover variability of different altitudinal zones and orientations was also discussed. Then, we explored the relationship between snow cover dynamics and both climate change and local tourism activities. The results show that snow cover area in the Shangri-La region continued a clear decreasing trend in the last 40 years, declining from 4188 km2 in 1974 to 901 km2 in 2012. The decrease of snow cover generally occurred from low to high altitude and was most pronounced at altitudes of 4000–5000 metres, with a reduction of 2800 km2 since 1974. Snow cover decreased more significantly in the northwest part of the area than in the southeast. The primary driving force for this decrease was attributed to the increase in air temperature (+0.22°C per decade in the area). Compared with a similar decreasing trend in the Meili Snow Mountains, a dramatic reduction of snow cover in the southeastern Yulong Snow Mountains is attributed partially to local tourism activities.

Geochronology and geochemistry of Late Cretaceous igneous intrusions and Mo–Cu–(W) mineralization in the southern Yidun Arc, SW China: Implications for metallogenesis and geodynamic setting

The Sanjiang Tethyan Metallogenic Domain (STMD) is an important part of the Tethyan giant metallogenic belt. The Yidun Arc is a part of the STMD in the eastern Tibetan Plateau. Recently, four newly discovered Mo–Cu–(W) ore deposits related to granitic intrusions were found distributed along the north-south strike in the southern Yidun Arc, which are identified as the Xiuwacu, Relin, Hongshan, and Tongchanggou deposits herein. These four deposits formed along high-angle north-northwest or north-west strike-slip faults, with vein-type and porphyry-type Mo–Cu mineralization developed in the intrusions. Molybdenite Re–Os and zircon U–Pb dating together with zircon Hf isotopes and whole-rock geochemistry of the intrusions were studied to discern the relationship between mineralization and magmatism, metallogenesis, and tectonic settings. Molybdenite from skarn-type mineralization at the Hongshan deposit has a Re–Os isochron age of 81.2±2.6Ma (MSWD=1.3, n=5) consistent with previously published zircon U–Pb ages and Re–Os ages of porphyry-type Mo mineralization. These results indicate that the Hongshan is a Late Cretaceous porphyry-skarn Cu–Mo deposit. Zircon U–Pb ages of the granitic intrusions in the Xiuwacu, Relin, and Tongchanggou deposits varying from ~87.4Ma to ~82.7Ma. Combined with published molybdenite Re–Os age spectrum (~85Ma to ~81.2Ma), it is proposed that the Mo–Cu–(W) mineralization in the Shangri-La region is spatially, temporally, and probably genetically related to the Late Cretaceous granitic intrusions. The Relin, Hongshan, and Tongchanggou intrusions have high SiO2 (65.2–70.0wt.%), Sr (363–905ppm), Sr/Y (22–72), and La/Yb (37–69) ratios, and low Y (11.6–17.0ppm) and Yb (0.97–1.59ppm), which displayed adakitic affinities. Their low MgO (0.66–1.44wt.%), Mg# (25–46), variable negative zircon εHf(t) values (−7.9 to −2.3), and Proterozoic two-stages Hf model ages (TDM2=1.13–1.62Ga) suggest that they were probably dominantly derived from partial melting of thickened lower continental crust. According to the tectonic evolution of the Bangong Meso-Tethys Ocean during the Late Mesozoic, the Late Cretaceous igneous event and mineralization in the Yidun Arc likely formed under a late- or post-collision extensional environment, probably related to the collision between the Lhasa and Qiangtang terranes during the Late Cretaceous.

Eating from the wild: diversity of wild edible plants used by Tibetans in Shangri-la region, Yunnan, China

BackgroundLocally harvested wild edible plants (WEPs) provide food as well as cash income for indigenous people and are of great importance in ensuring global food security. Some also play a significant role in maintaining the productivity and stability of traditional agro-ecosystems. Shangri-la region of Yunnan Province, SW China, is regarded as a biodiversity hotspot. People living there have accumulated traditional knowledge about plants. However, with economic development, WEPs are threatened and the associated traditional knowledge is in danger of being lost. Therefore, ethnobotanical surveys were conducted throughout this area to investigate and document the wild edible plants traditionally used by local Tibetan people.MethodsTwenty-nine villages were selected to carry out the field investigations. Information was collected using direct observation, semi-structured interviews, individual discussions, key informant interviews, focus group discussions, questionnaires and participatory rural appraisal (PRA).ResultsInformation about 168 wild edible plant species in 116 genera of 62 families was recorded and specimens were collected. Most species were edible greens (80 species) or fruits (78). These WEPs are sources for local people, especially those living in remote rural areas, to obtain mineral elements and vitamins. More than half of the species (70%) have multiple use(s) besides food value. Some are crop wild relatives that could be used for crop improvement. Several also have potential values for further commercial exploitation. However, the utilization of WEPs and related knowledge are eroding rapidly, especially in the areas with convenient transportation and booming tourism.ConclusionWild food plants species are abundant and diverse in Shangri-la region. They provide food and nutrients to local people and could also be a source of cash income. However, both WEPs and their associated indigenous knowledge are facing various threats. Thus, conservation and sustainable utilization of these plants in this area are of the utmost importance. Documentation of these species may provide basic information for conservation, possibly further exploitation, and will preserve local traditional knowledge.

Provenance and tectonic setting of the Triassic Yidun Group, the Yidun Terrane, Tibet

The Yidun Group extends from the Shangri-La region to the south and the Changtai region to the north, and is an important component of the Triassic Yidun arc in the eastern Tibetan plateau. It is composed of the Lieyi, Qugasi, Tumugou and Lanashan Formations from the base upward. Both the Lieyi and Lanashan Formations consist dominantly of black or gray slate and sandstone, whereas the Qugasi and Tumugou Formations have variable amounts of mafic to felsic volcanic rocks and tuffs accompanied with gray slate and sandstone.Sandstone from the Yidun Group has variable CIA values from 55 to 76, indicative of mild to moderate weathering condition for the source rocks. All the sandstones define a general weathering trend nearly parallel to the A-CN boundary in the A-CN-K triangular diagram, implying limited effect of diagenetic and post-depositional K-metasomatism. Dominant detrital quartz and feldspar grains of the sandstones suggest predominantly felsic sources. Relatively high Y/Ni and low Cr/V ratios of sandstones from the Yidun Group indicate more contribution from felsic than mafic sources. Similarly, the Yidun sandstones have Co/Th and La/Sc ratios generally similar to upper continental crust (UCC) and cluster between UCC and felsic sources, indicating felsic rocks as primary sources. Granodiorite represents the average chemical composition of sources as evaluated by extending the predicted weathering trend back to the feldspar join in A-CN-K diagram.Prominently high Zr/Sc ratio or Hf concentration and Paleoproterozoic Nd modal ages (1.94–2.21 Ga) point to input of recycling components derived from old sedimentary source in a relatively stable tectonic setting.

Constraints of detrital zircon U–Pb ages and Hf isotopes on the provenance of the Triassic Yidun Group and tectonic evolution of the Yidun Terrane, Eastern Tibet

Eastern Tibet to the west of the Yangtze Block consists of the Yidun and Songpan–Ganzi Terranes, separated by the Ganzi–Litang suture zone. The Yidun Terrane includes the Zhongza Massif to the west, but the eastern part of the Yidun terrane is covered by the Yidun Group extending from the south (Shangri-La region) to the north (Changtai region). The Yidun Group, from the base upward, includes the Lieyi, Qugasi, Tumugou and Lanashan formations, which are mainly composed of volcanic-flysch successions. Based on the ages of volcanic interlayers and plutonic intrusions, depositional ages of the Qugasi and Tumugou formations are considered to be slightly older than 230Ma and ca. 220–230Ma respectively, which are prominently older than the previous estimates. The Yidun Group in the Changtai region has two prominent detrital zircon age peaks at 400–480 and 880–980Ma and a minor peak at 2.45–2.50Ga. This pattern suggests a detritus source from the Zhongza Massif, which was a micro-continent separated from the western Yangtze Block. In contrast, the Yidun Group in the Shangri-La region has various zircon age spectra among different formations. The Qugasi Formation in this region has detrital zircon age patterns similar to the Yidun Group in the Changtai region. However, the overlying Tumugou Formation shows distinct age peaks at Triassic (220–240Ma), Neoproterozoic (~720–880Ma), and Paleoproterozoic (~1.75–1.90Ga). This age pattern is similar to that of the Xikang Group of the Songpan–Ganzi Terrane to the east. The detrital zircon age difference between the Qugasi and Tumugou formations in this region indicates a transition of sedimentary sources from the Zhongza Massif to locally distributed Triassic magmatic rocks at ~230Ma. It is thus suggested that the Songpan–Ganzi Terrane may have been connected to or collided with the southern part of the Yidun Terrane during the Late Triassic, whereas the Songpan–Ganzi Terrane and the northern part of the Yidun Terrane were still separated by the Ganzi–Litang Ocean.

Genetic diversity analysis of hulless barley from Shangri-la region revealed by SSR and AFLP markers

For adding the hulless barley resources of Shangri-la region to the global barley resource library, a basic work was done by us to assess their genetic diversity of this region. The genetic diversity of 60 hulless barley samples collected from three counties in Shangri-la region of Yunnan Province, were studied using SSR (simple sequence repeats) and AFLP (amplified fragment length polymorphism) markers. A total of 70 alleles were detected for 19 pairs of SSR primers, and 525 band containing 464 polymorphic bands were revealed for 5 pairs of AFLP primers. The value of polymorphism information content (PIC) ranged from 0.03 to 0.86 for SSR primers. The total numbers of alleles were 51, 55, 43 in three populations and the polymorphic bands were 188, 205 and 141. The genetic distances and genetic identity among the three populations showed their close relationship. The gene diversity among populations relative to the total population diversity (Gst) was 0.13 for SSR markers and 0.02 for AFLP markers and indicated that just 13 and 2% variations were among populations, respectively. The UPGMA cluster analysis revealed that all of the samples grouped randomly rather than clustered into distinct groups corresponding to their populations, row types and spring/fall types. We concluded that there was high genetic diversity in the population of Shangri-la region and the formation of diversity was related to complex environment and inhabitants' traditional practices.

Late Triassic porphyritic intrusions and associated volcanic rocks from the Shangri-La region, Yidun terrane, Eastern Tibetan Plateau: Adakitic magmatism and porphyry copper mineralization

Early Mesozoic porphyritic intrusions in the Shangri-La region, southern Yidun terrane, SW China, are spatially associated with andesites and dacites. These intrusions are composed of diorite and quartz diorite, and are closely related to copper mineralization. LA-ICP-MS zircon U–Pb ages of the intrusions range from 230 to 215Ma. The associated andesites and dacites are interlayered with slates and sandstones and have ages of around 220Ma. All of the intrusive and extrusive rocks have similar, highly fractionated REE patterns and high La/Yb (13–49) ratios with no prominent Eu anomalies. They display pronounced negative Nb–Ta and Ti anomalies on primitive mantle-normalized spidergrams. Their SiO2 contents range from 56.6 to 67.1wt.%, Al2O3 from 14.2 to 17.4wt.% and MgO from1.9 to 4.2wt.%. All the rocks have high Sr (258–1980ppm), and low Y (13–21ppm) with high Sr/Y ratios (29–102). These features suggest that both the volcanic rocks and porphyritic intrusions were derived from adakitic magmas. They have similar initial 87Sr/86Sr ratios (0.7058 to 0.7077) and εNd (−1.88 to −4.93) values, but belong to high silica (HSA) and low silica adakitic rocks (LSA). The HSA represent an early stage of magmatism (230 to 215Ma) and were derived from oceanic slab melts with limited interaction with the overlying mantle wedge during ascent. At 215Ma, more extensive interaction produced the LSA. We propose that the early adakitic magmas (HSA) formed by flat subduction leading to melting of oceanic slab, whereas subsequent slab break-off caused the significant interaction between slab melts and the mantle wedge and thus the generation of the later adakitic magmas (LSA).

Cytotoxic Diterpenoids from Isodon adenolomus

Aim To study the chemical constituents of the aerial parts of Isodon adennolmus collected in the Shangrila region of Yunnan Province, China. Method Compounds 1–10 were separated and purified by silica gel and C 18 reversed phase silica gel column chromatography. The structures were elucidated by extensive spectroscopic methods (IR, UV, MS and NMR), and the absolute configuration of 1 was determined by single crystal X-ray diffraction analysis. Compounds 2–5 and 10 were evaluated for their in vitro cytotoxicity against human tumor cell lines, HL-60, SMMC-7721, A-549, MCF-7, and SW-480. Results One ent-abietane, two abietane, and seven ent-kaurane diterpenoids were isolated and identified. Conclusion Compounds 1–3 are new diterpenoids. Compounds 2–4 and 10 showed moderate inhibitory effects on several of the five tumor cell lines.

Indigenous knowledge and traditional conservation of hulless barley (Hordeum vulgare) germplasm resources in the Tibetan communities of Shangri-la, Yunnan, SW China

Hulless barley (Hordeum vulgare L. s. l.) is the staple food crop of Tibetan communities in the Qinghai-Tibet Plateau, covering Tibet, Qinghai, Gansu, Sichuan and Yunnan provinces in China. Participatory Rural Appraisal methodolgies were employed in twenty-seven villages that were randomly selected in Shangri-la region, or Diqing Prefecture of Yunnan Province to document the ethnobotanical and indigenous knowledge related to the production, diversity, use and conservation of hulless barley. For Tibetans in Shangri-la, the crop has a high socio-cultural value. The genetic diversity of landraces managed by the farmers in Shangri-la is an extremely important germplasm resource. We recorded a total of 54 landraces that are primarily described by farmers based on their cooking quality, growth cycle, color and size of the grains. The ethnobotanical and indigenous knowledge recorded in this study contributes to the understanding of the genetic diversity of hulless barley in Shangri-la and even in the Qinghai-Tibet Plateau, and in defining appropriate strategies for its conservation on farm.